Case Letter

To the Editor:

Methemoglobinemia (MetHb) is a condition caused by elevated levels of methemoglobin in the blood, which leads to an overall reduced ability of red blood cells to release oxygen to tissues, causing tissue hypoxia. Methemoglobinemia may be congenital or acquired. Various antibiotics and local anesthetics have been reported to induce acquired MetHb.¹ We describe an adult who presented with MetHb resulting from excessive topical application of local anesthetics for painful scrotal ulcers.

A 54-year-old man presented with multiple scrotal and penile shaft ulcers of a few weeks’ duration with no systemic concerns. His medical history included chronic hepatitis C virus (HCV) and lumbar disc disease. Physical examination revealed multiple erosions and ulcers on an erythematous base involving the scrotal skin and distal penile shaft (Figure). Histopathology revealed acute leukocytoclastic vasculitis, and a laboratory workup was positive for mixed cryoglobulinemia that was thought to be HCV related. The patient was started on a systemic corticosteroid treatment in addition to sofosbuvir-velpatasvir for the treatment of HCV-related mixed cryoglobulinemic vasculitis. Concomitantly, the patient self-treated for pain with a local anesthetic cream containing lidocaine 2.5% and prilocaine 2.5%, applying it excessively every few hours daily for 2 weeks. He also intermittently used occlusive dressings.

After 2 weeks of application, the patient developed lightheadedness and shortness of breath. He returned and was admitted for further evaluation. He had dyspnea and tachypnea of 22 breaths per minute. He also had mild tachycardia (109 beats per minute). He did not have a fever, and his blood pressure was normal. The oxygen saturation measured in ambient room air by pulse oximetry was 82%. A neurologic examination was normal except for mild drowsiness. The lungs were clear, and heart sounds were normal. A 12-lead electrocardiogram also was normal. A complete blood cell count showed severe macrocytic anemia with a hemoglobin level of 7 g/dL, which was a severe decline from the patient’s baseline level of 14 g/dL (reference range, 13–17 g/dL). A MetHb blood level of 11% was reported on co-oximetry. An arterial blood gas analysis revealed a pH of 7.46; partial pressure of carbon dioxide of 41 mm Hg; and partial pressure of oxygen of 63 mm Hg. The haptoglobin level was low at 2.6 mg/dL (reference range, 30–200 mg/dL). An absolute reticulocyte count was markedly elevated at 0.4×10⁶/mL (reference range, 0.03–0.08×10⁶/mL), lactate dehydrogenase was elevated at 430 U/L (reference range, 125–220 U/L), and indirect billirubin was high at 0.9 mg/dL (reference range, 0–0.5 mg/dL), consistent with hemolytic anemia. Electrolyte serum levels and renal function tests were within reference range. A diagnosis of MetHb induced by the lidocaine-prilocaine cream was rendered, and intravenous methylene blue 72 mg (1 mg/kg) was administered over 10 minutes. Within the next 60 minutes, the patient’s drowsiness and arterial desaturation resolved. A subsequent MetHb measurement taken several hours later was reduced to 4%. The patient remained asymptomatic and was eventually discharged.

Methemoglobinemia is an altered state of hemoglobin where the ferrous (Fe2⁺) ions of heme are oxidized to the ferric (Fe3⁺) state. These ferric ions are unable to bind oxygen, resulting in impaired oxygen delivery to tissues.¹ Local anesthetics, which are strong oxidizers, have been reported to induce MetHb.² In our patient, the extensive use of lidocaine 2.5%–prilocaine 2.5% cream resulted in severe life-threatening MetHb. The oxidizing properties of local anesthetics can be attributed to their chemical structure. Benzocaine is metabolized to potent oxidizers such as aniline, phenylhydroxylamine, and nitrobenzene.³ Prilocaine and another potent oxidizer, ortho-toluidine, which is a metabolite of prilocaine, can oxidize the iron in hemoglobin from ferrous (Fe2⁺) to ferric (Fe3⁺), leading to MetHb.^2,3

Cases of anesthetic-induced MetHb primarily are associated with overuse of the product by applying it to large surface areas or using it for prolonged periods of time. In one case report, the occlusive dressing of the lidocaine-prilocaine cream applied to skin of the legs that was already abraded by laser epilation therapy resulted in MetHb.⁴ In our patient, applying the topical anesthetic to the eroded high-absorptive mucosal surface of the scrotal skin and the use of occlusive dressings increased the risk for toxicity. Absorption from scrotal skin is 40-times higher than the forearm.⁵ The face, axillae, and scalp also exhibit increased absorption compared to the forearm—10-, 4-, and 3-times higher, respectively.

In recent years, the use of topical anesthetics has greatly expanded due to the popularity of aesthetic and cosmetic procedures. These procedures often are performed in an outpatient setting.⁶ Dermatologists should be well aware of MetHb as a serious adverse effect and guide patients accordingly, as patients do not tend to consider a local anesthetic to be a drug. Drug interactions also may affect free lidocaine concentrations by liver cytochrome P450 metabolism; although this was not the case with our patient, special attention should be given to potential interactions that may exacerbate this serious adverse effect. Consideration should be given to patients applying the anesthetic to areas with high absorption capacity.

To the Editor:

Methemoglobinemia (MetHb) is a condition caused by elevated levels of methemoglobin in the blood, which leads to an overall reduced ability of red blood cells to release oxygen to tissues, causing tissue hypoxia. Methemoglobinemia may be congenital or acquired. Various antibiotics and local anesthetics have been reported to induce acquired MetHb.¹ We describe an adult who presented with MetHb resulting from excessive topical application of local anesthetics for painful scrotal ulcers.

A 54-year-old man presented with multiple scrotal and penile shaft ulcers of a few weeks’ duration with no systemic concerns. His medical history included chronic hepatitis C virus (HCV) and lumbar disc disease. Physical examination revealed multiple erosions and ulcers on an erythematous base involving the scrotal skin and distal penile shaft (Figure). Histopathology revealed acute leukocytoclastic vasculitis, and a laboratory workup was positive for mixed cryoglobulinemia that was thought to be HCV related. The patient was started on a systemic corticosteroid treatment in addition to sofosbuvir-velpatasvir for the treatment of HCV-related mixed cryoglobulinemic vasculitis. Concomitantly, the patient self-treated for pain with a local anesthetic cream containing lidocaine 2.5% and prilocaine 2.5%, applying it excessively every few hours daily for 2 weeks. He also intermittently used occlusive dressings.

After 2 weeks of application, the patient developed lightheadedness and shortness of breath. He returned and was admitted for further evaluation. He had dyspnea and tachypnea of 22 breaths per minute. He also had mild tachycardia (109 beats per minute). He did not have a fever, and his blood pressure was normal. The oxygen saturation measured in ambient room air by pulse oximetry was 82%. A neurologic examination was normal except for mild drowsiness. The lungs were clear, and heart sounds were normal. A 12-lead electrocardiogram also was normal. A complete blood cell count showed severe macrocytic anemia with a hemoglobin level of 7 g/dL, which was a severe decline from the patient’s baseline level of 14 g/dL (reference range, 13–17 g/dL). A MetHb blood level of 11% was reported on co-oximetry. An arterial blood gas analysis revealed a pH of 7.46; partial pressure of carbon dioxide of 41 mm Hg; and partial pressure of oxygen of 63 mm Hg. The haptoglobin level was low at 2.6 mg/dL (reference range, 30–200 mg/dL). An absolute reticulocyte count was markedly elevated at 0.4×10⁶/mL (reference range, 0.03–0.08×10⁶/mL), lactate dehydrogenase was elevated at 430 U/L (reference range, 125–220 U/L), and indirect billirubin was high at 0.9 mg/dL (reference range, 0–0.5 mg/dL), consistent with hemolytic anemia. Electrolyte serum levels and renal function tests were within reference range. A diagnosis of MetHb induced by the lidocaine-prilocaine cream was rendered, and intravenous methylene blue 72 mg (1 mg/kg) was administered over 10 minutes. Within the next 60 minutes, the patient’s drowsiness and arterial desaturation resolved. A subsequent MetHb measurement taken several hours later was reduced to 4%. The patient remained asymptomatic and was eventually discharged.

Methemoglobinemia is an altered state of hemoglobin where the ferrous (Fe2⁺) ions of heme are oxidized to the ferric (Fe3⁺) state. These ferric ions are unable to bind oxygen, resulting in impaired oxygen delivery to tissues.¹ Local anesthetics, which are strong oxidizers, have been reported to induce MetHb.² In our patient, the extensive use of lidocaine 2.5%–prilocaine 2.5% cream resulted in severe life-threatening MetHb. The oxidizing properties of local anesthetics can be attributed to their chemical structure. Benzocaine is metabolized to potent oxidizers such as aniline, phenylhydroxylamine, and nitrobenzene.³ Prilocaine and another potent oxidizer, ortho-toluidine, which is a metabolite of prilocaine, can oxidize the iron in hemoglobin from ferrous (Fe2⁺) to ferric (Fe3⁺), leading to MetHb.^2,3

Cases of anesthetic-induced MetHb primarily are associated with overuse of the product by applying it to large surface areas or using it for prolonged periods of time. In one case report, the occlusive dressing of the lidocaine-prilocaine cream applied to skin of the legs that was already abraded by laser epilation therapy resulted in MetHb.⁴ In our patient, applying the topical anesthetic to the eroded high-absorptive mucosal surface of the scrotal skin and the use of occlusive dressings increased the risk for toxicity. Absorption from scrotal skin is 40-times higher than the forearm.⁵ The face, axillae, and scalp also exhibit increased absorption compared to the forearm—10-, 4-, and 3-times higher, respectively.

In recent years, the use of topical anesthetics has greatly expanded due to the popularity of aesthetic and cosmetic procedures. These procedures often are performed in an outpatient setting.⁶ Dermatologists should be well aware of MetHb as a serious adverse effect and guide patients accordingly, as patients do not tend to consider a local anesthetic to be a drug. Drug interactions also may affect free lidocaine concentrations by liver cytochrome P450 metabolism; although this was not the case with our patient, special attention should be given to potential interactions that may exacerbate this serious adverse effect. Consideration should be given to patients applying the anesthetic to areas with high absorption capacity.

To the Editor:

Methemoglobinemia (MetHb) is a condition caused by elevated levels of methemoglobin in the blood, which leads to an overall reduced ability of red blood cells to release oxygen to tissues, causing tissue hypoxia. Methemoglobinemia may be congenital or acquired. Various antibiotics and local anesthetics have been reported to induce acquired MetHb.¹ We describe an adult who presented with MetHb resulting from excessive topical application of local anesthetics for painful scrotal ulcers.

A 54-year-old man presented with multiple scrotal and penile shaft ulcers of a few weeks’ duration with no systemic concerns. His medical history included chronic hepatitis C virus (HCV) and lumbar disc disease. Physical examination revealed multiple erosions and ulcers on an erythematous base involving the scrotal skin and distal penile shaft (Figure). Histopathology revealed acute leukocytoclastic vasculitis, and a laboratory workup was positive for mixed cryoglobulinemia that was thought to be HCV related. The patient was started on a systemic corticosteroid treatment in addition to sofosbuvir-velpatasvir for the treatment of HCV-related mixed cryoglobulinemic vasculitis. Concomitantly, the patient self-treated for pain with a local anesthetic cream containing lidocaine 2.5% and prilocaine 2.5%, applying it excessively every few hours daily for 2 weeks. He also intermittently used occlusive dressings.

After 2 weeks of application, the patient developed lightheadedness and shortness of breath. He returned and was admitted for further evaluation. He had dyspnea and tachypnea of 22 breaths per minute. He also had mild tachycardia (109 beats per minute). He did not have a fever, and his blood pressure was normal. The oxygen saturation measured in ambient room air by pulse oximetry was 82%. A neurologic examination was normal except for mild drowsiness. The lungs were clear, and heart sounds were normal. A 12-lead electrocardiogram also was normal. A complete blood cell count showed severe macrocytic anemia with a hemoglobin level of 7 g/dL, which was a severe decline from the patient’s baseline level of 14 g/dL (reference range, 13–17 g/dL). A MetHb blood level of 11% was reported on co-oximetry. An arterial blood gas analysis revealed a pH of 7.46; partial pressure of carbon dioxide of 41 mm Hg; and partial pressure of oxygen of 63 mm Hg. The haptoglobin level was low at 2.6 mg/dL (reference range, 30–200 mg/dL). An absolute reticulocyte count was markedly elevated at 0.4×10⁶/mL (reference range, 0.03–0.08×10⁶/mL), lactate dehydrogenase was elevated at 430 U/L (reference range, 125–220 U/L), and indirect billirubin was high at 0.9 mg/dL (reference range, 0–0.5 mg/dL), consistent with hemolytic anemia. Electrolyte serum levels and renal function tests were within reference range. A diagnosis of MetHb induced by the lidocaine-prilocaine cream was rendered, and intravenous methylene blue 72 mg (1 mg/kg) was administered over 10 minutes. Within the next 60 minutes, the patient’s drowsiness and arterial desaturation resolved. A subsequent MetHb measurement taken several hours later was reduced to 4%. The patient remained asymptomatic and was eventually discharged.

Methemoglobinemia is an altered state of hemoglobin where the ferrous (Fe2⁺) ions of heme are oxidized to the ferric (Fe3⁺) state. These ferric ions are unable to bind oxygen, resulting in impaired oxygen delivery to tissues.¹ Local anesthetics, which are strong oxidizers, have been reported to induce MetHb.² In our patient, the extensive use of lidocaine 2.5%–prilocaine 2.5% cream resulted in severe life-threatening MetHb. The oxidizing properties of local anesthetics can be attributed to their chemical structure. Benzocaine is metabolized to potent oxidizers such as aniline, phenylhydroxylamine, and nitrobenzene.³ Prilocaine and another potent oxidizer, ortho-toluidine, which is a metabolite of prilocaine, can oxidize the iron in hemoglobin from ferrous (Fe2⁺) to ferric (Fe3⁺), leading to MetHb.^2,3

Cases of anesthetic-induced MetHb primarily are associated with overuse of the product by applying it to large surface areas or using it for prolonged periods of time. In one case report, the occlusive dressing of the lidocaine-prilocaine cream applied to skin of the legs that was already abraded by laser epilation therapy resulted in MetHb.⁴ In our patient, applying the topical anesthetic to the eroded high-absorptive mucosal surface of the scrotal skin and the use of occlusive dressings increased the risk for toxicity. Absorption from scrotal skin is 40-times higher than the forearm.⁵ The face, axillae, and scalp also exhibit increased absorption compared to the forearm—10-, 4-, and 3-times higher, respectively.

In recent years, the use of topical anesthetics has greatly expanded due to the popularity of aesthetic and cosmetic procedures. These procedures often are performed in an outpatient setting.⁶ Dermatologists should be well aware of MetHb as a serious adverse effect and guide patients accordingly, as patients do not tend to consider a local anesthetic to be a drug. Drug interactions also may affect free lidocaine concentrations by liver cytochrome P450 metabolism; although this was not the case with our patient, special attention should be given to potential interactions that may exacerbate this serious adverse effect. Consideration should be given to patients applying the anesthetic to areas with high absorption capacity.

To the Editor:

Herpes vegetans (HV) is an uncommon infection caused by human herpesvirus (HHV) in patients who are immunocompromised, such as those who are HIV positive.¹ Unlike typical HHV infection, HV can present with exophytic exudative ulcers and papillomatous vegetations. The presentation of ulcerated genital nodules, especially in an immunocompromised patient, yields an array of disorders in the differential diagnosis, including condyloma latum, condyloma acuminatum, pyogenic granuloma (PG), and verrucous carcinoma.^2,3 Histopathology of HV reveals pseudoepitheliomatous hyperplasia, plasma cell infiltration, and positivity for HHV type 1 (HHV-1) and/or HHV type 2 (HHV-2). Herpes vegetans lesions typically require a multimodal treatment approach because many cases are resistant to acyclovir. Treatment options include the nucleoside analogues foscarnet and cidofovir; immunomodulators such as topical imiquimod; and the topical antiviral trifluridine.^1,4-6 We describe a case of HV in a patient with a history of well-controlled HIV infection who presented with a painful fungating penile lesion.

