Case Reports

In late 2019 a new pandemic started in Wuhan, China, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) due to its similarities with the virus responsible for the SARS outbreak of 2003. The disease manifestations are named coronavirus disease 2019 (COVID-19).¹

Pseudothrombocytopenia, or platelet clumping, visualized on the peripheral blood smear, is a common cause for artificial thrombocytopenia laboratory reporting and is frequently attributed to laboratory artifact. In this case presentation, a critically ill patient with COVID-19 developed pan-pseudothrombocytopenia (ethylenediaminetetraacetic acid [EDTA], sodium citrate, and heparin tubes) just prior to his death from a ST-segment elevation myocardial infarction (STEMI) in the setting of therapeutic anticoagulation during a prolonged hospitalization. This case raises the possibility that pseudothrombocytopenia in the setting of COVID-19 critical illness may represent an ominous feature of COVID-19-associated coagulopathy (CAC). Furthermore, it prompts the question whether pseudothrombocytopenia in this setting is representative of increased platelet aggregation activity in vivo.

Case Presentation

A 50-year-old African American man who was diagnosed with COVID-19 3 days prior to admission presented to the emergency department of the W.G. (Bill) Hefner VA Medical Center in Salisbury, North Carolina, with worsening dyspnea and fever. His primary chronic medical problems included obesity (body mass index, 33), type 2 diabetes mellitus (hemoglobin A_1c 2 months prior of 6.6%), migraine headaches, and obstructive sleep apnea. Shortly after presentation, his respiratory status declined, requiring intubation. He was admitted to the medical intensive care unit for further management.

Notable findings at admission included > 20 mcg/mL FEU D-dimer (normal range, 0-0.56 mcg/mL FEU), 20.4 mg/dL C-reactive protein (normal range, < 1 mg/dL), 30 mm/h erythrocyte sedimentation rate (normal range, 0-25 mm/h), and 3.56 ng/mL procalcitonin (normal range, 0.05-1.99 ng/mL). Patient’s hemoglobin and platelet counts were normal. Empiric antimicrobial therapy was initiated with ceftriaxone (2 g IV daily) and doxycycline (100 mg IV twice daily) due to concern of superimposed infection in the setting of an elevated procalcitonin.

A heparin infusion was initiated (5,000 U IV bolus followed by continuous infusion with goal partial thromboplastin time [PTT] of 1.5x the upper limit of normal) on admission to treat CAC. Renal function worsened requiring intermittent renal replacement therapy on day 3. His lactate dehydrogenase was elevated to 1,188 U/L (normal range: 100-240 U/L) and ferritin was elevated to 2,603 ng/mL (normal range: 25-350 ng/mL) (Table). Initial neuromuscular blockade and prone positioning maneuvers were instituted to optimize oxygenation based on the latest literature for respiratory distress in the COVID-19 management.²

Intermittent norepinephrine infusion (5 mcg/min with a 2 mcg/min titration every 5 minutes as needed to maintain mean arterial pressure of > 65 mm Hg) was required for hemodynamic support throughout the patient’s course. Several therapies for COVID-19 were considered and were a reflection of the rapidly evolving literature during the care of patients with this disease. The patient originally received hydroxychloroquine (200 mg by mouth twice daily) in accordance with the US Department of Veterans Affairs (VA) institutional protocol between day 2 and day 4; however, hydroxychloroquine was stopped due to concerns of QTc prolongation. The patient also received 1 unit of convalescent plasma on day 6 after being enrolled in the expanded access program.³ The patient was not a candidate for remdesivir due to his unstable renal function and need for vasopressors. Finally, interleukin-6 inhibitors also were considered; however, the risk of superimposed infection precluded its use.

On day 7 antimicrobial therapy was transitioned to linezolid (600 mg IV twice daily) due to the persistence of fever and a portable chest radiograph revealing diffuse infiltrates throughout the bilateral lungs, worse compared with prior radiograph on day 5, suggesting a worsening of pneumonia. On day 12, the patient was transitioned to cefepime (1 gram IV daily) to broaden antimicrobial coverage and was continued thereafter. Blood cultures were negative throughout his hospitalization.

Given his worsening clinical scenario there was a question about whether or not the patient was still shedding virus for prognostic and therapeutic implications. Therefore, his SARS-CoV-2 test by polymerase chain reaction nasopharyngeal was positive again on day 18. On day 20, the patient developed leukocytosis, his fever persisted, and a portable chest radiograph revealed extensive bilateral pulmonary opacities with focal worsening in left lower base. Due to this constellation of findings, a vancomycin IV (1,500 mg once) was started for empirical treatment of hospital-acquired pneumonia. Sputum samples obtained on day 20 revealed Staphylococcus aureus on subsequent days.

From a hematologic perspective, on day 9 due to challenges to maintain a therapeutic level of anticoagulation with heparin infusion thought to be related to antithrombin deficiency, anticoagulation was changed to argatroban infusion (0.5 mcg/kg/min targeting a PTT of 70-105 seconds) for ongoing management of CAC. Although D-dimer was > 20 mcg/mL FEU on admission and on days 4 and 5, D-dimer trended down to 12.5 mcg/mL FEU on day 16.

Throughout the patient’s hospital stay, no significant bleeding was seen. Hemoglobin was 15.2 g/dL on admission, but anemia developed with a nadir of 6.5 g/dL, warranting transfusion of red blood cells on day 22. Platelet count was 165,000 per microliter on admission and remained within normal limits until platelet clumping was noted on day 15 laboratory collection.

Hematology was consulted on day 20 to obtain an accurate platelet count. A peripheral blood smear from a sodium citrate containing tube was remarkable for prominent platelet clumping, particularly at the periphery of the slide (Figure 1). Platelet clumping was reproduced in samples containing EDTA and heparin. Other features of the peripheral blood smear included the presence of echinocytes with rare schistocytes. To investigate for presence of disseminated intravascular coagulation on day 22, fibrinogen was found to be mildly elevated at 538 mg/dL (normal range: 243-517 mg/dL) and a D-dimer value of 11.96 mcg/mL FEU.

On day 22, the patient’s ventilator requirements escalated to requiring 100% FiO₂ and 10 cm H₂0 of positive end-expiratory pressure with mean arterial pressures in the 50 to 60 mm Hg range. Within 30 minutes an electrocardiogram (EKG) obtained revealed a STEMI (Figure 2). Troponin was measured at 0.65 ng/mL (normal range: 0.02-0.06 ng/mL). Just after an EKG was performed, the patient developed a ventricular fibrillation arrest and was unable to obtain return of spontaneous circulation. The patient was pronounced dead. The family declined an autopsy.

Discussion

Pseudothrombocytopenia, or platelet clumping (agglutination), is estimated to be present in up to 2% of hospitalized patients.⁴ Pseudothrombocytopenia was found to be the root cause of thrombocytopenia hematology consultations in up to 4% of hospitalized patients.⁵ The etiology is commonly ascribed to EDTA inducing a conformational change in the GpIIb-IIIa platelet complex, rendering it susceptible to binding of autoantibodies, which cause subsequent platelet agglutination.⁶ In most cases (83%), the use of a non-EDTA anticoagulant, such as sodium citrate, resolves the platelet agglutination and allows for accurate platelet count reporting.⁴ Pseudothrombocytopenia in most cases is considered an in vitro finding without clinical relevance.⁷ However, in this patient’s case, his pan-pseudothrombocytopenia was temporally associated with an arterial occlusive event (STEMI) leading to his demise despite therapeutic anticoagulation in the setting of CAC. This temporal association raises the possibility that pseudothrombocytopenia seen on the peripheral blood smear is an accurate representation of in vivo activity.

Pseudothrombocytopenia has been associated with sepsis from bacterial and viral causes as well as autoimmune and medication effect.^4,8-10 Li and colleagues reported transient EDTA-dependent pseudothrombocytopenia in a patient with COVID-19 infection; however, platelet clumping resolved with use of a citrate tube, and the EDTA-dependent pseudothrombocytopenia phenomenon resolved with patient recovery.¹¹ The frequency of COVID-19-related pseudothrombocytopenia is currently unknown.

Although the understanding of COVID-19-associated CAC continues to evolve, it seems that initial reports support the idea that hemostatic dysfunction tends to more thrombosis than to bleeding.¹² Rather than overt disseminated intravascular coagulation with reduced fibrinogen and bleeding, CAC is more closely associated with blood clotting, as demonstrated by autopsy studies revealing microvascular thrombosis in the lungs.¹³ The D-dimer test has been identified as the most useful biomarker by the International Society of Thrombosis and Hemostasis to screen for CAC and stratify patients who warrant admission or closer monitoring.¹² Other identified features of CAC include prolonged prothrombin time and thrombocytopenia.¹²

There have been varying clinical approaches to CAC management. A retrospective review found that prophylactic heparin doses were associated with improved mortality in those with elevated D-dimer > 3.0 mg/L.¹⁴ There continues to be a diversity of varying clinical approaches with many medical centers advocating for an intensified prophylactic twice daily low molecular-weight heparin compared with others advocating for full therapeutic dose anticoagulation for patients with elevated D-dimer.¹⁵ This patient was treated aggressively with full-dose anticoagulation, and despite his having a down-trend in D-dimer, he suffered a lethal arterial thrombosis in the form of a STEMI.

Varatharajah and Rajah believe that CAC is more closely aligned with endotheliopathy-associated vascular microthrombotic disease (EA-VMTD).¹⁶ EA-VMTD involves a disequilibrium state between insufficient ADAMTS13 enzyme and excessive exocytosis of ultralarge von Willebrand factor (ULvWF) multimers from endothelial cells affected by COVID-19. This theory endorses that ULvWF multimers cause platelet adhesion and subsequent rapid platelet activation, causing platelet aggregation and formation of microthrombi.¹⁷ As these platelet aggregates grow to a certain point, they can no longer remain adhered to ULvWF, causing these platelet aggregates to be released into the circulation and causing thrombotic sequelae.¹⁶ Therefore, a plausible explanation for the patient’s pan-pseudothrombocytopenia may be the detection of these circulating platelet aggregates, which, in turn, was the same process leading to his STEMI. Interestingly, this patient’s fatal arterial event occurred in the presence of therapeutic anticoagulation, raising the question of whether other therapeutic interventions to treat CAC, such as further antithrombotic therapy (eg, aspirin, clopidogrel) or novel strategies would be of benefit.

Conclusions

This patient’s case highlights the presence of pan-pseudothrombocytopenia despite the use of a sodium citrate and heparin containing tube in a COVID-19 infection with multiorgan dysfunction. This developed 1 week prior to the patient suffering a STEMI despite therapeutic anticoagulation. Although the exact nature of CAC remains to be worked out, it is possible that platelet agglutination/clumping seen on the peripheral blood smear is representative of in vivo activity and serves as a harbinger for worsening thrombosis. The frequency of such phenomenon and efficacy of further interventions has yet to be explored.

In late 2019 a new pandemic started in Wuhan, China, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) due to its similarities with the virus responsible for the SARS outbreak of 2003. The disease manifestations are named coronavirus disease 2019 (COVID-19).¹

Pseudothrombocytopenia, or platelet clumping, visualized on the peripheral blood smear, is a common cause for artificial thrombocytopenia laboratory reporting and is frequently attributed to laboratory artifact. In this case presentation, a critically ill patient with COVID-19 developed pan-pseudothrombocytopenia (ethylenediaminetetraacetic acid [EDTA], sodium citrate, and heparin tubes) just prior to his death from a ST-segment elevation myocardial infarction (STEMI) in the setting of therapeutic anticoagulation during a prolonged hospitalization. This case raises the possibility that pseudothrombocytopenia in the setting of COVID-19 critical illness may represent an ominous feature of COVID-19-associated coagulopathy (CAC). Furthermore, it prompts the question whether pseudothrombocytopenia in this setting is representative of increased platelet aggregation activity in vivo.

Case Presentation

A 50-year-old African American man who was diagnosed with COVID-19 3 days prior to admission presented to the emergency department of the W.G. (Bill) Hefner VA Medical Center in Salisbury, North Carolina, with worsening dyspnea and fever. His primary chronic medical problems included obesity (body mass index, 33), type 2 diabetes mellitus (hemoglobin A_1c 2 months prior of 6.6%), migraine headaches, and obstructive sleep apnea. Shortly after presentation, his respiratory status declined, requiring intubation. He was admitted to the medical intensive care unit for further management.

Notable findings at admission included > 20 mcg/mL FEU D-dimer (normal range, 0-0.56 mcg/mL FEU), 20.4 mg/dL C-reactive protein (normal range, < 1 mg/dL), 30 mm/h erythrocyte sedimentation rate (normal range, 0-25 mm/h), and 3.56 ng/mL procalcitonin (normal range, 0.05-1.99 ng/mL). Patient’s hemoglobin and platelet counts were normal. Empiric antimicrobial therapy was initiated with ceftriaxone (2 g IV daily) and doxycycline (100 mg IV twice daily) due to concern of superimposed infection in the setting of an elevated procalcitonin.

A heparin infusion was initiated (5,000 U IV bolus followed by continuous infusion with goal partial thromboplastin time [PTT] of 1.5x the upper limit of normal) on admission to treat CAC. Renal function worsened requiring intermittent renal replacement therapy on day 3. His lactate dehydrogenase was elevated to 1,188 U/L (normal range: 100-240 U/L) and ferritin was elevated to 2,603 ng/mL (normal range: 25-350 ng/mL) (Table). Initial neuromuscular blockade and prone positioning maneuvers were instituted to optimize oxygenation based on the latest literature for respiratory distress in the COVID-19 management.²

Intermittent norepinephrine infusion (5 mcg/min with a 2 mcg/min titration every 5 minutes as needed to maintain mean arterial pressure of > 65 mm Hg) was required for hemodynamic support throughout the patient’s course. Several therapies for COVID-19 were considered and were a reflection of the rapidly evolving literature during the care of patients with this disease. The patient originally received hydroxychloroquine (200 mg by mouth twice daily) in accordance with the US Department of Veterans Affairs (VA) institutional protocol between day 2 and day 4; however, hydroxychloroquine was stopped due to concerns of QTc prolongation. The patient also received 1 unit of convalescent plasma on day 6 after being enrolled in the expanded access program.³ The patient was not a candidate for remdesivir due to his unstable renal function and need for vasopressors. Finally, interleukin-6 inhibitors also were considered; however, the risk of superimposed infection precluded its use.

On day 7 antimicrobial therapy was transitioned to linezolid (600 mg IV twice daily) due to the persistence of fever and a portable chest radiograph revealing diffuse infiltrates throughout the bilateral lungs, worse compared with prior radiograph on day 5, suggesting a worsening of pneumonia. On day 12, the patient was transitioned to cefepime (1 gram IV daily) to broaden antimicrobial coverage and was continued thereafter. Blood cultures were negative throughout his hospitalization.

Given his worsening clinical scenario there was a question about whether or not the patient was still shedding virus for prognostic and therapeutic implications. Therefore, his SARS-CoV-2 test by polymerase chain reaction nasopharyngeal was positive again on day 18. On day 20, the patient developed leukocytosis, his fever persisted, and a portable chest radiograph revealed extensive bilateral pulmonary opacities with focal worsening in left lower base. Due to this constellation of findings, a vancomycin IV (1,500 mg once) was started for empirical treatment of hospital-acquired pneumonia. Sputum samples obtained on day 20 revealed Staphylococcus aureus on subsequent days.

From a hematologic perspective, on day 9 due to challenges to maintain a therapeutic level of anticoagulation with heparin infusion thought to be related to antithrombin deficiency, anticoagulation was changed to argatroban infusion (0.5 mcg/kg/min targeting a PTT of 70-105 seconds) for ongoing management of CAC. Although D-dimer was > 20 mcg/mL FEU on admission and on days 4 and 5, D-dimer trended down to 12.5 mcg/mL FEU on day 16.

Throughout the patient’s hospital stay, no significant bleeding was seen. Hemoglobin was 15.2 g/dL on admission, but anemia developed with a nadir of 6.5 g/dL, warranting transfusion of red blood cells on day 22. Platelet count was 165,000 per microliter on admission and remained within normal limits until platelet clumping was noted on day 15 laboratory collection.

Hematology was consulted on day 20 to obtain an accurate platelet count. A peripheral blood smear from a sodium citrate containing tube was remarkable for prominent platelet clumping, particularly at the periphery of the slide (Figure 1). Platelet clumping was reproduced in samples containing EDTA and heparin. Other features of the peripheral blood smear included the presence of echinocytes with rare schistocytes. To investigate for presence of disseminated intravascular coagulation on day 22, fibrinogen was found to be mildly elevated at 538 mg/dL (normal range: 243-517 mg/dL) and a D-dimer value of 11.96 mcg/mL FEU.

On day 22, the patient’s ventilator requirements escalated to requiring 100% FiO₂ and 10 cm H₂0 of positive end-expiratory pressure with mean arterial pressures in the 50 to 60 mm Hg range. Within 30 minutes an electrocardiogram (EKG) obtained revealed a STEMI (Figure 2). Troponin was measured at 0.65 ng/mL (normal range: 0.02-0.06 ng/mL). Just after an EKG was performed, the patient developed a ventricular fibrillation arrest and was unable to obtain return of spontaneous circulation. The patient was pronounced dead. The family declined an autopsy.

Discussion

Pseudothrombocytopenia, or platelet clumping (agglutination), is estimated to be present in up to 2% of hospitalized patients.⁴ Pseudothrombocytopenia was found to be the root cause of thrombocytopenia hematology consultations in up to 4% of hospitalized patients.⁵ The etiology is commonly ascribed to EDTA inducing a conformational change in the GpIIb-IIIa platelet complex, rendering it susceptible to binding of autoantibodies, which cause subsequent platelet agglutination.⁶ In most cases (83%), the use of a non-EDTA anticoagulant, such as sodium citrate, resolves the platelet agglutination and allows for accurate platelet count reporting.⁴ Pseudothrombocytopenia in most cases is considered an in vitro finding without clinical relevance.⁷ However, in this patient’s case, his pan-pseudothrombocytopenia was temporally associated with an arterial occlusive event (STEMI) leading to his demise despite therapeutic anticoagulation in the setting of CAC. This temporal association raises the possibility that pseudothrombocytopenia seen on the peripheral blood smear is an accurate representation of in vivo activity.

Pseudothrombocytopenia has been associated with sepsis from bacterial and viral causes as well as autoimmune and medication effect.^4,8-10 Li and colleagues reported transient EDTA-dependent pseudothrombocytopenia in a patient with COVID-19 infection; however, platelet clumping resolved with use of a citrate tube, and the EDTA-dependent pseudothrombocytopenia phenomenon resolved with patient recovery.¹¹ The frequency of COVID-19-related pseudothrombocytopenia is currently unknown.

Although the understanding of COVID-19-associated CAC continues to evolve, it seems that initial reports support the idea that hemostatic dysfunction tends to more thrombosis than to bleeding.¹² Rather than overt disseminated intravascular coagulation with reduced fibrinogen and bleeding, CAC is more closely associated with blood clotting, as demonstrated by autopsy studies revealing microvascular thrombosis in the lungs.¹³ The D-dimer test has been identified as the most useful biomarker by the International Society of Thrombosis and Hemostasis to screen for CAC and stratify patients who warrant admission or closer monitoring.¹² Other identified features of CAC include prolonged prothrombin time and thrombocytopenia.¹²

There have been varying clinical approaches to CAC management. A retrospective review found that prophylactic heparin doses were associated with improved mortality in those with elevated D-dimer > 3.0 mg/L.¹⁴ There continues to be a diversity of varying clinical approaches with many medical centers advocating for an intensified prophylactic twice daily low molecular-weight heparin compared with others advocating for full therapeutic dose anticoagulation for patients with elevated D-dimer.¹⁵ This patient was treated aggressively with full-dose anticoagulation, and despite his having a down-trend in D-dimer, he suffered a lethal arterial thrombosis in the form of a STEMI.

Varatharajah and Rajah believe that CAC is more closely aligned with endotheliopathy-associated vascular microthrombotic disease (EA-VMTD).¹⁶ EA-VMTD involves a disequilibrium state between insufficient ADAMTS13 enzyme and excessive exocytosis of ultralarge von Willebrand factor (ULvWF) multimers from endothelial cells affected by COVID-19. This theory endorses that ULvWF multimers cause platelet adhesion and subsequent rapid platelet activation, causing platelet aggregation and formation of microthrombi.¹⁷ As these platelet aggregates grow to a certain point, they can no longer remain adhered to ULvWF, causing these platelet aggregates to be released into the circulation and causing thrombotic sequelae.¹⁶ Therefore, a plausible explanation for the patient’s pan-pseudothrombocytopenia may be the detection of these circulating platelet aggregates, which, in turn, was the same process leading to his STEMI. Interestingly, this patient’s fatal arterial event occurred in the presence of therapeutic anticoagulation, raising the question of whether other therapeutic interventions to treat CAC, such as further antithrombotic therapy (eg, aspirin, clopidogrel) or novel strategies would be of benefit.

Conclusions

This patient’s case highlights the presence of pan-pseudothrombocytopenia despite the use of a sodium citrate and heparin containing tube in a COVID-19 infection with multiorgan dysfunction. This developed 1 week prior to the patient suffering a STEMI despite therapeutic anticoagulation. Although the exact nature of CAC remains to be worked out, it is possible that platelet agglutination/clumping seen on the peripheral blood smear is representative of in vivo activity and serves as a harbinger for worsening thrombosis. The frequency of such phenomenon and efficacy of further interventions has yet to be explored.

In late 2019 a new pandemic started in Wuhan, China, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) due to its similarities with the virus responsible for the SARS outbreak of 2003. The disease manifestations are named coronavirus disease 2019 (COVID-19).¹

Pseudothrombocytopenia, or platelet clumping, visualized on the peripheral blood smear, is a common cause for artificial thrombocytopenia laboratory reporting and is frequently attributed to laboratory artifact. In this case presentation, a critically ill patient with COVID-19 developed pan-pseudothrombocytopenia (ethylenediaminetetraacetic acid [EDTA], sodium citrate, and heparin tubes) just prior to his death from a ST-segment elevation myocardial infarction (STEMI) in the setting of therapeutic anticoagulation during a prolonged hospitalization. This case raises the possibility that pseudothrombocytopenia in the setting of COVID-19 critical illness may represent an ominous feature of COVID-19-associated coagulopathy (CAC). Furthermore, it prompts the question whether pseudothrombocytopenia in this setting is representative of increased platelet aggregation activity in vivo.

Case Presentation

A 50-year-old African American man who was diagnosed with COVID-19 3 days prior to admission presented to the emergency department of the W.G. (Bill) Hefner VA Medical Center in Salisbury, North Carolina, with worsening dyspnea and fever. His primary chronic medical problems included obesity (body mass index, 33), type 2 diabetes mellitus (hemoglobin A_1c 2 months prior of 6.6%), migraine headaches, and obstructive sleep apnea. Shortly after presentation, his respiratory status declined, requiring intubation. He was admitted to the medical intensive care unit for further management.

Notable findings at admission included > 20 mcg/mL FEU D-dimer (normal range, 0-0.56 mcg/mL FEU), 20.4 mg/dL C-reactive protein (normal range, < 1 mg/dL), 30 mm/h erythrocyte sedimentation rate (normal range, 0-25 mm/h), and 3.56 ng/mL procalcitonin (normal range, 0.05-1.99 ng/mL). Patient’s hemoglobin and platelet counts were normal. Empiric antimicrobial therapy was initiated with ceftriaxone (2 g IV daily) and doxycycline (100 mg IV twice daily) due to concern of superimposed infection in the setting of an elevated procalcitonin.

A heparin infusion was initiated (5,000 U IV bolus followed by continuous infusion with goal partial thromboplastin time [PTT] of 1.5x the upper limit of normal) on admission to treat CAC. Renal function worsened requiring intermittent renal replacement therapy on day 3. His lactate dehydrogenase was elevated to 1,188 U/L (normal range: 100-240 U/L) and ferritin was elevated to 2,603 ng/mL (normal range: 25-350 ng/mL) (Table). Initial neuromuscular blockade and prone positioning maneuvers were instituted to optimize oxygenation based on the latest literature for respiratory distress in the COVID-19 management.²

Intermittent norepinephrine infusion (5 mcg/min with a 2 mcg/min titration every 5 minutes as needed to maintain mean arterial pressure of > 65 mm Hg) was required for hemodynamic support throughout the patient’s course. Several therapies for COVID-19 were considered and were a reflection of the rapidly evolving literature during the care of patients with this disease. The patient originally received hydroxychloroquine (200 mg by mouth twice daily) in accordance with the US Department of Veterans Affairs (VA) institutional protocol between day 2 and day 4; however, hydroxychloroquine was stopped due to concerns of QTc prolongation. The patient also received 1 unit of convalescent plasma on day 6 after being enrolled in the expanded access program.³ The patient was not a candidate for remdesivir due to his unstable renal function and need for vasopressors. Finally, interleukin-6 inhibitors also were considered; however, the risk of superimposed infection precluded its use.

On day 7 antimicrobial therapy was transitioned to linezolid (600 mg IV twice daily) due to the persistence of fever and a portable chest radiograph revealing diffuse infiltrates throughout the bilateral lungs, worse compared with prior radiograph on day 5, suggesting a worsening of pneumonia. On day 12, the patient was transitioned to cefepime (1 gram IV daily) to broaden antimicrobial coverage and was continued thereafter. Blood cultures were negative throughout his hospitalization.