A 55-year-old man presented to the hospital with a painful expanding mass on the distal aspect of the penis of 3 months’ duration. He had a history of HIV infection that was well-controlled by antiretroviral therapy, prior hepatitis B virus infection and acyclovir-resistant genital HHV-2 infection. Physical examination revealed a large, firm, circumferential, exophytic, verrucous plaque with various areas of ulceration and purulent drainage on the distal shaft and glans of the penis (Figure 1). The patient’s most recent absolute CD4 count was 425 cells/mm³ (reference range, 500–1500 cells/mm³). His HIV viral load was undetectable at less than 30 copies/mL. Histopathology with hematoxylin and eosin staining of biopsy material from the penile lesion demonstrated pseudoepitheliomatous epidermal hyperplasia with focal ulceration and a mixed inflammatory infiltrate (Figure 2A). At higher magnification, clear viral cytopathic changes of HHV were noted, including multinucleation, nuclear molding, and homogenous gray nuclei (Figure 2B). Additional staining for fungi, mycobacteria, and spirochetes was negative. In-situ hybridization was negative for human papillomavirus subtypes. A bacterial culture of swabs of the purulent drainage was positive for Staphylococcus aureus and Proteus mirabilis.

Given the patient’s known history of acyclovir-resistant HHV-2 infection, he received a 28-day course of intravenous foscarnet 40 mg/kg every 12 hours. He also was given a 14-day course of intravenous ampicillin-sulbactam 3 g every 6 hours. The patient gradually improved during a 35-day hospital stay. He was discharged with cidofovir cream 1% and oral valacyclovir; the latter was subsequently discontinued by dermatology because of his known history of acyclovir resistance. Four months after discharge, the patient underwent a circumcision performed by urology to decrease the risk for recurrence and achieve the best cosmetic outcome. At the 6-month follow-up visit, dramatic clinical improvement was evident, with complete resolution of the plaque and only isolated areas of scarring (Figure 3). The patient reported that penile function was preserved.

Herpes vegetans represents a rare infection with HHV-1 or HHV-2, typically in patients who are considerably immunosuppressed, such as those with cancer, those undergoing transplantation, and those with uncontrolled HIV infection.¹ Few cases of HV have been described in an immunocompetent patient.² Our case is unique because the patient’s HIV infection was well controlled at the time HV was diagnosed, demonstrated by his modestly low CD4 count and undetectable HIV viral load.

Patients with HV can present diagnostic and therapeutic challenges. Typically, a diagnosis of cutaneous HHV infection does not require a biopsy; most cases appear as clustered vesicular lesions, making the disease easy to diagnose clinically. However, biopsies and cultures are necessary to identify the underlying cause of atypical verrucous exophytic lesions. Other conditions with clinical features similar to HV include squamous cell carcinoma, condyloma acuminatum, and deep fungal and mycobacterial infections.^2,3 A tissue biopsy, histologic staining, and tissue culture should be performed to identify the causative pathogen and potential targets for treatment. Definitive diagnosis is vital to deliver proper treatment modalities, which often involve a multimodal multidisciplinary approach. 

Several pathogenic mechanisms of HV have been proposed. One theory suggests that in an immunocompetent patient, HHV typically triggers a lymphocytic response, which leads to activation of interferon alpha. However, in an immunocompromised patient, such as an individual with AIDS, this interferon response is diminished, which explains why these patients typically have a chronic and resistant HHV infection. HIV has an affinity for infecting dermal dendritic cells, which signals activation of tumor necrosis factor and interleukin.⁶ Both cytokines contribute to an antiapoptotic environment that promotes continued proliferation of these viral cells in the epidermis. Over time, propagation of disinhibited cells can lead to the verrucous and hyperkeratotic-appearing skin that is common in patients with HV.⁷

Another theorized mechanism underlying hypertrophic herpetic lesions was described in the context of HHV-1 infection and subsequent PG. El Hayderi et al⁸ reported that histologic and immunohistochemical examination of a patient’s lesion revealed sparse epithelial cell aggregates within PG as well as HHV-1 antigens in the nuclei and cytoplasm of normal-appearing and cytopathic epithelial cells. Immunohistochemical examination also revealed vascular endothelial growth factor within HHV-1–infected epithelial cells and PG endothelial cells, suggesting that PG formation may be indirectly driven by vascular endothelial growth factor and its proangiogenic properties. The pathogenesis of PG in the setting of HHV-1 infection displays many similarities to hyperkeratotic lesions observed in atypical cutaneous manifestations of HHV-2.⁸

The management of patients with HV continues to be complex, often requiring a multimodal regimen. Although acyclovir has been shown to be highly effective for treating and preventing most HHV infections, acyclovir resistance frequently has been reported in immunocompromised populations.⁵ Acyclovir resistance can be correlated with the severity of immunodeficiency as well as the duration of acyclovir exposure. Resistance to acyclovir often results from deficient intracellular phosphorylation, which is required for activation of the drug. If patients show resistance to acyclovir and its derivatives, alternate drug classes that do not depend on thymidine kinase phosphorylation should be considered.

Our patient received a combination of intravenous foscarnet and a course of ampicillin-sulbactam while an inpatient due to his documented history of acyclovir-resistant HHV-2 infection, and he was discharged on cidofovir cream 1%. Cidofovir is US Food and Drug Administration approved for treating cytomegalovirus retinitis in patients with AIDS. Although data are limited, topical and intralesional cidofovir have been used to treat acyclovir-resistant cases of HV with documented success.^1,9 In refractory HV or when the disease is slow to resolve, intralesional cidofovir has been documented to be an additional treatment option. Intralesional and topical cidofovir carry a much lower risk for adverse effects such as kidney dysfunction compared to intravenous cidofovir¹ and can be considered in patients with minimal clinical improvement and those at increased risk for side effects.

Our case demonstrated how a patient with HV may require a complex and prolonged hospital course for appropriate treatment. Our patient required an array of both medical and surgical modalities to reach the desired outcome. Here, a multitude of specialties including infectious disease, dermatology, and urology worked together to reach a positive clinical and cosmetic outcome for this patient. 

To the Editor:

Herpes vegetans (HV) is an uncommon infection caused by human herpesvirus (HHV) in patients who are immunocompromised, such as those who are HIV positive.¹ Unlike typical HHV infection, HV can present with exophytic exudative ulcers and papillomatous vegetations. The presentation of ulcerated genital nodules, especially in an immunocompromised patient, yields an array of disorders in the differential diagnosis, including condyloma latum, condyloma acuminatum, pyogenic granuloma (PG), and verrucous carcinoma.^2,3 Histopathology of HV reveals pseudoepitheliomatous hyperplasia, plasma cell infiltration, and positivity for HHV type 1 (HHV-1) and/or HHV type 2 (HHV-2). Herpes vegetans lesions typically require a multimodal treatment approach because many cases are resistant to acyclovir. Treatment options include the nucleoside analogues foscarnet and cidofovir; immunomodulators such as topical imiquimod; and the topical antiviral trifluridine.^1,4-6 We describe a case of HV in a patient with a history of well-controlled HIV infection who presented with a painful fungating penile lesion.

A 55-year-old man presented to the hospital with a painful expanding mass on the distal aspect of the penis of 3 months’ duration. He had a history of HIV infection that was well-controlled by antiretroviral therapy, prior hepatitis B virus infection and acyclovir-resistant genital HHV-2 infection. Physical examination revealed a large, firm, circumferential, exophytic, verrucous plaque with various areas of ulceration and purulent drainage on the distal shaft and glans of the penis (Figure 1). The patient’s most recent absolute CD4 count was 425 cells/mm³ (reference range, 500–1500 cells/mm³). His HIV viral load was undetectable at less than 30 copies/mL. Histopathology with hematoxylin and eosin staining of biopsy material from the penile lesion demonstrated pseudoepitheliomatous epidermal hyperplasia with focal ulceration and a mixed inflammatory infiltrate (Figure 2A). At higher magnification, clear viral cytopathic changes of HHV were noted, including multinucleation, nuclear molding, and homogenous gray nuclei (Figure 2B). Additional staining for fungi, mycobacteria, and spirochetes was negative. In-situ hybridization was negative for human papillomavirus subtypes. A bacterial culture of swabs of the purulent drainage was positive for Staphylococcus aureus and Proteus mirabilis.

Given the patient’s known history of acyclovir-resistant HHV-2 infection, he received a 28-day course of intravenous foscarnet 40 mg/kg every 12 hours. He also was given a 14-day course of intravenous ampicillin-sulbactam 3 g every 6 hours. The patient gradually improved during a 35-day hospital stay. He was discharged with cidofovir cream 1% and oral valacyclovir; the latter was subsequently discontinued by dermatology because of his known history of acyclovir resistance. Four months after discharge, the patient underwent a circumcision performed by urology to decrease the risk for recurrence and achieve the best cosmetic outcome. At the 6-month follow-up visit, dramatic clinical improvement was evident, with complete resolution of the plaque and only isolated areas of scarring (Figure 3). The patient reported that penile function was preserved.

Herpes vegetans represents a rare infection with HHV-1 or HHV-2, typically in patients who are considerably immunosuppressed, such as those with cancer, those undergoing transplantation, and those with uncontrolled HIV infection.¹ Few cases of HV have been described in an immunocompetent patient.² Our case is unique because the patient’s HIV infection was well controlled at the time HV was diagnosed, demonstrated by his modestly low CD4 count and undetectable HIV viral load.

Patients with HV can present diagnostic and therapeutic challenges. Typically, a diagnosis of cutaneous HHV infection does not require a biopsy; most cases appear as clustered vesicular lesions, making the disease easy to diagnose clinically. However, biopsies and cultures are necessary to identify the underlying cause of atypical verrucous exophytic lesions. Other conditions with clinical features similar to HV include squamous cell carcinoma, condyloma acuminatum, and deep fungal and mycobacterial infections.^2,3 A tissue biopsy, histologic staining, and tissue culture should be performed to identify the causative pathogen and potential targets for treatment. Definitive diagnosis is vital to deliver proper treatment modalities, which often involve a multimodal multidisciplinary approach. 

Several pathogenic mechanisms of HV have been proposed. One theory suggests that in an immunocompetent patient, HHV typically triggers a lymphocytic response, which leads to activation of interferon alpha. However, in an immunocompromised patient, such as an individual with AIDS, this interferon response is diminished, which explains why these patients typically have a chronic and resistant HHV infection. HIV has an affinity for infecting dermal dendritic cells, which signals activation of tumor necrosis factor and interleukin.⁶ Both cytokines contribute to an antiapoptotic environment that promotes continued proliferation of these viral cells in the epidermis. Over time, propagation of disinhibited cells can lead to the verrucous and hyperkeratotic-appearing skin that is common in patients with HV.⁷

Another theorized mechanism underlying hypertrophic herpetic lesions was described in the context of HHV-1 infection and subsequent PG. El Hayderi et al⁸ reported that histologic and immunohistochemical examination of a patient’s lesion revealed sparse epithelial cell aggregates within PG as well as HHV-1 antigens in the nuclei and cytoplasm of normal-appearing and cytopathic epithelial cells. Immunohistochemical examination also revealed vascular endothelial growth factor within HHV-1–infected epithelial cells and PG endothelial cells, suggesting that PG formation may be indirectly driven by vascular endothelial growth factor and its proangiogenic properties. The pathogenesis of PG in the setting of HHV-1 infection displays many similarities to hyperkeratotic lesions observed in atypical cutaneous manifestations of HHV-2.⁸

The management of patients with HV continues to be complex, often requiring a multimodal regimen. Although acyclovir has been shown to be highly effective for treating and preventing most HHV infections, acyclovir resistance frequently has been reported in immunocompromised populations.⁵ Acyclovir resistance can be correlated with the severity of immunodeficiency as well as the duration of acyclovir exposure. Resistance to acyclovir often results from deficient intracellular phosphorylation, which is required for activation of the drug. If patients show resistance to acyclovir and its derivatives, alternate drug classes that do not depend on thymidine kinase phosphorylation should be considered.

Our patient received a combination of intravenous foscarnet and a course of ampicillin-sulbactam while an inpatient due to his documented history of acyclovir-resistant HHV-2 infection, and he was discharged on cidofovir cream 1%. Cidofovir is US Food and Drug Administration approved for treating cytomegalovirus retinitis in patients with AIDS. Although data are limited, topical and intralesional cidofovir have been used to treat acyclovir-resistant cases of HV with documented success.^1,9 In refractory HV or when the disease is slow to resolve, intralesional cidofovir has been documented to be an additional treatment option. Intralesional and topical cidofovir carry a much lower risk for adverse effects such as kidney dysfunction compared to intravenous cidofovir¹ and can be considered in patients with minimal clinical improvement and those at increased risk for side effects.

Our case demonstrated how a patient with HV may require a complex and prolonged hospital course for appropriate treatment. Our patient required an array of both medical and surgical modalities to reach the desired outcome. Here, a multitude of specialties including infectious disease, dermatology, and urology worked together to reach a positive clinical and cosmetic outcome for this patient. 

To the Editor:

Herpes vegetans (HV) is an uncommon infection caused by human herpesvirus (HHV) in patients who are immunocompromised, such as those who are HIV positive.¹ Unlike typical HHV infection, HV can present with exophytic exudative ulcers and papillomatous vegetations. The presentation of ulcerated genital nodules, especially in an immunocompromised patient, yields an array of disorders in the differential diagnosis, including condyloma latum, condyloma acuminatum, pyogenic granuloma (PG), and verrucous carcinoma.^2,3 Histopathology of HV reveals pseudoepitheliomatous hyperplasia, plasma cell infiltration, and positivity for HHV type 1 (HHV-1) and/or HHV type 2 (HHV-2). Herpes vegetans lesions typically require a multimodal treatment approach because many cases are resistant to acyclovir. Treatment options include the nucleoside analogues foscarnet and cidofovir; immunomodulators such as topical imiquimod; and the topical antiviral trifluridine.^1,4-6 We describe a case of HV in a patient with a history of well-controlled HIV infection who presented with a painful fungating penile lesion.

A 55-year-old man presented to the hospital with a painful expanding mass on the distal aspect of the penis of 3 months’ duration. He had a history of HIV infection that was well-controlled by antiretroviral therapy, prior hepatitis B virus infection and acyclovir-resistant genital HHV-2 infection. Physical examination revealed a large, firm, circumferential, exophytic, verrucous plaque with various areas of ulceration and purulent drainage on the distal shaft and glans of the penis (Figure 1). The patient’s most recent absolute CD4 count was 425 cells/mm³ (reference range, 500–1500 cells/mm³). His HIV viral load was undetectable at less than 30 copies/mL. Histopathology with hematoxylin and eosin staining of biopsy material from the penile lesion demonstrated pseudoepitheliomatous epidermal hyperplasia with focal ulceration and a mixed inflammatory infiltrate (Figure 2A). At higher magnification, clear viral cytopathic changes of HHV were noted, including multinucleation, nuclear molding, and homogenous gray nuclei (Figure 2B). Additional staining for fungi, mycobacteria, and spirochetes was negative. In-situ hybridization was negative for human papillomavirus subtypes. A bacterial culture of swabs of the purulent drainage was positive for Staphylococcus aureus and Proteus mirabilis.

Given the patient’s known history of acyclovir-resistant HHV-2 infection, he received a 28-day course of intravenous foscarnet 40 mg/kg every 12 hours. He also was given a 14-day course of intravenous ampicillin-sulbactam 3 g every 6 hours. The patient gradually improved during a 35-day hospital stay. He was discharged with cidofovir cream 1% and oral valacyclovir; the latter was subsequently discontinued by dermatology because of his known history of acyclovir resistance. Four months after discharge, the patient underwent a circumcision performed by urology to decrease the risk for recurrence and achieve the best cosmetic outcome. At the 6-month follow-up visit, dramatic clinical improvement was evident, with complete resolution of the plaque and only isolated areas of scarring (Figure 3). The patient reported that penile function was preserved.

Herpes vegetans represents a rare infection with HHV-1 or HHV-2, typically in patients who are considerably immunosuppressed, such as those with cancer, those undergoing transplantation, and those with uncontrolled HIV infection.¹ Few cases of HV have been described in an immunocompetent patient.² Our case is unique because the patient’s HIV infection was well controlled at the time HV was diagnosed, demonstrated by his modestly low CD4 count and undetectable HIV viral load.

Patients with HV can present diagnostic and therapeutic challenges. Typically, a diagnosis of cutaneous HHV infection does not require a biopsy; most cases appear as clustered vesicular lesions, making the disease easy to diagnose clinically. However, biopsies and cultures are necessary to identify the underlying cause of atypical verrucous exophytic lesions. Other conditions with clinical features similar to HV include squamous cell carcinoma, condyloma acuminatum, and deep fungal and mycobacterial infections.^2,3 A tissue biopsy, histologic staining, and tissue culture should be performed to identify the causative pathogen and potential targets for treatment. Definitive diagnosis is vital to deliver proper treatment modalities, which often involve a multimodal multidisciplinary approach. 

Several pathogenic mechanisms of HV have been proposed. One theory suggests that in an immunocompetent patient, HHV typically triggers a lymphocytic response, which leads to activation of interferon alpha. However, in an immunocompromised patient, such as an individual with AIDS, this interferon response is diminished, which explains why these patients typically have a chronic and resistant HHV infection. HIV has an affinity for infecting dermal dendritic cells, which signals activation of tumor necrosis factor and interleukin.⁶ Both cytokines contribute to an antiapoptotic environment that promotes continued proliferation of these viral cells in the epidermis. Over time, propagation of disinhibited cells can lead to the verrucous and hyperkeratotic-appearing skin that is common in patients with HV.⁷

Another theorized mechanism underlying hypertrophic herpetic lesions was described in the context of HHV-1 infection and subsequent PG. El Hayderi et al⁸ reported that histologic and immunohistochemical examination of a patient’s lesion revealed sparse epithelial cell aggregates within PG as well as HHV-1 antigens in the nuclei and cytoplasm of normal-appearing and cytopathic epithelial cells. Immunohistochemical examination also revealed vascular endothelial growth factor within HHV-1–infected epithelial cells and PG endothelial cells, suggesting that PG formation may be indirectly driven by vascular endothelial growth factor and its proangiogenic properties. The pathogenesis of PG in the setting of HHV-1 infection displays many similarities to hyperkeratotic lesions observed in atypical cutaneous manifestations of HHV-2.⁸

The management of patients with HV continues to be complex, often requiring a multimodal regimen. Although acyclovir has been shown to be highly effective for treating and preventing most HHV infections, acyclovir resistance frequently has been reported in immunocompromised populations.⁵ Acyclovir resistance can be correlated with the severity of immunodeficiency as well as the duration of acyclovir exposure. Resistance to acyclovir often results from deficient intracellular phosphorylation, which is required for activation of the drug. If patients show resistance to acyclovir and its derivatives, alternate drug classes that do not depend on thymidine kinase phosphorylation should be considered.

Our patient received a combination of intravenous foscarnet and a course of ampicillin-sulbactam while an inpatient due to his documented history of acyclovir-resistant HHV-2 infection, and he was discharged on cidofovir cream 1%. Cidofovir is US Food and Drug Administration approved for treating cytomegalovirus retinitis in patients with AIDS. Although data are limited, topical and intralesional cidofovir have been used to treat acyclovir-resistant cases of HV with documented success.^1,9 In refractory HV or when the disease is slow to resolve, intralesional cidofovir has been documented to be an additional treatment option. Intralesional and topical cidofovir carry a much lower risk for adverse effects such as kidney dysfunction compared to intravenous cidofovir¹ and can be considered in patients with minimal clinical improvement and those at increased risk for side effects.

Our case demonstrated how a patient with HV may require a complex and prolonged hospital course for appropriate treatment. Our patient required an array of both medical and surgical modalities to reach the desired outcome. Here, a multitude of specialties including infectious disease, dermatology, and urology worked together to reach a positive clinical and cosmetic outcome for this patient. 

To the Editor:

Most cutaneous squamous cell carcinomas (cSCCs) are successfully treated with standard modalities such as surgical excision; however, a subset of tumors is not amenable to surgical resection.^1,2 Patients who are not able to undergo surgical treatment may instead receive radiation therapy, topical 5-fluorouracil (5-FU), imiquimod, cryosurgery, photodynamic therapy, or systemic treatment (eg, immunotherapy) in addition to intralesional approaches for localized disease.^1-4 However, the adverse effects associated with these treatments and their modest effect in preventing the recurrence of cutaneous lesions limit their efficacy against unresectable cSCC.^4-6 We present a case that demonstrates the efficacy of electrodesiccation and curettage (ED&C) followed by topical 5-FU for an invasive cSCC not amenable to surgical therapy.

A 58-year-old woman presented for evaluation of a 3.5×3.4-cm, incisional biopsy–proven, invasive stage T2a cSCC (Brigham and Women’s Hospital tumor staging system [Boston, Massachusetts]) on the dorsal aspect of the left foot, which had developed over several months (Figure 1A). She had a history of treatment with psoralen plus UV light therapy for erythroderma of unknown cause and peripheral neuropathy. She was not a surgical candidate because of suspected underlying cutaneous sclerosis and a history of poor wound healing on the lower legs.

Prior to presentation to dermatology, the patient had been treated with intralesional methotrexate, intralesional 5-FU, and the antiangiogenic and antiproliferative combination agent OLCAT-005³—consisting of equal parts [by volume] of diclofenac gel 3%, imiquimod cream 5%, hydrocortisone valerate cream 0.2%, calcipotriene cream 0.005%, and tretinoin cream 0.05—which failed, and the patient reported that OLCAT-005 made the pain from the cSCC worse.

Upon growth of the lesion over several months, the patient was referred to the High-Risk Skin Cancer Clinic at Massachusetts General Hospital (Boston, Massachusetts). A repeat biopsy demonstrated an invasive well-differentiated cSCC (Figure 2). The size and invasive features of the lesion on clinical examination prompted a referral to surgical oncology for a wide local excision. However, surgical oncology concluded she was not a surgical candidate.

Magnetic resonance imaging showed no deep invasion of the cSCC to the tendons or bones. Electrodesiccation and curettage was performed to debulk the tumor, followed by twice-daily application of topical 5-FU for 4 weeks to improve the odds of tumor clearance (Figure 1B). Fourteen weeks after completion of 5-FU treatment, the cSCC showed complete clinical regression (Figure 1C). No recurrence has been detected clinically more than 3 years following treatment.

Prior to the advent of Mohs micrographic surgery, ED&C commonly was used to treat skin cancer, with a lower cost and a cure rate close to 95%.^7,8 We postulate that the mechanism of tumor regression in our patient was ED&C-mediated removal and necrosis of neoplastic tissue combined with 5-FU–induced cancer-cell DNA damage and apoptosis. An antitumor immune response also may have contributed to the complete regression of the cSCC.

Although antiangiogenic and antiproliferative agents are suitable for primary cSCC treatment, it is possible that this patient’s prior therapies alone—in the absence of debulking by ED&C to sufficiently reduce disease burden—did not allow for tumor clearance and were ineffective. Many clinicians are reluctant to apply 5-FU to a wound bed because it can impede wound healing.⁹ In this case, re-epithelialization likely occurred primarily after completion of 5-FU treatment.

We recommend consideration of ED&C with 5-FU for similar malignant lesions that are not amenable to surgical excision. Nevertheless, Mohs micrographic surgery and wide local excision remain the gold standards for definitive treatment of invasive skin cancer in a patient who is a candidate for surgical treatment.

To the Editor:

Most cutaneous squamous cell carcinomas (cSCCs) are successfully treated with standard modalities such as surgical excision; however, a subset of tumors is not amenable to surgical resection.^1,2 Patients who are not able to undergo surgical treatment may instead receive radiation therapy, topical 5-fluorouracil (5-FU), imiquimod, cryosurgery, photodynamic therapy, or systemic treatment (eg, immunotherapy) in addition to intralesional approaches for localized disease.^1-4 However, the adverse effects associated with these treatments and their modest effect in preventing the recurrence of cutaneous lesions limit their efficacy against unresectable cSCC.^4-6 We present a case that demonstrates the efficacy of electrodesiccation and curettage (ED&C) followed by topical 5-FU for an invasive cSCC not amenable to surgical therapy.

A 58-year-old woman presented for evaluation of a 3.5×3.4-cm, incisional biopsy–proven, invasive stage T2a cSCC (Brigham and Women’s Hospital tumor staging system [Boston, Massachusetts]) on the dorsal aspect of the left foot, which had developed over several months (Figure 1A). She had a history of treatment with psoralen plus UV light therapy for erythroderma of unknown cause and peripheral neuropathy. She was not a surgical candidate because of suspected underlying cutaneous sclerosis and a history of poor wound healing on the lower legs.

Prior to presentation to dermatology, the patient had been treated with intralesional methotrexate, intralesional 5-FU, and the antiangiogenic and antiproliferative combination agent OLCAT-005³—consisting of equal parts [by volume] of diclofenac gel 3%, imiquimod cream 5%, hydrocortisone valerate cream 0.2%, calcipotriene cream 0.005%, and tretinoin cream 0.05—which failed, and the patient reported that OLCAT-005 made the pain from the cSCC worse.

Upon growth of the lesion over several months, the patient was referred to the High-Risk Skin Cancer Clinic at Massachusetts General Hospital (Boston, Massachusetts). A repeat biopsy demonstrated an invasive well-differentiated cSCC (Figure 2). The size and invasive features of the lesion on clinical examination prompted a referral to surgical oncology for a wide local excision. However, surgical oncology concluded she was not a surgical candidate.

Magnetic resonance imaging showed no deep invasion of the cSCC to the tendons or bones. Electrodesiccation and curettage was performed to debulk the tumor, followed by twice-daily application of topical 5-FU for 4 weeks to improve the odds of tumor clearance (Figure 1B). Fourteen weeks after completion of 5-FU treatment, the cSCC showed complete clinical regression (Figure 1C). No recurrence has been detected clinically more than 3 years following treatment.

Prior to the advent of Mohs micrographic surgery, ED&C commonly was used to treat skin cancer, with a lower cost and a cure rate close to 95%.^7,8 We postulate that the mechanism of tumor regression in our patient was ED&C-mediated removal and necrosis of neoplastic tissue combined with 5-FU–induced cancer-cell DNA damage and apoptosis. An antitumor immune response also may have contributed to the complete regression of the cSCC.

Although antiangiogenic and antiproliferative agents are suitable for primary cSCC treatment, it is possible that this patient’s prior therapies alone—in the absence of debulking by ED&C to sufficiently reduce disease burden—did not allow for tumor clearance and were ineffective. Many clinicians are reluctant to apply 5-FU to a wound bed because it can impede wound healing.⁹ In this case, re-epithelialization likely occurred primarily after completion of 5-FU treatment.

We recommend consideration of ED&C with 5-FU for similar malignant lesions that are not amenable to surgical excision. Nevertheless, Mohs micrographic surgery and wide local excision remain the gold standards for definitive treatment of invasive skin cancer in a patient who is a candidate for surgical treatment.

To the Editor:

Most cutaneous squamous cell carcinomas (cSCCs) are successfully treated with standard modalities such as surgical excision; however, a subset of tumors is not amenable to surgical resection.^1,2 Patients who are not able to undergo surgical treatment may instead receive radiation therapy, topical 5-fluorouracil (5-FU), imiquimod, cryosurgery, photodynamic therapy, or systemic treatment (eg, immunotherapy) in addition to intralesional approaches for localized disease.^1-4 However, the adverse effects associated with these treatments and their modest effect in preventing the recurrence of cutaneous lesions limit their efficacy against unresectable cSCC.^4-6 We present a case that demonstrates the efficacy of electrodesiccation and curettage (ED&C) followed by topical 5-FU for an invasive cSCC not amenable to surgical therapy.

A 58-year-old woman presented for evaluation of a 3.5×3.4-cm, incisional biopsy–proven, invasive stage T2a cSCC (Brigham and Women’s Hospital tumor staging system [Boston, Massachusetts]) on the dorsal aspect of the left foot, which had developed over several months (Figure 1A). She had a history of treatment with psoralen plus UV light therapy for erythroderma of unknown cause and peripheral neuropathy. She was not a surgical candidate because of suspected underlying cutaneous sclerosis and a history of poor wound healing on the lower legs.

Prior to presentation to dermatology, the patient had been treated with intralesional methotrexate, intralesional 5-FU, and the antiangiogenic and antiproliferative combination agent OLCAT-005³—consisting of equal parts [by volume] of diclofenac gel 3%, imiquimod cream 5%, hydrocortisone valerate cream 0.2%, calcipotriene cream 0.005%, and tretinoin cream 0.05—which failed, and the patient reported that OLCAT-005 made the pain from the cSCC worse.

Upon growth of the lesion over several months, the patient was referred to the High-Risk Skin Cancer Clinic at Massachusetts General Hospital (Boston, Massachusetts). A repeat biopsy demonstrated an invasive well-differentiated cSCC (Figure 2). The size and invasive features of the lesion on clinical examination prompted a referral to surgical oncology for a wide local excision. However, surgical oncology concluded she was not a surgical candidate.

Magnetic resonance imaging showed no deep invasion of the cSCC to the tendons or bones. Electrodesiccation and curettage was performed to debulk the tumor, followed by twice-daily application of topical 5-FU for 4 weeks to improve the odds of tumor clearance (Figure 1B). Fourteen weeks after completion of 5-FU treatment, the cSCC showed complete clinical regression (Figure 1C). No recurrence has been detected clinically more than 3 years following treatment.

Prior to the advent of Mohs micrographic surgery, ED&C commonly was used to treat skin cancer, with a lower cost and a cure rate close to 95%.^7,8 We postulate that the mechanism of tumor regression in our patient was ED&C-mediated removal and necrosis of neoplastic tissue combined with 5-FU–induced cancer-cell DNA damage and apoptosis. An antitumor immune response also may have contributed to the complete regression of the cSCC.

Although antiangiogenic and antiproliferative agents are suitable for primary cSCC treatment, it is possible that this patient’s prior therapies alone—in the absence of debulking by ED&C to sufficiently reduce disease burden—did not allow for tumor clearance and were ineffective. Many clinicians are reluctant to apply 5-FU to a wound bed because it can impede wound healing.⁹ In this case, re-epithelialization likely occurred primarily after completion of 5-FU treatment.

We recommend consideration of ED&C with 5-FU for similar malignant lesions that are not amenable to surgical excision. Nevertheless, Mohs micrographic surgery and wide local excision remain the gold standards for definitive treatment of invasive skin cancer in a patient who is a candidate for surgical treatment.