Given his worsening clinical scenario there was a question about whether or not the patient was still shedding virus for prognostic and therapeutic implications. Therefore, his SARS-CoV-2 test by polymerase chain reaction nasopharyngeal was positive again on day 18. On day 20, the patient developed leukocytosis, his fever persisted, and a portable chest radiograph revealed extensive bilateral pulmonary opacities with focal worsening in left lower base. Due to this constellation of findings, a vancomycin IV (1,500 mg once) was started for empirical treatment of hospital-acquired pneumonia. Sputum samples obtained on day 20 revealed Staphylococcus aureus on subsequent days.

From a hematologic perspective, on day 9 due to challenges to maintain a therapeutic level of anticoagulation with heparin infusion thought to be related to antithrombin deficiency, anticoagulation was changed to argatroban infusion (0.5 mcg/kg/min targeting a PTT of 70-105 seconds) for ongoing management of CAC. Although D-dimer was > 20 mcg/mL FEU on admission and on days 4 and 5, D-dimer trended down to 12.5 mcg/mL FEU on day 16.

Throughout the patient’s hospital stay, no significant bleeding was seen. Hemoglobin was 15.2 g/dL on admission, but anemia developed with a nadir of 6.5 g/dL, warranting transfusion of red blood cells on day 22. Platelet count was 165,000 per microliter on admission and remained within normal limits until platelet clumping was noted on day 15 laboratory collection.

Hematology was consulted on day 20 to obtain an accurate platelet count. A peripheral blood smear from a sodium citrate containing tube was remarkable for prominent platelet clumping, particularly at the periphery of the slide (Figure 1). Platelet clumping was reproduced in samples containing EDTA and heparin. Other features of the peripheral blood smear included the presence of echinocytes with rare schistocytes. To investigate for presence of disseminated intravascular coagulation on day 22, fibrinogen was found to be mildly elevated at 538 mg/dL (normal range: 243-517 mg/dL) and a D-dimer value of 11.96 mcg/mL FEU.

On day 22, the patient’s ventilator requirements escalated to requiring 100% FiO₂ and 10 cm H₂0 of positive end-expiratory pressure with mean arterial pressures in the 50 to 60 mm Hg range. Within 30 minutes an electrocardiogram (EKG) obtained revealed a STEMI (Figure 2). Troponin was measured at 0.65 ng/mL (normal range: 0.02-0.06 ng/mL). Just after an EKG was performed, the patient developed a ventricular fibrillation arrest and was unable to obtain return of spontaneous circulation. The patient was pronounced dead. The family declined an autopsy.

Discussion

Pseudothrombocytopenia, or platelet clumping (agglutination), is estimated to be present in up to 2% of hospitalized patients.⁴ Pseudothrombocytopenia was found to be the root cause of thrombocytopenia hematology consultations in up to 4% of hospitalized patients.⁵ The etiology is commonly ascribed to EDTA inducing a conformational change in the GpIIb-IIIa platelet complex, rendering it susceptible to binding of autoantibodies, which cause subsequent platelet agglutination.⁶ In most cases (83%), the use of a non-EDTA anticoagulant, such as sodium citrate, resolves the platelet agglutination and allows for accurate platelet count reporting.⁴ Pseudothrombocytopenia in most cases is considered an in vitro finding without clinical relevance.⁷ However, in this patient’s case, his pan-pseudothrombocytopenia was temporally associated with an arterial occlusive event (STEMI) leading to his demise despite therapeutic anticoagulation in the setting of CAC. This temporal association raises the possibility that pseudothrombocytopenia seen on the peripheral blood smear is an accurate representation of in vivo activity.

Pseudothrombocytopenia has been associated with sepsis from bacterial and viral causes as well as autoimmune and medication effect.^4,8-10 Li and colleagues reported transient EDTA-dependent pseudothrombocytopenia in a patient with COVID-19 infection; however, platelet clumping resolved with use of a citrate tube, and the EDTA-dependent pseudothrombocytopenia phenomenon resolved with patient recovery.¹¹ The frequency of COVID-19-related pseudothrombocytopenia is currently unknown.

Although the understanding of COVID-19-associated CAC continues to evolve, it seems that initial reports support the idea that hemostatic dysfunction tends to more thrombosis than to bleeding.¹² Rather than overt disseminated intravascular coagulation with reduced fibrinogen and bleeding, CAC is more closely associated with blood clotting, as demonstrated by autopsy studies revealing microvascular thrombosis in the lungs.¹³ The D-dimer test has been identified as the most useful biomarker by the International Society of Thrombosis and Hemostasis to screen for CAC and stratify patients who warrant admission or closer monitoring.¹² Other identified features of CAC include prolonged prothrombin time and thrombocytopenia.¹²

There have been varying clinical approaches to CAC management. A retrospective review found that prophylactic heparin doses were associated with improved mortality in those with elevated D-dimer > 3.0 mg/L.¹⁴ There continues to be a diversity of varying clinical approaches with many medical centers advocating for an intensified prophylactic twice daily low molecular-weight heparin compared with others advocating for full therapeutic dose anticoagulation for patients with elevated D-dimer.¹⁵ This patient was treated aggressively with full-dose anticoagulation, and despite his having a down-trend in D-dimer, he suffered a lethal arterial thrombosis in the form of a STEMI.

Varatharajah and Rajah believe that CAC is more closely aligned with endotheliopathy-associated vascular microthrombotic disease (EA-VMTD).¹⁶ EA-VMTD involves a disequilibrium state between insufficient ADAMTS13 enzyme and excessive exocytosis of ultralarge von Willebrand factor (ULvWF) multimers from endothelial cells affected by COVID-19. This theory endorses that ULvWF multimers cause platelet adhesion and subsequent rapid platelet activation, causing platelet aggregation and formation of microthrombi.¹⁷ As these platelet aggregates grow to a certain point, they can no longer remain adhered to ULvWF, causing these platelet aggregates to be released into the circulation and causing thrombotic sequelae.¹⁶ Therefore, a plausible explanation for the patient’s pan-pseudothrombocytopenia may be the detection of these circulating platelet aggregates, which, in turn, was the same process leading to his STEMI. Interestingly, this patient’s fatal arterial event occurred in the presence of therapeutic anticoagulation, raising the question of whether other therapeutic interventions to treat CAC, such as further antithrombotic therapy (eg, aspirin, clopidogrel) or novel strategies would be of benefit.

Conclusions

This patient’s case highlights the presence of pan-pseudothrombocytopenia despite the use of a sodium citrate and heparin containing tube in a COVID-19 infection with multiorgan dysfunction. This developed 1 week prior to the patient suffering a STEMI despite therapeutic anticoagulation. Although the exact nature of CAC remains to be worked out, it is possible that platelet agglutination/clumping seen on the peripheral blood smear is representative of in vivo activity and serves as a harbinger for worsening thrombosis. The frequency of such phenomenon and efficacy of further interventions has yet to be explored.

Psoriasis is a chronic inflammatory skin disease that affects 2% to 3% of individuals worldwide.¹ Despite extensive research, the majority of clinical data are in white patients with limited data in patients of color, yet a number of differences are known. The prevalence of psoriasis differs among racial and ethnic groups, with lower prevalence in racial minorities.² A cross-sectional American study using data from 2009 through 2010 showed the prevalence for psoriasis was 3.6% in white patients, 1.9% in black patients, 1.6% in Hispanic patients, and 1.4% in other racial groups.³ Psoriasis presents differently in patients of color, both in morphology and severity. Cultural differences and stigma may contribute to the differences seen in severity but also to the psychological impact and treatment choices in patients of color compared to white patients.⁴ It has even been theorized that treatment efficacy could differ because of potential genetic differences.⁵ Psoriasis in patients of color is an emerging clinical issue that requires further attention so that dermatologists can learn about, diagnose, and treat them.

We report 3 cases of patients of color with psoriasis who presented to an urban and racially diverse dermatology clinic affiliated with Scarborough General Hospital in Toronto, Ontario, Canada. A retrospective chart review was performed on these high-yield representative cases to demonstrate differences in color and morphology, disease severity, and treatment in patients of various races seen at our clinic. After informed consent was obtained, photographs were taken of patient cutaneous findings to illustrate these differences. Discussion with these selected patients yielded supplementary qualitative data, highlighting individual perspectives of their disease.

Case Series

Patient 1
A 53-year-old black man from Grenada presented to our clinic with a history of psoriasis for a number of years that presented as violaceous plaques throughout large portions of the body (Figure 1). He previously had achieved inadequate results while using topical therapies, methotrexate, acitretin, apremilast, ustekinumab, ixekizumab, and guselkumab at adequate or even maximum doses. His disease affected 30% of the body surface area, with a psoriasis area and severity index score of 27 and a dermatology life quality index score of 23. The patient’s life was quite affected by psoriasis, with emphasis on choice of clothing worn and effect on body image. He also discussed the stigma psoriasis may have in black patients, stating that he has been told multiple times that “black people do not get psoriasis.”

Patient 2
A 27-year-old man from India presented with guttate psoriasis (Figure 2). He was treated with methotrexate 2 years prior and currently is on maintenance therapy with topical treatments alone. His main concerns pertained to the persistent dyschromia that occurred secondary to the psoriatic lesions. Through discussion, the patient stated that he “would do anything to get rid of it.”

Comment

Clinical differences in patients of color with psoriasis affect the management of the disease. Special consideration should be given to variances in morphology, presentation, treatment, and psychosocial factors in the management of psoriasis for these patient populations, as summarized in the eTable.

Morphology
At our clinic, patients of color have been found to have differences in morphology, including lesions that are more violaceous in color, as seen in patient 1; less noticeable inflammation; and more postinflammatory hypopigmentation and hyperpigmentation changes, as seen in patient 2. These changes are supported by the literature and differ from typical psoriasis plaques, which are pink-red and have more overlying scale. The varied morphology also may affect the differential, and other mimickers may be considered, such as lichen planus, cutaneous lupus erythematosus, and sarcoidosis.²

Presentation
There are differences in presentation among patients of color, particularly in distribution, type of psoriasis, and severity. As seen in patient 3, Asian and black patients are more likely to present with scalp psoriasis.^2,5 Hairstyling and hair care practices can differ considerably between racial groups. Given the differences in hairstyling, scalp psoriasis also may have a greater impact on patient quality of life (QOL).

Racial differences affect the type of psoriasis seen. Asian patients are more likely to present with pustular and erythrodermic psoriasis and less likely to present with inverse psoriasis compared to white patients. Hispanic patients are more likely to present with pustular psoriasis.¹¹ Black patients have been reported to have lower frequencies of psoriatic arthritis compared to white patients.¹² Recognition of these differences may help guide initial choice for therapeutics.

Notably, patients of color may present with much more severe psoriasis, particularly Asian and Hispanic patients.⁷ One retrospective study looking at patients with psoriasis treated with etanercept found that Asian patients were more likely to have greater baseline body surface area involvement.⁶ An American cross-sectional study reported higher psoriasis area and severity index scores in black patients compared to white patients,¹² possibly because patients of color do not normalize the experience of having psoriasis and feel stigmatized, which can cause delays in seeking medical attention and worsen disease burden. For patient 1, the stigma of black patients having psoriasis affected his body image and may have led to a delay in seeking medical attention due to him not believing it was possible for people of his skin color to have psoriasis. Increased disease severity may contribute to treatment resistance or numerous trials of topicals or biologics before the disease improves. Patient education in the community as well as patient support groups are paramount, and increased awareness of psoriasis can help improve disease management.

Treatment
Topical therapies are the first-line treatment of psoriasis. Although there is no evidence showing differences in topical treatment efficacy, patient preference for different topical treatments may vary based on race. For example, patients with Afro-textured hair may prefer foams and lotions and would avoid shampoo therapies, as frequent hair washing may not be feasible with certain hairstyles and may cause hair breakage or dryness.²

UV therapy can be an effective treatment modality for patients with psoriasis. The strength of therapy tends to be dictated by the Fitzpatrick skin phototype rather than race. Darker-skinned individuals may have an increased risk for hyperpigmentation, so caution should be taken to prevent burning during therapy. Suberythemogenic dosing—70% of minimal erythema dose—of narrowband UVB treatments has shown the same efficacy as using minimal erythema dose in patients with darker skin types in addition to fair-skinned patients.⁸

Although we found poor efficacy of systemic treatments in patient 1, to our knowledge, studies examining the efficacy of systemic therapeutic options have not shown differences in patients of color.^6,13 Studies show similar efficacy in treatments among races, particularly biologic therapies.⁵ However, patients with skin of color historically have been underrepresented in clinical trials,⁹ which may contribute to these patients, particularly black patients, being less familiar with biologics as a treatment option for psoriasis, as reported by Takeshita et al.¹⁰ Therefore, patient-centered discussions regarding treatment choices are important to ensure patients understand all options available to manage their disease.

Psychosocial Impact
Because of its chronic remitting course, psoriasis has a notable psychosocial impact on the lives of all patients, though the literature suggests there may be more of an impact on QOL in patients of color. Higher baseline dermatology life quality index scores have been reported in patients of color compared to white patients.⁶ Kerr et al¹² reported significantly greater psoriasis area and severity index scores (P=.06) and greater psychological impact in black patients compared to white patients. Stress also was more likely to be reported as a trigger for psoriasis in patients of Hispanic background compared to white patients.¹⁴ Many patients report body image issues with large physical lesions; however, the difference may lie in personal and cultural views about psoriasis, as one of our patients stated, “black people do not get psoriasis.” In addition to the cosmetic challenges that patients face with active lesions, postinflammatory pigmentary changes can be equally as burdensome to patients, as one of our patients stated he “would do anything to get rid of it.” Increased rates of depression and anxiety in patients of color can worsen their outlook on the condition.^15,16 The increased stigma and burden of psoriasis in patients of color calls for clinicians to counsel and address psoriasis in a holistic way and refer patients to psoriasis support groups when appropriate. Although the burden of psoriasis is clear, more studies can be carried out to investigate the impact on QOL in different ethnic populations.

Dermatology Education
Although differences have been found in patients of color with psoriasis, dissemination of this knowledge continues to be a challenge. In dermatology residency programs, the majority of teaching is provided with examples of skin diseases in white patients, which can complicate pattern recognition and diagnostic ability for trainees. Although dermatologists recognize that ethnic skin has unique dermatologic considerations, there is a persistent need for increasing skin of color education within dermatology residency programs.^17,18 Implementing more educational programs on skin of color has been proposed, and these programs will continue to be in demand as our population increasingly diversifies.¹⁹

Conclusion

Psoriasis in patients of color carries unique challenges when compared to psoriasis in white patients. Differences in morphology and presentation can make the disease difficult to accurately diagnose. These differences in addition to cultural differences may contribute to a greater impact on QOL and psychological health. Although treatment preferences and recognition may differ, treatment efficacy has so far been similar, albeit with a low proportion of patients with skin of color included in clinical trials.

Further focus should now lie within knowledge translation of these differences, which would normalize the condition for patients, support them seeking medical attention sooner, and inform them of all treatment options possible. For clinicians, more attention on the differences would help make earlier diagnoses, personalize physician-patient conversations, and advocate for further education on this issue in residency training programs.

Psoriasis is a chronic inflammatory skin disease that affects 2% to 3% of individuals worldwide.¹ Despite extensive research, the majority of clinical data are in white patients with limited data in patients of color, yet a number of differences are known. The prevalence of psoriasis differs among racial and ethnic groups, with lower prevalence in racial minorities.² A cross-sectional American study using data from 2009 through 2010 showed the prevalence for psoriasis was 3.6% in white patients, 1.9% in black patients, 1.6% in Hispanic patients, and 1.4% in other racial groups.³ Psoriasis presents differently in patients of color, both in morphology and severity. Cultural differences and stigma may contribute to the differences seen in severity but also to the psychological impact and treatment choices in patients of color compared to white patients.⁴ It has even been theorized that treatment efficacy could differ because of potential genetic differences.⁵ Psoriasis in patients of color is an emerging clinical issue that requires further attention so that dermatologists can learn about, diagnose, and treat them.

We report 3 cases of patients of color with psoriasis who presented to an urban and racially diverse dermatology clinic affiliated with Scarborough General Hospital in Toronto, Ontario, Canada. A retrospective chart review was performed on these high-yield representative cases to demonstrate differences in color and morphology, disease severity, and treatment in patients of various races seen at our clinic. After informed consent was obtained, photographs were taken of patient cutaneous findings to illustrate these differences. Discussion with these selected patients yielded supplementary qualitative data, highlighting individual perspectives of their disease.

Case Series

Patient 1
A 53-year-old black man from Grenada presented to our clinic with a history of psoriasis for a number of years that presented as violaceous plaques throughout large portions of the body (Figure 1). He previously had achieved inadequate results while using topical therapies, methotrexate, acitretin, apremilast, ustekinumab, ixekizumab, and guselkumab at adequate or even maximum doses. His disease affected 30% of the body surface area, with a psoriasis area and severity index score of 27 and a dermatology life quality index score of 23. The patient’s life was quite affected by psoriasis, with emphasis on choice of clothing worn and effect on body image. He also discussed the stigma psoriasis may have in black patients, stating that he has been told multiple times that “black people do not get psoriasis.”

Patient 2
A 27-year-old man from India presented with guttate psoriasis (Figure 2). He was treated with methotrexate 2 years prior and currently is on maintenance therapy with topical treatments alone. His main concerns pertained to the persistent dyschromia that occurred secondary to the psoriatic lesions. Through discussion, the patient stated that he “would do anything to get rid of it.”

Comment

Clinical differences in patients of color with psoriasis affect the management of the disease. Special consideration should be given to variances in morphology, presentation, treatment, and psychosocial factors in the management of psoriasis for these patient populations, as summarized in the eTable.

Morphology
At our clinic, patients of color have been found to have differences in morphology, including lesions that are more violaceous in color, as seen in patient 1; less noticeable inflammation; and more postinflammatory hypopigmentation and hyperpigmentation changes, as seen in patient 2. These changes are supported by the literature and differ from typical psoriasis plaques, which are pink-red and have more overlying scale. The varied morphology also may affect the differential, and other mimickers may be considered, such as lichen planus, cutaneous lupus erythematosus, and sarcoidosis.²

Presentation
There are differences in presentation among patients of color, particularly in distribution, type of psoriasis, and severity. As seen in patient 3, Asian and black patients are more likely to present with scalp psoriasis.^2,5 Hairstyling and hair care practices can differ considerably between racial groups. Given the differences in hairstyling, scalp psoriasis also may have a greater impact on patient quality of life (QOL).

Racial differences affect the type of psoriasis seen. Asian patients are more likely to present with pustular and erythrodermic psoriasis and less likely to present with inverse psoriasis compared to white patients. Hispanic patients are more likely to present with pustular psoriasis.¹¹ Black patients have been reported to have lower frequencies of psoriatic arthritis compared to white patients.¹² Recognition of these differences may help guide initial choice for therapeutics.

Notably, patients of color may present with much more severe psoriasis, particularly Asian and Hispanic patients.⁷ One retrospective study looking at patients with psoriasis treated with etanercept found that Asian patients were more likely to have greater baseline body surface area involvement.⁶ An American cross-sectional study reported higher psoriasis area and severity index scores in black patients compared to white patients,¹² possibly because patients of color do not normalize the experience of having psoriasis and feel stigmatized, which can cause delays in seeking medical attention and worsen disease burden. For patient 1, the stigma of black patients having psoriasis affected his body image and may have led to a delay in seeking medical attention due to him not believing it was possible for people of his skin color to have psoriasis. Increased disease severity may contribute to treatment resistance or numerous trials of topicals or biologics before the disease improves. Patient education in the community as well as patient support groups are paramount, and increased awareness of psoriasis can help improve disease management.

Treatment
Topical therapies are the first-line treatment of psoriasis. Although there is no evidence showing differences in topical treatment efficacy, patient preference for different topical treatments may vary based on race. For example, patients with Afro-textured hair may prefer foams and lotions and would avoid shampoo therapies, as frequent hair washing may not be feasible with certain hairstyles and may cause hair breakage or dryness.²

UV therapy can be an effective treatment modality for patients with psoriasis. The strength of therapy tends to be dictated by the Fitzpatrick skin phototype rather than race. Darker-skinned individuals may have an increased risk for hyperpigmentation, so caution should be taken to prevent burning during therapy. Suberythemogenic dosing—70% of minimal erythema dose—of narrowband UVB treatments has shown the same efficacy as using minimal erythema dose in patients with darker skin types in addition to fair-skinned patients.⁸

Although we found poor efficacy of systemic treatments in patient 1, to our knowledge, studies examining the efficacy of systemic therapeutic options have not shown differences in patients of color.^6,13 Studies show similar efficacy in treatments among races, particularly biologic therapies.⁵ However, patients with skin of color historically have been underrepresented in clinical trials,⁹ which may contribute to these patients, particularly black patients, being less familiar with biologics as a treatment option for psoriasis, as reported by Takeshita et al.¹⁰ Therefore, patient-centered discussions regarding treatment choices are important to ensure patients understand all options available to manage their disease.

Psychosocial Impact
Because of its chronic remitting course, psoriasis has a notable psychosocial impact on the lives of all patients, though the literature suggests there may be more of an impact on QOL in patients of color. Higher baseline dermatology life quality index scores have been reported in patients of color compared to white patients.⁶ Kerr et al¹² reported significantly greater psoriasis area and severity index scores (P=.06) and greater psychological impact in black patients compared to white patients. Stress also was more likely to be reported as a trigger for psoriasis in patients of Hispanic background compared to white patients.¹⁴ Many patients report body image issues with large physical lesions; however, the difference may lie in personal and cultural views about psoriasis, as one of our patients stated, “black people do not get psoriasis.” In addition to the cosmetic challenges that patients face with active lesions, postinflammatory pigmentary changes can be equally as burdensome to patients, as one of our patients stated he “would do anything to get rid of it.” Increased rates of depression and anxiety in patients of color can worsen their outlook on the condition.^15,16 The increased stigma and burden of psoriasis in patients of color calls for clinicians to counsel and address psoriasis in a holistic way and refer patients to psoriasis support groups when appropriate. Although the burden of psoriasis is clear, more studies can be carried out to investigate the impact on QOL in different ethnic populations.

Dermatology Education
Although differences have been found in patients of color with psoriasis, dissemination of this knowledge continues to be a challenge. In dermatology residency programs, the majority of teaching is provided with examples of skin diseases in white patients, which can complicate pattern recognition and diagnostic ability for trainees. Although dermatologists recognize that ethnic skin has unique dermatologic considerations, there is a persistent need for increasing skin of color education within dermatology residency programs.^17,18 Implementing more educational programs on skin of color has been proposed, and these programs will continue to be in demand as our population increasingly diversifies.¹⁹

Conclusion

Psoriasis in patients of color carries unique challenges when compared to psoriasis in white patients. Differences in morphology and presentation can make the disease difficult to accurately diagnose. These differences in addition to cultural differences may contribute to a greater impact on QOL and psychological health. Although treatment preferences and recognition may differ, treatment efficacy has so far been similar, albeit with a low proportion of patients with skin of color included in clinical trials.

Further focus should now lie within knowledge translation of these differences, which would normalize the condition for patients, support them seeking medical attention sooner, and inform them of all treatment options possible. For clinicians, more attention on the differences would help make earlier diagnoses, personalize physician-patient conversations, and advocate for further education on this issue in residency training programs.

Psoriasis is a chronic inflammatory skin disease that affects 2% to 3% of individuals worldwide.¹ Despite extensive research, the majority of clinical data are in white patients with limited data in patients of color, yet a number of differences are known. The prevalence of psoriasis differs among racial and ethnic groups, with lower prevalence in racial minorities.² A cross-sectional American study using data from 2009 through 2010 showed the prevalence for psoriasis was 3.6% in white patients, 1.9% in black patients, 1.6% in Hispanic patients, and 1.4% in other racial groups.³ Psoriasis presents differently in patients of color, both in morphology and severity. Cultural differences and stigma may contribute to the differences seen in severity but also to the psychological impact and treatment choices in patients of color compared to white patients.⁴ It has even been theorized that treatment efficacy could differ because of potential genetic differences.⁵ Psoriasis in patients of color is an emerging clinical issue that requires further attention so that dermatologists can learn about, diagnose, and treat them.

We report 3 cases of patients of color with psoriasis who presented to an urban and racially diverse dermatology clinic affiliated with Scarborough General Hospital in Toronto, Ontario, Canada. A retrospective chart review was performed on these high-yield representative cases to demonstrate differences in color and morphology, disease severity, and treatment in patients of various races seen at our clinic. After informed consent was obtained, photographs were taken of patient cutaneous findings to illustrate these differences. Discussion with these selected patients yielded supplementary qualitative data, highlighting individual perspectives of their disease.

Case Series

Patient 1
A 53-year-old black man from Grenada presented to our clinic with a history of psoriasis for a number of years that presented as violaceous plaques throughout large portions of the body (Figure 1). He previously had achieved inadequate results while using topical therapies, methotrexate, acitretin, apremilast, ustekinumab, ixekizumab, and guselkumab at adequate or even maximum doses. His disease affected 30% of the body surface area, with a psoriasis area and severity index score of 27 and a dermatology life quality index score of 23. The patient’s life was quite affected by psoriasis, with emphasis on choice of clothing worn and effect on body image. He also discussed the stigma psoriasis may have in black patients, stating that he has been told multiple times that “black people do not get psoriasis.”

Patient 2
A 27-year-old man from India presented with guttate psoriasis (Figure 2). He was treated with methotrexate 2 years prior and currently is on maintenance therapy with topical treatments alone. His main concerns pertained to the persistent dyschromia that occurred secondary to the psoriatic lesions. Through discussion, the patient stated that he “would do anything to get rid of it.”

Comment

Clinical differences in patients of color with psoriasis affect the management of the disease. Special consideration should be given to variances in morphology, presentation, treatment, and psychosocial factors in the management of psoriasis for these patient populations, as summarized in the eTable.

Morphology
At our clinic, patients of color have been found to have differences in morphology, including lesions that are more violaceous in color, as seen in patient 1; less noticeable inflammation; and more postinflammatory hypopigmentation and hyperpigmentation changes, as seen in patient 2. These changes are supported by the literature and differ from typical psoriasis plaques, which are pink-red and have more overlying scale. The varied morphology also may affect the differential, and other mimickers may be considered, such as lichen planus, cutaneous lupus erythematosus, and sarcoidosis.²

Presentation
There are differences in presentation among patients of color, particularly in distribution, type of psoriasis, and severity. As seen in patient 3, Asian and black patients are more likely to present with scalp psoriasis.^2,5 Hairstyling and hair care practices can differ considerably between racial groups. Given the differences in hairstyling, scalp psoriasis also may have a greater impact on patient quality of life (QOL).

Racial differences affect the type of psoriasis seen. Asian patients are more likely to present with pustular and erythrodermic psoriasis and less likely to present with inverse psoriasis compared to white patients. Hispanic patients are more likely to present with pustular psoriasis.¹¹ Black patients have been reported to have lower frequencies of psoriatic arthritis compared to white patients.¹² Recognition of these differences may help guide initial choice for therapeutics.

Notably, patients of color may present with much more severe psoriasis, particularly Asian and Hispanic patients.⁷ One retrospective study looking at patients with psoriasis treated with etanercept found that Asian patients were more likely to have greater baseline body surface area involvement.⁶ An American cross-sectional study reported higher psoriasis area and severity index scores in black patients compared to white patients,¹² possibly because patients of color do not normalize the experience of having psoriasis and feel stigmatized, which can cause delays in seeking medical attention and worsen disease burden. For patient 1, the stigma of black patients having psoriasis affected his body image and may have led to a delay in seeking medical attention due to him not believing it was possible for people of his skin color to have psoriasis. Increased disease severity may contribute to treatment resistance or numerous trials of topicals or biologics before the disease improves. Patient education in the community as well as patient support groups are paramount, and increased awareness of psoriasis can help improve disease management.

Treatment
Topical therapies are the first-line treatment of psoriasis. Although there is no evidence showing differences in topical treatment efficacy, patient preference for different topical treatments may vary based on race. For example, patients with Afro-textured hair may prefer foams and lotions and would avoid shampoo therapies, as frequent hair washing may not be feasible with certain hairstyles and may cause hair breakage or dryness.²

UV therapy can be an effective treatment modality for patients with psoriasis. The strength of therapy tends to be dictated by the Fitzpatrick skin phototype rather than race. Darker-skinned individuals may have an increased risk for hyperpigmentation, so caution should be taken to prevent burning during therapy. Suberythemogenic dosing—70% of minimal erythema dose—of narrowband UVB treatments has shown the same efficacy as using minimal erythema dose in patients with darker skin types in addition to fair-skinned patients.⁸

Although we found poor efficacy of systemic treatments in patient 1, to our knowledge, studies examining the efficacy of systemic therapeutic options have not shown differences in patients of color.^6,13 Studies show similar efficacy in treatments among races, particularly biologic therapies.⁵ However, patients with skin of color historically have been underrepresented in clinical trials,⁹ which may contribute to these patients, particularly black patients, being less familiar with biologics as a treatment option for psoriasis, as reported by Takeshita et al.¹⁰ Therefore, patient-centered discussions regarding treatment choices are important to ensure patients understand all options available to manage their disease.

Psychosocial Impact
Because of its chronic remitting course, psoriasis has a notable psychosocial impact on the lives of all patients, though the literature suggests there may be more of an impact on QOL in patients of color. Higher baseline dermatology life quality index scores have been reported in patients of color compared to white patients.⁶ Kerr et al¹² reported significantly greater psoriasis area and severity index scores (P=.06) and greater psychological impact in black patients compared to white patients. Stress also was more likely to be reported as a trigger for psoriasis in patients of Hispanic background compared to white patients.¹⁴ Many patients report body image issues with large physical lesions; however, the difference may lie in personal and cultural views about psoriasis, as one of our patients stated, “black people do not get psoriasis.” In addition to the cosmetic challenges that patients face with active lesions, postinflammatory pigmentary changes can be equally as burdensome to patients, as one of our patients stated he “would do anything to get rid of it.” Increased rates of depression and anxiety in patients of color can worsen their outlook on the condition.^15,16 The increased stigma and burden of psoriasis in patients of color calls for clinicians to counsel and address psoriasis in a holistic way and refer patients to psoriasis support groups when appropriate. Although the burden of psoriasis is clear, more studies can be carried out to investigate the impact on QOL in different ethnic populations.

Dermatology Education
Although differences have been found in patients of color with psoriasis, dissemination of this knowledge continues to be a challenge. In dermatology residency programs, the majority of teaching is provided with examples of skin diseases in white patients, which can complicate pattern recognition and diagnostic ability for trainees. Although dermatologists recognize that ethnic skin has unique dermatologic considerations, there is a persistent need for increasing skin of color education within dermatology residency programs.^17,18 Implementing more educational programs on skin of color has been proposed, and these programs will continue to be in demand as our population increasingly diversifies.¹⁹

Conclusion

Psoriasis in patients of color carries unique challenges when compared to psoriasis in white patients. Differences in morphology and presentation can make the disease difficult to accurately diagnose. These differences in addition to cultural differences may contribute to a greater impact on QOL and psychological health. Although treatment preferences and recognition may differ, treatment efficacy has so far been similar, albeit with a low proportion of patients with skin of color included in clinical trials.

Further focus should now lie within knowledge translation of these differences, which would normalize the condition for patients, support them seeking medical attention sooner, and inform them of all treatment options possible. For clinicians, more attention on the differences would help make earlier diagnoses, personalize physician-patient conversations, and advocate for further education on this issue in residency training programs.

THE CASE

A 50-year-old man presented to the primary care office for evaluation of foot pain. The day before, his left fifth toe had become exquisitely tender. He distinctly remembered that when he awoke, there was no discoloration or pain, but the toe later became “purple.” He denied any trauma. His medical record was notable for an extensive smoking history and a family history of early cardiovascular disease.

The patient appeared well but in obvious distress, secondary to the pain. His vital signs were unremarkable. His head, neck, lung, and cardiac exams revealed no abnormalities. Physical examination revealed a left fifth toe that was dusky purple and warm to the touch. Pain disproportionate to examination was noted on the anterior aspect of the toe, with limited range of motion. The patient walked with a compensated gait. Pulses were palpable on the posterior tibial (PT) and dorsalis pedis (DP) regions.

DIAGNOSIS

Based on our exam findings, we suspected a vascular injury and recommended an emergency consult by Podiatry, for which he was scheduled the following morning. The podiatric evaluation confirmed concern for a vascular injury and prompted a request for an emergent evaluation by Vascular Surgery.

The patient was seen emergently on Day 4 for a vascular surgery evaluation. Examination at that time showed a nearly absent femoral pulse on the left side and diminished and monophasic DP and PT pulses. His left foot demonstrated nonblanchable purpura that was clinically consistent with cholesterol embolization syndrome (CES).

We calculated the patient’s ankle-brachial index, and computed tomography angiography (CTA) was performed. While results were pending, the patient was started on aspirin 81 mg, clopidogrel 75 mg, and atorvastatin 40 mg, for a suspected slowly progressing iliac artery stenosis with a resulting acute atheroembolic event.

The CTA report showed a high-grade stenosis at the bifurcation of the left iliac artery, extending into both external and internal arteries. Of note, mild atherosclerotic disease without significant occlusion and runoff to the foot was observed into the tibial arteries. The stenosis extended into the profonda femoris artery, as well.

DISCUSSION

Atherosclerotic plaques are commonly encountered in patients with atherosclerotic disease; however, there are 2 varieties of emboli that arise from these plaques and one is often overlooked.^1-4 The more common of these variants, thromboemboli, originates from an atherosclerotic plaque and can become lodged in a medium or large vessel as a single embolus.

Continue to: By contrast...

By contrast, atheroemboli (commonly known as cholesterol emboli or cholesterol crystal embolization) originate from atherosclerotic plaques in the aorta or another large artery,⁵ which are prone to embolize if the underlying plaque experiences stress. As the plaque erodes, cholesterol crystals break off and embolize distally. These smaller crystals flood into the circulation, allowing a shower of emboli over time to occlude the arterioles. As occlusion spreads through the arterioles, multiple organ systems are affected. (It was previously thought that procedure-associated cases were common, but a literature review has not borne this out.⁵)

The shower of emboli often triggers a systemic inflammatory response, causing nondescript abnormalities of laboratory inflammatory markers.^6,7 Interestingly, hypereosinophilia is noted in about 80% of patients with CES.⁸It is not uncommon for atheroemboli of the lower extremity to manifest, as it did in this case, as “blue toe syndrome.”

No disease-specific testing. A confounding factor in validating the diagnosis of CES is the lack of disease-specific testing. However, CES should be considered in a patient with acute kidney injury and hypereosinophilia. Making the diagnosis requires a high degree of clinical suspicion. Any organ can be affected, although the brain, kidneys, gastrointestinal tract, skin, and skeletal muscles of the lower extremities are most frequently involved.⁹ If left undiagnosed, the results can be devastating: slow and chronic injury to a variety of organ systems over time, which may not be recognized as a harbinger of an insidious underlying process causing end-organ damage.

Technically, definitive diagnosis can be made by biopsy of an affected organ. However, biopsy’s utility is limited due to potential for sampling error, accessibility (as noted, the location of the involved organ[s] may make biopsy nearly impossible without additional surgical risk⁹), and risk of poor healing to the biopsy site.¹⁰

Treatment is two-fold: supportive care for the affected end organ and prevention of subsequent embolic events. The latter entails aggressive risk factor reduction strategies, such as smoking cessation, statin therapy, blood pressure control, and blood sugar control. Warfarin is not recommended for treatment of CES due to the risk of further plaque rupture, hemorrhage, acute and chronic renal failure, and cholesterol microembolization to other organs.^11,12

Continue to: Our patient

Our patient. After testing confirmed the diagnosis, the patient underwent an angioplasty. A stent was placed in his left iliac artery. He was continued on antiplatelet and statin therapy and was again counseled regarding smoking cessation.

THE TAKEAWAY

When patients present with symptoms suggestive of a vascular origin, consider CES. Although it can affect a multitude of organs, acute kidney injury and hypereosinophilia are the most common signs. Immediate intervention is required to save the affected organ; strategizing to reduce the risk for further embolic events is also key.

Warfarin is not recommended for treatment of cholesterol embolization syndrome due to the risk of further plaque rupture, hemorrhage, and cholesterol microembolization to other organs.

Prompt recognition of vascular emergencies, including those that are harbingers of atherosclerotic disease, is essential. As clinicians, it is imperative that we use all resources to address significant population health burdens. If CES is more prevalent than commonly thought, consideration should be given to increasing education about early detection and treatment of this disorder, including the reinforcement of primary prevention and aggressive treatment of risk factors for atherosclerotic cardiovascular disease.

CORRESPONDENCE
Meagan Vermeulen, MD, FAAFP, Department of Family Medicine, Rowan University School of Osteopathic Medicine, 42 East Laurel Road, Suite 2100A, Stratford, NJ 08084; [email protected]

THE CASE

A 50-year-old man presented to the primary care office for evaluation of foot pain. The day before, his left fifth toe had become exquisitely tender. He distinctly remembered that when he awoke, there was no discoloration or pain, but the toe later became “purple.” He denied any trauma. His medical record was notable for an extensive smoking history and a family history of early cardiovascular disease.

The patient appeared well but in obvious distress, secondary to the pain. His vital signs were unremarkable. His head, neck, lung, and cardiac exams revealed no abnormalities. Physical examination revealed a left fifth toe that was dusky purple and warm to the touch. Pain disproportionate to examination was noted on the anterior aspect of the toe, with limited range of motion. The patient walked with a compensated gait. Pulses were palpable on the posterior tibial (PT) and dorsalis pedis (DP) regions.

DIAGNOSIS

Based on our exam findings, we suspected a vascular injury and recommended an emergency consult by Podiatry, for which he was scheduled the following morning. The podiatric evaluation confirmed concern for a vascular injury and prompted a request for an emergent evaluation by Vascular Surgery.

The patient was seen emergently on Day 4 for a vascular surgery evaluation. Examination at that time showed a nearly absent femoral pulse on the left side and diminished and monophasic DP and PT pulses. His left foot demonstrated nonblanchable purpura that was clinically consistent with cholesterol embolization syndrome (CES).

We calculated the patient’s ankle-brachial index, and computed tomography angiography (CTA) was performed. While results were pending, the patient was started on aspirin 81 mg, clopidogrel 75 mg, and atorvastatin 40 mg, for a suspected slowly progressing iliac artery stenosis with a resulting acute atheroembolic event.

The CTA report showed a high-grade stenosis at the bifurcation of the left iliac artery, extending into both external and internal arteries. Of note, mild atherosclerotic disease without significant occlusion and runoff to the foot was observed into the tibial arteries. The stenosis extended into the profonda femoris artery, as well.

DISCUSSION

Atherosclerotic plaques are commonly encountered in patients with atherosclerotic disease; however, there are 2 varieties of emboli that arise from these plaques and one is often overlooked.^1-4 The more common of these variants, thromboemboli, originates from an atherosclerotic plaque and can become lodged in a medium or large vessel as a single embolus.

Continue to: By contrast...

By contrast, atheroemboli (commonly known as cholesterol emboli or cholesterol crystal embolization) originate from atherosclerotic plaques in the aorta or another large artery,⁵ which are prone to embolize if the underlying plaque experiences stress. As the plaque erodes, cholesterol crystals break off and embolize distally. These smaller crystals flood into the circulation, allowing a shower of emboli over time to occlude the arterioles. As occlusion spreads through the arterioles, multiple organ systems are affected. (It was previously thought that procedure-associated cases were common, but a literature review has not borne this out.⁵)

The shower of emboli often triggers a systemic inflammatory response, causing nondescript abnormalities of laboratory inflammatory markers.^6,7 Interestingly, hypereosinophilia is noted in about 80% of patients with CES.⁸It is not uncommon for atheroemboli of the lower extremity to manifest, as it did in this case, as “blue toe syndrome.”

No disease-specific testing. A confounding factor in validating the diagnosis of CES is the lack of disease-specific testing. However, CES should be considered in a patient with acute kidney injury and hypereosinophilia. Making the diagnosis requires a high degree of clinical suspicion. Any organ can be affected, although the brain, kidneys, gastrointestinal tract, skin, and skeletal muscles of the lower extremities are most frequently involved.⁹ If left undiagnosed, the results can be devastating: slow and chronic injury to a variety of organ systems over time, which may not be recognized as a harbinger of an insidious underlying process causing end-organ damage.

Technically, definitive diagnosis can be made by biopsy of an affected organ. However, biopsy’s utility is limited due to potential for sampling error, accessibility (as noted, the location of the involved organ[s] may make biopsy nearly impossible without additional surgical risk⁹), and risk of poor healing to the biopsy site.¹⁰

Treatment is two-fold: supportive care for the affected end organ and prevention of subsequent embolic events. The latter entails aggressive risk factor reduction strategies, such as smoking cessation, statin therapy, blood pressure control, and blood sugar control. Warfarin is not recommended for treatment of CES due to the risk of further plaque rupture, hemorrhage, acute and chronic renal failure, and cholesterol microembolization to other organs.^11,12

Continue to: Our patient

Our patient. After testing confirmed the diagnosis, the patient underwent an angioplasty. A stent was placed in his left iliac artery. He was continued on antiplatelet and statin therapy and was again counseled regarding smoking cessation.

THE TAKEAWAY

When patients present with symptoms suggestive of a vascular origin, consider CES. Although it can affect a multitude of organs, acute kidney injury and hypereosinophilia are the most common signs. Immediate intervention is required to save the affected organ; strategizing to reduce the risk for further embolic events is also key.

Warfarin is not recommended for treatment of cholesterol embolization syndrome due to the risk of further plaque rupture, hemorrhage, and cholesterol microembolization to other organs.

Prompt recognition of vascular emergencies, including those that are harbingers of atherosclerotic disease, is essential. As clinicians, it is imperative that we use all resources to address significant population health burdens. If CES is more prevalent than commonly thought, consideration should be given to increasing education about early detection and treatment of this disorder, including the reinforcement of primary prevention and aggressive treatment of risk factors for atherosclerotic cardiovascular disease.

CORRESPONDENCE
Meagan Vermeulen, MD, FAAFP, Department of Family Medicine, Rowan University School of Osteopathic Medicine, 42 East Laurel Road, Suite 2100A, Stratford, NJ 08084; [email protected]

THE CASE

A 50-year-old man presented to the primary care office for evaluation of foot pain. The day before, his left fifth toe had become exquisitely tender. He distinctly remembered that when he awoke, there was no discoloration or pain, but the toe later became “purple.” He denied any trauma. His medical record was notable for an extensive smoking history and a family history of early cardiovascular disease.

The patient appeared well but in obvious distress, secondary to the pain. His vital signs were unremarkable. His head, neck, lung, and cardiac exams revealed no abnormalities. Physical examination revealed a left fifth toe that was dusky purple and warm to the touch. Pain disproportionate to examination was noted on the anterior aspect of the toe, with limited range of motion. The patient walked with a compensated gait. Pulses were palpable on the posterior tibial (PT) and dorsalis pedis (DP) regions.

DIAGNOSIS

Based on our exam findings, we suspected a vascular injury and recommended an emergency consult by Podiatry, for which he was scheduled the following morning. The podiatric evaluation confirmed concern for a vascular injury and prompted a request for an emergent evaluation by Vascular Surgery.

The patient was seen emergently on Day 4 for a vascular surgery evaluation. Examination at that time showed a nearly absent femoral pulse on the left side and diminished and monophasic DP and PT pulses. His left foot demonstrated nonblanchable purpura that was clinically consistent with cholesterol embolization syndrome (CES).

We calculated the patient’s ankle-brachial index, and computed tomography angiography (CTA) was performed. While results were pending, the patient was started on aspirin 81 mg, clopidogrel 75 mg, and atorvastatin 40 mg, for a suspected slowly progressing iliac artery stenosis with a resulting acute atheroembolic event.

The CTA report showed a high-grade stenosis at the bifurcation of the left iliac artery, extending into both external and internal arteries. Of note, mild atherosclerotic disease without significant occlusion and runoff to the foot was observed into the tibial arteries. The stenosis extended into the profonda femoris artery, as well.

DISCUSSION

Atherosclerotic plaques are commonly encountered in patients with atherosclerotic disease; however, there are 2 varieties of emboli that arise from these plaques and one is often overlooked.^1-4 The more common of these variants, thromboemboli, originates from an atherosclerotic plaque and can become lodged in a medium or large vessel as a single embolus.

Continue to: By contrast...

By contrast, atheroemboli (commonly known as cholesterol emboli or cholesterol crystal embolization) originate from atherosclerotic plaques in the aorta or another large artery,⁵ which are prone to embolize if the underlying plaque experiences stress. As the plaque erodes, cholesterol crystals break off and embolize distally. These smaller crystals flood into the circulation, allowing a shower of emboli over time to occlude the arterioles. As occlusion spreads through the arterioles, multiple organ systems are affected. (It was previously thought that procedure-associated cases were common, but a literature review has not borne this out.⁵)

The shower of emboli often triggers a systemic inflammatory response, causing nondescript abnormalities of laboratory inflammatory markers.^6,7 Interestingly, hypereosinophilia is noted in about 80% of patients with CES.⁸It is not uncommon for atheroemboli of the lower extremity to manifest, as it did in this case, as “blue toe syndrome.”

No disease-specific testing. A confounding factor in validating the diagnosis of CES is the lack of disease-specific testing. However, CES should be considered in a patient with acute kidney injury and hypereosinophilia. Making the diagnosis requires a high degree of clinical suspicion. Any organ can be affected, although the brain, kidneys, gastrointestinal tract, skin, and skeletal muscles of the lower extremities are most frequently involved.⁹ If left undiagnosed, the results can be devastating: slow and chronic injury to a variety of organ systems over time, which may not be recognized as a harbinger of an insidious underlying process causing end-organ damage.

Technically, definitive diagnosis can be made by biopsy of an affected organ. However, biopsy’s utility is limited due to potential for sampling error, accessibility (as noted, the location of the involved organ[s] may make biopsy nearly impossible without additional surgical risk⁹), and risk of poor healing to the biopsy site.¹⁰

Treatment is two-fold: supportive care for the affected end organ and prevention of subsequent embolic events. The latter entails aggressive risk factor reduction strategies, such as smoking cessation, statin therapy, blood pressure control, and blood sugar control. Warfarin is not recommended for treatment of CES due to the risk of further plaque rupture, hemorrhage, acute and chronic renal failure, and cholesterol microembolization to other organs.^11,12

Continue to: Our patient

Our patient. After testing confirmed the diagnosis, the patient underwent an angioplasty. A stent was placed in his left iliac artery. He was continued on antiplatelet and statin therapy and was again counseled regarding smoking cessation.

THE TAKEAWAY

When patients present with symptoms suggestive of a vascular origin, consider CES. Although it can affect a multitude of organs, acute kidney injury and hypereosinophilia are the most common signs. Immediate intervention is required to save the affected organ; strategizing to reduce the risk for further embolic events is also key.

Warfarin is not recommended for treatment of cholesterol embolization syndrome due to the risk of further plaque rupture, hemorrhage, and cholesterol microembolization to other organs.

Prompt recognition of vascular emergencies, including those that are harbingers of atherosclerotic disease, is essential. As clinicians, it is imperative that we use all resources to address significant population health burdens. If CES is more prevalent than commonly thought, consideration should be given to increasing education about early detection and treatment of this disorder, including the reinforcement of primary prevention and aggressive treatment of risk factors for atherosclerotic cardiovascular disease.

CORRESPONDENCE
Meagan Vermeulen, MD, FAAFP, Department of Family Medicine, Rowan University School of Osteopathic Medicine, 42 East Laurel Road, Suite 2100A, Stratford, NJ 08084; [email protected]

THE CASE

A 67-year-old woman with type 2 diabetes mellitus and hypertension presented to our family medicine office for evaluation of excessive flatulence, belching, and bloating that had worsened over the previous 6 months. The patient said the symptoms occurred throughout the day but were most noticeable after eating meals. She had a 5-year history of heartburn and chronic cough. We initially suspected gastroesophageal reflux disease (GERD). However, trials with several different proton pump inhibitors (PPIs) over a 3-year period did not provide any relief. Lifestyle modifications such as losing weight; remaining upright for at least 3 hours after eating; and eliminating gluten, dairy, soy, and alcohol from her diet did not alleviate her symptoms.

At the current presentation, the physical examination was normal, and an upper endoscopy was unremarkable except for some mild gastric irritation. A urea breath test was negative for Helicobacter pylori, and a chest radiograph to investigate the cause of the chronic cough was normal. The patient’s increased symptoms after eating indicated that a sensitivity to food antibodies might be at work. The absence of urticaria and anaphylaxis correlated with an IgG-mediated rather than an IgE-mediated reaction.

Due to the high cost of IgG testing, we recommended that the patient start a 6-week elimination diet that excluded the most common culprits for food allergies: dairy, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, and soy.¹ We also recommended that she eliminate alcohol (because of its role in exacerbating GERD); however, excluding these foods from her diet did not provide sufficient relief of her symptoms. We subsequently recommended a serum IgG food antibody test.

THE DIAGNOSIS

The results of the test were positive for IgG-mediated allergy to vegetables in the onion family, as indicated by a high (3+) antibody presence. The patient told us she consumed onions up to 3 times daily in her meals. We recommended that she eliminate onions from her diet. At a follow-up appointment 3 months later, the patient reported that the flatulence, belching, and bloating after eating had resolved and her heartburn had decreased. When we asked about her chronic cough, the patient mentioned she had not experienced it for a few months and had forgotten about it.

DISCUSSION

The most common food sensitivity test is the scratch test, which only measures IgE antibodies. However, past studies have suggested that IgE is not the only mediator in certain symptoms related to food allergy. It is thought that these symptoms may instead be IgG mediated.² Normally, IgG antibodies do not form in the digestive tract because the epithelium creates a barrier that is impermeable to antigens. However, antigens can bypass the epithelium and reach immune cells in states of inflammation where the epithelium is damaged. This contact with immune cells provides an opportunity for development of IgG antibodies.³ Successive interactions with these antigens leads to defensive and inflammatory processes that manifest as food allergies.

Rather than the typical IgE-mediated presentations (eg, urticaria, anaphylaxis), patients with IgG-mediated allergies experience more subtle symptoms, such as bloating, heartburn, and cough.