To the Editor:

Porocarcinoma, or malignant poroma, is a rare adnexal malignancy of a predominantly glandular origin that comprises less than 0.01% of all cutaneous neoplasms.^1,2 Although exposure to UV radiation and immunosuppression have been implicated in the malignant degeneration of benign poromas into porocarcinomas, at least half of all malignant variants will arise de novo.^3,4 Patients present with an evolving nodule or plaque and often are in their seventh or eighth decade of life at the time of diagnosis.² Localized trauma from burns or radiation exposure has been causatively linked to de novo porocarcinoma formation.^2,5 These suppressive and traumatic stimuli drive increased genetic heterogeneity along with characteristic gene mutations in known tumor suppressor genes.⁶

A 62-year-old man presented with a nonhealing wound on the right hand of 5 years’ duration that had previously been attributed to a penetrating injury with a piece of copper from a refrigerant coolant system. The wound initially blistered and then eventually callused and developed areas of ulceration. The patient consulted multiple physicians for treatment of the intensely pruritic and ulcerated lesion. He received prescriptions for cephalexin, trimethoprim-sulfamethoxazole, doxycycline, clindamycin, and clobetasol cream, all of which offered minimal improvement. Home therapies including vitamin E and tea tree oil yielded no benefit. The lesion roughly quadrupled in size over the last 5 years.

Physical examination revealed a 7.5×4.2-cm ulcerated plaque with ragged borders and abundant central neoepithelialization on the right palmar surface (Figure 1). No gross motor or sensory defects were identified. There was no epitrochlear, axillary, cervical, or supraclavicular lymphadenopathy. A shave biopsy of the plaque’s edge was performed, which demonstrated a hyperplastic epidermis comprising atypical poroid cells with frequent mitoses, scant necrosis, and regular ductal structures confined to the epidermis (Figure 2). Immunohistochemical profiling results were positive for anticytokeratin (CAM 5.2) and Ber-EP4 (Figure 3). When evaluated in aggregate, these findings were consistent with porocarcinoma in situ.

The patient was referred to a surgical oncologist for evaluation. At that time, an exophytic mass had developed in the central lesion. Although no lymphadenopathy was identified upon examination, the patient had developed tremoring and a contracture deformity of the right hand. Extensive imaging and urgent surgical resection were recommended, but the patient did not wish to pursue these options, opting instead to continue home remedies. At a 15-month follow-up via telephone, the patient reported that the home therapy had failed and he had moved back to Vietnam. Partial limb amputation had been recommended by a local provider. Unfortunately, the patient was subsequently lost to follow-up, and his current status is unknown.

Porocarcinomas are rare tumors, comprising just 0.005% to 0.01% of all cutaneous epithelial tumors.^1,2,5 They affect men and women equally, with an average age at diagnosis of 60 to 70 years.^1,2 At least half of all porocarcinomas develop de novo, while 18% to 50% arise from the degeneration of an existing poroma.^2,3 Exposure to UV light and immunosuppression, particularly following organ transplantation, represent 2 commonly suspected catalysts for this malignant transformation.⁴ De novo porocarcinomas are most causatively linked to localized trauma from burns or radiation exposure.⁵ Gene mutations in classic tumor suppressor genes—tumor protein p53 (TP53), phosphatase and tensin homolog (PTEN), rearranged during transfection (RET), adenomatous polyposis coli (APC)—and increased genetic heterogeneity follow these stimuli.⁶

The morphologic presentation of porocarcinoma is highly variable and may manifest as papules, nodules, or plaques in various states of erosion, ulceration, or excoriation. Diagnoses of basal and squamous cell carcinoma, primary adnexal tumors, seborrheic keratosis, pyogenic granuloma, and melanoma must all be considered and methodically ruled out.⁷ Porocarcinomas may arise nearly anywhere on the body, with a particular predilection for the lower extremities (35%), head/neck (24%), and upper extremities (14%).^3,4 Primary lesions arising from the extremities, genitalia, or buttocks herald a higher risk for lymphatic invasion and distant metastasis, while head and neck tumors more commonly remain localized.⁸ Bleeding, ulceration, or rapid expansion of a preexisting poroma is suggestive of malignant transformation and may portend a more aggressive disease pattern.^2,9

Unequivocal diagnosis relies on histological and immunohistochemical studies due to the marked clinical variance of this neoplasm.⁷ An irregular histologic pattern of poromatous basaloid cells with ductal differentiation and cytologic atypia commonly are seen with porocarcinomas.^2,8 Nuclear pleomorphism with cellular necrosis, increased mitotic figures, and abortive ductal formation with a distinct lack of retraction around cellular aggregates often are found. Immunohistochemical staining is needed to confirm the primary tumor diagnosis. Histochemical stains commonly employed include carcinoembryonic antigen (CEA), cytokeratin AE1/AE3, epithelial membrane antigen, p53, p63, Ki67, and periodic acid-Schiff.¹⁰ The use of BerEP4 has been reported as efficacious in highlighting sweat structures, which can be particularly useful in cases when basal cell carcinoma is not in the histologic differential.¹¹ These staining profiles afford confirmation of ductal differentiation with CEA, epithelial membrane antigen, and BerEP4, while p63 and Ki67 are used as surrogates for primary cutaneous neoplasia and cell proliferation, respectively.^5,11 Porocarcinoma lesions may be most sensitive to CEA and most specific to CK19 (a component of cytokeratin AE1/AE3), though these findings have not been widely reproduced.⁷

The treatment and prognosis of porocarcinoma vary widely. Surgically excised lesions recur in roughly 20% of cases, though these rates likely include tumors that were incompletely resected in the primary attempt. Although wide local excision with an average 1-cm margin remains the most employed removal technique, Mohs micrographic surgery may more effectively limit recurrence and metastasis of localized disease.^7,8,12 Metastatic disease foretells a mortality rate of at least 65%, which is problematic in that 10% to 20% of patients have metastatic disease at the time of diagnosis and another 20% will show metastasis following primary tumor excision.^8,10 Neoplasms with high mitotic rates and depths greater than 7 mm should prompt thorough diagnostic imaging, such as positron emission tomography or magnetic resonance imaging. A sentinel lymph node biopsy should be strongly considered and discussed with the patient.¹⁰ Treatment options for nodal and distant metastases include a combination of localized surgery, lymphadenectomy, radiotherapy, and chemotherapeutic agents.^2,4,5 The response to systemic treatment and radiotherapy often is quite poor, though the use of combinations of docetaxel, paclitaxel, cetuximab, and immunotherapy have been efficacious in smaller studies.^8,10 The highest rates of morbidity and mortality are seen in patients with metastases on presentation or with localized tumors in the groin and buttocks.⁸

The diagnosis of porocarcinoma may be elusive due to its relatively rare occurrence. Therefore, it is critical to consider this neoplasm in high-risk sites in older patients who present with an evolving nodule or tumor on an extremity. Routine histology and astute histochemical profiling are necessary to exclude diseases that mimic porocarcinoma. Once diagnosis is confirmed, management with prompt excision and diagnostic imaging is recommended, including a lymph node biopsy if appropriate. Due to its high metastatic potential and associated morbidity and mortality, patients with porocarcinoma should be followed closely by a multidisciplinary care team.

To the Editor:

Porocarcinoma, or malignant poroma, is a rare adnexal malignancy of a predominantly glandular origin that comprises less than 0.01% of all cutaneous neoplasms.^1,2 Although exposure to UV radiation and immunosuppression have been implicated in the malignant degeneration of benign poromas into porocarcinomas, at least half of all malignant variants will arise de novo.^3,4 Patients present with an evolving nodule or plaque and often are in their seventh or eighth decade of life at the time of diagnosis.² Localized trauma from burns or radiation exposure has been causatively linked to de novo porocarcinoma formation.^2,5 These suppressive and traumatic stimuli drive increased genetic heterogeneity along with characteristic gene mutations in known tumor suppressor genes.⁶

A 62-year-old man presented with a nonhealing wound on the right hand of 5 years’ duration that had previously been attributed to a penetrating injury with a piece of copper from a refrigerant coolant system. The wound initially blistered and then eventually callused and developed areas of ulceration. The patient consulted multiple physicians for treatment of the intensely pruritic and ulcerated lesion. He received prescriptions for cephalexin, trimethoprim-sulfamethoxazole, doxycycline, clindamycin, and clobetasol cream, all of which offered minimal improvement. Home therapies including vitamin E and tea tree oil yielded no benefit. The lesion roughly quadrupled in size over the last 5 years.

Physical examination revealed a 7.5×4.2-cm ulcerated plaque with ragged borders and abundant central neoepithelialization on the right palmar surface (Figure 1). No gross motor or sensory defects were identified. There was no epitrochlear, axillary, cervical, or supraclavicular lymphadenopathy. A shave biopsy of the plaque’s edge was performed, which demonstrated a hyperplastic epidermis comprising atypical poroid cells with frequent mitoses, scant necrosis, and regular ductal structures confined to the epidermis (Figure 2). Immunohistochemical profiling results were positive for anticytokeratin (CAM 5.2) and Ber-EP4 (Figure 3). When evaluated in aggregate, these findings were consistent with porocarcinoma in situ.

The patient was referred to a surgical oncologist for evaluation. At that time, an exophytic mass had developed in the central lesion. Although no lymphadenopathy was identified upon examination, the patient had developed tremoring and a contracture deformity of the right hand. Extensive imaging and urgent surgical resection were recommended, but the patient did not wish to pursue these options, opting instead to continue home remedies. At a 15-month follow-up via telephone, the patient reported that the home therapy had failed and he had moved back to Vietnam. Partial limb amputation had been recommended by a local provider. Unfortunately, the patient was subsequently lost to follow-up, and his current status is unknown.

Porocarcinomas are rare tumors, comprising just 0.005% to 0.01% of all cutaneous epithelial tumors.^1,2,5 They affect men and women equally, with an average age at diagnosis of 60 to 70 years.^1,2 At least half of all porocarcinomas develop de novo, while 18% to 50% arise from the degeneration of an existing poroma.^2,3 Exposure to UV light and immunosuppression, particularly following organ transplantation, represent 2 commonly suspected catalysts for this malignant transformation.⁴ De novo porocarcinomas are most causatively linked to localized trauma from burns or radiation exposure.⁵ Gene mutations in classic tumor suppressor genes—tumor protein p53 (TP53), phosphatase and tensin homolog (PTEN), rearranged during transfection (RET), adenomatous polyposis coli (APC)—and increased genetic heterogeneity follow these stimuli.⁶

The morphologic presentation of porocarcinoma is highly variable and may manifest as papules, nodules, or plaques in various states of erosion, ulceration, or excoriation. Diagnoses of basal and squamous cell carcinoma, primary adnexal tumors, seborrheic keratosis, pyogenic granuloma, and melanoma must all be considered and methodically ruled out.⁷ Porocarcinomas may arise nearly anywhere on the body, with a particular predilection for the lower extremities (35%), head/neck (24%), and upper extremities (14%).^3,4 Primary lesions arising from the extremities, genitalia, or buttocks herald a higher risk for lymphatic invasion and distant metastasis, while head and neck tumors more commonly remain localized.⁸ Bleeding, ulceration, or rapid expansion of a preexisting poroma is suggestive of malignant transformation and may portend a more aggressive disease pattern.^2,9

Unequivocal diagnosis relies on histological and immunohistochemical studies due to the marked clinical variance of this neoplasm.⁷ An irregular histologic pattern of poromatous basaloid cells with ductal differentiation and cytologic atypia commonly are seen with porocarcinomas.^2,8 Nuclear pleomorphism with cellular necrosis, increased mitotic figures, and abortive ductal formation with a distinct lack of retraction around cellular aggregates often are found. Immunohistochemical staining is needed to confirm the primary tumor diagnosis. Histochemical stains commonly employed include carcinoembryonic antigen (CEA), cytokeratin AE1/AE3, epithelial membrane antigen, p53, p63, Ki67, and periodic acid-Schiff.¹⁰ The use of BerEP4 has been reported as efficacious in highlighting sweat structures, which can be particularly useful in cases when basal cell carcinoma is not in the histologic differential.¹¹ These staining profiles afford confirmation of ductal differentiation with CEA, epithelial membrane antigen, and BerEP4, while p63 and Ki67 are used as surrogates for primary cutaneous neoplasia and cell proliferation, respectively.^5,11 Porocarcinoma lesions may be most sensitive to CEA and most specific to CK19 (a component of cytokeratin AE1/AE3), though these findings have not been widely reproduced.⁷

The treatment and prognosis of porocarcinoma vary widely. Surgically excised lesions recur in roughly 20% of cases, though these rates likely include tumors that were incompletely resected in the primary attempt. Although wide local excision with an average 1-cm margin remains the most employed removal technique, Mohs micrographic surgery may more effectively limit recurrence and metastasis of localized disease.^7,8,12 Metastatic disease foretells a mortality rate of at least 65%, which is problematic in that 10% to 20% of patients have metastatic disease at the time of diagnosis and another 20% will show metastasis following primary tumor excision.^8,10 Neoplasms with high mitotic rates and depths greater than 7 mm should prompt thorough diagnostic imaging, such as positron emission tomography or magnetic resonance imaging. A sentinel lymph node biopsy should be strongly considered and discussed with the patient.¹⁰ Treatment options for nodal and distant metastases include a combination of localized surgery, lymphadenectomy, radiotherapy, and chemotherapeutic agents.^2,4,5 The response to systemic treatment and radiotherapy often is quite poor, though the use of combinations of docetaxel, paclitaxel, cetuximab, and immunotherapy have been efficacious in smaller studies.^8,10 The highest rates of morbidity and mortality are seen in patients with metastases on presentation or with localized tumors in the groin and buttocks.⁸

The diagnosis of porocarcinoma may be elusive due to its relatively rare occurrence. Therefore, it is critical to consider this neoplasm in high-risk sites in older patients who present with an evolving nodule or tumor on an extremity. Routine histology and astute histochemical profiling are necessary to exclude diseases that mimic porocarcinoma. Once diagnosis is confirmed, management with prompt excision and diagnostic imaging is recommended, including a lymph node biopsy if appropriate. Due to its high metastatic potential and associated morbidity and mortality, patients with porocarcinoma should be followed closely by a multidisciplinary care team.

To the Editor:

Porocarcinoma, or malignant poroma, is a rare adnexal malignancy of a predominantly glandular origin that comprises less than 0.01% of all cutaneous neoplasms.^1,2 Although exposure to UV radiation and immunosuppression have been implicated in the malignant degeneration of benign poromas into porocarcinomas, at least half of all malignant variants will arise de novo.^3,4 Patients present with an evolving nodule or plaque and often are in their seventh or eighth decade of life at the time of diagnosis.² Localized trauma from burns or radiation exposure has been causatively linked to de novo porocarcinoma formation.^2,5 These suppressive and traumatic stimuli drive increased genetic heterogeneity along with characteristic gene mutations in known tumor suppressor genes.⁶

A 62-year-old man presented with a nonhealing wound on the right hand of 5 years’ duration that had previously been attributed to a penetrating injury with a piece of copper from a refrigerant coolant system. The wound initially blistered and then eventually callused and developed areas of ulceration. The patient consulted multiple physicians for treatment of the intensely pruritic and ulcerated lesion. He received prescriptions for cephalexin, trimethoprim-sulfamethoxazole, doxycycline, clindamycin, and clobetasol cream, all of which offered minimal improvement. Home therapies including vitamin E and tea tree oil yielded no benefit. The lesion roughly quadrupled in size over the last 5 years.

Physical examination revealed a 7.5×4.2-cm ulcerated plaque with ragged borders and abundant central neoepithelialization on the right palmar surface (Figure 1). No gross motor or sensory defects were identified. There was no epitrochlear, axillary, cervical, or supraclavicular lymphadenopathy. A shave biopsy of the plaque’s edge was performed, which demonstrated a hyperplastic epidermis comprising atypical poroid cells with frequent mitoses, scant necrosis, and regular ductal structures confined to the epidermis (Figure 2). Immunohistochemical profiling results were positive for anticytokeratin (CAM 5.2) and Ber-EP4 (Figure 3). When evaluated in aggregate, these findings were consistent with porocarcinoma in situ.

The patient was referred to a surgical oncologist for evaluation. At that time, an exophytic mass had developed in the central lesion. Although no lymphadenopathy was identified upon examination, the patient had developed tremoring and a contracture deformity of the right hand. Extensive imaging and urgent surgical resection were recommended, but the patient did not wish to pursue these options, opting instead to continue home remedies. At a 15-month follow-up via telephone, the patient reported that the home therapy had failed and he had moved back to Vietnam. Partial limb amputation had been recommended by a local provider. Unfortunately, the patient was subsequently lost to follow-up, and his current status is unknown.

Porocarcinomas are rare tumors, comprising just 0.005% to 0.01% of all cutaneous epithelial tumors.^1,2,5 They affect men and women equally, with an average age at diagnosis of 60 to 70 years.^1,2 At least half of all porocarcinomas develop de novo, while 18% to 50% arise from the degeneration of an existing poroma.^2,3 Exposure to UV light and immunosuppression, particularly following organ transplantation, represent 2 commonly suspected catalysts for this malignant transformation.⁴ De novo porocarcinomas are most causatively linked to localized trauma from burns or radiation exposure.⁵ Gene mutations in classic tumor suppressor genes—tumor protein p53 (TP53), phosphatase and tensin homolog (PTEN), rearranged during transfection (RET), adenomatous polyposis coli (APC)—and increased genetic heterogeneity follow these stimuli.⁶

The morphologic presentation of porocarcinoma is highly variable and may manifest as papules, nodules, or plaques in various states of erosion, ulceration, or excoriation. Diagnoses of basal and squamous cell carcinoma, primary adnexal tumors, seborrheic keratosis, pyogenic granuloma, and melanoma must all be considered and methodically ruled out.⁷ Porocarcinomas may arise nearly anywhere on the body, with a particular predilection for the lower extremities (35%), head/neck (24%), and upper extremities (14%).^3,4 Primary lesions arising from the extremities, genitalia, or buttocks herald a higher risk for lymphatic invasion and distant metastasis, while head and neck tumors more commonly remain localized.⁸ Bleeding, ulceration, or rapid expansion of a preexisting poroma is suggestive of malignant transformation and may portend a more aggressive disease pattern.^2,9

Unequivocal diagnosis relies on histological and immunohistochemical studies due to the marked clinical variance of this neoplasm.⁷ An irregular histologic pattern of poromatous basaloid cells with ductal differentiation and cytologic atypia commonly are seen with porocarcinomas.^2,8 Nuclear pleomorphism with cellular necrosis, increased mitotic figures, and abortive ductal formation with a distinct lack of retraction around cellular aggregates often are found. Immunohistochemical staining is needed to confirm the primary tumor diagnosis. Histochemical stains commonly employed include carcinoembryonic antigen (CEA), cytokeratin AE1/AE3, epithelial membrane antigen, p53, p63, Ki67, and periodic acid-Schiff.¹⁰ The use of BerEP4 has been reported as efficacious in highlighting sweat structures, which can be particularly useful in cases when basal cell carcinoma is not in the histologic differential.¹¹ These staining profiles afford confirmation of ductal differentiation with CEA, epithelial membrane antigen, and BerEP4, while p63 and Ki67 are used as surrogates for primary cutaneous neoplasia and cell proliferation, respectively.^5,11 Porocarcinoma lesions may be most sensitive to CEA and most specific to CK19 (a component of cytokeratin AE1/AE3), though these findings have not been widely reproduced.⁷

The treatment and prognosis of porocarcinoma vary widely. Surgically excised lesions recur in roughly 20% of cases, though these rates likely include tumors that were incompletely resected in the primary attempt. Although wide local excision with an average 1-cm margin remains the most employed removal technique, Mohs micrographic surgery may more effectively limit recurrence and metastasis of localized disease.^7,8,12 Metastatic disease foretells a mortality rate of at least 65%, which is problematic in that 10% to 20% of patients have metastatic disease at the time of diagnosis and another 20% will show metastasis following primary tumor excision.^8,10 Neoplasms with high mitotic rates and depths greater than 7 mm should prompt thorough diagnostic imaging, such as positron emission tomography or magnetic resonance imaging. A sentinel lymph node biopsy should be strongly considered and discussed with the patient.¹⁰ Treatment options for nodal and distant metastases include a combination of localized surgery, lymphadenectomy, radiotherapy, and chemotherapeutic agents.^2,4,5 The response to systemic treatment and radiotherapy often is quite poor, though the use of combinations of docetaxel, paclitaxel, cetuximab, and immunotherapy have been efficacious in smaller studies.^8,10 The highest rates of morbidity and mortality are seen in patients with metastases on presentation or with localized tumors in the groin and buttocks.⁸

The diagnosis of porocarcinoma may be elusive due to its relatively rare occurrence. Therefore, it is critical to consider this neoplasm in high-risk sites in older patients who present with an evolving nodule or tumor on an extremity. Routine histology and astute histochemical profiling are necessary to exclude diseases that mimic porocarcinoma. Once diagnosis is confirmed, management with prompt excision and diagnostic imaging is recommended, including a lymph node biopsy if appropriate. Due to its high metastatic potential and associated morbidity and mortality, patients with porocarcinoma should be followed closely by a multidisciplinary care team.

To the Editor:

Porocarcinoma is a rare malignancy of the eccrine sweat glands and is commonly misdiagnosed clinically. We present 2 cases of porocarcinoma and highlight key features of this uncommon disease.

A 65-year-old man presented to the emergency department with a chief concern of a bump on the head of 8 months' duration that gradually enlarged. The lesion recently became painful and contributed to frequent headaches. He reported a history of smoking 1 pack per day and denied trauma to the area or history of immunosuppression. He had no personal or family history of skin cancer. Physical examination revealed a 1.4-cm, heterochromic, pedunculated, keratotic tumor with crusting on the right temporal scalp (Figure 1). No lymphadenopathy was appreciated. The clinical differential diagnosis included irritated seborrheic keratosis, pyogenic granuloma, polypoid malignant melanoma, and nonmelanoma skin cancer. A biopsy of the lesion demonstrated a proliferation of cuboidal cells with focal ductular differentiation arranged in interanastamosing strands arising from the epidermis (Figure 2). Scattered mitotic figures, including atypical forms, cytologic atypia, and foci of necrosis, also were present. The findings were consistent with features of porocarcinoma. Contrast computed tomography of the neck showed no evidence of metastatic disease within the neck. A wide local excision was performed and yielded a tumor measuring 1.8×1.6×0.7 cm with a depth of 0.3 cm and uninvolved margins. No lymphovascular or perineural invasion was identified. At 4-month follow-up, the patient had a well-healed scar on the right scalp without evidence of recurrence or lymphadenopathy.

A 32-year-old woman presented to dermatology with a chief concern of a mass on the back of 2 years’ duration that rapidly enlarged and became painful following irritation from her bra strap 2 months earlier. She had no relevant medical history. Physical examination revealed a firm, tender, heterochromic nodule measuring 3.0×2.8 cm on the left mid back inferior to the left scapula (Figure 3). The lesion expressed serosanguineous discharge. No lymphadenopathy was appreciated on examination. The clinical differential diagnosis included an inflamed cyst, nodular melanoma, cutaneous metastasis, and nonmelanoma skin cancer. The patient underwent an excisional biopsy, which demonstrated porocarcinoma with positive margins, microsatellitosis, and evidence of lymphovascular invasion. Carcinoembryonic antigen immunohistochemistry highlighted ducts within the tumor (Figure 4). The patient underwent re-excision with 2-cm margins, and no residual tumor was appreciated on pathology.

Positron emission tomography and computed tomography revealed a hypermetabolic left axillary lymph node. Ultrasound-guided fine-needle aspiration was positive for malignant cells consistent with metastatic carcinoma. Dissection of left axillary lymph nodes yielded metastatic porocarcinoma in 2 of 13 nodes. The largest tumor deposit measured 0.9 cm, and no extracapsular extension was identified. The patient continues to be monitored with semiannual full-body skin examinations as well as positron emission tomography and computed tomography scans, with no evidence of recurrence 2 years later.

Porocarcinoma is a rare malignancy of the skin arising from the eccrine sweat glands¹ with an incidence rate of 0.4 cases per 1 million person-years in the United States. These tumors represent 0.005% to 0.01% of all skin cancers.² The mean age of onset is approximately 65 years with no predilection for sex. The mean time from initial presentation to treatment is 5.6 to 8.5 years.^3-5

Eccrine sweat glands consist of a straight intradermal duct (syrinx); coiled intradermal duct; and spiral intraepidermal duct (acrosyringium), which opens onto the skin. Both eccrine poromas (solitary benign eccrine gland tumors) and eccrine porocarcinomas develop from the acrosyringium. Eccrine poromas most commonly are found in sites containing the highest density of eccrine glands such as the palms, soles, axillae, and forehead, whereas porocarcinomas most commonly are found on the head, neck, arms, and legs.^1,3,4,6,7 A solitary painless nodule that may ulcerate or bleed is the most common presentation.^1,3-5,7

The etiology of eccrine porocarcinoma is poorly understood, but it has been found to arise de novo or to develop from pre-existing poromas or even from nevus sebaceus of Jadassohn. Chronic sunlight exposure, irradiation, lymphedema, trauma, and immunosuppression (eg, Hodgkin disease, chronic lymphocytic leukemia, HIV) have been reported as potential predisposing factors.^3,4,6,8,9

Eccrine porocarcinoma often is clinically misdiagnosed as nonmelanoma skin cancer, pyogenic granuloma, amelanotic melanoma, fibroma, verruca vulgaris, or metastatic carcinoma. Appropriate classification is essential, as metastasis is present in 25% to 31% of cases, and local recurrence occurs in 20% to 25% of cases.^1,3-5,7

Microscopically, porocarcinomas are comprised of atypical basaloid epithelial cells with focal ductular differentiation. Typically, there is an extensive intraepidermal component that invades into the dermis in anastomosing ribbons and cords. The degree of nuclear atypia, mitotic activity, and invasive growth pattern, as well as the presence of necrosis, are useful histologic features to differentiate porocarcinoma from poroma, which may be present in the background. Given the sometimes-extensive squamous differentiation, porocarcinoma can be confused with squamous cell carcinoma. In these cases, immunohistochemical stains such as epithelial membrane antigen or carcinoembryonic antigen can be used to highlight the ductal differentiation.^1,5,8,10

Poor histologic prognostic indicators include a high mitotic index (>14 mitoses per field), a tumor depth greater than 7 mm, and evidence of lymphovascular invasion. Positive lymph node involvement is associated with a 65% to 67% mortality rate.^1,8

Because of its propensity to metastasize via the lymphatic system and the high mortality rate associated with such metastases, early identification and treatment are essential. Treatment is accomplished via Mohs micrographic surgery or wide local excision with negative margins. Lymphadenectomy is indicated if regional lymph nodes are involved. Radiation and chemotherapy have been used in patients with metastatic and recurrent disease with mixed results.^1,3-5,7 There is no adequate standardized chemotherapy or drug regimen established for porocarcinoma.⁵ Tsunoda et al¹¹ proposed that sentinel lymph node biopsy should be considered first-line management of eccrine porocarcinoma; however, this remains unproven on the basis of a limited case series. Others conclude that sentinel lymph node biopsy should be recommended for cases with poor histologic prognostic features.^1,5

To the Editor:

Porocarcinoma is a rare malignancy of the eccrine sweat glands and is commonly misdiagnosed clinically. We present 2 cases of porocarcinoma and highlight key features of this uncommon disease.

A 65-year-old man presented to the emergency department with a chief concern of a bump on the head of 8 months' duration that gradually enlarged. The lesion recently became painful and contributed to frequent headaches. He reported a history of smoking 1 pack per day and denied trauma to the area or history of immunosuppression. He had no personal or family history of skin cancer. Physical examination revealed a 1.4-cm, heterochromic, pedunculated, keratotic tumor with crusting on the right temporal scalp (Figure 1). No lymphadenopathy was appreciated. The clinical differential diagnosis included irritated seborrheic keratosis, pyogenic granuloma, polypoid malignant melanoma, and nonmelanoma skin cancer. A biopsy of the lesion demonstrated a proliferation of cuboidal cells with focal ductular differentiation arranged in interanastamosing strands arising from the epidermis (Figure 2). Scattered mitotic figures, including atypical forms, cytologic atypia, and foci of necrosis, also were present. The findings were consistent with features of porocarcinoma. Contrast computed tomography of the neck showed no evidence of metastatic disease within the neck. A wide local excision was performed and yielded a tumor measuring 1.8×1.6×0.7 cm with a depth of 0.3 cm and uninvolved margins. No lymphovascular or perineural invasion was identified. At 4-month follow-up, the patient had a well-healed scar on the right scalp without evidence of recurrence or lymphadenopathy.

A 32-year-old woman presented to dermatology with a chief concern of a mass on the back of 2 years’ duration that rapidly enlarged and became painful following irritation from her bra strap 2 months earlier. She had no relevant medical history. Physical examination revealed a firm, tender, heterochromic nodule measuring 3.0×2.8 cm on the left mid back inferior to the left scapula (Figure 3). The lesion expressed serosanguineous discharge. No lymphadenopathy was appreciated on examination. The clinical differential diagnosis included an inflamed cyst, nodular melanoma, cutaneous metastasis, and nonmelanoma skin cancer. The patient underwent an excisional biopsy, which demonstrated porocarcinoma with positive margins, microsatellitosis, and evidence of lymphovascular invasion. Carcinoembryonic antigen immunohistochemistry highlighted ducts within the tumor (Figure 4). The patient underwent re-excision with 2-cm margins, and no residual tumor was appreciated on pathology.

Positron emission tomography and computed tomography revealed a hypermetabolic left axillary lymph node. Ultrasound-guided fine-needle aspiration was positive for malignant cells consistent with metastatic carcinoma. Dissection of left axillary lymph nodes yielded metastatic porocarcinoma in 2 of 13 nodes. The largest tumor deposit measured 0.9 cm, and no extracapsular extension was identified. The patient continues to be monitored with semiannual full-body skin examinations as well as positron emission tomography and computed tomography scans, with no evidence of recurrence 2 years later.