Rather than the typical IgE-mediated presentations (eg, urticaria, anaphylaxis), patients with IgG-mediated allergies experience more subtle symptoms, such as nausea, abdominal pain, diarrhea, flatulence, cramping, bloating, heartburn, cough, bronchoconstriction, eczema, stiff joints, headache, and/or increased risk of infection.⁴ One study showed that eliminating IgG-sensitive foods (eg, dairy, eggs) improved symptoms in migraine patients.⁵ Likewise, a separate study showed that patients with irritable bowel syndrome experienced improved symptoms after eliminating foods for which they had high IgG sensitivity.⁶

Casting a wider net. Whereas scratch testing only looks at IgE-mediated allergies, serum IgG food antibody testing looks for both IgE- and IgG-mediated reactions. IgE-mediated food allergies are monitored via the scratch test as a visual expression of a histamine reaction on the skin. However, serum IgG food antibody testing identifies culprit foods via enzyme-linked immunosorbent assay.

Continue to: Furthermore, the serum antibody test...

Furthermore, the serum antibody test also identifies allergenic foods whose symptoms have a delayed onset of 4 to 72 hours.⁷ Without this test, those symptoms may be wrongfully attributed to other conditions, and prescribed treatments will not treat the root cause of the reaction.⁸ The information provided in the serum antibody test allows the patient to develop a tailored elimination diet and eliminate causative food(s) faster. Without this test, we may not have identified onions as the allergenic food in our patient.

THE TAKEAWAY

Recent guidelines emphasize that IgG testing plays no role in the diagnosis of food allergies or intolerance.¹ This may indeed be true for the general population, but other studies have shown IgG testing to be of value for specific diagnoses such as migraines or irritable bowel syndrome.^5,6 Given our patient’s unique presentation and lack of response to traditional treatments, IgG testing was warranted. This case demonstrates the importance of IgG food antibody testing as part of a second-tier diagnostic workup when a patient’s gastrointestinal symptoms are not alleviated by traditional interventions.

CORRESPONDENCE
Elizabeth A. Khan, MD, Personalized Longevity Medical Center, 1146 South Cedar Crest Boulevard, Allentown, PA 18103; [email protected].

THE CASE

A 67-year-old woman with type 2 diabetes mellitus and hypertension presented to our family medicine office for evaluation of excessive flatulence, belching, and bloating that had worsened over the previous 6 months. The patient said the symptoms occurred throughout the day but were most noticeable after eating meals. She had a 5-year history of heartburn and chronic cough. We initially suspected gastroesophageal reflux disease (GERD). However, trials with several different proton pump inhibitors (PPIs) over a 3-year period did not provide any relief. Lifestyle modifications such as losing weight; remaining upright for at least 3 hours after eating; and eliminating gluten, dairy, soy, and alcohol from her diet did not alleviate her symptoms.

At the current presentation, the physical examination was normal, and an upper endoscopy was unremarkable except for some mild gastric irritation. A urea breath test was negative for Helicobacter pylori, and a chest radiograph to investigate the cause of the chronic cough was normal. The patient’s increased symptoms after eating indicated that a sensitivity to food antibodies might be at work. The absence of urticaria and anaphylaxis correlated with an IgG-mediated rather than an IgE-mediated reaction.

Due to the high cost of IgG testing, we recommended that the patient start a 6-week elimination diet that excluded the most common culprits for food allergies: dairy, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, and soy.¹ We also recommended that she eliminate alcohol (because of its role in exacerbating GERD); however, excluding these foods from her diet did not provide sufficient relief of her symptoms. We subsequently recommended a serum IgG food antibody test.

THE DIAGNOSIS

The results of the test were positive for IgG-mediated allergy to vegetables in the onion family, as indicated by a high (3+) antibody presence. The patient told us she consumed onions up to 3 times daily in her meals. We recommended that she eliminate onions from her diet. At a follow-up appointment 3 months later, the patient reported that the flatulence, belching, and bloating after eating had resolved and her heartburn had decreased. When we asked about her chronic cough, the patient mentioned she had not experienced it for a few months and had forgotten about it.

DISCUSSION

The most common food sensitivity test is the scratch test, which only measures IgE antibodies. However, past studies have suggested that IgE is not the only mediator in certain symptoms related to food allergy. It is thought that these symptoms may instead be IgG mediated.² Normally, IgG antibodies do not form in the digestive tract because the epithelium creates a barrier that is impermeable to antigens. However, antigens can bypass the epithelium and reach immune cells in states of inflammation where the epithelium is damaged. This contact with immune cells provides an opportunity for development of IgG antibodies.³ Successive interactions with these antigens leads to defensive and inflammatory processes that manifest as food allergies.

Rather than the typical IgE-mediated presentations (eg, urticaria, anaphylaxis), patients with IgG-mediated allergies experience more subtle symptoms, such as bloating, heartburn, and cough.

Rather than the typical IgE-mediated presentations (eg, urticaria, anaphylaxis), patients with IgG-mediated allergies experience more subtle symptoms, such as nausea, abdominal pain, diarrhea, flatulence, cramping, bloating, heartburn, cough, bronchoconstriction, eczema, stiff joints, headache, and/or increased risk of infection.⁴ One study showed that eliminating IgG-sensitive foods (eg, dairy, eggs) improved symptoms in migraine patients.⁵ Likewise, a separate study showed that patients with irritable bowel syndrome experienced improved symptoms after eliminating foods for which they had high IgG sensitivity.⁶

Casting a wider net. Whereas scratch testing only looks at IgE-mediated allergies, serum IgG food antibody testing looks for both IgE- and IgG-mediated reactions. IgE-mediated food allergies are monitored via the scratch test as a visual expression of a histamine reaction on the skin. However, serum IgG food antibody testing identifies culprit foods via enzyme-linked immunosorbent assay.

Continue to: Furthermore, the serum antibody test...

Furthermore, the serum antibody test also identifies allergenic foods whose symptoms have a delayed onset of 4 to 72 hours.⁷ Without this test, those symptoms may be wrongfully attributed to other conditions, and prescribed treatments will not treat the root cause of the reaction.⁸ The information provided in the serum antibody test allows the patient to develop a tailored elimination diet and eliminate causative food(s) faster. Without this test, we may not have identified onions as the allergenic food in our patient.

THE TAKEAWAY

Recent guidelines emphasize that IgG testing plays no role in the diagnosis of food allergies or intolerance.¹ This may indeed be true for the general population, but other studies have shown IgG testing to be of value for specific diagnoses such as migraines or irritable bowel syndrome.^5,6 Given our patient’s unique presentation and lack of response to traditional treatments, IgG testing was warranted. This case demonstrates the importance of IgG food antibody testing as part of a second-tier diagnostic workup when a patient’s gastrointestinal symptoms are not alleviated by traditional interventions.

CORRESPONDENCE
Elizabeth A. Khan, MD, Personalized Longevity Medical Center, 1146 South Cedar Crest Boulevard, Allentown, PA 18103; [email protected].

THE CASE

A 67-year-old woman with type 2 diabetes mellitus and hypertension presented to our family medicine office for evaluation of excessive flatulence, belching, and bloating that had worsened over the previous 6 months. The patient said the symptoms occurred throughout the day but were most noticeable after eating meals. She had a 5-year history of heartburn and chronic cough. We initially suspected gastroesophageal reflux disease (GERD). However, trials with several different proton pump inhibitors (PPIs) over a 3-year period did not provide any relief. Lifestyle modifications such as losing weight; remaining upright for at least 3 hours after eating; and eliminating gluten, dairy, soy, and alcohol from her diet did not alleviate her symptoms.

At the current presentation, the physical examination was normal, and an upper endoscopy was unremarkable except for some mild gastric irritation. A urea breath test was negative for Helicobacter pylori, and a chest radiograph to investigate the cause of the chronic cough was normal. The patient’s increased symptoms after eating indicated that a sensitivity to food antibodies might be at work. The absence of urticaria and anaphylaxis correlated with an IgG-mediated rather than an IgE-mediated reaction.

Due to the high cost of IgG testing, we recommended that the patient start a 6-week elimination diet that excluded the most common culprits for food allergies: dairy, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, and soy.¹ We also recommended that she eliminate alcohol (because of its role in exacerbating GERD); however, excluding these foods from her diet did not provide sufficient relief of her symptoms. We subsequently recommended a serum IgG food antibody test.

THE DIAGNOSIS

The results of the test were positive for IgG-mediated allergy to vegetables in the onion family, as indicated by a high (3+) antibody presence. The patient told us she consumed onions up to 3 times daily in her meals. We recommended that she eliminate onions from her diet. At a follow-up appointment 3 months later, the patient reported that the flatulence, belching, and bloating after eating had resolved and her heartburn had decreased. When we asked about her chronic cough, the patient mentioned she had not experienced it for a few months and had forgotten about it.

DISCUSSION

The most common food sensitivity test is the scratch test, which only measures IgE antibodies. However, past studies have suggested that IgE is not the only mediator in certain symptoms related to food allergy. It is thought that these symptoms may instead be IgG mediated.² Normally, IgG antibodies do not form in the digestive tract because the epithelium creates a barrier that is impermeable to antigens. However, antigens can bypass the epithelium and reach immune cells in states of inflammation where the epithelium is damaged. This contact with immune cells provides an opportunity for development of IgG antibodies.³ Successive interactions with these antigens leads to defensive and inflammatory processes that manifest as food allergies.

Rather than the typical IgE-mediated presentations (eg, urticaria, anaphylaxis), patients with IgG-mediated allergies experience more subtle symptoms, such as bloating, heartburn, and cough.

Rather than the typical IgE-mediated presentations (eg, urticaria, anaphylaxis), patients with IgG-mediated allergies experience more subtle symptoms, such as nausea, abdominal pain, diarrhea, flatulence, cramping, bloating, heartburn, cough, bronchoconstriction, eczema, stiff joints, headache, and/or increased risk of infection.⁴ One study showed that eliminating IgG-sensitive foods (eg, dairy, eggs) improved symptoms in migraine patients.⁵ Likewise, a separate study showed that patients with irritable bowel syndrome experienced improved symptoms after eliminating foods for which they had high IgG sensitivity.⁶

Casting a wider net. Whereas scratch testing only looks at IgE-mediated allergies, serum IgG food antibody testing looks for both IgE- and IgG-mediated reactions. IgE-mediated food allergies are monitored via the scratch test as a visual expression of a histamine reaction on the skin. However, serum IgG food antibody testing identifies culprit foods via enzyme-linked immunosorbent assay.

Continue to: Furthermore, the serum antibody test...

Furthermore, the serum antibody test also identifies allergenic foods whose symptoms have a delayed onset of 4 to 72 hours.⁷ Without this test, those symptoms may be wrongfully attributed to other conditions, and prescribed treatments will not treat the root cause of the reaction.⁸ The information provided in the serum antibody test allows the patient to develop a tailored elimination diet and eliminate causative food(s) faster. Without this test, we may not have identified onions as the allergenic food in our patient.

THE TAKEAWAY

Recent guidelines emphasize that IgG testing plays no role in the diagnosis of food allergies or intolerance.¹ This may indeed be true for the general population, but other studies have shown IgG testing to be of value for specific diagnoses such as migraines or irritable bowel syndrome.^5,6 Given our patient’s unique presentation and lack of response to traditional treatments, IgG testing was warranted. This case demonstrates the importance of IgG food antibody testing as part of a second-tier diagnostic workup when a patient’s gastrointestinal symptoms are not alleviated by traditional interventions.

CORRESPONDENCE
Elizabeth A. Khan, MD, Personalized Longevity Medical Center, 1146 South Cedar Crest Boulevard, Allentown, PA 18103; [email protected].

Hypercalcemia is found when the corrected serum calcium level is > 10.5 mg/dL.¹ Its symptoms are not specific and may include polyuria, dehydration, polydipsia, anorexia, nausea and/or vomiting, constipation, and other central nervous system manifestations, including confusion, delirium, cognitive impairment, muscle weakness, psychotic symptoms, and even coma.^1,2

Hypercalcemia has varied etiologies; however, malignancy-induced hypercalcemia is one of the most common causes. In the US, the most common causes of malignancy-induced hypercalcemia are primary tumors of the lung or breast, multiple myeloma (MM), squamous cell carcinoma of the head or neck, renal cancer, and ovarian cancer.¹

Men with prostate cancer and bone metastasis have relatively worse prognosis than do patient with no metastasis.³ In a recent meta-analysis of patients with bone-involved castration-resistant prostate cancer, the median survival was 21 months.³

Hypercalcemia is a rare manifestation of prostate cancer. In a retrospective study conducted between 2009 and 2013 using the Oncology Services Comprehensive Electronic Records (OSCER) warehouse of electronic health records (EHR), the rates of malignancy-induced hypercalcemia were the lowest among patients with prostate cancer, ranging from 1.4 to 2.1%.¹

We present this case to discuss different pathophysiologic mechanisms leading to hypercalcemia in a patient with prostate cancer with bone metastasis and to study the role of humoral and growth factors in the pathogenesis of the disease.

Case Presentation

An African American man aged 69 years presented to the emergency department (ED) with generalized weakness, fatigue, and lower extremities muscle weakness. He reported a 40-lb weight loss over the past 3 months, intermittent lower back pain, and a 50 pack-year smoking history. A physical examination suggested clinical signs of dehydration.

Laboratory test results indicated hypercalcemia, macrocytic anemia, and thrombocytopenia: calcium 15.8 mg/dL, serum albumin 4.1 mg/dL, alkaline phosphatase 139 μ/L, blood urea nitrogen 55 mg/dL, creatinine 3.4 mg/dL (baseline 1.4-1.5 mg/dL), hemoglobin 8 g/dL, mean corpuscular volume 99.6 fL, and platelets 100,000/μL. The patient was admitted for hypercalcemia. His intact parathyroid hormone (iPTH) was suppressed at 16 pg/mL, phosphorous was 3.8 mg/dL, parathyroid hormone-related peptide (PTHrP) was < 0.74 pmol/L, vitamin D (25 hydroxy cholecalciferol) was mildly decreased at 17.2 ng/mL, and 1,25 dihydroxy cholecalciferol (calcitriol) was < 5.0 (normal range 20-79.3 pg/mL).

A computed tomography (CT) scan of the chest and abdomen was taken due to the patient’s heavy smoking history, an incidentally detected right lung base nodule on chest X-ray, and hypercalcemia. The CT scan showed multiple right middle lobe lung nodules with and without calcifications and calcified right hilar lymph nodes (Figure 1).

To evaluate the pancytopenia, a bone marrow biopsy was done, which showed that 80 to 90% of the marrow space was replaced by fibrosis and metastatic malignancy. Trilinear hematopoiesis was not seen (Figure 2). The tumor cells were positive for prostate- specific membrane antigen (PSMA) and negative for cytokeratin 7 and 20 (CK7 and CK20).⁴ The former is a membrane protein expressed on prostate tissues, including cancer; the latter is a form of protein used to identify adenocarcinoma of unknown primary origin (CK7 usually found in primary/ metastatic lung adenocarcinoma and CK20 usually in primary and some metastatic diseases of colon adenocarcinoma).⁵ A prostatic specific antigen (PSA) test was markedly elevated: 335.94 ng/mL (1.46 ng/mL on a previous 2011 test).

Metastatic adenocarcinoma of the prostate was diagnosed without a prostate biopsy. To determine the extent of bone metastases, a technetium-99m-methylene diphosphonate (MDP) bone scintigraphy demonstrated a superscan with intense foci of increased radiotracer uptake involving the bilateral shoulders, sternoclavicular joints, and sternum with heterogeneous uptake involving bilateral anterior and posterior ribs; cervical, thoracic, and lumbar spines; sacrum, pelvis, and bilateral hips, including the femoral head/neck and intertrochanteric regions. Also noted were several foci of radiotracer uptake involving the mandible and bilateral skull in the region of the temporomandibular joints (Figure 3).

The patient was initially treated with IV isotonic saline, followed by calcitonin and then pamidronate after kidney function improved. His calcium level responded to the therapy, and a plan was made by medical oncology to start androgen deprivation therapy (ADT) prior to discharge.

He was initially treated with bicalutamide, while a luteinizing hormone-releasing hormone agonist (leuprolide) was added 1 week later. Bicalutamide was then discontinued and a combined androgen blockade consisting of leuprolide, ketoconazole, and hydrocortisone was started. This therapy resulted in remission, and PSA declined to 1.73 ng/ mL 3 months later. At that time the patient enrolled in a clinical trial with leuprolide and bicalutamide combined therapy. About 6 months after his diagnosis, patient’s cancer progressed and became hormone refractory disease. At that time, bicalutamide was discontinued, and his therapy was switched to combined leuprolide and enzalutamide. After 6 months of therapy with enzalutamide, the patient’s cancer progressed again. He was later treated with docetaxel chemotherapy but died 16 months after diagnosis.

showed improvement of hypercalcemia at the time of discharge, but 9 months later and toward the time of expiration, our patient developed secondary hyperparathyroidism, with calcium maintained in the normal range, while iPTH was significantly elevated, a finding likely explained by a decline in kidney function and a fall in glomerular filtration rate (Table).

Discussion

Hypercalcemia in the setting of prostate cancer is a rare complication with an uncertain pathophysiology.6 Several mechanisms have been proposed for hypercalcemia of malignancy, these comprise humoral hypercalcemia of malignancy mediated by increased PTHrP; local osteolytic hypercalcemia with secretion of other humoral factors; excess extrarenal activation of vitamin D (1,25[OH]2D); PTH secretion, ectopic or primary; and multiple concurrent etiologies.⁷

PTHrP is the predominant mediator for hypercalcemia of malignancy and is estimated to account for 80% of hypercalcemia in patients with cancer. This protein shares a substantial sequence homology with PTH; in fact, 8 of the first 13 amino acids at the N-terminal portion of PTH were identical.⁸ PTHrP has multiple isoforms (PTHrP 141, PTHrP 139, and PTHrP 173). Like PTH, it enhances renal tubular reabsorption of calcium while increasing urinary phosphorus excretion.⁷ The result is both hypercalcemia and hypophosphatemia. However, unlike PTH, PTHrP does not increase 1,25(OH)2D and thus does not increase intestinal absorption of calcium and phosphorus. PTHrP acts on osteoblasts, leading to enhanced synthesis of receptor activator of nuclear factor-κB ligand (RANKL).⁷

In one study, PTHrP was detected immunohistochemically in prostate cancer cells. Iwamura and colleagues used 33 radical prostatectomy specimens from patients with clinically localized carcinoma of the prostate.⁹ None of these patients demonstrated hypercalcemia prior to the surgery. Using a mouse monoclonal antibody to an amino acid fragment, all cases demonstrated some degree of immunoreactivity throughout the cytoplasm of the tumor cells, but immunostaining was absent from inflammatory and stromal cells.⁹Furthermore, the intensity of the staining appeared to directly correlate with increasing tumor grade.⁹

Another study by Iwamura and colleagues suggested that PTHrP may play a significant role in the growth of prostate cancer by acting locally in an autocrine fashion.¹⁰ In this study, all prostate cancer cell lines from different sources expressed PTHrP immunoreactivity as well as evidence of DNA synthesis, the latter being measured by thymidine incorporation assay. Moreover, when these cells were incubated with various concentrations of mouse monoclonal antibody directed to PTHrP fragment, PTHrP-induced DNA synthesis was inhibited in a dose-dependent manner and almost completely neutralized at a specific concentration. Interestingly, the study demonstrated that cancer cell line derived from bone metastatic lesions secreted significantly greater amounts of PTHrP than did the cell line derived from the metastasis in the brain or in the lymph node. These findings suggest that PTHrP production may confer some advantage on the ability of prostate cancer cells to grow in bone.¹⁰

Ando and colleagues reported that neuroendocrine dedifferentiated prostate cancer can develop as a result of long-term ADT even after several years of therapy and has the potential to worsen and develop severe hypercalcemia.⁸ Neuron-specific enolase was used as the specific marker for the neuroendocrine cell, which suggested that the prostate cancer cell derived from the neuroendocrine cell might synthesize PTHrP and be responsible for the observed hypercalcemia.⁸

Other mechanisms cited for hypercalcemia of malignancy include other humoral factors associated with increased remodeling and comprise interleukin 1, 3, 6 (IL-1, IL-3, IL-6); tumor necrosis factor α; transforming growth factor A and B observed in metastatic bone lesions in breast cancer; lymphotoxin; E series prostaglandins; and macrophage inflammatory protein 1α seen in MM.

Local osteolytic hypercalcemia accounts for about 20% of cases and is usually associated with extensive bone metastases. It is most commonly seen in MM and metastatic breast cancer and less commonly in leukemia. The proposed mechanism is thought to be because of the release of local cytokines from the tumor, resulting in excess osteoclast activation and enhanced bone resorption often through RANK/RANKL interaction.

Extrarenal production of 1,25(OH)2D by the tumor accounts for about 1% of cases of hypercalcemia in malignancy. 1,25(OH)2D causes increased intestinal absorption of calcium and enhances osteolytic bone resorption, resulting in increased serum calcium. This mechanism is most commonly seen with Hodgkin and non-Hodgkin lymphoma and had been reported in ovarian dysgerminoma.⁷

In our patient, bone imaging showed osteoblastic lesions, a finding that likely contrasts the local osteolytic bone destruction theory. PTHrP was not significantly elevated in the serum, and PTH levels ruled out any form of primary hyperparathyroidism. In addition, histopathology showed no evidence of mosaicism or neuroendocrine dedifferentiation.

Findings in aggregate tell us that an exact pathophysiologic mechanism leading to hypercalcemia in prostate cancer is still unclear and may involve an interplay between growth factors and possible osteolytic materials, yet it must be studied thoroughly.

Conclusions

Hypercalcemia in pure metastatic adenocarcinoma of prostate is a rare finding and is of uncertain significance. Some studies suggested a search for unusual histopathologies, including neuroendocrine cancer and neuroendocrine dedifferentiation.^8,11 However, in adenocarcinoma alone, it has an uncertain pathophysiology that needs to be further studied. Studies needed to investigate the role of PTHrP as a growth factor for both prostate cancer cells and development of hypercalcemia and possibly target-directed monoclonal antibody therapies may need to be extensively researched.

Hypercalcemia is found when the corrected serum calcium level is > 10.5 mg/dL.¹ Its symptoms are not specific and may include polyuria, dehydration, polydipsia, anorexia, nausea and/or vomiting, constipation, and other central nervous system manifestations, including confusion, delirium, cognitive impairment, muscle weakness, psychotic symptoms, and even coma.^1,2

Hypercalcemia has varied etiologies; however, malignancy-induced hypercalcemia is one of the most common causes. In the US, the most common causes of malignancy-induced hypercalcemia are primary tumors of the lung or breast, multiple myeloma (MM), squamous cell carcinoma of the head or neck, renal cancer, and ovarian cancer.¹

Men with prostate cancer and bone metastasis have relatively worse prognosis than do patient with no metastasis.³ In a recent meta-analysis of patients with bone-involved castration-resistant prostate cancer, the median survival was 21 months.³

Hypercalcemia is a rare manifestation of prostate cancer. In a retrospective study conducted between 2009 and 2013 using the Oncology Services Comprehensive Electronic Records (OSCER) warehouse of electronic health records (EHR), the rates of malignancy-induced hypercalcemia were the lowest among patients with prostate cancer, ranging from 1.4 to 2.1%.¹

We present this case to discuss different pathophysiologic mechanisms leading to hypercalcemia in a patient with prostate cancer with bone metastasis and to study the role of humoral and growth factors in the pathogenesis of the disease.

Case Presentation

An African American man aged 69 years presented to the emergency department (ED) with generalized weakness, fatigue, and lower extremities muscle weakness. He reported a 40-lb weight loss over the past 3 months, intermittent lower back pain, and a 50 pack-year smoking history. A physical examination suggested clinical signs of dehydration.

Laboratory test results indicated hypercalcemia, macrocytic anemia, and thrombocytopenia: calcium 15.8 mg/dL, serum albumin 4.1 mg/dL, alkaline phosphatase 139 μ/L, blood urea nitrogen 55 mg/dL, creatinine 3.4 mg/dL (baseline 1.4-1.5 mg/dL), hemoglobin 8 g/dL, mean corpuscular volume 99.6 fL, and platelets 100,000/μL. The patient was admitted for hypercalcemia. His intact parathyroid hormone (iPTH) was suppressed at 16 pg/mL, phosphorous was 3.8 mg/dL, parathyroid hormone-related peptide (PTHrP) was < 0.74 pmol/L, vitamin D (25 hydroxy cholecalciferol) was mildly decreased at 17.2 ng/mL, and 1,25 dihydroxy cholecalciferol (calcitriol) was < 5.0 (normal range 20-79.3 pg/mL).

A computed tomography (CT) scan of the chest and abdomen was taken due to the patient’s heavy smoking history, an incidentally detected right lung base nodule on chest X-ray, and hypercalcemia. The CT scan showed multiple right middle lobe lung nodules with and without calcifications and calcified right hilar lymph nodes (Figure 1).

To evaluate the pancytopenia, a bone marrow biopsy was done, which showed that 80 to 90% of the marrow space was replaced by fibrosis and metastatic malignancy. Trilinear hematopoiesis was not seen (Figure 2). The tumor cells were positive for prostate- specific membrane antigen (PSMA) and negative for cytokeratin 7 and 20 (CK7 and CK20).⁴ The former is a membrane protein expressed on prostate tissues, including cancer; the latter is a form of protein used to identify adenocarcinoma of unknown primary origin (CK7 usually found in primary/ metastatic lung adenocarcinoma and CK20 usually in primary and some metastatic diseases of colon adenocarcinoma).⁵ A prostatic specific antigen (PSA) test was markedly elevated: 335.94 ng/mL (1.46 ng/mL on a previous 2011 test).

Metastatic adenocarcinoma of the prostate was diagnosed without a prostate biopsy. To determine the extent of bone metastases, a technetium-99m-methylene diphosphonate (MDP) bone scintigraphy demonstrated a superscan with intense foci of increased radiotracer uptake involving the bilateral shoulders, sternoclavicular joints, and sternum with heterogeneous uptake involving bilateral anterior and posterior ribs; cervical, thoracic, and lumbar spines; sacrum, pelvis, and bilateral hips, including the femoral head/neck and intertrochanteric regions. Also noted were several foci of radiotracer uptake involving the mandible and bilateral skull in the region of the temporomandibular joints (Figure 3).

The patient was initially treated with IV isotonic saline, followed by calcitonin and then pamidronate after kidney function improved. His calcium level responded to the therapy, and a plan was made by medical oncology to start androgen deprivation therapy (ADT) prior to discharge.

He was initially treated with bicalutamide, while a luteinizing hormone-releasing hormone agonist (leuprolide) was added 1 week later. Bicalutamide was then discontinued and a combined androgen blockade consisting of leuprolide, ketoconazole, and hydrocortisone was started. This therapy resulted in remission, and PSA declined to 1.73 ng/ mL 3 months later. At that time the patient enrolled in a clinical trial with leuprolide and bicalutamide combined therapy. About 6 months after his diagnosis, patient’s cancer progressed and became hormone refractory disease. At that time, bicalutamide was discontinued, and his therapy was switched to combined leuprolide and enzalutamide. After 6 months of therapy with enzalutamide, the patient’s cancer progressed again. He was later treated with docetaxel chemotherapy but died 16 months after diagnosis.

showed improvement of hypercalcemia at the time of discharge, but 9 months later and toward the time of expiration, our patient developed secondary hyperparathyroidism, with calcium maintained in the normal range, while iPTH was significantly elevated, a finding likely explained by a decline in kidney function and a fall in glomerular filtration rate (Table).

Discussion

Hypercalcemia in the setting of prostate cancer is a rare complication with an uncertain pathophysiology.6 Several mechanisms have been proposed for hypercalcemia of malignancy, these comprise humoral hypercalcemia of malignancy mediated by increased PTHrP; local osteolytic hypercalcemia with secretion of other humoral factors; excess extrarenal activation of vitamin D (1,25[OH]2D); PTH secretion, ectopic or primary; and multiple concurrent etiologies.⁷

PTHrP is the predominant mediator for hypercalcemia of malignancy and is estimated to account for 80% of hypercalcemia in patients with cancer. This protein shares a substantial sequence homology with PTH; in fact, 8 of the first 13 amino acids at the N-terminal portion of PTH were identical.⁸ PTHrP has multiple isoforms (PTHrP 141, PTHrP 139, and PTHrP 173). Like PTH, it enhances renal tubular reabsorption of calcium while increasing urinary phosphorus excretion.⁷ The result is both hypercalcemia and hypophosphatemia. However, unlike PTH, PTHrP does not increase 1,25(OH)2D and thus does not increase intestinal absorption of calcium and phosphorus. PTHrP acts on osteoblasts, leading to enhanced synthesis of receptor activator of nuclear factor-κB ligand (RANKL).⁷

In one study, PTHrP was detected immunohistochemically in prostate cancer cells. Iwamura and colleagues used 33 radical prostatectomy specimens from patients with clinically localized carcinoma of the prostate.⁹ None of these patients demonstrated hypercalcemia prior to the surgery. Using a mouse monoclonal antibody to an amino acid fragment, all cases demonstrated some degree of immunoreactivity throughout the cytoplasm of the tumor cells, but immunostaining was absent from inflammatory and stromal cells.⁹Furthermore, the intensity of the staining appeared to directly correlate with increasing tumor grade.⁹

Another study by Iwamura and colleagues suggested that PTHrP may play a significant role in the growth of prostate cancer by acting locally in an autocrine fashion.¹⁰ In this study, all prostate cancer cell lines from different sources expressed PTHrP immunoreactivity as well as evidence of DNA synthesis, the latter being measured by thymidine incorporation assay. Moreover, when these cells were incubated with various concentrations of mouse monoclonal antibody directed to PTHrP fragment, PTHrP-induced DNA synthesis was inhibited in a dose-dependent manner and almost completely neutralized at a specific concentration. Interestingly, the study demonstrated that cancer cell line derived from bone metastatic lesions secreted significantly greater amounts of PTHrP than did the cell line derived from the metastasis in the brain or in the lymph node. These findings suggest that PTHrP production may confer some advantage on the ability of prostate cancer cells to grow in bone.¹⁰

Ando and colleagues reported that neuroendocrine dedifferentiated prostate cancer can develop as a result of long-term ADT even after several years of therapy and has the potential to worsen and develop severe hypercalcemia.⁸ Neuron-specific enolase was used as the specific marker for the neuroendocrine cell, which suggested that the prostate cancer cell derived from the neuroendocrine cell might synthesize PTHrP and be responsible for the observed hypercalcemia.⁸

Other mechanisms cited for hypercalcemia of malignancy include other humoral factors associated with increased remodeling and comprise interleukin 1, 3, 6 (IL-1, IL-3, IL-6); tumor necrosis factor α; transforming growth factor A and B observed in metastatic bone lesions in breast cancer; lymphotoxin; E series prostaglandins; and macrophage inflammatory protein 1α seen in MM.

Local osteolytic hypercalcemia accounts for about 20% of cases and is usually associated with extensive bone metastases. It is most commonly seen in MM and metastatic breast cancer and less commonly in leukemia. The proposed mechanism is thought to be because of the release of local cytokines from the tumor, resulting in excess osteoclast activation and enhanced bone resorption often through RANK/RANKL interaction.

Extrarenal production of 1,25(OH)2D by the tumor accounts for about 1% of cases of hypercalcemia in malignancy. 1,25(OH)2D causes increased intestinal absorption of calcium and enhances osteolytic bone resorption, resulting in increased serum calcium. This mechanism is most commonly seen with Hodgkin and non-Hodgkin lymphoma and had been reported in ovarian dysgerminoma.⁷

In our patient, bone imaging showed osteoblastic lesions, a finding that likely contrasts the local osteolytic bone destruction theory. PTHrP was not significantly elevated in the serum, and PTH levels ruled out any form of primary hyperparathyroidism. In addition, histopathology showed no evidence of mosaicism or neuroendocrine dedifferentiation.

Findings in aggregate tell us that an exact pathophysiologic mechanism leading to hypercalcemia in prostate cancer is still unclear and may involve an interplay between growth factors and possible osteolytic materials, yet it must be studied thoroughly.

Conclusions

Hypercalcemia in pure metastatic adenocarcinoma of prostate is a rare finding and is of uncertain significance. Some studies suggested a search for unusual histopathologies, including neuroendocrine cancer and neuroendocrine dedifferentiation.^8,11 However, in adenocarcinoma alone, it has an uncertain pathophysiology that needs to be further studied. Studies needed to investigate the role of PTHrP as a growth factor for both prostate cancer cells and development of hypercalcemia and possibly target-directed monoclonal antibody therapies may need to be extensively researched.

Hypercalcemia is found when the corrected serum calcium level is > 10.5 mg/dL.¹ Its symptoms are not specific and may include polyuria, dehydration, polydipsia, anorexia, nausea and/or vomiting, constipation, and other central nervous system manifestations, including confusion, delirium, cognitive impairment, muscle weakness, psychotic symptoms, and even coma.^1,2

Hypercalcemia has varied etiologies; however, malignancy-induced hypercalcemia is one of the most common causes. In the US, the most common causes of malignancy-induced hypercalcemia are primary tumors of the lung or breast, multiple myeloma (MM), squamous cell carcinoma of the head or neck, renal cancer, and ovarian cancer.¹

Men with prostate cancer and bone metastasis have relatively worse prognosis than do patient with no metastasis.³ In a recent meta-analysis of patients with bone-involved castration-resistant prostate cancer, the median survival was 21 months.³

Hypercalcemia is a rare manifestation of prostate cancer. In a retrospective study conducted between 2009 and 2013 using the Oncology Services Comprehensive Electronic Records (OSCER) warehouse of electronic health records (EHR), the rates of malignancy-induced hypercalcemia were the lowest among patients with prostate cancer, ranging from 1.4 to 2.1%.¹

We present this case to discuss different pathophysiologic mechanisms leading to hypercalcemia in a patient with prostate cancer with bone metastasis and to study the role of humoral and growth factors in the pathogenesis of the disease.

Case Presentation

An African American man aged 69 years presented to the emergency department (ED) with generalized weakness, fatigue, and lower extremities muscle weakness. He reported a 40-lb weight loss over the past 3 months, intermittent lower back pain, and a 50 pack-year smoking history. A physical examination suggested clinical signs of dehydration.

Laboratory test results indicated hypercalcemia, macrocytic anemia, and thrombocytopenia: calcium 15.8 mg/dL, serum albumin 4.1 mg/dL, alkaline phosphatase 139 μ/L, blood urea nitrogen 55 mg/dL, creatinine 3.4 mg/dL (baseline 1.4-1.5 mg/dL), hemoglobin 8 g/dL, mean corpuscular volume 99.6 fL, and platelets 100,000/μL. The patient was admitted for hypercalcemia. His intact parathyroid hormone (iPTH) was suppressed at 16 pg/mL, phosphorous was 3.8 mg/dL, parathyroid hormone-related peptide (PTHrP) was < 0.74 pmol/L, vitamin D (25 hydroxy cholecalciferol) was mildly decreased at 17.2 ng/mL, and 1,25 dihydroxy cholecalciferol (calcitriol) was < 5.0 (normal range 20-79.3 pg/mL).

A computed tomography (CT) scan of the chest and abdomen was taken due to the patient’s heavy smoking history, an incidentally detected right lung base nodule on chest X-ray, and hypercalcemia. The CT scan showed multiple right middle lobe lung nodules with and without calcifications and calcified right hilar lymph nodes (Figure 1).

To evaluate the pancytopenia, a bone marrow biopsy was done, which showed that 80 to 90% of the marrow space was replaced by fibrosis and metastatic malignancy. Trilinear hematopoiesis was not seen (Figure 2). The tumor cells were positive for prostate- specific membrane antigen (PSMA) and negative for cytokeratin 7 and 20 (CK7 and CK20).⁴ The former is a membrane protein expressed on prostate tissues, including cancer; the latter is a form of protein used to identify adenocarcinoma of unknown primary origin (CK7 usually found in primary/ metastatic lung adenocarcinoma and CK20 usually in primary and some metastatic diseases of colon adenocarcinoma).⁵ A prostatic specific antigen (PSA) test was markedly elevated: 335.94 ng/mL (1.46 ng/mL on a previous 2011 test).

Metastatic adenocarcinoma of the prostate was diagnosed without a prostate biopsy. To determine the extent of bone metastases, a technetium-99m-methylene diphosphonate (MDP) bone scintigraphy demonstrated a superscan with intense foci of increased radiotracer uptake involving the bilateral shoulders, sternoclavicular joints, and sternum with heterogeneous uptake involving bilateral anterior and posterior ribs; cervical, thoracic, and lumbar spines; sacrum, pelvis, and bilateral hips, including the femoral head/neck and intertrochanteric regions. Also noted were several foci of radiotracer uptake involving the mandible and bilateral skull in the region of the temporomandibular joints (Figure 3).

The patient was initially treated with IV isotonic saline, followed by calcitonin and then pamidronate after kidney function improved. His calcium level responded to the therapy, and a plan was made by medical oncology to start androgen deprivation therapy (ADT) prior to discharge.

He was initially treated with bicalutamide, while a luteinizing hormone-releasing hormone agonist (leuprolide) was added 1 week later. Bicalutamide was then discontinued and a combined androgen blockade consisting of leuprolide, ketoconazole, and hydrocortisone was started. This therapy resulted in remission, and PSA declined to 1.73 ng/ mL 3 months later. At that time the patient enrolled in a clinical trial with leuprolide and bicalutamide combined therapy. About 6 months after his diagnosis, patient’s cancer progressed and became hormone refractory disease. At that time, bicalutamide was discontinued, and his therapy was switched to combined leuprolide and enzalutamide. After 6 months of therapy with enzalutamide, the patient’s cancer progressed again. He was later treated with docetaxel chemotherapy but died 16 months after diagnosis.

showed improvement of hypercalcemia at the time of discharge, but 9 months later and toward the time of expiration, our patient developed secondary hyperparathyroidism, with calcium maintained in the normal range, while iPTH was significantly elevated, a finding likely explained by a decline in kidney function and a fall in glomerular filtration rate (Table).

Discussion

Hypercalcemia in the setting of prostate cancer is a rare complication with an uncertain pathophysiology.6 Several mechanisms have been proposed for hypercalcemia of malignancy, these comprise humoral hypercalcemia of malignancy mediated by increased PTHrP; local osteolytic hypercalcemia with secretion of other humoral factors; excess extrarenal activation of vitamin D (1,25[OH]2D); PTH secretion, ectopic or primary; and multiple concurrent etiologies.⁷

PTHrP is the predominant mediator for hypercalcemia of malignancy and is estimated to account for 80% of hypercalcemia in patients with cancer. This protein shares a substantial sequence homology with PTH; in fact, 8 of the first 13 amino acids at the N-terminal portion of PTH were identical.⁸ PTHrP has multiple isoforms (PTHrP 141, PTHrP 139, and PTHrP 173). Like PTH, it enhances renal tubular reabsorption of calcium while increasing urinary phosphorus excretion.⁷ The result is both hypercalcemia and hypophosphatemia. However, unlike PTH, PTHrP does not increase 1,25(OH)2D and thus does not increase intestinal absorption of calcium and phosphorus. PTHrP acts on osteoblasts, leading to enhanced synthesis of receptor activator of nuclear factor-κB ligand (RANKL).⁷

In one study, PTHrP was detected immunohistochemically in prostate cancer cells. Iwamura and colleagues used 33 radical prostatectomy specimens from patients with clinically localized carcinoma of the prostate.⁹ None of these patients demonstrated hypercalcemia prior to the surgery. Using a mouse monoclonal antibody to an amino acid fragment, all cases demonstrated some degree of immunoreactivity throughout the cytoplasm of the tumor cells, but immunostaining was absent from inflammatory and stromal cells.⁹Furthermore, the intensity of the staining appeared to directly correlate with increasing tumor grade.⁹

Another study by Iwamura and colleagues suggested that PTHrP may play a significant role in the growth of prostate cancer by acting locally in an autocrine fashion.¹⁰ In this study, all prostate cancer cell lines from different sources expressed PTHrP immunoreactivity as well as evidence of DNA synthesis, the latter being measured by thymidine incorporation assay. Moreover, when these cells were incubated with various concentrations of mouse monoclonal antibody directed to PTHrP fragment, PTHrP-induced DNA synthesis was inhibited in a dose-dependent manner and almost completely neutralized at a specific concentration. Interestingly, the study demonstrated that cancer cell line derived from bone metastatic lesions secreted significantly greater amounts of PTHrP than did the cell line derived from the metastasis in the brain or in the lymph node. These findings suggest that PTHrP production may confer some advantage on the ability of prostate cancer cells to grow in bone.¹⁰

Ando and colleagues reported that neuroendocrine dedifferentiated prostate cancer can develop as a result of long-term ADT even after several years of therapy and has the potential to worsen and develop severe hypercalcemia.⁸ Neuron-specific enolase was used as the specific marker for the neuroendocrine cell, which suggested that the prostate cancer cell derived from the neuroendocrine cell might synthesize PTHrP and be responsible for the observed hypercalcemia.⁸

Other mechanisms cited for hypercalcemia of malignancy include other humoral factors associated with increased remodeling and comprise interleukin 1, 3, 6 (IL-1, IL-3, IL-6); tumor necrosis factor α; transforming growth factor A and B observed in metastatic bone lesions in breast cancer; lymphotoxin; E series prostaglandins; and macrophage inflammatory protein 1α seen in MM.

Local osteolytic hypercalcemia accounts for about 20% of cases and is usually associated with extensive bone metastases. It is most commonly seen in MM and metastatic breast cancer and less commonly in leukemia. The proposed mechanism is thought to be because of the release of local cytokines from the tumor, resulting in excess osteoclast activation and enhanced bone resorption often through RANK/RANKL interaction.

Extrarenal production of 1,25(OH)2D by the tumor accounts for about 1% of cases of hypercalcemia in malignancy. 1,25(OH)2D causes increased intestinal absorption of calcium and enhances osteolytic bone resorption, resulting in increased serum calcium. This mechanism is most commonly seen with Hodgkin and non-Hodgkin lymphoma and had been reported in ovarian dysgerminoma.⁷

In our patient, bone imaging showed osteoblastic lesions, a finding that likely contrasts the local osteolytic bone destruction theory. PTHrP was not significantly elevated in the serum, and PTH levels ruled out any form of primary hyperparathyroidism. In addition, histopathology showed no evidence of mosaicism or neuroendocrine dedifferentiation.

Findings in aggregate tell us that an exact pathophysiologic mechanism leading to hypercalcemia in prostate cancer is still unclear and may involve an interplay between growth factors and possible osteolytic materials, yet it must be studied thoroughly.

Conclusions

Hypercalcemia in pure metastatic adenocarcinoma of prostate is a rare finding and is of uncertain significance. Some studies suggested a search for unusual histopathologies, including neuroendocrine cancer and neuroendocrine dedifferentiation.^8,11 However, in adenocarcinoma alone, it has an uncertain pathophysiology that needs to be further studied. Studies needed to investigate the role of PTHrP as a growth factor for both prostate cancer cells and development of hypercalcemia and possibly target-directed monoclonal antibody therapies may need to be extensively researched.

Phymatous rosacea is a rare and severe form of rosacea that manifests as disfiguring soft-tissue hypertrophy and hyperplasia as well as fibrosis of the sebaceous glands. ¹ Treatments for phymatous rosacea include pharmacotherapeutic and surgical modalities; most cases are treated surgically. Surgical modalities vary, ranging from cryosurgery to conventional excision, and consensus guidelines for surgical management do not exist because data are largely limited to case reports and small case series. ² The Versajet II Hydrosurgery System (Smith-Nephew) is a high-pressure, pulsatile lavage system that has been used for phymatous rosacea and then only for rosacea of the nose (rhinophyma). We present the case of a patient with phymatous rosacea of the nose, cheeks, and chin who was successfully treated with the Versajet II Hydrosurgery System beyond just the nose region.

Case Report

A 75-year-old man presented to the dermatology clinic for evaluation of severe phymatous rosacea of the nose, cheeks, and chin that had been present for several years. Examination revealed verruciform, thickened, erythematous skin of the nose, cheeks, and chin; marked blue-gray hyperpigmentation on the neck and hands; generalized facial redness; and cystic and depressed scars (Figure 1). The patient had been treated with topical metronidazole without response, and isotretinoin worsened the symptoms. He also was taking minocycline but stopped it at our request because of concern that the drug was causing the blue-gray hyperpigmentation. The patient was referred to plastic surgery and tangential excision was recommended. Fractional ablative laser therapy was considered but deferred because the patient wanted quicker results.

The patient received tangential excision of the phymatous areas of the chin, bilateral cheeks, and nose with the Versajet II Hydrosurgery System until a pleasing contour was noted. At 1-month follow-up, the patient had an excellent contour of the nose, cheeks, and chin (Figure 2).

Comment

Phymatous rosacea is a rare disfiguring disease that most commonly presents on the nose but also can affect the chin, cheeks, eyelids, ears, and forehead. Incidence is greater in individuals of Scottish descent and in men due to the influence of androgens. The etiology of the condition is unknown.¹

Aside from clinical findings of hyperplastic and fibrotic sebaceous glands in conjunction with enlargement of the affected facial areas, histopathologic findings of phymatous rosacea vary but typically include hypertrophy of subcutaneous tissue, enlarged sebaceous ducts filled with keratin and sebum, atrophy of the dermis, and abnormal vascular development in the form of telangiectases.

Phymatous rosacea adversely affects patients’ physical, mental, and social well-being. Left untreated, it can cause nasal obstruction and recurrent bacterial infections. Furthermore, because of the potential extent of facial deformity, phymatous rosacea can be highly stigmatizing.³ Nonmelanoma skin cancers have been reported within phymatous skin, but evidence of an association between the 2 diseases remains inconclusive.⁴ Excised tissue from our patient was not submitted to pathology for analysis.

Given the far-reaching physical and psychological consequences of phymatous rosacea, treatment is critical but, regrettably, challenging. Although medical and surgical interventions exist, surgery is the most common practice. Oral isotretinoin may help, but many cases are recalcitrant, as was the disease in our patient. Therefore, procedural remedies often are sought, including scalpel excision, cryosurgery, argon laser, CO₂ laser, dermabrasion, and electrocautery.²

Our patient underwent Versajet II Hydrosurgery System treatment of the phymatous rosacea on the nose, cheeks, and chin. Versajet is not yet commonly used to treat phymatous rosacea, likely due to the upfront cost of obtaining a new device, lack of physician familiarity, and few reports of its use for phymatous skin. A search of PubMed, EMBASE, and the Web of Science using the terms Rosacea AND (Versajet OR Hydrosurgery) yielded only 6 cases of rosacea treated by hydrosurgery; all were limited to rhinophyma and reported excellent cosmetic and functional results.^5-10 Our case was unique in that hydrosurgery was used to treat phymatous rosacea beyond the nose.

Hydrosurgery has many advantages in the treatment of phymatous rosacea and other conditions in which surgical debridement is necessary, such as burns and wounds. A randomized clinical trial demonstrated that hydrosurgery is more cost-effective than conventional excision because of decreased operative time and intraoperative blood loss, fewer debridement procedures, and fewer postoperative complications.¹¹

Rennekampff et al¹² showed that Versajet debridement is superior to conventional surgery in contouring facial and acral sites and has a lower probability of infection. They proposed that by running a highly pressurized constant stream of saline across the device, Versajet clears blood and debris from the surgical site during excision.¹² Hydrosurgical debridement also has been shown to reduce Staphylococcus aureus inoculate levels from in vitro–contaminated equine models significantly more than conventional debridement methods (P<.05).¹³

Versajet surgery appears to be well tolerated, with side effects comparable to those of classic surgical excision. A randomized controlled trial in burn patients in which treatment with Versajet was compared to traditional debridement found no significant difference in postoperative pain, healing time, and contracture rate.¹³

Overall, tangential excision of our patient’s phymatous rosacea using the Versajet II Hydrosurgery System yielded excellent contouring. However, due to the paucity of literature on the subject, it is difficult to discern the optimal treatment modality. Therefore, more research—ideally randomized trials—should be pursued to examine the comparative effectiveness of different interventions for phymatous rosacea.

Phymatous rosacea is a rare and severe form of rosacea that manifests as disfiguring soft-tissue hypertrophy and hyperplasia as well as fibrosis of the sebaceous glands. ¹ Treatments for phymatous rosacea include pharmacotherapeutic and surgical modalities; most cases are treated surgically. Surgical modalities vary, ranging from cryosurgery to conventional excision, and consensus guidelines for surgical management do not exist because data are largely limited to case reports and small case series. ² The Versajet II Hydrosurgery System (Smith-Nephew) is a high-pressure, pulsatile lavage system that has been used for phymatous rosacea and then only for rosacea of the nose (rhinophyma). We present the case of a patient with phymatous rosacea of the nose, cheeks, and chin who was successfully treated with the Versajet II Hydrosurgery System beyond just the nose region.

Case Report

A 75-year-old man presented to the dermatology clinic for evaluation of severe phymatous rosacea of the nose, cheeks, and chin that had been present for several years. Examination revealed verruciform, thickened, erythematous skin of the nose, cheeks, and chin; marked blue-gray hyperpigmentation on the neck and hands; generalized facial redness; and cystic and depressed scars (Figure 1). The patient had been treated with topical metronidazole without response, and isotretinoin worsened the symptoms. He also was taking minocycline but stopped it at our request because of concern that the drug was causing the blue-gray hyperpigmentation. The patient was referred to plastic surgery and tangential excision was recommended. Fractional ablative laser therapy was considered but deferred because the patient wanted quicker results.

The patient received tangential excision of the phymatous areas of the chin, bilateral cheeks, and nose with the Versajet II Hydrosurgery System until a pleasing contour was noted. At 1-month follow-up, the patient had an excellent contour of the nose, cheeks, and chin (Figure 2).

Comment

Phymatous rosacea is a rare disfiguring disease that most commonly presents on the nose but also can affect the chin, cheeks, eyelids, ears, and forehead. Incidence is greater in individuals of Scottish descent and in men due to the influence of androgens. The etiology of the condition is unknown.¹

Aside from clinical findings of hyperplastic and fibrotic sebaceous glands in conjunction with enlargement of the affected facial areas, histopathologic findings of phymatous rosacea vary but typically include hypertrophy of subcutaneous tissue, enlarged sebaceous ducts filled with keratin and sebum, atrophy of the dermis, and abnormal vascular development in the form of telangiectases.

Phymatous rosacea adversely affects patients’ physical, mental, and social well-being. Left untreated, it can cause nasal obstruction and recurrent bacterial infections. Furthermore, because of the potential extent of facial deformity, phymatous rosacea can be highly stigmatizing.³ Nonmelanoma skin cancers have been reported within phymatous skin, but evidence of an association between the 2 diseases remains inconclusive.⁴ Excised tissue from our patient was not submitted to pathology for analysis.