Porocarcinoma is a rare malignancy of the skin arising from the eccrine sweat glands¹ with an incidence rate of 0.4 cases per 1 million person-years in the United States. These tumors represent 0.005% to 0.01% of all skin cancers.² The mean age of onset is approximately 65 years with no predilection for sex. The mean time from initial presentation to treatment is 5.6 to 8.5 years.^3-5

Eccrine sweat glands consist of a straight intradermal duct (syrinx); coiled intradermal duct; and spiral intraepidermal duct (acrosyringium), which opens onto the skin. Both eccrine poromas (solitary benign eccrine gland tumors) and eccrine porocarcinomas develop from the acrosyringium. Eccrine poromas most commonly are found in sites containing the highest density of eccrine glands such as the palms, soles, axillae, and forehead, whereas porocarcinomas most commonly are found on the head, neck, arms, and legs.^1,3,4,6,7 A solitary painless nodule that may ulcerate or bleed is the most common presentation.^1,3-5,7

The etiology of eccrine porocarcinoma is poorly understood, but it has been found to arise de novo or to develop from pre-existing poromas or even from nevus sebaceus of Jadassohn. Chronic sunlight exposure, irradiation, lymphedema, trauma, and immunosuppression (eg, Hodgkin disease, chronic lymphocytic leukemia, HIV) have been reported as potential predisposing factors.^3,4,6,8,9

Eccrine porocarcinoma often is clinically misdiagnosed as nonmelanoma skin cancer, pyogenic granuloma, amelanotic melanoma, fibroma, verruca vulgaris, or metastatic carcinoma. Appropriate classification is essential, as metastasis is present in 25% to 31% of cases, and local recurrence occurs in 20% to 25% of cases.^1,3-5,7

Microscopically, porocarcinomas are comprised of atypical basaloid epithelial cells with focal ductular differentiation. Typically, there is an extensive intraepidermal component that invades into the dermis in anastomosing ribbons and cords. The degree of nuclear atypia, mitotic activity, and invasive growth pattern, as well as the presence of necrosis, are useful histologic features to differentiate porocarcinoma from poroma, which may be present in the background. Given the sometimes-extensive squamous differentiation, porocarcinoma can be confused with squamous cell carcinoma. In these cases, immunohistochemical stains such as epithelial membrane antigen or carcinoembryonic antigen can be used to highlight the ductal differentiation.^1,5,8,10

Poor histologic prognostic indicators include a high mitotic index (>14 mitoses per field), a tumor depth greater than 7 mm, and evidence of lymphovascular invasion. Positive lymph node involvement is associated with a 65% to 67% mortality rate.^1,8

Because of its propensity to metastasize via the lymphatic system and the high mortality rate associated with such metastases, early identification and treatment are essential. Treatment is accomplished via Mohs micrographic surgery or wide local excision with negative margins. Lymphadenectomy is indicated if regional lymph nodes are involved. Radiation and chemotherapy have been used in patients with metastatic and recurrent disease with mixed results.^1,3-5,7 There is no adequate standardized chemotherapy or drug regimen established for porocarcinoma.⁵ Tsunoda et al¹¹ proposed that sentinel lymph node biopsy should be considered first-line management of eccrine porocarcinoma; however, this remains unproven on the basis of a limited case series. Others conclude that sentinel lymph node biopsy should be recommended for cases with poor histologic prognostic features.^1,5

To the Editor:

Porocarcinoma is a rare malignancy of the eccrine sweat glands and is commonly misdiagnosed clinically. We present 2 cases of porocarcinoma and highlight key features of this uncommon disease.

A 65-year-old man presented to the emergency department with a chief concern of a bump on the head of 8 months' duration that gradually enlarged. The lesion recently became painful and contributed to frequent headaches. He reported a history of smoking 1 pack per day and denied trauma to the area or history of immunosuppression. He had no personal or family history of skin cancer. Physical examination revealed a 1.4-cm, heterochromic, pedunculated, keratotic tumor with crusting on the right temporal scalp (Figure 1). No lymphadenopathy was appreciated. The clinical differential diagnosis included irritated seborrheic keratosis, pyogenic granuloma, polypoid malignant melanoma, and nonmelanoma skin cancer. A biopsy of the lesion demonstrated a proliferation of cuboidal cells with focal ductular differentiation arranged in interanastamosing strands arising from the epidermis (Figure 2). Scattered mitotic figures, including atypical forms, cytologic atypia, and foci of necrosis, also were present. The findings were consistent with features of porocarcinoma. Contrast computed tomography of the neck showed no evidence of metastatic disease within the neck. A wide local excision was performed and yielded a tumor measuring 1.8×1.6×0.7 cm with a depth of 0.3 cm and uninvolved margins. No lymphovascular or perineural invasion was identified. At 4-month follow-up, the patient had a well-healed scar on the right scalp without evidence of recurrence or lymphadenopathy.

A 32-year-old woman presented to dermatology with a chief concern of a mass on the back of 2 years’ duration that rapidly enlarged and became painful following irritation from her bra strap 2 months earlier. She had no relevant medical history. Physical examination revealed a firm, tender, heterochromic nodule measuring 3.0×2.8 cm on the left mid back inferior to the left scapula (Figure 3). The lesion expressed serosanguineous discharge. No lymphadenopathy was appreciated on examination. The clinical differential diagnosis included an inflamed cyst, nodular melanoma, cutaneous metastasis, and nonmelanoma skin cancer. The patient underwent an excisional biopsy, which demonstrated porocarcinoma with positive margins, microsatellitosis, and evidence of lymphovascular invasion. Carcinoembryonic antigen immunohistochemistry highlighted ducts within the tumor (Figure 4). The patient underwent re-excision with 2-cm margins, and no residual tumor was appreciated on pathology.

Positron emission tomography and computed tomography revealed a hypermetabolic left axillary lymph node. Ultrasound-guided fine-needle aspiration was positive for malignant cells consistent with metastatic carcinoma. Dissection of left axillary lymph nodes yielded metastatic porocarcinoma in 2 of 13 nodes. The largest tumor deposit measured 0.9 cm, and no extracapsular extension was identified. The patient continues to be monitored with semiannual full-body skin examinations as well as positron emission tomography and computed tomography scans, with no evidence of recurrence 2 years later.

Porocarcinoma is a rare malignancy of the skin arising from the eccrine sweat glands¹ with an incidence rate of 0.4 cases per 1 million person-years in the United States. These tumors represent 0.005% to 0.01% of all skin cancers.² The mean age of onset is approximately 65 years with no predilection for sex. The mean time from initial presentation to treatment is 5.6 to 8.5 years.^3-5

Eccrine sweat glands consist of a straight intradermal duct (syrinx); coiled intradermal duct; and spiral intraepidermal duct (acrosyringium), which opens onto the skin. Both eccrine poromas (solitary benign eccrine gland tumors) and eccrine porocarcinomas develop from the acrosyringium. Eccrine poromas most commonly are found in sites containing the highest density of eccrine glands such as the palms, soles, axillae, and forehead, whereas porocarcinomas most commonly are found on the head, neck, arms, and legs.^1,3,4,6,7 A solitary painless nodule that may ulcerate or bleed is the most common presentation.^1,3-5,7

The etiology of eccrine porocarcinoma is poorly understood, but it has been found to arise de novo or to develop from pre-existing poromas or even from nevus sebaceus of Jadassohn. Chronic sunlight exposure, irradiation, lymphedema, trauma, and immunosuppression (eg, Hodgkin disease, chronic lymphocytic leukemia, HIV) have been reported as potential predisposing factors.^3,4,6,8,9

Eccrine porocarcinoma often is clinically misdiagnosed as nonmelanoma skin cancer, pyogenic granuloma, amelanotic melanoma, fibroma, verruca vulgaris, or metastatic carcinoma. Appropriate classification is essential, as metastasis is present in 25% to 31% of cases, and local recurrence occurs in 20% to 25% of cases.^1,3-5,7

Microscopically, porocarcinomas are comprised of atypical basaloid epithelial cells with focal ductular differentiation. Typically, there is an extensive intraepidermal component that invades into the dermis in anastomosing ribbons and cords. The degree of nuclear atypia, mitotic activity, and invasive growth pattern, as well as the presence of necrosis, are useful histologic features to differentiate porocarcinoma from poroma, which may be present in the background. Given the sometimes-extensive squamous differentiation, porocarcinoma can be confused with squamous cell carcinoma. In these cases, immunohistochemical stains such as epithelial membrane antigen or carcinoembryonic antigen can be used to highlight the ductal differentiation.^1,5,8,10

Poor histologic prognostic indicators include a high mitotic index (>14 mitoses per field), a tumor depth greater than 7 mm, and evidence of lymphovascular invasion. Positive lymph node involvement is associated with a 65% to 67% mortality rate.^1,8

Because of its propensity to metastasize via the lymphatic system and the high mortality rate associated with such metastases, early identification and treatment are essential. Treatment is accomplished via Mohs micrographic surgery or wide local excision with negative margins. Lymphadenectomy is indicated if regional lymph nodes are involved. Radiation and chemotherapy have been used in patients with metastatic and recurrent disease with mixed results.^1,3-5,7 There is no adequate standardized chemotherapy or drug regimen established for porocarcinoma.⁵ Tsunoda et al¹¹ proposed that sentinel lymph node biopsy should be considered first-line management of eccrine porocarcinoma; however, this remains unproven on the basis of a limited case series. Others conclude that sentinel lymph node biopsy should be recommended for cases with poor histologic prognostic features.^1,5

To the Editor:

A 58-year-old woman presented to our dermatology clinic with a pruritic weeping eruption circumferentially on the distal digits of both hands of 5 weeks’ duration. The patient disclosed that she had been receiving dip powder manicures at a local nail salon approximately every 2 weeks over the last 3 to 6 months. She had received frequent acrylic nail extensions over the last 8 years prior to starting the dip powder manicures. Physical examination revealed well-demarcated eczematous plaques involving the lateral and proximal nail folds of the right thumb with an overlying serous crust and loss of the cuticle (Figure 1A). Erythematous plaques with firm deep-seated microvesicles also were present on the other digits, distributed distal to the distal interphalangeal joints (Figure 1B). She was diagnosed with dyshidroticlike contact dermatitis and paronychia. Treatment included phenol 1.5% colorless solution and clobetasol ointment 0.05% for twice-daily application to the affected areas. The patient also was advised to stop receiving manicures. At 1-month follow-up, the paronychia had resolved and the dermatitis had nearly resolved.

Dip powder manicures use a wet adhesive base coat with acrylic powder and an activator topcoat to initiate a chemical reaction that hardens and sets the nail polish. The colored powder typically is applied by dipping the digit up to the distal interphalangeal joint into a small container of loose powder and then brushing away the excess (Figure 2). Acrylate, a chemical present in dip powders, is a known allergen and has been associated with the development of allergic contact dermatitis and onychodystrophy in patients after receiving acrylic and UV-cured gel polish manicures.^1,2 Inadequate sanitation practices at nail salons also have been associated with infection transmission.^3,4 Additionally, the news media has covered the potential risk of infection due to contamination from reused dip manicure powder and the use of communal powder containers.⁵

To increase clinical awareness of the dip manicure technique, we describe the presentation and successful treatment of dyshidroticlike contact dermatitis and paronychia that occurred in a patient after she received a dip powder manicure. Dermatoses and infection limited to the distal phalanges will present in patients more frequently as dip powder manicures continue to increase in popularity and frequency.

To the Editor:

A 58-year-old woman presented to our dermatology clinic with a pruritic weeping eruption circumferentially on the distal digits of both hands of 5 weeks’ duration. The patient disclosed that she had been receiving dip powder manicures at a local nail salon approximately every 2 weeks over the last 3 to 6 months. She had received frequent acrylic nail extensions over the last 8 years prior to starting the dip powder manicures. Physical examination revealed well-demarcated eczematous plaques involving the lateral and proximal nail folds of the right thumb with an overlying serous crust and loss of the cuticle (Figure 1A). Erythematous plaques with firm deep-seated microvesicles also were present on the other digits, distributed distal to the distal interphalangeal joints (Figure 1B). She was diagnosed with dyshidroticlike contact dermatitis and paronychia. Treatment included phenol 1.5% colorless solution and clobetasol ointment 0.05% for twice-daily application to the affected areas. The patient also was advised to stop receiving manicures. At 1-month follow-up, the paronychia had resolved and the dermatitis had nearly resolved.

Dip powder manicures use a wet adhesive base coat with acrylic powder and an activator topcoat to initiate a chemical reaction that hardens and sets the nail polish. The colored powder typically is applied by dipping the digit up to the distal interphalangeal joint into a small container of loose powder and then brushing away the excess (Figure 2). Acrylate, a chemical present in dip powders, is a known allergen and has been associated with the development of allergic contact dermatitis and onychodystrophy in patients after receiving acrylic and UV-cured gel polish manicures.^1,2 Inadequate sanitation practices at nail salons also have been associated with infection transmission.^3,4 Additionally, the news media has covered the potential risk of infection due to contamination from reused dip manicure powder and the use of communal powder containers.⁵

To increase clinical awareness of the dip manicure technique, we describe the presentation and successful treatment of dyshidroticlike contact dermatitis and paronychia that occurred in a patient after she received a dip powder manicure. Dermatoses and infection limited to the distal phalanges will present in patients more frequently as dip powder manicures continue to increase in popularity and frequency.

To the Editor:

A 58-year-old woman presented to our dermatology clinic with a pruritic weeping eruption circumferentially on the distal digits of both hands of 5 weeks’ duration. The patient disclosed that she had been receiving dip powder manicures at a local nail salon approximately every 2 weeks over the last 3 to 6 months. She had received frequent acrylic nail extensions over the last 8 years prior to starting the dip powder manicures. Physical examination revealed well-demarcated eczematous plaques involving the lateral and proximal nail folds of the right thumb with an overlying serous crust and loss of the cuticle (Figure 1A). Erythematous plaques with firm deep-seated microvesicles also were present on the other digits, distributed distal to the distal interphalangeal joints (Figure 1B). She was diagnosed with dyshidroticlike contact dermatitis and paronychia. Treatment included phenol 1.5% colorless solution and clobetasol ointment 0.05% for twice-daily application to the affected areas. The patient also was advised to stop receiving manicures. At 1-month follow-up, the paronychia had resolved and the dermatitis had nearly resolved.

Dip powder manicures use a wet adhesive base coat with acrylic powder and an activator topcoat to initiate a chemical reaction that hardens and sets the nail polish. The colored powder typically is applied by dipping the digit up to the distal interphalangeal joint into a small container of loose powder and then brushing away the excess (Figure 2). Acrylate, a chemical present in dip powders, is a known allergen and has been associated with the development of allergic contact dermatitis and onychodystrophy in patients after receiving acrylic and UV-cured gel polish manicures.^1,2 Inadequate sanitation practices at nail salons also have been associated with infection transmission.^3,4 Additionally, the news media has covered the potential risk of infection due to contamination from reused dip manicure powder and the use of communal powder containers.⁵

To increase clinical awareness of the dip manicure technique, we describe the presentation and successful treatment of dyshidroticlike contact dermatitis and paronychia that occurred in a patient after she received a dip powder manicure. Dermatoses and infection limited to the distal phalanges will present in patients more frequently as dip powder manicures continue to increase in popularity and frequency.

Scabies is caused by cutaneous ectoparasitic infection by the mite Sarcoptes scabiei var hominis. The infection is highly contagious via direct skin-to-skin contact or indirectly through infested bedding, clothing or fomites.^1,2 Scabies occurs at all ages, in all ethnic groups, and at all socioeconomic levels.¹ Analysis by the Global Burden of Disease estimates that 200 million individuals have been infected with scabies worldwide. The World Health Organization has declared scabies a neglected tropical disease.³

Crusted scabies is a severe and rare form of scabies, with hyperinfestation of thousands to millions of mites, and more commonly is associated with immunosuppressed states, including HIV and hematologic malignancies.^1,2,4 Crusted scabies has a high mortality rate due to sepsis when left untreated.^3,5

Occasionally, iatrogenic immunosuppression contributes to the development of crusted scabies.^1,2 Iatrogenic immunosuppression leading to crusted scabies most commonly occurs secondary to immunosuppression after bone marrow or solid organ transplantation.⁶ Less often, crusted scabies is caused by iatrogenic immunosuppression from other clinical scenarios.^1,2

We describe a patient with iatrogenic immunosuppression due to azathioprine-induced myelosuppression for the treatment of granulomatosis with polyangiitis (GPA) who developed crusted scabies that clinically presented as erythroderma. Crusted scabies should be included in the differential diagnosis of erythroderma, especially in the setting of iatrogenic immunosuppression, for timely and appropriate management.