Given the far-reaching physical and psychological consequences of phymatous rosacea, treatment is critical but, regrettably, challenging. Although medical and surgical interventions exist, surgery is the most common practice. Oral isotretinoin may help, but many cases are recalcitrant, as was the disease in our patient. Therefore, procedural remedies often are sought, including scalpel excision, cryosurgery, argon laser, CO₂ laser, dermabrasion, and electrocautery.²

Our patient underwent Versajet II Hydrosurgery System treatment of the phymatous rosacea on the nose, cheeks, and chin. Versajet is not yet commonly used to treat phymatous rosacea, likely due to the upfront cost of obtaining a new device, lack of physician familiarity, and few reports of its use for phymatous skin. A search of PubMed, EMBASE, and the Web of Science using the terms Rosacea AND (Versajet OR Hydrosurgery) yielded only 6 cases of rosacea treated by hydrosurgery; all were limited to rhinophyma and reported excellent cosmetic and functional results.^5-10 Our case was unique in that hydrosurgery was used to treat phymatous rosacea beyond the nose.

Hydrosurgery has many advantages in the treatment of phymatous rosacea and other conditions in which surgical debridement is necessary, such as burns and wounds. A randomized clinical trial demonstrated that hydrosurgery is more cost-effective than conventional excision because of decreased operative time and intraoperative blood loss, fewer debridement procedures, and fewer postoperative complications.¹¹

Rennekampff et al¹² showed that Versajet debridement is superior to conventional surgery in contouring facial and acral sites and has a lower probability of infection. They proposed that by running a highly pressurized constant stream of saline across the device, Versajet clears blood and debris from the surgical site during excision.¹² Hydrosurgical debridement also has been shown to reduce Staphylococcus aureus inoculate levels from in vitro–contaminated equine models significantly more than conventional debridement methods (P<.05).¹³

Versajet surgery appears to be well tolerated, with side effects comparable to those of classic surgical excision. A randomized controlled trial in burn patients in which treatment with Versajet was compared to traditional debridement found no significant difference in postoperative pain, healing time, and contracture rate.¹³

Overall, tangential excision of our patient’s phymatous rosacea using the Versajet II Hydrosurgery System yielded excellent contouring. However, due to the paucity of literature on the subject, it is difficult to discern the optimal treatment modality. Therefore, more research—ideally randomized trials—should be pursued to examine the comparative effectiveness of different interventions for phymatous rosacea.

Phymatous rosacea is a rare and severe form of rosacea that manifests as disfiguring soft-tissue hypertrophy and hyperplasia as well as fibrosis of the sebaceous glands. ¹ Treatments for phymatous rosacea include pharmacotherapeutic and surgical modalities; most cases are treated surgically. Surgical modalities vary, ranging from cryosurgery to conventional excision, and consensus guidelines for surgical management do not exist because data are largely limited to case reports and small case series. ² The Versajet II Hydrosurgery System (Smith-Nephew) is a high-pressure, pulsatile lavage system that has been used for phymatous rosacea and then only for rosacea of the nose (rhinophyma). We present the case of a patient with phymatous rosacea of the nose, cheeks, and chin who was successfully treated with the Versajet II Hydrosurgery System beyond just the nose region.

Case Report

A 75-year-old man presented to the dermatology clinic for evaluation of severe phymatous rosacea of the nose, cheeks, and chin that had been present for several years. Examination revealed verruciform, thickened, erythematous skin of the nose, cheeks, and chin; marked blue-gray hyperpigmentation on the neck and hands; generalized facial redness; and cystic and depressed scars (Figure 1). The patient had been treated with topical metronidazole without response, and isotretinoin worsened the symptoms. He also was taking minocycline but stopped it at our request because of concern that the drug was causing the blue-gray hyperpigmentation. The patient was referred to plastic surgery and tangential excision was recommended. Fractional ablative laser therapy was considered but deferred because the patient wanted quicker results.

The patient received tangential excision of the phymatous areas of the chin, bilateral cheeks, and nose with the Versajet II Hydrosurgery System until a pleasing contour was noted. At 1-month follow-up, the patient had an excellent contour of the nose, cheeks, and chin (Figure 2).

Comment

Phymatous rosacea is a rare disfiguring disease that most commonly presents on the nose but also can affect the chin, cheeks, eyelids, ears, and forehead. Incidence is greater in individuals of Scottish descent and in men due to the influence of androgens. The etiology of the condition is unknown.¹

Aside from clinical findings of hyperplastic and fibrotic sebaceous glands in conjunction with enlargement of the affected facial areas, histopathologic findings of phymatous rosacea vary but typically include hypertrophy of subcutaneous tissue, enlarged sebaceous ducts filled with keratin and sebum, atrophy of the dermis, and abnormal vascular development in the form of telangiectases.

Phymatous rosacea adversely affects patients’ physical, mental, and social well-being. Left untreated, it can cause nasal obstruction and recurrent bacterial infections. Furthermore, because of the potential extent of facial deformity, phymatous rosacea can be highly stigmatizing.³ Nonmelanoma skin cancers have been reported within phymatous skin, but evidence of an association between the 2 diseases remains inconclusive.⁴ Excised tissue from our patient was not submitted to pathology for analysis.

Given the far-reaching physical and psychological consequences of phymatous rosacea, treatment is critical but, regrettably, challenging. Although medical and surgical interventions exist, surgery is the most common practice. Oral isotretinoin may help, but many cases are recalcitrant, as was the disease in our patient. Therefore, procedural remedies often are sought, including scalpel excision, cryosurgery, argon laser, CO₂ laser, dermabrasion, and electrocautery.²

Our patient underwent Versajet II Hydrosurgery System treatment of the phymatous rosacea on the nose, cheeks, and chin. Versajet is not yet commonly used to treat phymatous rosacea, likely due to the upfront cost of obtaining a new device, lack of physician familiarity, and few reports of its use for phymatous skin. A search of PubMed, EMBASE, and the Web of Science using the terms Rosacea AND (Versajet OR Hydrosurgery) yielded only 6 cases of rosacea treated by hydrosurgery; all were limited to rhinophyma and reported excellent cosmetic and functional results.^5-10 Our case was unique in that hydrosurgery was used to treat phymatous rosacea beyond the nose.

Hydrosurgery has many advantages in the treatment of phymatous rosacea and other conditions in which surgical debridement is necessary, such as burns and wounds. A randomized clinical trial demonstrated that hydrosurgery is more cost-effective than conventional excision because of decreased operative time and intraoperative blood loss, fewer debridement procedures, and fewer postoperative complications.¹¹

Rennekampff et al¹² showed that Versajet debridement is superior to conventional surgery in contouring facial and acral sites and has a lower probability of infection. They proposed that by running a highly pressurized constant stream of saline across the device, Versajet clears blood and debris from the surgical site during excision.¹² Hydrosurgical debridement also has been shown to reduce Staphylococcus aureus inoculate levels from in vitro–contaminated equine models significantly more than conventional debridement methods (P<.05).¹³

Versajet surgery appears to be well tolerated, with side effects comparable to those of classic surgical excision. A randomized controlled trial in burn patients in which treatment with Versajet was compared to traditional debridement found no significant difference in postoperative pain, healing time, and contracture rate.¹³

Overall, tangential excision of our patient’s phymatous rosacea using the Versajet II Hydrosurgery System yielded excellent contouring. However, due to the paucity of literature on the subject, it is difficult to discern the optimal treatment modality. Therefore, more research—ideally randomized trials—should be pursued to examine the comparative effectiveness of different interventions for phymatous rosacea.

Immune checkpoint inhibitors are used for a variety of advanced malignancies, including melanoma, non–small cell lung cancer, urothelial cancer, and renal cell carcinoma. Anti–programmed cell death 1 (PD1) targeted therapies, such as pembrolizumab and nivolumab, are improving patient survival. This class of immunotherapy is revolutionary but is associated with autoimmune adverse effects. A rare but increasingly reported adverse effect of anti-PD1 therapy is bullous pemphigoid (BP), an autoimmune blistering disease directed against BP antigen 1 and BP antigen 2 in the basement membrane of the epidermis. Lopez et al¹ reported that development of BP leads to discontinuation of immunotherapy in more than 70% of patients.

High clinical suspicion, early diagnosis, and proper management of immunotherapy-related BP are imperative for keeping patients on life-prolonging treatment. We present 3 cases of BP secondary to anti-PD1 immunotherapy in patients with melanoma or non–small cell lung cancer to highlight the diagnosis and treatment of BP as well as emphasize the importance of the dermatologist in the care of patients with immunotherapy-related skin disease.

Case Reports

Patient 1
​​​​​​​A 72-year-old woman with metastatic BRAF-mutated melanoma from an unknown primary site presented with intensely pruritic papules on the back, chest, and extremities of 4 months’ duration. She described her symptoms as insidious in onset and refractory to clobetasol ointment, oral diphenhydramine, and over-the-counter anti-itch creams. The patient had been treated with oral dabrafenib 150 mg twice daily and trametinib 2 mg/d but was switched to pembrolizumab when the disease progressed. After 8 months, she had a complete radiologic response to pembrolizumab 2 mg/kg every 3 weeks, which was discontinued in favor of observation 3 months prior to presentation to dermatology.

At the current presentation, physical examination revealed innumerable erythematous, excoriated, 2- to 4-mm, red papules diffusely scattered on the upper back, chest, abdomen, and thighs, with one 8×4-mm vesicle on the right side of the upper back (Figure 1). Discrete areas of depigmented macules, consistent with vitiligo, coalesced into patches on the legs, thighs, arms, and back. The patient was started on a 3-week oral prednisone taper for symptom relief. A hematoxylin and eosin (H&E)–stained punch biopsy of the back revealed a subepidermal split with eosinophils and a dense eosinophilic infiltrate in the dermis (Figure 2). Direct immunofluorescence (DIF) studies from a specimen adjacent to the biopsy collected for H&E staining showed linear deposition of IgA, IgG, and C3 along the dermoepidermal junction (Figure 3). Histologic findings were consistent with BP.

The patient was started on doxycycline 100 mg twice daily and clobetasol ointment 0.05% once daily to supplement the prednisone taper. At 3-week follow-up, she reported pruritus and a few erythematous macules but no new bullae. At 12 weeks, some papules persisted; however, the patient was averse to using systemic agents and decided that symptoms were adequately controlled with clobetasol ointment and oral doxycycline.

Because the patient currently remains in clinical and radiologic remission, anti-PD1 immune checkpoint inhibitors have not been restarted but remain an option for the future if disease recurs

Six months prior to presenting to dermatology, the patient underwent immunotherapy with 4 cycles of ipilimumab 200 mg intravenous (IV) and nivolumab 240 mg IV every 2 weeks, receiving ipilimumab during the first cycle only because of a lack of availability at the pharmacy. He then received nivolumab 240 mg IV every 2 weeks as maintenance therapy. After the second dose of nivolumab maintenance therapy, however, he developed generalized bullae and pruritus. Dermatology was consulted during an oncology appointment, and his oncologist decided to hold nivolumab.

Physical examination revealed generalized tense and eroded bullae covering more than 50% of the body surface area and affecting the scalp, arms, legs, torso, and buttocks. Two punch biopsies were obtained. Hematoxylin and eosin staining revealed a subepidermal split with predominantly eosinophils and scattered neutrophils. Direct immunofluorescence studies showed linear deposition of IgG, IgA, and C3 along the dermoepidermal junction, consistent with BP.

The patient’s BP was difficult to control, requiring several hospital admissions for wound care, high-dose systemic steroids, and initiation of mycophenolate mofetil. After 4 months of waxing and waning symptoms, the BP was controlled with mycophenolate mofetil 1500 mg/d; clobetasol ointment 0.05%; and diphenhydramine for pruritus. Due to the prolonged recovery and severity of BP, the patient’s oncologist deemed that he was not a candidate for future immunotherapy.

Patient 3
A 68-year-old man with PD1-negative, metastatic, well-differentiated squamous cell carcinoma of the lung presented to dermatology with a pruritic rash of 3 weeks’ duration. He had been receiving nivolumab for 2 years after disease progressed on prior chemotherapies and experienced several grade 1 or grade 2 nivolumab-induced autoimmune reactions including thyroiditis, dermatitis, and nephritis, for which he was taking prednisone 5 mg/d for suppression.

Physical examination revealed psoriasiform pink plaques on the arms, chest, and legs. The differential diagnosis at the time favored psoriasiform dermatitis over lichenoid dermatitis. A punch biopsy revealed psoriasiform dermatitis. The patient was prescribed fluocinonide ointment 0.05% daily. His plaques improved with topical steroids.

The patient returned approximately 1 month later with a report of a new blistering rash on the legs. Physical examination revealed interval improvement of the psoriasiform plaques on the scalp, torso, and extremities, but tense bullae were seen on the thighs, with surrounding superficial erosions at sites of recent bullae. Punch biopsies of the skin for H&E staining and DIF showed BP.

Prednisone was increased to 50 mg/d for a 3-week taper. Doxycycline 100 mg twice daily was started. The patient’s skin disease continued to be difficult to control with therapy; nivolumab was held by his oncologist.

Comment

Immunotherapy with immune checkpoint blockade represents a successful application of immune recognition to treat metastatic cancers, including melanoma, non–small cell lung cancer, urothelial cancer, and renal cell carcinoma. Programmed cell death 1 downregulates T-cell immune function through blocking interaction with its ligand, programmed death ligand 1. Inhibiting this brake on the immune system permits T cells to attack malignant cells.

Anti-PD1 targeted therapies improve survival in solid and hematologic malignancies, with a response rate as high as 40% in melanoma.² Although these medications can prolong survival, many are associated with loss of self-tolerance and severe autoimmunelike events that can limit therapy.³ An exception is PD1-induced vitiligo, which patient 1 developed and has been associated with a better response to therapy.⁴

Anti-PD1–induced BP is a newly reported adverse effect. In its early stages, BP can be difficult to differentiate from eczematous or urticarial dermatitis.^5-8 Discontinuation of immunotherapy has been reported in more than 70% of patients who develop BP.¹ There are reports of successful treatment of BP with a course of a PD1 inhibitor,⁹ but 2 of our patients had severe BP that led to discontinuation of immunotherapy.

Consider Prescreening
Given that development of BP often leads to cessation of therapy, identifying patients at risk prior to starting an immune checkpoint inhibitor might have clinical utility. Biopsy with DIF is the gold standard for diagnosis, but serologic testing can be a useful adjunct because enzyme-linked immunosorbent assay for BP antigen 1 and BP antigen 2 has a reported sensitivity and specificity of 87% and 98%, respectively.¹⁰ Serologic testing prior to starting therapy with an immune checkpoint inhibitor can provide a baseline for patients. A rise in titer, in conjunction with onset of a rash, might aid in earlier diagnosis, particularly because urticarial BP can be difficult to diagnose clinically.

Further study on the utility vs cost-benefit of these screening modalities is warranted. Their predictive utility might be limited, however, and positive serologic test results might have unanticipated consequences, such as hesitation in treating patients, thus leading to a delay in therapy or access to these medications.

Conclusion

The expanding use of immune checkpoint inhibitors is increasing survival in patients with metastatic melanoma and other malignancies. Adverse effects are part of the continuum of immune system stimulation, with overstimulation resulting in dermatitis; thyroiditis; pneumonitis; and less commonly hypophysitis, vitiligo, and colitis.

Rarely, immune checkpoint inhibition induces BP. Development of BP leads to discontinuation of therapy in more than half of reported cases due to lack of adequate treatment for this skin disease and its impact on quality of life. Therefore, quick diagnosis of BP in patients on immunotherapy and successful management techniques can prevent discontinuation of these lifesaving cancer therapies. For that reason, dermatologists play an important role in the management of patients on immune checkpoint inhibitors for cancer.

Immune checkpoint inhibitors are used for a variety of advanced malignancies, including melanoma, non–small cell lung cancer, urothelial cancer, and renal cell carcinoma. Anti–programmed cell death 1 (PD1) targeted therapies, such as pembrolizumab and nivolumab, are improving patient survival. This class of immunotherapy is revolutionary but is associated with autoimmune adverse effects. A rare but increasingly reported adverse effect of anti-PD1 therapy is bullous pemphigoid (BP), an autoimmune blistering disease directed against BP antigen 1 and BP antigen 2 in the basement membrane of the epidermis. Lopez et al¹ reported that development of BP leads to discontinuation of immunotherapy in more than 70% of patients.

High clinical suspicion, early diagnosis, and proper management of immunotherapy-related BP are imperative for keeping patients on life-prolonging treatment. We present 3 cases of BP secondary to anti-PD1 immunotherapy in patients with melanoma or non–small cell lung cancer to highlight the diagnosis and treatment of BP as well as emphasize the importance of the dermatologist in the care of patients with immunotherapy-related skin disease.

Case Reports

Patient 1
​​​​​​​A 72-year-old woman with metastatic BRAF-mutated melanoma from an unknown primary site presented with intensely pruritic papules on the back, chest, and extremities of 4 months’ duration. She described her symptoms as insidious in onset and refractory to clobetasol ointment, oral diphenhydramine, and over-the-counter anti-itch creams. The patient had been treated with oral dabrafenib 150 mg twice daily and trametinib 2 mg/d but was switched to pembrolizumab when the disease progressed. After 8 months, she had a complete radiologic response to pembrolizumab 2 mg/kg every 3 weeks, which was discontinued in favor of observation 3 months prior to presentation to dermatology.

At the current presentation, physical examination revealed innumerable erythematous, excoriated, 2- to 4-mm, red papules diffusely scattered on the upper back, chest, abdomen, and thighs, with one 8×4-mm vesicle on the right side of the upper back (Figure 1). Discrete areas of depigmented macules, consistent with vitiligo, coalesced into patches on the legs, thighs, arms, and back. The patient was started on a 3-week oral prednisone taper for symptom relief. A hematoxylin and eosin (H&E)–stained punch biopsy of the back revealed a subepidermal split with eosinophils and a dense eosinophilic infiltrate in the dermis (Figure 2). Direct immunofluorescence (DIF) studies from a specimen adjacent to the biopsy collected for H&E staining showed linear deposition of IgA, IgG, and C3 along the dermoepidermal junction (Figure 3). Histologic findings were consistent with BP.

The patient was started on doxycycline 100 mg twice daily and clobetasol ointment 0.05% once daily to supplement the prednisone taper. At 3-week follow-up, she reported pruritus and a few erythematous macules but no new bullae. At 12 weeks, some papules persisted; however, the patient was averse to using systemic agents and decided that symptoms were adequately controlled with clobetasol ointment and oral doxycycline.

Because the patient currently remains in clinical and radiologic remission, anti-PD1 immune checkpoint inhibitors have not been restarted but remain an option for the future if disease recurs

Six months prior to presenting to dermatology, the patient underwent immunotherapy with 4 cycles of ipilimumab 200 mg intravenous (IV) and nivolumab 240 mg IV every 2 weeks, receiving ipilimumab during the first cycle only because of a lack of availability at the pharmacy. He then received nivolumab 240 mg IV every 2 weeks as maintenance therapy. After the second dose of nivolumab maintenance therapy, however, he developed generalized bullae and pruritus. Dermatology was consulted during an oncology appointment, and his oncologist decided to hold nivolumab.

Physical examination revealed generalized tense and eroded bullae covering more than 50% of the body surface area and affecting the scalp, arms, legs, torso, and buttocks. Two punch biopsies were obtained. Hematoxylin and eosin staining revealed a subepidermal split with predominantly eosinophils and scattered neutrophils. Direct immunofluorescence studies showed linear deposition of IgG, IgA, and C3 along the dermoepidermal junction, consistent with BP.

The patient’s BP was difficult to control, requiring several hospital admissions for wound care, high-dose systemic steroids, and initiation of mycophenolate mofetil. After 4 months of waxing and waning symptoms, the BP was controlled with mycophenolate mofetil 1500 mg/d; clobetasol ointment 0.05%; and diphenhydramine for pruritus. Due to the prolonged recovery and severity of BP, the patient’s oncologist deemed that he was not a candidate for future immunotherapy.

Patient 3
A 68-year-old man with PD1-negative, metastatic, well-differentiated squamous cell carcinoma of the lung presented to dermatology with a pruritic rash of 3 weeks’ duration. He had been receiving nivolumab for 2 years after disease progressed on prior chemotherapies and experienced several grade 1 or grade 2 nivolumab-induced autoimmune reactions including thyroiditis, dermatitis, and nephritis, for which he was taking prednisone 5 mg/d for suppression.

Physical examination revealed psoriasiform pink plaques on the arms, chest, and legs. The differential diagnosis at the time favored psoriasiform dermatitis over lichenoid dermatitis. A punch biopsy revealed psoriasiform dermatitis. The patient was prescribed fluocinonide ointment 0.05% daily. His plaques improved with topical steroids.

The patient returned approximately 1 month later with a report of a new blistering rash on the legs. Physical examination revealed interval improvement of the psoriasiform plaques on the scalp, torso, and extremities, but tense bullae were seen on the thighs, with surrounding superficial erosions at sites of recent bullae. Punch biopsies of the skin for H&E staining and DIF showed BP.

Prednisone was increased to 50 mg/d for a 3-week taper. Doxycycline 100 mg twice daily was started. The patient’s skin disease continued to be difficult to control with therapy; nivolumab was held by his oncologist.

Comment

Immunotherapy with immune checkpoint blockade represents a successful application of immune recognition to treat metastatic cancers, including melanoma, non–small cell lung cancer, urothelial cancer, and renal cell carcinoma. Programmed cell death 1 downregulates T-cell immune function through blocking interaction with its ligand, programmed death ligand 1. Inhibiting this brake on the immune system permits T cells to attack malignant cells.

Anti-PD1 targeted therapies improve survival in solid and hematologic malignancies, with a response rate as high as 40% in melanoma.² Although these medications can prolong survival, many are associated with loss of self-tolerance and severe autoimmunelike events that can limit therapy.³ An exception is PD1-induced vitiligo, which patient 1 developed and has been associated with a better response to therapy.⁴

Anti-PD1–induced BP is a newly reported adverse effect. In its early stages, BP can be difficult to differentiate from eczematous or urticarial dermatitis.^5-8 Discontinuation of immunotherapy has been reported in more than 70% of patients who develop BP.¹ There are reports of successful treatment of BP with a course of a PD1 inhibitor,⁹ but 2 of our patients had severe BP that led to discontinuation of immunotherapy.

Consider Prescreening
Given that development of BP often leads to cessation of therapy, identifying patients at risk prior to starting an immune checkpoint inhibitor might have clinical utility. Biopsy with DIF is the gold standard for diagnosis, but serologic testing can be a useful adjunct because enzyme-linked immunosorbent assay for BP antigen 1 and BP antigen 2 has a reported sensitivity and specificity of 87% and 98%, respectively.¹⁰ Serologic testing prior to starting therapy with an immune checkpoint inhibitor can provide a baseline for patients. A rise in titer, in conjunction with onset of a rash, might aid in earlier diagnosis, particularly because urticarial BP can be difficult to diagnose clinically.

Further study on the utility vs cost-benefit of these screening modalities is warranted. Their predictive utility might be limited, however, and positive serologic test results might have unanticipated consequences, such as hesitation in treating patients, thus leading to a delay in therapy or access to these medications.

Conclusion

The expanding use of immune checkpoint inhibitors is increasing survival in patients with metastatic melanoma and other malignancies. Adverse effects are part of the continuum of immune system stimulation, with overstimulation resulting in dermatitis; thyroiditis; pneumonitis; and less commonly hypophysitis, vitiligo, and colitis.

Rarely, immune checkpoint inhibition induces BP. Development of BP leads to discontinuation of therapy in more than half of reported cases due to lack of adequate treatment for this skin disease and its impact on quality of life. Therefore, quick diagnosis of BP in patients on immunotherapy and successful management techniques can prevent discontinuation of these lifesaving cancer therapies. For that reason, dermatologists play an important role in the management of patients on immune checkpoint inhibitors for cancer.

Immune checkpoint inhibitors are used for a variety of advanced malignancies, including melanoma, non–small cell lung cancer, urothelial cancer, and renal cell carcinoma. Anti–programmed cell death 1 (PD1) targeted therapies, such as pembrolizumab and nivolumab, are improving patient survival. This class of immunotherapy is revolutionary but is associated with autoimmune adverse effects. A rare but increasingly reported adverse effect of anti-PD1 therapy is bullous pemphigoid (BP), an autoimmune blistering disease directed against BP antigen 1 and BP antigen 2 in the basement membrane of the epidermis. Lopez et al¹ reported that development of BP leads to discontinuation of immunotherapy in more than 70% of patients.

High clinical suspicion, early diagnosis, and proper management of immunotherapy-related BP are imperative for keeping patients on life-prolonging treatment. We present 3 cases of BP secondary to anti-PD1 immunotherapy in patients with melanoma or non–small cell lung cancer to highlight the diagnosis and treatment of BP as well as emphasize the importance of the dermatologist in the care of patients with immunotherapy-related skin disease.

Case Reports

Patient 1
​​​​​​​A 72-year-old woman with metastatic BRAF-mutated melanoma from an unknown primary site presented with intensely pruritic papules on the back, chest, and extremities of 4 months’ duration. She described her symptoms as insidious in onset and refractory to clobetasol ointment, oral diphenhydramine, and over-the-counter anti-itch creams. The patient had been treated with oral dabrafenib 150 mg twice daily and trametinib 2 mg/d but was switched to pembrolizumab when the disease progressed. After 8 months, she had a complete radiologic response to pembrolizumab 2 mg/kg every 3 weeks, which was discontinued in favor of observation 3 months prior to presentation to dermatology.

At the current presentation, physical examination revealed innumerable erythematous, excoriated, 2- to 4-mm, red papules diffusely scattered on the upper back, chest, abdomen, and thighs, with one 8×4-mm vesicle on the right side of the upper back (Figure 1). Discrete areas of depigmented macules, consistent with vitiligo, coalesced into patches on the legs, thighs, arms, and back. The patient was started on a 3-week oral prednisone taper for symptom relief. A hematoxylin and eosin (H&E)–stained punch biopsy of the back revealed a subepidermal split with eosinophils and a dense eosinophilic infiltrate in the dermis (Figure 2). Direct immunofluorescence (DIF) studies from a specimen adjacent to the biopsy collected for H&E staining showed linear deposition of IgA, IgG, and C3 along the dermoepidermal junction (Figure 3). Histologic findings were consistent with BP.

The patient was started on doxycycline 100 mg twice daily and clobetasol ointment 0.05% once daily to supplement the prednisone taper. At 3-week follow-up, she reported pruritus and a few erythematous macules but no new bullae. At 12 weeks, some papules persisted; however, the patient was averse to using systemic agents and decided that symptoms were adequately controlled with clobetasol ointment and oral doxycycline.

Because the patient currently remains in clinical and radiologic remission, anti-PD1 immune checkpoint inhibitors have not been restarted but remain an option for the future if disease recurs

Six months prior to presenting to dermatology, the patient underwent immunotherapy with 4 cycles of ipilimumab 200 mg intravenous (IV) and nivolumab 240 mg IV every 2 weeks, receiving ipilimumab during the first cycle only because of a lack of availability at the pharmacy. He then received nivolumab 240 mg IV every 2 weeks as maintenance therapy. After the second dose of nivolumab maintenance therapy, however, he developed generalized bullae and pruritus. Dermatology was consulted during an oncology appointment, and his oncologist decided to hold nivolumab.

Physical examination revealed generalized tense and eroded bullae covering more than 50% of the body surface area and affecting the scalp, arms, legs, torso, and buttocks. Two punch biopsies were obtained. Hematoxylin and eosin staining revealed a subepidermal split with predominantly eosinophils and scattered neutrophils. Direct immunofluorescence studies showed linear deposition of IgG, IgA, and C3 along the dermoepidermal junction, consistent with BP.

The patient’s BP was difficult to control, requiring several hospital admissions for wound care, high-dose systemic steroids, and initiation of mycophenolate mofetil. After 4 months of waxing and waning symptoms, the BP was controlled with mycophenolate mofetil 1500 mg/d; clobetasol ointment 0.05%; and diphenhydramine for pruritus. Due to the prolonged recovery and severity of BP, the patient’s oncologist deemed that he was not a candidate for future immunotherapy.

Patient 3
A 68-year-old man with PD1-negative, metastatic, well-differentiated squamous cell carcinoma of the lung presented to dermatology with a pruritic rash of 3 weeks’ duration. He had been receiving nivolumab for 2 years after disease progressed on prior chemotherapies and experienced several grade 1 or grade 2 nivolumab-induced autoimmune reactions including thyroiditis, dermatitis, and nephritis, for which he was taking prednisone 5 mg/d for suppression.

Physical examination revealed psoriasiform pink plaques on the arms, chest, and legs. The differential diagnosis at the time favored psoriasiform dermatitis over lichenoid dermatitis. A punch biopsy revealed psoriasiform dermatitis. The patient was prescribed fluocinonide ointment 0.05% daily. His plaques improved with topical steroids.

The patient returned approximately 1 month later with a report of a new blistering rash on the legs. Physical examination revealed interval improvement of the psoriasiform plaques on the scalp, torso, and extremities, but tense bullae were seen on the thighs, with surrounding superficial erosions at sites of recent bullae. Punch biopsies of the skin for H&E staining and DIF showed BP.

Prednisone was increased to 50 mg/d for a 3-week taper. Doxycycline 100 mg twice daily was started. The patient’s skin disease continued to be difficult to control with therapy; nivolumab was held by his oncologist.

Comment

Immunotherapy with immune checkpoint blockade represents a successful application of immune recognition to treat metastatic cancers, including melanoma, non–small cell lung cancer, urothelial cancer, and renal cell carcinoma. Programmed cell death 1 downregulates T-cell immune function through blocking interaction with its ligand, programmed death ligand 1. Inhibiting this brake on the immune system permits T cells to attack malignant cells.

Anti-PD1 targeted therapies improve survival in solid and hematologic malignancies, with a response rate as high as 40% in melanoma.² Although these medications can prolong survival, many are associated with loss of self-tolerance and severe autoimmunelike events that can limit therapy.³ An exception is PD1-induced vitiligo, which patient 1 developed and has been associated with a better response to therapy.⁴

Anti-PD1–induced BP is a newly reported adverse effect. In its early stages, BP can be difficult to differentiate from eczematous or urticarial dermatitis.^5-8 Discontinuation of immunotherapy has been reported in more than 70% of patients who develop BP.¹ There are reports of successful treatment of BP with a course of a PD1 inhibitor,⁹ but 2 of our patients had severe BP that led to discontinuation of immunotherapy.

Consider Prescreening
Given that development of BP often leads to cessation of therapy, identifying patients at risk prior to starting an immune checkpoint inhibitor might have clinical utility. Biopsy with DIF is the gold standard for diagnosis, but serologic testing can be a useful adjunct because enzyme-linked immunosorbent assay for BP antigen 1 and BP antigen 2 has a reported sensitivity and specificity of 87% and 98%, respectively.¹⁰ Serologic testing prior to starting therapy with an immune checkpoint inhibitor can provide a baseline for patients. A rise in titer, in conjunction with onset of a rash, might aid in earlier diagnosis, particularly because urticarial BP can be difficult to diagnose clinically.

Further study on the utility vs cost-benefit of these screening modalities is warranted. Their predictive utility might be limited, however, and positive serologic test results might have unanticipated consequences, such as hesitation in treating patients, thus leading to a delay in therapy or access to these medications.

Conclusion

The expanding use of immune checkpoint inhibitors is increasing survival in patients with metastatic melanoma and other malignancies. Adverse effects are part of the continuum of immune system stimulation, with overstimulation resulting in dermatitis; thyroiditis; pneumonitis; and less commonly hypophysitis, vitiligo, and colitis.

Rarely, immune checkpoint inhibition induces BP. Development of BP leads to discontinuation of therapy in more than half of reported cases due to lack of adequate treatment for this skin disease and its impact on quality of life. Therefore, quick diagnosis of BP in patients on immunotherapy and successful management techniques can prevent discontinuation of these lifesaving cancer therapies. For that reason, dermatologists play an important role in the management of patients on immune checkpoint inhibitors for cancer.

Neuroendocrine tumors (NETs) account for about 0.5% of all newly diagnosed malignancies.¹ Pulmonary NETs are rare, accounting for 1 to 2% of all invasive lung malignancies and involve about 20 to 25% of primary lung malignancies. ^2,3 Their prevalence has increased by an estimated 6% per year over the past 30 years.² Nonetheless, the time of diagnosis is frequently delayed because of nonspecific symptoms that may imitate other pulmonary conditions.

In the normal pleural space, there is a steady state in which there is a roughly equal rate of fluid formation and absorption. Any disequilibrium may produce a pleural effusion. Pleural fluids can be transudates or exudates. Transudates result from imbalances in hydrostatic and oncotic pressures in the pleural space. Exudates result primarily from pleural and/or lung inflammation or from impaired lymphatic drainage of the pleural space. Clinical manifestations include cough, wheezing, recurrent pneumonia, hemoptysis and pleural effusions. We present a case of a man who developed a large left pleural effusion with a pathology report suggesting a pulmonary NET as the etiology. Being aware of this rare entity may help improve prognosis by making an earlier diagnosis and starting treatment sooner.

Case Presentation

A 90-year-old man with a medical history of arterial hypertension, hyperlipidemia, type 2 diabetes mellitus, coronary artery disease, and vascular dementia presented to the emergency department with hypoactivity, poor appetite, productive cough, and shortness of breath. The patient was a former smoker (unknown pack-years) who quit smoking cigarettes 7 years prior. Vital signs showed sinus tachycardia and peripheral oxygen saturation of 90% at room air. The initial physical examination was remarkable for decreased breath sounds and crackles at the left lung base. Laboratory findings showed leukocytosis with neutrophilia and chronic normocytic anemia. Chest computed tomography (CT) showed a large left-sided pleural effusion occupying most of the left hemithorax with adjacent atelectatic lung, enlarged pretracheal, subcarinal, and left perihilar lymph nodes (Figure 1).

The patient was admitted to the internal medicine ward with the diagnosis of left pneumonic process and started on IV levofloxacin. However, despite 7 days of antibiotic therapy, the patient’s respiratory symptoms worsened. This clinical deterioration prompted pulmonary service consultation. Chest radiography demonstrated an enlarging left pleural effusion (Figure 2). A thoracentesis drained 1.2 L of serosanguineous pleural fluid. Pleural fluid analysis showed a cell count of 947/cm3 with 79% of lymphocytes, total protein 3.8 g/dL, lactic dehydrogenase (LDH) level 607 U/L, and glucose level 109 mg/dL. Serum total protein was 6.62 g/dL, LDH 666 U/L and glucose 92 mg/dL (Tables 1 and 2). Alanine transaminase (ALT) and aspartate aminotransferase (AST) were 11 U/L and 21 U/L, respectively. Using Light criteria, the pleural:serum protein ratio was 0.57, the pleural:serum LDH ratio was 0.91, and the pleural LDH was more than two-thirds of the serum LDH. These calculations were consistent with an exudative effusion. An infectious disease workup, including blood and pleural fluid cultures, was negative.

The pleural fluid concentrated cell block hematoxylin and eosin (H&E) staining showed chromatin, prominent nucleoli, and nuclear molding, which was compatible with high-grade lung NET (Figure 3). The cell block immunohistochemistry (IHC) was positive for synaptophysin, chromogranin A, and neuron specific enolase (NSE) also consistent with a high-grade pulmonary NET (Figure 4). The proliferation marker protein Ki-67 labeling index (LI) showed a proliferation index > 20% (Figure 5). The patient did not have decision-making capacity given vascular dementia. Multiple attempts to contact the next of kin or family members were unsuccessful. Risks vs benefits were evaluated, and given the patient’s advanced age and multiple comorbidities, a conservative management approach under palliative care was chosen. For this reason, further genomic studies were not done.

Discussion

NETs are a group of neoplasms that differ in site, amount of cell propagation, and clinical manifestations.⁴ These tumors are rare with an estimated incidence of 25 to 50 per 100,000.4 The most commonly affected organ systems are the gastroenteropancreatic and the bronchopulmonary tracts, accounting for 60% and 25% of the tumors, respectively.4 The incidence is increasing over the past years in part because of novel diagnostic techniques.

The average age of diagnosis is between the fourth and sixth decades, affecting more women than men.⁵ Smoking has been identified as a possible culprit for the development of these neoplasms; nonetheless, the association is still not clear.⁴ For example, poorly differentiated pulmonary NETs have a strong association with smoking but not well-differentiated pulmonary NETs.²

Patients typically present with cough, wheezing, hemoptysis, and recurrent pneumonias, which are in part a consequence of obstruction caused by the mass.² Sometimes, obstruction may yield persistent pleural effusions. Hemoptysis may be seen secondary to the vascularity of pulmonary NETs.

The diagnosis is often delayed because patients are frequently treated for infection before being diagnosed with the malignancy, such as in our case. Radiologic image findings include round opacities, central masses, and atelectasis. Pulmonary NETs are frequently found incidentally as solitary lung nodules. The CT scan is the most common diagnostic modality and can provide information about the borders of the tumor, the location and surrounding structures, including the presence of atelectasis.⁵ Pulmonary NETs are usually centrally located in an accessible region for lung biopsy. In cases where the mass is not easily reachable, thoracentesis may provide the only available specimen.

The 2015 World Health Organization classification has identified 4 histologic types of pulmonary NETs, namely, typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC).⁶ The low-grade pulmonary NET, the typical carcinoid, is slow growing and has lower rates of metastasis. The intermediate-grade NET, the atypical carcinoid, is more aggressive. The highgrade NETs, the LCNEC and the SCLC, are aggressive and spread quickly to other places.⁶ Consequently, LCNEC and SCLC have higher mortalities with a 5-year survival, ranging from 13 to 57% and 5%, respectively.⁷

Tumors may be histomorphologically classified by H&E staining. The main characteristics that differentiate the low- and high-grade NETs are the presence of necrosis and the mitotic rate. Both categories form neuropeptides and have dense granular cores when seen with an electron microscopy^.6 The TC and AC have welldefined, organized histologic patterns, no necrosis, and scarce mitosis. On the other hand, the LCNEC and SCLC are poorly differentiated tumors with necrosis, atypia, and mitosis.6 LCNEC can be separated from SCLC and other tumors by IHC staining, whereas SCLC is primarily distinguished by morphology.

If the biopsy sample size is small, then IHC morphology and markers are helpful for subclassification.⁸ IHC is used to discern between neuroendocrine (NE) vs non-NE. The evaluation of pleural fluid includes preparation of cell blocks. Cell block staining is deemed better for IHC because it mimics a small biopsy that enables superior stains.⁹ The need for a pleural biopsy in cases where the cytology is negative depends on treatment aims, the kind of tumor, and the presence of metastasis.¹⁰ In almost 80% of cases, pleural biopsy and cytology are the only specimens obtained for analysis.Therefore, identification of these markers is practical for diagnosis.¹⁰ For this reason, pleural effusion samples are appropriate options to lung biopsy for molecular studies.¹⁰

Ki-67 LI in samples has the highest specificity and sensitivity for low-tointermediate- grade vs high-grade tumors. It is being used for guiding clinical and treatment decisions.⁶ In SCLC, the Ki-67 LI is not necessary for diagnosis but will be about 80%.¹¹ The tumor cells will show epithelial characteristics with positive cytokeratin AE1/AE3 and monoclonal antibody CAM5.² and neuroendocrine markers, including NCAM/CD56, chromogranin A, and synaptophysin.¹¹

Thyroid transcription factor-1 (TTF- 1) is positive in most cases. In LCNEC, the Ki-67 LI is between 40% and 80%. NCAM/ CD56, chromogranin A, and synaptophysin are present in 92 to 100%, 80 to 85%, and 50 to 60%, respectively.¹¹ TTF-1 is identified in half of the tumors. All these tumors express pancytokeratin (AE1/AE3), cytokeratin 7 or low-molecular-weight cytokeratin. Likewise, the carcinoids will show markers, such as chromogranin A, synaptophysin, CD56, and epithelial markers like pancytokeratin.¹¹ However, the high-molecular-weight cytokeratin and TTF-1 are negative. Furthermore, NSE is considered a good tumor marker in the diagnosis and prognosis of SCLC. NSE also has been reported in NSCLC. The level of NSE correlates with tumor burden, number of metastatic sites, and response to treatment. ¹² A potentially useful marker is the insulinoma-associated protein 1, which is a nuclear determinant of NE differentiation that stains all types of pulmonary NETs irrespective of the histology but does not stain adenocarcinoma or squamous cell carcinoma (SCC).⁶

Recently, genomic studies have identified gene alterations that have become standard of care for diagnosis and targeted therapies.⁸ For example, epidermal growth factor receptor (EGFR) and echinoderm microtubule- associated proteinlike 4, and anaplastic lymphoma kinase (EML4-ALK) mutations have been found in about 25% of lung adenocarcinomas. ⁸ Other abnormalities in LKB1/STK11, NF1, CDKN2A, SMARCA4 and KEAP1, KRAS, MET, ROS1, and RET have also been identified.8 On the other hand, SCC rarely have derangements in EGFR and EML4-ALK, but do show changes in RTKs, DDR2M, FGGRs, among others.8 In TC and AC, observed molecular alterations include MEN1 mutations, mTOR, and SSTRs pathway activation, and GC/ CEACAM1 and CD44/OTP expression.¹³ LCNEC and SCLC have shown TP53 and RB1 mutations and CDX2/VIL1/BAI3 expression. DLL3 expression and MET mutations may be present in SCLC.13 Last, chromatin remodeling gene mutations have been identified in all these lung NET types.¹³

Furthermore, neuropeptides and neuroamines may be measured in the blood and urine.¹⁴ Pulmonary NETs may be functional and secrete these substances, leading to systemic symptoms based on the released molecules.¹⁵ However, pulmonary NETs produce less serotonin than gastrointestinal NETs; therefore, carcinoid syndrome is less frequent in pulmonary NETs.¹⁶ Liver metastasis is often present when it occurs.⁵ Other possible clinical features include Cushing syndrome and acromegaly depending on the secreted hormones.⁵

In a recent metanalysis, serum LDH has been found to have a prognostic role in Ewing sarcoma, urologic cancers, malignant mesothelioma, among others.¹⁷ It demonstrated that a higher LDH concentration is associated with worse survival in patients with lung cancer.¹⁷ Serum LDH is an enzyme that catalyzes the reaction between lactic acid and pyruvic acid that typically takes place in anaerobic conditions.¹⁷ LDH levels are elevated in malignancies because tumors have an anaerobic environment. Elevated LDH levels correlate with the anaerobic metabolism in the tumor. Other studies also have noted that patients with high metastatic score have higher LDH levels.¹⁷ Therefore, LDH may reflect tumor extension.

In addition, other techniques, such as somatostatin- receptor imaging are specifically beneficial in tumors that express the somatostatin receptor.¹⁶ For this reason, this type of study is typically indicated in patients with known metastasis, not in patients with low-grade tumors. Abdominal CT scans are done because the liver is a common site for metastasis.

Our case report demonstrates how biomarkers help diagnose these potentially aggressive and life-threatening tumors that may present as a common condition such as a pleural effusion. Using a less invasive and quicker approach with thoracentesis rather than with lung biopsies is a diagnostic tool in this entity. IHC in cell blocks is a reasonable diagnostic method especially in patients in whom performing a lung biopsy is difficult.

Conclusions

The presence of a symptomatic and recurrent unilateral pleural effusion must urge physicians to consider thoracentesis with mindful use of biomarkers not only for therapeutic purposes, but also for diagnosis of a variety of etiologies, both benign and malignant.

Neuroendocrine tumors (NETs) account for about 0.5% of all newly diagnosed malignancies.¹ Pulmonary NETs are rare, accounting for 1 to 2% of all invasive lung malignancies and involve about 20 to 25% of primary lung malignancies. ^2,3 Their prevalence has increased by an estimated 6% per year over the past 30 years.² Nonetheless, the time of diagnosis is frequently delayed because of nonspecific symptoms that may imitate other pulmonary conditions.

In the normal pleural space, there is a steady state in which there is a roughly equal rate of fluid formation and absorption. Any disequilibrium may produce a pleural effusion. Pleural fluids can be transudates or exudates. Transudates result from imbalances in hydrostatic and oncotic pressures in the pleural space. Exudates result primarily from pleural and/or lung inflammation or from impaired lymphatic drainage of the pleural space. Clinical manifestations include cough, wheezing, recurrent pneumonia, hemoptysis and pleural effusions. We present a case of a man who developed a large left pleural effusion with a pathology report suggesting a pulmonary NET as the etiology. Being aware of this rare entity may help improve prognosis by making an earlier diagnosis and starting treatment sooner.

Case Presentation

A 90-year-old man with a medical history of arterial hypertension, hyperlipidemia, type 2 diabetes mellitus, coronary artery disease, and vascular dementia presented to the emergency department with hypoactivity, poor appetite, productive cough, and shortness of breath. The patient was a former smoker (unknown pack-years) who quit smoking cigarettes 7 years prior. Vital signs showed sinus tachycardia and peripheral oxygen saturation of 90% at room air. The initial physical examination was remarkable for decreased breath sounds and crackles at the left lung base. Laboratory findings showed leukocytosis with neutrophilia and chronic normocytic anemia. Chest computed tomography (CT) showed a large left-sided pleural effusion occupying most of the left hemithorax with adjacent atelectatic lung, enlarged pretracheal, subcarinal, and left perihilar lymph nodes (Figure 1).

The patient was admitted to the internal medicine ward with the diagnosis of left pneumonic process and started on IV levofloxacin. However, despite 7 days of antibiotic therapy, the patient’s respiratory symptoms worsened. This clinical deterioration prompted pulmonary service consultation. Chest radiography demonstrated an enlarging left pleural effusion (Figure 2). A thoracentesis drained 1.2 L of serosanguineous pleural fluid. Pleural fluid analysis showed a cell count of 947/cm3 with 79% of lymphocytes, total protein 3.8 g/dL, lactic dehydrogenase (LDH) level 607 U/L, and glucose level 109 mg/dL. Serum total protein was 6.62 g/dL, LDH 666 U/L and glucose 92 mg/dL (Tables 1 and 2). Alanine transaminase (ALT) and aspartate aminotransferase (AST) were 11 U/L and 21 U/L, respectively. Using Light criteria, the pleural:serum protein ratio was 0.57, the pleural:serum LDH ratio was 0.91, and the pleural LDH was more than two-thirds of the serum LDH. These calculations were consistent with an exudative effusion. An infectious disease workup, including blood and pleural fluid cultures, was negative.

The pleural fluid concentrated cell block hematoxylin and eosin (H&E) staining showed chromatin, prominent nucleoli, and nuclear molding, which was compatible with high-grade lung NET (Figure 3). The cell block immunohistochemistry (IHC) was positive for synaptophysin, chromogranin A, and neuron specific enolase (NSE) also consistent with a high-grade pulmonary NET (Figure 4). The proliferation marker protein Ki-67 labeling index (LI) showed a proliferation index > 20% (Figure 5). The patient did not have decision-making capacity given vascular dementia. Multiple attempts to contact the next of kin or family members were unsuccessful. Risks vs benefits were evaluated, and given the patient’s advanced age and multiple comorbidities, a conservative management approach under palliative care was chosen. For this reason, further genomic studies were not done.

Discussion

NETs are a group of neoplasms that differ in site, amount of cell propagation, and clinical manifestations.⁴ These tumors are rare with an estimated incidence of 25 to 50 per 100,000.4 The most commonly affected organ systems are the gastroenteropancreatic and the bronchopulmonary tracts, accounting for 60% and 25% of the tumors, respectively.4 The incidence is increasing over the past years in part because of novel diagnostic techniques.

The average age of diagnosis is between the fourth and sixth decades, affecting more women than men.⁵ Smoking has been identified as a possible culprit for the development of these neoplasms; nonetheless, the association is still not clear.⁴ For example, poorly differentiated pulmonary NETs have a strong association with smoking but not well-differentiated pulmonary NETs.²

Patients typically present with cough, wheezing, hemoptysis, and recurrent pneumonias, which are in part a consequence of obstruction caused by the mass.² Sometimes, obstruction may yield persistent pleural effusions. Hemoptysis may be seen secondary to the vascularity of pulmonary NETs.

The diagnosis is often delayed because patients are frequently treated for infection before being diagnosed with the malignancy, such as in our case. Radiologic image findings include round opacities, central masses, and atelectasis. Pulmonary NETs are frequently found incidentally as solitary lung nodules. The CT scan is the most common diagnostic modality and can provide information about the borders of the tumor, the location and surrounding structures, including the presence of atelectasis.⁵ Pulmonary NETs are usually centrally located in an accessible region for lung biopsy. In cases where the mass is not easily reachable, thoracentesis may provide the only available specimen.

The 2015 World Health Organization classification has identified 4 histologic types of pulmonary NETs, namely, typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC).⁶ The low-grade pulmonary NET, the typical carcinoid, is slow growing and has lower rates of metastasis. The intermediate-grade NET, the atypical carcinoid, is more aggressive. The highgrade NETs, the LCNEC and the SCLC, are aggressive and spread quickly to other places.⁶ Consequently, LCNEC and SCLC have higher mortalities with a 5-year survival, ranging from 13 to 57% and 5%, respectively.⁷

Tumors may be histomorphologically classified by H&E staining. The main characteristics that differentiate the low- and high-grade NETs are the presence of necrosis and the mitotic rate. Both categories form neuropeptides and have dense granular cores when seen with an electron microscopy^.6 The TC and AC have welldefined, organized histologic patterns, no necrosis, and scarce mitosis. On the other hand, the LCNEC and SCLC are poorly differentiated tumors with necrosis, atypia, and mitosis.6 LCNEC can be separated from SCLC and other tumors by IHC staining, whereas SCLC is primarily distinguished by morphology.