Case Report

An 84-year-old man presented with worsening pruritus, erythema, and thick yellow scale that progressed to erythroderma over the last 2 weeks. He was diagnosed with GPA 6 months prior to presentation and was treated with azathioprine 150 mg/d, prednisone 10 mg/d, and sulfamethoxazole 800 mg plus trimethoprim 160 mg twice weekly for prophylaxis against Pneumocystis jirovecii pneumonia.

Three weeks prior to presentation, the patient was hospitalized for pancytopenia attributed to azathioprine-induced myelosuppression (hemoglobin, 6.1 g/dL [reference range, 13.5–18.0 g/dL]; hematocrit, 17.5% [reference range, 42%–52%]; white blood cell count, 1.66×10³/μL [reference range, 4.0–10.5×10³/μL]; platelet count, 146×10³/μL [reference range, 150–450×10³/μL]; absolute neutrophil count, 1.29×10³/μL [reference range, 1.4–6.5×10³/μL]). He was transferred to a skilled nursing facility after discharge and referred to dermatology for evaluation of the worsening pruritic rash.

At the current presentation, the patient denied close contact with anyone who had a similar rash at home or at the skilled nursing facility. Physical examination revealed diffuse erythroderma with yellow scale on the scalp, trunk, arms, and legs (Figure 1). The palms showed scattered 2- to 3-mm pustules. The mucosal surfaces did not have lesions. A punch biopsy of a pustule from the right arm revealed focal spongiosis, parakeratosis, and acanthosis, as well as a perivascular and interstitial mixed inflammatory infiltrate with lymphocytes and eosinophils. Organisms morphologically compatible with scabies were found in the stratum corneum (Figure 2). Another punch biopsy of a pustule from the right arm was performed for direct immunofluorescence (DIF) and was negative for immunoglobulin deposition. Mineral oil preparation from pustules on the palm was positive for mites.

The patient was treated with permethrin cream 5% and oral ivermectin 200 μg/kg on day 1 and day 10. The prednisone dosage was increased from 10 mg/d to 50 mg/d and tapered over 2 weeks to treat the symptomatic rash and GPA. He remains on maintenance rituximab for GPA, without recurrence of scabies.

Comment

Pathogenesis—As an obligate parasite, S scabiei spends its entire life cycle within the host. Impregnated female mites burrow into the epidermis after mating and lay eggs daily for 1 to 2 months. Eggs hatch 2 or 3 days later. Larvae then migrate to the skin surface; burrow into the stratum corneum, where they mature into adults; and then mate on the skin surface.^1,4

Clinical Presentation and Sequelae—Typically, scabies presents 2 to 6 weeks after initial exposure with generalized and intense itching and inflammatory pruritic papules on the finger webs, wrists, elbows, axillae, buttocks, umbilicus, genitalia, and areolae.¹ Burrows are specific for scabies but may not always be present. Often, there are nonspecific secondary lesions, including excoriations, dermatitis, and impetiginization.

Complications of scabies can be severe, with initial colonization and infection of the skin resulting in impetigo and cellulitis. Systematic sequelae from local skin infection include post-streptococcal glomerulonephritis, rheumatic fever, and sepsis. Mortality from sepsis in scabies can be high.^3,5

Classic Crusted Scabies and Other Variants—Crusted scabies presents with psoriasiform hyperkeratotic plaques involving the hands and feet with potential nail involvement that can become more generalized.¹ Alterations in CD4⁺ T-cell function have been implicated in the development of crusted scabies, in which an excessive helper T cell (T_H2) response is elicited against the ectoparasite, which may help explain the intense pruritus of scabies.⁶ Occasionally, iatrogenic immunosuppression contributes to development of crusted scabies,¹ as was the case with our patient. However, it is rare for crusted scabies to present with erythroderma.⁷

Other atypical presentations of scabies include a seborrheic dermatitis–like presentation in infants, nodular lesions in the groin and axillae in more chronic scabies, and vesicles or bullous lesions.¹

Diagnosis—Identification of mites, eggs, or feces is necessary for definitive diagnosis of scabies.⁸ These materials can be obtained through skin scrapings with mineral oil and observed under light microscopy or direct dermoscopy. Multiple scrapings on many lesions should be performed because failure to identify mites can be common and does not rule out scabies. Dermoscopic examination of active lesions under low power also can be helpful, given that identification of dark brown triangular structures can correspond to visualization of the pigmented anterior section of the mite.^9-11 A skin biopsy can help identify mites, but histopathology often shows a nonspecific hypersensitivity reaction.¹² Therefore, empiric treatment often is necessary.

Differential Diagnosis—The differential diagnosis of erythroderma is broad and includes a drug eruption; Sézary syndrome; and pre-existing skin diseases, including psoriasis, atopic dermatitis, pityriasis rubra pilaris, pemphigus foliaceus, and bullous pemphigoid. Histopathology is critical to differentiate these diagnoses. Bullous pemphigoid and pemphigus foliaceus are immunobullous diseases that typically are positive for immunoglobulin deposition on DIF. In rare cases, scabies also can present with bullae and positive DIF test results.¹³

Treatment—First-line treatment of crusted scabies in the United States is permethrin cream 5%, followed by oral ivermectin 200 μg/kg.^4,5,14,15 Other scabicides include topicals such as benzyl benzoate 10% to 25%; precipitated sulfur 2% to 10%; crotamiton 10%; malathion 0.5%; and lindane 1%.⁵ The association of neurotoxicity with lindane has considerably reduced the drug’s use.¹

During treatment of scabies, it is important to isolate patients to mitigate the possibility of spread.⁴ Pruritus can persist for a few weeks after completion of therapy.⁵ Patients should be closely monitored to ensure that this symptom is secondary to skin inflammation and not incomplete treatment.

Treatment of crusted scabies may require repeated treatments to decrease the notable mite burden as well as the associated crusting and scale. Adding a keratolytic such as 5% to 10% salicylic acid in petrolatum to the treatment regimen may be useful for breaking up thick scale.⁵

Immunosuppression—With numerous immunomodulatory drugs for treating autoimmunity comes an increased risk for iatrogenic immunosuppression that may contribute to the development of crusted scabies.¹⁶ In a number of autoimmune diseases such as rheumatoid arthritis,^17-19 psoriasis,^20,21 pemphigus vulgaris,²² systemic lupus erythematosus,²³ systemic sclerosis,^22,24 bullous pemphigoid,^25,26 and dermatomyositis,²⁷ patients have developed crusted scabies secondary to treatment-related immunosuppression. These immunosuppressive therapies include systemic steroids,^22-24,26-31 methotrexate,²³ infliximab,¹⁸ adalimumab,²¹ toclizumab,¹⁹ and etanercept.²⁰ In a case of drug-induced Stevens-Johnson syndrome, the patient developed crusted scabies during long-term use of oral steroids.²²

Patients with a malignancy who are being treated with chemotherapy also can develop crusted scabies.²⁸ Crusted scabies has even been associated with long-term topical steroid^32-34 and topical calcineurin inhibitor use.¹⁶

Iatrogenic immunosuppression in our patient resulted from treatment of GPA with azathioprine, an immunosuppressive drug that acts as an antagonist of the breakdown of purines, leading to inhibition of DNA, RNA, and protein synthesis.³⁵ On occasion, azathioprine can induce immunosuppression in the form of myelosuppression and resulting pancytopenia, as was the case with our patient.

Conclusion

Although scabies is designated as a neglected tropical disease by the World Health Organization, it still causes a notable burden worldwide, regardless of the economics. Our case highlights an unusual presentation of scabies as erythroderma in the setting of iatrogenic immunosuppression from azathioprine use. Dermatologists should consider crusted scabies in the differential diagnosis of erythroderma, especially in immunocompromised patients, to avoid delays in diagnosis and treatment. Immunosuppressive therapy is an important mainstay in the treatment of many conditions, but it is important to consider that these medications can place patients at an increased risk for rare opportunistic infections. Therefore, patients receiving such treatment should be closely monitored.

Scabies is caused by cutaneous ectoparasitic infection by the mite Sarcoptes scabiei var hominis. The infection is highly contagious via direct skin-to-skin contact or indirectly through infested bedding, clothing or fomites.^1,2 Scabies occurs at all ages, in all ethnic groups, and at all socioeconomic levels.¹ Analysis by the Global Burden of Disease estimates that 200 million individuals have been infected with scabies worldwide. The World Health Organization has declared scabies a neglected tropical disease.³

Crusted scabies is a severe and rare form of scabies, with hyperinfestation of thousands to millions of mites, and more commonly is associated with immunosuppressed states, including HIV and hematologic malignancies.^1,2,4 Crusted scabies has a high mortality rate due to sepsis when left untreated.^3,5

Occasionally, iatrogenic immunosuppression contributes to the development of crusted scabies.^1,2 Iatrogenic immunosuppression leading to crusted scabies most commonly occurs secondary to immunosuppression after bone marrow or solid organ transplantation.⁶ Less often, crusted scabies is caused by iatrogenic immunosuppression from other clinical scenarios.^1,2

We describe a patient with iatrogenic immunosuppression due to azathioprine-induced myelosuppression for the treatment of granulomatosis with polyangiitis (GPA) who developed crusted scabies that clinically presented as erythroderma. Crusted scabies should be included in the differential diagnosis of erythroderma, especially in the setting of iatrogenic immunosuppression, for timely and appropriate management.

Case Report

An 84-year-old man presented with worsening pruritus, erythema, and thick yellow scale that progressed to erythroderma over the last 2 weeks. He was diagnosed with GPA 6 months prior to presentation and was treated with azathioprine 150 mg/d, prednisone 10 mg/d, and sulfamethoxazole 800 mg plus trimethoprim 160 mg twice weekly for prophylaxis against Pneumocystis jirovecii pneumonia.

Three weeks prior to presentation, the patient was hospitalized for pancytopenia attributed to azathioprine-induced myelosuppression (hemoglobin, 6.1 g/dL [reference range, 13.5–18.0 g/dL]; hematocrit, 17.5% [reference range, 42%–52%]; white blood cell count, 1.66×10³/μL [reference range, 4.0–10.5×10³/μL]; platelet count, 146×10³/μL [reference range, 150–450×10³/μL]; absolute neutrophil count, 1.29×10³/μL [reference range, 1.4–6.5×10³/μL]). He was transferred to a skilled nursing facility after discharge and referred to dermatology for evaluation of the worsening pruritic rash.

At the current presentation, the patient denied close contact with anyone who had a similar rash at home or at the skilled nursing facility. Physical examination revealed diffuse erythroderma with yellow scale on the scalp, trunk, arms, and legs (Figure 1). The palms showed scattered 2- to 3-mm pustules. The mucosal surfaces did not have lesions. A punch biopsy of a pustule from the right arm revealed focal spongiosis, parakeratosis, and acanthosis, as well as a perivascular and interstitial mixed inflammatory infiltrate with lymphocytes and eosinophils. Organisms morphologically compatible with scabies were found in the stratum corneum (Figure 2). Another punch biopsy of a pustule from the right arm was performed for direct immunofluorescence (DIF) and was negative for immunoglobulin deposition. Mineral oil preparation from pustules on the palm was positive for mites.

The patient was treated with permethrin cream 5% and oral ivermectin 200 μg/kg on day 1 and day 10. The prednisone dosage was increased from 10 mg/d to 50 mg/d and tapered over 2 weeks to treat the symptomatic rash and GPA. He remains on maintenance rituximab for GPA, without recurrence of scabies.

Comment

Pathogenesis—As an obligate parasite, S scabiei spends its entire life cycle within the host. Impregnated female mites burrow into the epidermis after mating and lay eggs daily for 1 to 2 months. Eggs hatch 2 or 3 days later. Larvae then migrate to the skin surface; burrow into the stratum corneum, where they mature into adults; and then mate on the skin surface.^1,4

Clinical Presentation and Sequelae—Typically, scabies presents 2 to 6 weeks after initial exposure with generalized and intense itching and inflammatory pruritic papules on the finger webs, wrists, elbows, axillae, buttocks, umbilicus, genitalia, and areolae.¹ Burrows are specific for scabies but may not always be present. Often, there are nonspecific secondary lesions, including excoriations, dermatitis, and impetiginization.

Complications of scabies can be severe, with initial colonization and infection of the skin resulting in impetigo and cellulitis. Systematic sequelae from local skin infection include post-streptococcal glomerulonephritis, rheumatic fever, and sepsis. Mortality from sepsis in scabies can be high.^3,5

Classic Crusted Scabies and Other Variants—Crusted scabies presents with psoriasiform hyperkeratotic plaques involving the hands and feet with potential nail involvement that can become more generalized.¹ Alterations in CD4⁺ T-cell function have been implicated in the development of crusted scabies, in which an excessive helper T cell (T_H2) response is elicited against the ectoparasite, which may help explain the intense pruritus of scabies.⁶ Occasionally, iatrogenic immunosuppression contributes to development of crusted scabies,¹ as was the case with our patient. However, it is rare for crusted scabies to present with erythroderma.⁷

Other atypical presentations of scabies include a seborrheic dermatitis–like presentation in infants, nodular lesions in the groin and axillae in more chronic scabies, and vesicles or bullous lesions.¹

Diagnosis—Identification of mites, eggs, or feces is necessary for definitive diagnosis of scabies.⁸ These materials can be obtained through skin scrapings with mineral oil and observed under light microscopy or direct dermoscopy. Multiple scrapings on many lesions should be performed because failure to identify mites can be common and does not rule out scabies. Dermoscopic examination of active lesions under low power also can be helpful, given that identification of dark brown triangular structures can correspond to visualization of the pigmented anterior section of the mite.^9-11 A skin biopsy can help identify mites, but histopathology often shows a nonspecific hypersensitivity reaction.¹² Therefore, empiric treatment often is necessary.

Differential Diagnosis—The differential diagnosis of erythroderma is broad and includes a drug eruption; Sézary syndrome; and pre-existing skin diseases, including psoriasis, atopic dermatitis, pityriasis rubra pilaris, pemphigus foliaceus, and bullous pemphigoid. Histopathology is critical to differentiate these diagnoses. Bullous pemphigoid and pemphigus foliaceus are immunobullous diseases that typically are positive for immunoglobulin deposition on DIF. In rare cases, scabies also can present with bullae and positive DIF test results.¹³

Treatment—First-line treatment of crusted scabies in the United States is permethrin cream 5%, followed by oral ivermectin 200 μg/kg.^4,5,14,15 Other scabicides include topicals such as benzyl benzoate 10% to 25%; precipitated sulfur 2% to 10%; crotamiton 10%; malathion 0.5%; and lindane 1%.⁵ The association of neurotoxicity with lindane has considerably reduced the drug’s use.¹

During treatment of scabies, it is important to isolate patients to mitigate the possibility of spread.⁴ Pruritus can persist for a few weeks after completion of therapy.⁵ Patients should be closely monitored to ensure that this symptom is secondary to skin inflammation and not incomplete treatment.

Treatment of crusted scabies may require repeated treatments to decrease the notable mite burden as well as the associated crusting and scale. Adding a keratolytic such as 5% to 10% salicylic acid in petrolatum to the treatment regimen may be useful for breaking up thick scale.⁵

Immunosuppression—With numerous immunomodulatory drugs for treating autoimmunity comes an increased risk for iatrogenic immunosuppression that may contribute to the development of crusted scabies.¹⁶ In a number of autoimmune diseases such as rheumatoid arthritis,^17-19 psoriasis,^20,21 pemphigus vulgaris,²² systemic lupus erythematosus,²³ systemic sclerosis,^22,24 bullous pemphigoid,^25,26 and dermatomyositis,²⁷ patients have developed crusted scabies secondary to treatment-related immunosuppression. These immunosuppressive therapies include systemic steroids,^22-24,26-31 methotrexate,²³ infliximab,¹⁸ adalimumab,²¹ toclizumab,¹⁹ and etanercept.²⁰ In a case of drug-induced Stevens-Johnson syndrome, the patient developed crusted scabies during long-term use of oral steroids.²²

Patients with a malignancy who are being treated with chemotherapy also can develop crusted scabies.²⁸ Crusted scabies has even been associated with long-term topical steroid^32-34 and topical calcineurin inhibitor use.¹⁶

Iatrogenic immunosuppression in our patient resulted from treatment of GPA with azathioprine, an immunosuppressive drug that acts as an antagonist of the breakdown of purines, leading to inhibition of DNA, RNA, and protein synthesis.³⁵ On occasion, azathioprine can induce immunosuppression in the form of myelosuppression and resulting pancytopenia, as was the case with our patient.