If the biopsy sample size is small, then IHC morphology and markers are helpful for subclassification.⁸ IHC is used to discern between neuroendocrine (NE) vs non-NE. The evaluation of pleural fluid includes preparation of cell blocks. Cell block staining is deemed better for IHC because it mimics a small biopsy that enables superior stains.⁹ The need for a pleural biopsy in cases where the cytology is negative depends on treatment aims, the kind of tumor, and the presence of metastasis.¹⁰ In almost 80% of cases, pleural biopsy and cytology are the only specimens obtained for analysis.Therefore, identification of these markers is practical for diagnosis.¹⁰ For this reason, pleural effusion samples are appropriate options to lung biopsy for molecular studies.¹⁰

Ki-67 LI in samples has the highest specificity and sensitivity for low-tointermediate- grade vs high-grade tumors. It is being used for guiding clinical and treatment decisions.⁶ In SCLC, the Ki-67 LI is not necessary for diagnosis but will be about 80%.¹¹ The tumor cells will show epithelial characteristics with positive cytokeratin AE1/AE3 and monoclonal antibody CAM5.² and neuroendocrine markers, including NCAM/CD56, chromogranin A, and synaptophysin.¹¹

Thyroid transcription factor-1 (TTF- 1) is positive in most cases. In LCNEC, the Ki-67 LI is between 40% and 80%. NCAM/ CD56, chromogranin A, and synaptophysin are present in 92 to 100%, 80 to 85%, and 50 to 60%, respectively.¹¹ TTF-1 is identified in half of the tumors. All these tumors express pancytokeratin (AE1/AE3), cytokeratin 7 or low-molecular-weight cytokeratin. Likewise, the carcinoids will show markers, such as chromogranin A, synaptophysin, CD56, and epithelial markers like pancytokeratin.¹¹ However, the high-molecular-weight cytokeratin and TTF-1 are negative. Furthermore, NSE is considered a good tumor marker in the diagnosis and prognosis of SCLC. NSE also has been reported in NSCLC. The level of NSE correlates with tumor burden, number of metastatic sites, and response to treatment. ¹² A potentially useful marker is the insulinoma-associated protein 1, which is a nuclear determinant of NE differentiation that stains all types of pulmonary NETs irrespective of the histology but does not stain adenocarcinoma or squamous cell carcinoma (SCC).⁶

Recently, genomic studies have identified gene alterations that have become standard of care for diagnosis and targeted therapies.⁸ For example, epidermal growth factor receptor (EGFR) and echinoderm microtubule- associated proteinlike 4, and anaplastic lymphoma kinase (EML4-ALK) mutations have been found in about 25% of lung adenocarcinomas. ⁸ Other abnormalities in LKB1/STK11, NF1, CDKN2A, SMARCA4 and KEAP1, KRAS, MET, ROS1, and RET have also been identified.8 On the other hand, SCC rarely have derangements in EGFR and EML4-ALK, but do show changes in RTKs, DDR2M, FGGRs, among others.8 In TC and AC, observed molecular alterations include MEN1 mutations, mTOR, and SSTRs pathway activation, and GC/ CEACAM1 and CD44/OTP expression.¹³ LCNEC and SCLC have shown TP53 and RB1 mutations and CDX2/VIL1/BAI3 expression. DLL3 expression and MET mutations may be present in SCLC.13 Last, chromatin remodeling gene mutations have been identified in all these lung NET types.¹³

Furthermore, neuropeptides and neuroamines may be measured in the blood and urine.¹⁴ Pulmonary NETs may be functional and secrete these substances, leading to systemic symptoms based on the released molecules.¹⁵ However, pulmonary NETs produce less serotonin than gastrointestinal NETs; therefore, carcinoid syndrome is less frequent in pulmonary NETs.¹⁶ Liver metastasis is often present when it occurs.⁵ Other possible clinical features include Cushing syndrome and acromegaly depending on the secreted hormones.⁵

In a recent metanalysis, serum LDH has been found to have a prognostic role in Ewing sarcoma, urologic cancers, malignant mesothelioma, among others.¹⁷ It demonstrated that a higher LDH concentration is associated with worse survival in patients with lung cancer.¹⁷ Serum LDH is an enzyme that catalyzes the reaction between lactic acid and pyruvic acid that typically takes place in anaerobic conditions.¹⁷ LDH levels are elevated in malignancies because tumors have an anaerobic environment. Elevated LDH levels correlate with the anaerobic metabolism in the tumor. Other studies also have noted that patients with high metastatic score have higher LDH levels.¹⁷ Therefore, LDH may reflect tumor extension.

In addition, other techniques, such as somatostatin- receptor imaging are specifically beneficial in tumors that express the somatostatin receptor.¹⁶ For this reason, this type of study is typically indicated in patients with known metastasis, not in patients with low-grade tumors. Abdominal CT scans are done because the liver is a common site for metastasis.

Our case report demonstrates how biomarkers help diagnose these potentially aggressive and life-threatening tumors that may present as a common condition such as a pleural effusion. Using a less invasive and quicker approach with thoracentesis rather than with lung biopsies is a diagnostic tool in this entity. IHC in cell blocks is a reasonable diagnostic method especially in patients in whom performing a lung biopsy is difficult.

Conclusions

The presence of a symptomatic and recurrent unilateral pleural effusion must urge physicians to consider thoracentesis with mindful use of biomarkers not only for therapeutic purposes, but also for diagnosis of a variety of etiologies, both benign and malignant.

Neuroendocrine tumors (NETs) account for about 0.5% of all newly diagnosed malignancies.¹ Pulmonary NETs are rare, accounting for 1 to 2% of all invasive lung malignancies and involve about 20 to 25% of primary lung malignancies. ^2,3 Their prevalence has increased by an estimated 6% per year over the past 30 years.² Nonetheless, the time of diagnosis is frequently delayed because of nonspecific symptoms that may imitate other pulmonary conditions.

In the normal pleural space, there is a steady state in which there is a roughly equal rate of fluid formation and absorption. Any disequilibrium may produce a pleural effusion. Pleural fluids can be transudates or exudates. Transudates result from imbalances in hydrostatic and oncotic pressures in the pleural space. Exudates result primarily from pleural and/or lung inflammation or from impaired lymphatic drainage of the pleural space. Clinical manifestations include cough, wheezing, recurrent pneumonia, hemoptysis and pleural effusions. We present a case of a man who developed a large left pleural effusion with a pathology report suggesting a pulmonary NET as the etiology. Being aware of this rare entity may help improve prognosis by making an earlier diagnosis and starting treatment sooner.

Case Presentation

A 90-year-old man with a medical history of arterial hypertension, hyperlipidemia, type 2 diabetes mellitus, coronary artery disease, and vascular dementia presented to the emergency department with hypoactivity, poor appetite, productive cough, and shortness of breath. The patient was a former smoker (unknown pack-years) who quit smoking cigarettes 7 years prior. Vital signs showed sinus tachycardia and peripheral oxygen saturation of 90% at room air. The initial physical examination was remarkable for decreased breath sounds and crackles at the left lung base. Laboratory findings showed leukocytosis with neutrophilia and chronic normocytic anemia. Chest computed tomography (CT) showed a large left-sided pleural effusion occupying most of the left hemithorax with adjacent atelectatic lung, enlarged pretracheal, subcarinal, and left perihilar lymph nodes (Figure 1).

The patient was admitted to the internal medicine ward with the diagnosis of left pneumonic process and started on IV levofloxacin. However, despite 7 days of antibiotic therapy, the patient’s respiratory symptoms worsened. This clinical deterioration prompted pulmonary service consultation. Chest radiography demonstrated an enlarging left pleural effusion (Figure 2). A thoracentesis drained 1.2 L of serosanguineous pleural fluid. Pleural fluid analysis showed a cell count of 947/cm3 with 79% of lymphocytes, total protein 3.8 g/dL, lactic dehydrogenase (LDH) level 607 U/L, and glucose level 109 mg/dL. Serum total protein was 6.62 g/dL, LDH 666 U/L and glucose 92 mg/dL (Tables 1 and 2). Alanine transaminase (ALT) and aspartate aminotransferase (AST) were 11 U/L and 21 U/L, respectively. Using Light criteria, the pleural:serum protein ratio was 0.57, the pleural:serum LDH ratio was 0.91, and the pleural LDH was more than two-thirds of the serum LDH. These calculations were consistent with an exudative effusion. An infectious disease workup, including blood and pleural fluid cultures, was negative.

The pleural fluid concentrated cell block hematoxylin and eosin (H&E) staining showed chromatin, prominent nucleoli, and nuclear molding, which was compatible with high-grade lung NET (Figure 3). The cell block immunohistochemistry (IHC) was positive for synaptophysin, chromogranin A, and neuron specific enolase (NSE) also consistent with a high-grade pulmonary NET (Figure 4). The proliferation marker protein Ki-67 labeling index (LI) showed a proliferation index > 20% (Figure 5). The patient did not have decision-making capacity given vascular dementia. Multiple attempts to contact the next of kin or family members were unsuccessful. Risks vs benefits were evaluated, and given the patient’s advanced age and multiple comorbidities, a conservative management approach under palliative care was chosen. For this reason, further genomic studies were not done.

Discussion

NETs are a group of neoplasms that differ in site, amount of cell propagation, and clinical manifestations.⁴ These tumors are rare with an estimated incidence of 25 to 50 per 100,000.4 The most commonly affected organ systems are the gastroenteropancreatic and the bronchopulmonary tracts, accounting for 60% and 25% of the tumors, respectively.4 The incidence is increasing over the past years in part because of novel diagnostic techniques.

The average age of diagnosis is between the fourth and sixth decades, affecting more women than men.⁵ Smoking has been identified as a possible culprit for the development of these neoplasms; nonetheless, the association is still not clear.⁴ For example, poorly differentiated pulmonary NETs have a strong association with smoking but not well-differentiated pulmonary NETs.²

Patients typically present with cough, wheezing, hemoptysis, and recurrent pneumonias, which are in part a consequence of obstruction caused by the mass.² Sometimes, obstruction may yield persistent pleural effusions. Hemoptysis may be seen secondary to the vascularity of pulmonary NETs.

The diagnosis is often delayed because patients are frequently treated for infection before being diagnosed with the malignancy, such as in our case. Radiologic image findings include round opacities, central masses, and atelectasis. Pulmonary NETs are frequently found incidentally as solitary lung nodules. The CT scan is the most common diagnostic modality and can provide information about the borders of the tumor, the location and surrounding structures, including the presence of atelectasis.⁵ Pulmonary NETs are usually centrally located in an accessible region for lung biopsy. In cases where the mass is not easily reachable, thoracentesis may provide the only available specimen.

The 2015 World Health Organization classification has identified 4 histologic types of pulmonary NETs, namely, typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC).⁶ The low-grade pulmonary NET, the typical carcinoid, is slow growing and has lower rates of metastasis. The intermediate-grade NET, the atypical carcinoid, is more aggressive. The highgrade NETs, the LCNEC and the SCLC, are aggressive and spread quickly to other places.⁶ Consequently, LCNEC and SCLC have higher mortalities with a 5-year survival, ranging from 13 to 57% and 5%, respectively.⁷

Tumors may be histomorphologically classified by H&E staining. The main characteristics that differentiate the low- and high-grade NETs are the presence of necrosis and the mitotic rate. Both categories form neuropeptides and have dense granular cores when seen with an electron microscopy^.6 The TC and AC have welldefined, organized histologic patterns, no necrosis, and scarce mitosis. On the other hand, the LCNEC and SCLC are poorly differentiated tumors with necrosis, atypia, and mitosis.6 LCNEC can be separated from SCLC and other tumors by IHC staining, whereas SCLC is primarily distinguished by morphology.

If the biopsy sample size is small, then IHC morphology and markers are helpful for subclassification.⁸ IHC is used to discern between neuroendocrine (NE) vs non-NE. The evaluation of pleural fluid includes preparation of cell blocks. Cell block staining is deemed better for IHC because it mimics a small biopsy that enables superior stains.⁹ The need for a pleural biopsy in cases where the cytology is negative depends on treatment aims, the kind of tumor, and the presence of metastasis.¹⁰ In almost 80% of cases, pleural biopsy and cytology are the only specimens obtained for analysis.Therefore, identification of these markers is practical for diagnosis.¹⁰ For this reason, pleural effusion samples are appropriate options to lung biopsy for molecular studies.¹⁰

Ki-67 LI in samples has the highest specificity and sensitivity for low-tointermediate- grade vs high-grade tumors. It is being used for guiding clinical and treatment decisions.⁶ In SCLC, the Ki-67 LI is not necessary for diagnosis but will be about 80%.¹¹ The tumor cells will show epithelial characteristics with positive cytokeratin AE1/AE3 and monoclonal antibody CAM5.² and neuroendocrine markers, including NCAM/CD56, chromogranin A, and synaptophysin.¹¹

Thyroid transcription factor-1 (TTF- 1) is positive in most cases. In LCNEC, the Ki-67 LI is between 40% and 80%. NCAM/ CD56, chromogranin A, and synaptophysin are present in 92 to 100%, 80 to 85%, and 50 to 60%, respectively.¹¹ TTF-1 is identified in half of the tumors. All these tumors express pancytokeratin (AE1/AE3), cytokeratin 7 or low-molecular-weight cytokeratin. Likewise, the carcinoids will show markers, such as chromogranin A, synaptophysin, CD56, and epithelial markers like pancytokeratin.¹¹ However, the high-molecular-weight cytokeratin and TTF-1 are negative. Furthermore, NSE is considered a good tumor marker in the diagnosis and prognosis of SCLC. NSE also has been reported in NSCLC. The level of NSE correlates with tumor burden, number of metastatic sites, and response to treatment. ¹² A potentially useful marker is the insulinoma-associated protein 1, which is a nuclear determinant of NE differentiation that stains all types of pulmonary NETs irrespective of the histology but does not stain adenocarcinoma or squamous cell carcinoma (SCC).⁶

Recently, genomic studies have identified gene alterations that have become standard of care for diagnosis and targeted therapies.⁸ For example, epidermal growth factor receptor (EGFR) and echinoderm microtubule- associated proteinlike 4, and anaplastic lymphoma kinase (EML4-ALK) mutations have been found in about 25% of lung adenocarcinomas. ⁸ Other abnormalities in LKB1/STK11, NF1, CDKN2A, SMARCA4 and KEAP1, KRAS, MET, ROS1, and RET have also been identified.8 On the other hand, SCC rarely have derangements in EGFR and EML4-ALK, but do show changes in RTKs, DDR2M, FGGRs, among others.8 In TC and AC, observed molecular alterations include MEN1 mutations, mTOR, and SSTRs pathway activation, and GC/ CEACAM1 and CD44/OTP expression.¹³ LCNEC and SCLC have shown TP53 and RB1 mutations and CDX2/VIL1/BAI3 expression. DLL3 expression and MET mutations may be present in SCLC.13 Last, chromatin remodeling gene mutations have been identified in all these lung NET types.¹³

Furthermore, neuropeptides and neuroamines may be measured in the blood and urine.¹⁴ Pulmonary NETs may be functional and secrete these substances, leading to systemic symptoms based on the released molecules.¹⁵ However, pulmonary NETs produce less serotonin than gastrointestinal NETs; therefore, carcinoid syndrome is less frequent in pulmonary NETs.¹⁶ Liver metastasis is often present when it occurs.⁵ Other possible clinical features include Cushing syndrome and acromegaly depending on the secreted hormones.⁵

In a recent metanalysis, serum LDH has been found to have a prognostic role in Ewing sarcoma, urologic cancers, malignant mesothelioma, among others.¹⁷ It demonstrated that a higher LDH concentration is associated with worse survival in patients with lung cancer.¹⁷ Serum LDH is an enzyme that catalyzes the reaction between lactic acid and pyruvic acid that typically takes place in anaerobic conditions.¹⁷ LDH levels are elevated in malignancies because tumors have an anaerobic environment. Elevated LDH levels correlate with the anaerobic metabolism in the tumor. Other studies also have noted that patients with high metastatic score have higher LDH levels.¹⁷ Therefore, LDH may reflect tumor extension.

In addition, other techniques, such as somatostatin- receptor imaging are specifically beneficial in tumors that express the somatostatin receptor.¹⁶ For this reason, this type of study is typically indicated in patients with known metastasis, not in patients with low-grade tumors. Abdominal CT scans are done because the liver is a common site for metastasis.

Our case report demonstrates how biomarkers help diagnose these potentially aggressive and life-threatening tumors that may present as a common condition such as a pleural effusion. Using a less invasive and quicker approach with thoracentesis rather than with lung biopsies is a diagnostic tool in this entity. IHC in cell blocks is a reasonable diagnostic method especially in patients in whom performing a lung biopsy is difficult.

Conclusions

The presence of a symptomatic and recurrent unilateral pleural effusion must urge physicians to consider thoracentesis with mindful use of biomarkers not only for therapeutic purposes, but also for diagnosis of a variety of etiologies, both benign and malignant.

Difluoroethane (DFE) is an easily acquired and inexpensive volatile substance that can be inhaled recreationally. ¹ It is found in common household items, including compressed air dusters, refrigerants, and propellants. DFE is a central nervous system (CNS) depressant associated with a brief sensation of euphoria when inhaled.² Prolonged or excessive use is associated with toxicity, and abrupt cessation can induce withdrawal.^3-5 We present a case of DFE abuse associated with skeletal fluorosis and withdrawal psychosis.

Case Presentation

A 39-year-old man with a 6-month history of inhaling 20 to 25 cans of DFE per day presented to the emergency department after abruptly stopping use 6 days prior. He described irritability, agitation, auditory hallucinations, and delusions of “demons trying to harm him.”

On presentation, the patient was afebrile with a mild sinus tachycardia. He was calm and cooperative but reported delusions and auditory hallucinations. He denied suicidal or homicidal ideation. His physical examination was remarkable for bony deformities of his hands (Figure 1).

The initial workup included a complete blood count; basic metabolic panel; liver function tests; urine toxicology; and testing for hepatitis B/C and HIV; all unremarkable. Psychiatry and poison control were consulted, and he was admitted.

After 72 hours, the patient's irritability, agitation, and sinus tachycardia resolved; however, his psychosis and hallucinations persisted. He was started on olanzapine and transferred to inpatient psychiatry. Additional laboratory tests revealed a serum fluoride of 0.35 mg/L (normal, 1-47 ug/L), C-telopeptide of 2,663 pg/mL (normal, 70-780 pg/mL), and hand X-rays showing diffuse bilateral periosteal reaction in the phalanges and distal ulnas (Figure 2).⁶

Discussion

DFE acts as a CNS depressant via glutamate and γ-aminobutyric acid receptors, causing a brief euphoria when inhaled.² Acute toxicity can cause nausea, vomiting, abdominal pain, and altered mental status. Severe complications include loss of consciousness, mucosal frostbite, angioedema, cardiac arrhythmias, and skeletal fluorosis.^2,7

Skeletal fluorosis is a rare ramification of excessive or prolonged DFE inhalation. DFE is metabolized into a fluorinated compound that accumulates and leaches calcium from bone, altering its structure. This can manifest as bony deformities with diffuse periosteal reaction and elevated serum fluoride levels. Furthermore, the elevated C-telopeptide level seen in this case may suggest increased bone turnover.

Approximately 50% of patients report withdrawal symptoms, but the timing, duration, and associated symptoms are not well understood.³ Withdrawal can include tremors, diaphoresis, nausea, vomiting, depression, anxiety, irritability, psychosis, and hallucinations. Symptoms typically start within 24 to 48 hours of cessation and last for 3 to 7 days.⁵ Psychotic symptoms often abate quickly; however, anxiety and insomnia can persist for weeks.⁵ There are no formal treatment guidelines, but poison control suggests observation and as-needed benzodiazepines. Although this patient’s irritability and agitation resolved, his psychosis and hallucinations persisted, raising concern for an underlying psychiatric diagnosis and prompting transfer to inpatient psychiatry.

Conslusion

Health care providers should recognize the symptoms of DFE toxicity, its complications, and withdrawal. Collaborating with psychiatry and poison control is beneficial in providing guidelines for supportive care.

Difluoroethane (DFE) is an easily acquired and inexpensive volatile substance that can be inhaled recreationally. ¹ It is found in common household items, including compressed air dusters, refrigerants, and propellants. DFE is a central nervous system (CNS) depressant associated with a brief sensation of euphoria when inhaled.² Prolonged or excessive use is associated with toxicity, and abrupt cessation can induce withdrawal.^3-5 We present a case of DFE abuse associated with skeletal fluorosis and withdrawal psychosis.

Case Presentation

A 39-year-old man with a 6-month history of inhaling 20 to 25 cans of DFE per day presented to the emergency department after abruptly stopping use 6 days prior. He described irritability, agitation, auditory hallucinations, and delusions of “demons trying to harm him.”

On presentation, the patient was afebrile with a mild sinus tachycardia. He was calm and cooperative but reported delusions and auditory hallucinations. He denied suicidal or homicidal ideation. His physical examination was remarkable for bony deformities of his hands (Figure 1).

The initial workup included a complete blood count; basic metabolic panel; liver function tests; urine toxicology; and testing for hepatitis B/C and HIV; all unremarkable. Psychiatry and poison control were consulted, and he was admitted.

After 72 hours, the patient's irritability, agitation, and sinus tachycardia resolved; however, his psychosis and hallucinations persisted. He was started on olanzapine and transferred to inpatient psychiatry. Additional laboratory tests revealed a serum fluoride of 0.35 mg/L (normal, 1-47 ug/L), C-telopeptide of 2,663 pg/mL (normal, 70-780 pg/mL), and hand X-rays showing diffuse bilateral periosteal reaction in the phalanges and distal ulnas (Figure 2).⁶

Discussion

DFE acts as a CNS depressant via glutamate and γ-aminobutyric acid receptors, causing a brief euphoria when inhaled.² Acute toxicity can cause nausea, vomiting, abdominal pain, and altered mental status. Severe complications include loss of consciousness, mucosal frostbite, angioedema, cardiac arrhythmias, and skeletal fluorosis.^2,7

Skeletal fluorosis is a rare ramification of excessive or prolonged DFE inhalation. DFE is metabolized into a fluorinated compound that accumulates and leaches calcium from bone, altering its structure. This can manifest as bony deformities with diffuse periosteal reaction and elevated serum fluoride levels. Furthermore, the elevated C-telopeptide level seen in this case may suggest increased bone turnover.

Approximately 50% of patients report withdrawal symptoms, but the timing, duration, and associated symptoms are not well understood.³ Withdrawal can include tremors, diaphoresis, nausea, vomiting, depression, anxiety, irritability, psychosis, and hallucinations. Symptoms typically start within 24 to 48 hours of cessation and last for 3 to 7 days.⁵ Psychotic symptoms often abate quickly; however, anxiety and insomnia can persist for weeks.⁵ There are no formal treatment guidelines, but poison control suggests observation and as-needed benzodiazepines. Although this patient’s irritability and agitation resolved, his psychosis and hallucinations persisted, raising concern for an underlying psychiatric diagnosis and prompting transfer to inpatient psychiatry.

Conslusion

Health care providers should recognize the symptoms of DFE toxicity, its complications, and withdrawal. Collaborating with psychiatry and poison control is beneficial in providing guidelines for supportive care.

Difluoroethane (DFE) is an easily acquired and inexpensive volatile substance that can be inhaled recreationally. ¹ It is found in common household items, including compressed air dusters, refrigerants, and propellants. DFE is a central nervous system (CNS) depressant associated with a brief sensation of euphoria when inhaled.² Prolonged or excessive use is associated with toxicity, and abrupt cessation can induce withdrawal.^3-5 We present a case of DFE abuse associated with skeletal fluorosis and withdrawal psychosis.

Case Presentation

A 39-year-old man with a 6-month history of inhaling 20 to 25 cans of DFE per day presented to the emergency department after abruptly stopping use 6 days prior. He described irritability, agitation, auditory hallucinations, and delusions of “demons trying to harm him.”

On presentation, the patient was afebrile with a mild sinus tachycardia. He was calm and cooperative but reported delusions and auditory hallucinations. He denied suicidal or homicidal ideation. His physical examination was remarkable for bony deformities of his hands (Figure 1).

The initial workup included a complete blood count; basic metabolic panel; liver function tests; urine toxicology; and testing for hepatitis B/C and HIV; all unremarkable. Psychiatry and poison control were consulted, and he was admitted.

After 72 hours, the patient's irritability, agitation, and sinus tachycardia resolved; however, his psychosis and hallucinations persisted. He was started on olanzapine and transferred to inpatient psychiatry. Additional laboratory tests revealed a serum fluoride of 0.35 mg/L (normal, 1-47 ug/L), C-telopeptide of 2,663 pg/mL (normal, 70-780 pg/mL), and hand X-rays showing diffuse bilateral periosteal reaction in the phalanges and distal ulnas (Figure 2).⁶

Discussion

DFE acts as a CNS depressant via glutamate and γ-aminobutyric acid receptors, causing a brief euphoria when inhaled.² Acute toxicity can cause nausea, vomiting, abdominal pain, and altered mental status. Severe complications include loss of consciousness, mucosal frostbite, angioedema, cardiac arrhythmias, and skeletal fluorosis.^2,7

Skeletal fluorosis is a rare ramification of excessive or prolonged DFE inhalation. DFE is metabolized into a fluorinated compound that accumulates and leaches calcium from bone, altering its structure. This can manifest as bony deformities with diffuse periosteal reaction and elevated serum fluoride levels. Furthermore, the elevated C-telopeptide level seen in this case may suggest increased bone turnover.

Approximately 50% of patients report withdrawal symptoms, but the timing, duration, and associated symptoms are not well understood.³ Withdrawal can include tremors, diaphoresis, nausea, vomiting, depression, anxiety, irritability, psychosis, and hallucinations. Symptoms typically start within 24 to 48 hours of cessation and last for 3 to 7 days.⁵ Psychotic symptoms often abate quickly; however, anxiety and insomnia can persist for weeks.⁵ There are no formal treatment guidelines, but poison control suggests observation and as-needed benzodiazepines. Although this patient’s irritability and agitation resolved, his psychosis and hallucinations persisted, raising concern for an underlying psychiatric diagnosis and prompting transfer to inpatient psychiatry.

Conslusion

Health care providers should recognize the symptoms of DFE toxicity, its complications, and withdrawal. Collaborating with psychiatry and poison control is beneficial in providing guidelines for supportive care.