Conclusion

Although scabies is designated as a neglected tropical disease by the World Health Organization, it still causes a notable burden worldwide, regardless of the economics. Our case highlights an unusual presentation of scabies as erythroderma in the setting of iatrogenic immunosuppression from azathioprine use. Dermatologists should consider crusted scabies in the differential diagnosis of erythroderma, especially in immunocompromised patients, to avoid delays in diagnosis and treatment. Immunosuppressive therapy is an important mainstay in the treatment of many conditions, but it is important to consider that these medications can place patients at an increased risk for rare opportunistic infections. Therefore, patients receiving such treatment should be closely monitored.

Scabies is caused by cutaneous ectoparasitic infection by the mite Sarcoptes scabiei var hominis. The infection is highly contagious via direct skin-to-skin contact or indirectly through infested bedding, clothing or fomites.^1,2 Scabies occurs at all ages, in all ethnic groups, and at all socioeconomic levels.¹ Analysis by the Global Burden of Disease estimates that 200 million individuals have been infected with scabies worldwide. The World Health Organization has declared scabies a neglected tropical disease.³

Crusted scabies is a severe and rare form of scabies, with hyperinfestation of thousands to millions of mites, and more commonly is associated with immunosuppressed states, including HIV and hematologic malignancies.^1,2,4 Crusted scabies has a high mortality rate due to sepsis when left untreated.^3,5

Occasionally, iatrogenic immunosuppression contributes to the development of crusted scabies.^1,2 Iatrogenic immunosuppression leading to crusted scabies most commonly occurs secondary to immunosuppression after bone marrow or solid organ transplantation.⁶ Less often, crusted scabies is caused by iatrogenic immunosuppression from other clinical scenarios.^1,2

We describe a patient with iatrogenic immunosuppression due to azathioprine-induced myelosuppression for the treatment of granulomatosis with polyangiitis (GPA) who developed crusted scabies that clinically presented as erythroderma. Crusted scabies should be included in the differential diagnosis of erythroderma, especially in the setting of iatrogenic immunosuppression, for timely and appropriate management.

Case Report

An 84-year-old man presented with worsening pruritus, erythema, and thick yellow scale that progressed to erythroderma over the last 2 weeks. He was diagnosed with GPA 6 months prior to presentation and was treated with azathioprine 150 mg/d, prednisone 10 mg/d, and sulfamethoxazole 800 mg plus trimethoprim 160 mg twice weekly for prophylaxis against Pneumocystis jirovecii pneumonia.

Three weeks prior to presentation, the patient was hospitalized for pancytopenia attributed to azathioprine-induced myelosuppression (hemoglobin, 6.1 g/dL [reference range, 13.5–18.0 g/dL]; hematocrit, 17.5% [reference range, 42%–52%]; white blood cell count, 1.66×10³/μL [reference range, 4.0–10.5×10³/μL]; platelet count, 146×10³/μL [reference range, 150–450×10³/μL]; absolute neutrophil count, 1.29×10³/μL [reference range, 1.4–6.5×10³/μL]). He was transferred to a skilled nursing facility after discharge and referred to dermatology for evaluation of the worsening pruritic rash.

At the current presentation, the patient denied close contact with anyone who had a similar rash at home or at the skilled nursing facility. Physical examination revealed diffuse erythroderma with yellow scale on the scalp, trunk, arms, and legs (Figure 1). The palms showed scattered 2- to 3-mm pustules. The mucosal surfaces did not have lesions. A punch biopsy of a pustule from the right arm revealed focal spongiosis, parakeratosis, and acanthosis, as well as a perivascular and interstitial mixed inflammatory infiltrate with lymphocytes and eosinophils. Organisms morphologically compatible with scabies were found in the stratum corneum (Figure 2). Another punch biopsy of a pustule from the right arm was performed for direct immunofluorescence (DIF) and was negative for immunoglobulin deposition. Mineral oil preparation from pustules on the palm was positive for mites.

The patient was treated with permethrin cream 5% and oral ivermectin 200 μg/kg on day 1 and day 10. The prednisone dosage was increased from 10 mg/d to 50 mg/d and tapered over 2 weeks to treat the symptomatic rash and GPA. He remains on maintenance rituximab for GPA, without recurrence of scabies.

Comment

Pathogenesis—As an obligate parasite, S scabiei spends its entire life cycle within the host. Impregnated female mites burrow into the epidermis after mating and lay eggs daily for 1 to 2 months. Eggs hatch 2 or 3 days later. Larvae then migrate to the skin surface; burrow into the stratum corneum, where they mature into adults; and then mate on the skin surface.^1,4

Clinical Presentation and Sequelae—Typically, scabies presents 2 to 6 weeks after initial exposure with generalized and intense itching and inflammatory pruritic papules on the finger webs, wrists, elbows, axillae, buttocks, umbilicus, genitalia, and areolae.¹ Burrows are specific for scabies but may not always be present. Often, there are nonspecific secondary lesions, including excoriations, dermatitis, and impetiginization.

Complications of scabies can be severe, with initial colonization and infection of the skin resulting in impetigo and cellulitis. Systematic sequelae from local skin infection include post-streptococcal glomerulonephritis, rheumatic fever, and sepsis. Mortality from sepsis in scabies can be high.^3,5

Classic Crusted Scabies and Other Variants—Crusted scabies presents with psoriasiform hyperkeratotic plaques involving the hands and feet with potential nail involvement that can become more generalized.¹ Alterations in CD4⁺ T-cell function have been implicated in the development of crusted scabies, in which an excessive helper T cell (T_H2) response is elicited against the ectoparasite, which may help explain the intense pruritus of scabies.⁶ Occasionally, iatrogenic immunosuppression contributes to development of crusted scabies,¹ as was the case with our patient. However, it is rare for crusted scabies to present with erythroderma.⁷

Other atypical presentations of scabies include a seborrheic dermatitis–like presentation in infants, nodular lesions in the groin and axillae in more chronic scabies, and vesicles or bullous lesions.¹

Diagnosis—Identification of mites, eggs, or feces is necessary for definitive diagnosis of scabies.⁸ These materials can be obtained through skin scrapings with mineral oil and observed under light microscopy or direct dermoscopy. Multiple scrapings on many lesions should be performed because failure to identify mites can be common and does not rule out scabies. Dermoscopic examination of active lesions under low power also can be helpful, given that identification of dark brown triangular structures can correspond to visualization of the pigmented anterior section of the mite.^9-11 A skin biopsy can help identify mites, but histopathology often shows a nonspecific hypersensitivity reaction.¹² Therefore, empiric treatment often is necessary.

Differential Diagnosis—The differential diagnosis of erythroderma is broad and includes a drug eruption; Sézary syndrome; and pre-existing skin diseases, including psoriasis, atopic dermatitis, pityriasis rubra pilaris, pemphigus foliaceus, and bullous pemphigoid. Histopathology is critical to differentiate these diagnoses. Bullous pemphigoid and pemphigus foliaceus are immunobullous diseases that typically are positive for immunoglobulin deposition on DIF. In rare cases, scabies also can present with bullae and positive DIF test results.¹³

Treatment—First-line treatment of crusted scabies in the United States is permethrin cream 5%, followed by oral ivermectin 200 μg/kg.^4,5,14,15 Other scabicides include topicals such as benzyl benzoate 10% to 25%; precipitated sulfur 2% to 10%; crotamiton 10%; malathion 0.5%; and lindane 1%.⁵ The association of neurotoxicity with lindane has considerably reduced the drug’s use.¹

During treatment of scabies, it is important to isolate patients to mitigate the possibility of spread.⁴ Pruritus can persist for a few weeks after completion of therapy.⁵ Patients should be closely monitored to ensure that this symptom is secondary to skin inflammation and not incomplete treatment.

Treatment of crusted scabies may require repeated treatments to decrease the notable mite burden as well as the associated crusting and scale. Adding a keratolytic such as 5% to 10% salicylic acid in petrolatum to the treatment regimen may be useful for breaking up thick scale.⁵

Immunosuppression—With numerous immunomodulatory drugs for treating autoimmunity comes an increased risk for iatrogenic immunosuppression that may contribute to the development of crusted scabies.¹⁶ In a number of autoimmune diseases such as rheumatoid arthritis,^17-19 psoriasis,^20,21 pemphigus vulgaris,²² systemic lupus erythematosus,²³ systemic sclerosis,^22,24 bullous pemphigoid,^25,26 and dermatomyositis,²⁷ patients have developed crusted scabies secondary to treatment-related immunosuppression. These immunosuppressive therapies include systemic steroids,^22-24,26-31 methotrexate,²³ infliximab,¹⁸ adalimumab,²¹ toclizumab,¹⁹ and etanercept.²⁰ In a case of drug-induced Stevens-Johnson syndrome, the patient developed crusted scabies during long-term use of oral steroids.²²

Patients with a malignancy who are being treated with chemotherapy also can develop crusted scabies.²⁸ Crusted scabies has even been associated with long-term topical steroid^32-34 and topical calcineurin inhibitor use.¹⁶

Iatrogenic immunosuppression in our patient resulted from treatment of GPA with azathioprine, an immunosuppressive drug that acts as an antagonist of the breakdown of purines, leading to inhibition of DNA, RNA, and protein synthesis.³⁵ On occasion, azathioprine can induce immunosuppression in the form of myelosuppression and resulting pancytopenia, as was the case with our patient.

Conclusion

Although scabies is designated as a neglected tropical disease by the World Health Organization, it still causes a notable burden worldwide, regardless of the economics. Our case highlights an unusual presentation of scabies as erythroderma in the setting of iatrogenic immunosuppression from azathioprine use. Dermatologists should consider crusted scabies in the differential diagnosis of erythroderma, especially in immunocompromised patients, to avoid delays in diagnosis and treatment. Immunosuppressive therapy is an important mainstay in the treatment of many conditions, but it is important to consider that these medications can place patients at an increased risk for rare opportunistic infections. Therefore, patients receiving such treatment should be closely monitored.

To the Editor:

A 47-year-old man presented to the dermatology service with an asymptomatic plaque on the right thigh of 2 months’ duration. He had a medical history of HIV and Kaposi sarcoma as well as a recently relapsed primary effusion lymphoma (PEL) subsequent to an allogeneic bone marrow transplant. He initially was diagnosed with PEL 3 years prior to the current presentation during a workup for fever and weight loss. Imaging at the time demonstrated a bladder mass, which was biopsied and demonstrated PEL. Further imaging demonstrated both sinus and bone marrow involvement. Prior to dermatologic consultation, he had been treated with 6 cycles of etoposide, prednisolone, vincristine, cyclophosphamide, and doxorubicin (EPOCH); 6 cycles of brentuximab; 4 cycles of rituximab with gemcitabine and oxaliplatin; and 2 cycles of ifosfamide, carboplatin, and etoposide. Despite these therapies, he had 3 relapses, and oncology determined the need for a matched unrelated donor allogeneic stem cell transplant for his PEL.

At the time of dermatology consultation, the patient was being managed on daratumumab and bortezomib. Physical examination revealed an infiltrative plaque on the right inferomedial thigh measuring approximately 6.0 cm (largest dimension) with a small amount of peripheral scale (Figure 1). An ultrasound revealed notable subcutaneous tissue edema and increased vascularity without a discrete mass or fluid collection. A 4-mm punch biopsy demonstrated a dense infiltrate comprised of collections of histiocytes admixed with scattered plasma cells and mature lymphoid aggregates. Additionally, rare enlarged plasmablastic cells with scant basophilic cytoplasm and slightly irregular nuclear contours were visualized (Figure 2A). Immunohistochemistry was positive for CD3 with a normal CD4:CD8 ratio, CD68-highlighted histiocytes within the lymphoid aggregates, and human herpesvirus 8 (HHV-8)(or Kaposi sarcoma–associated herpesvirus) demonstrated stippled nuclear staining within the scattered large cells (Figure 2B). Epstein-Barr virus–encoded RNA staining was negative, though the area of interest was lost on deeper sectioning of the tissue block. The histopathologic findings were consistent with cutaneous extracavitary PEL. Shortly after this diagnosis, he died from disease complications.

Primary effusion lymphoma is an aggressive non-Hodgkin B-cell lymphoma that was first described by Knowles et al¹ in 1989. Primary effusion lymphoma occurs exclusively in the setting of HHV-8 infection and typically is associated with chronic immunosuppression related to HIV/AIDS. Cases that are negative for HIV-1 are rare but have been reported in organ transplant recipients and elderly men from areas with a high prevalence of HHV-8 infections. Most HIV-associated cases show concurrent Epstein-Barr virus infection, though the pathogenic meaning of this co-infection remains unclear.^2,3

Primary effusion lymphoma classically presents as an isolated effusion of malignant lymphoid cells within body cavities in the absence of solid tumor masses. The pleural, peritoneal, and pericardial spaces most commonly are involved. Extracavitary PEL, a rare variant, may present as a solid mass without effusion. In general, extracavitary tumors may occur in the setting of de novo malignancy or recurrent PEL.⁴ Cutaneous manifestations associated with extracavitary PEL are rare; 4 cases have been described in which skin lesions were the heralding sign of the disease.³ Interestingly, despite obligatory underlying HHV-8 infection, a review by Pielasinski et al³ noted only 2 patients with cutaneous PEL who had prior or concurrent Kaposi sarcoma. This heterogeneity in HHV-8–related phenotypes may be related to differences in microRNA expression, but further study is needed.⁵

The diagnosis of PEL relies on histologic, immunophenotypic, and molecular analysis of the affected tissue. The malignant cells typically are large with round to irregular nuclei. These cells may demonstrate a variety of appearances, including anaplastic, plasmablastic, and immunoblastic morphologies.^6,7 The immunophenotype displays CD45 positivity and markers of lymphocyte activation (CD30, CD38, CD71), while typical B-cell (CD19, CD20, CD79a) and T-cell (CD3, CD4, CD8) markers often are absent.^6-8 Human herpesvirus 8 detection by polymerase chain reaction testing of the peripheral blood or by immunohistochemistry staining of the affected tissue is required for diagnosis.^6,7 Epstein-Barr virus infection may be detected via in situ hybridization, though it is not required for diagnosis.

The overall prognosis for PEL is poor; Brimo et al⁶ reported a median survival of less than 6 months, and Guillet et al⁹ reported 5-year overall survival (OS) for PEL vs extracavitary PEL to be 43% vs 39%. Another review noted variation in survival contingent on the number of body cavities involved; patients with a single body cavity involved experienced a median OS of 18 months, whereas patients with multiple involved cavities experienced a median OS of 4 months,⁷ possibly due to the limited study of treatment regimens or disease aggressiveness. Even in cases of successful initial treatment, relapse within 6 to 8 months is common. Extracavitary PEL may have improved disease-free survival relative to classic PEL, though the data were less clear for OS.⁹ Limitations of the Guillet et al⁹ study included a small sample size, the impossibility to randomize to disease type, and loss of power on the log-rank test for OS in the setting of possible nonproportional hazards (crossing survival curves). Overall, prognostic differences between the groups may be challenging to ascertain until further data are obtained.

As with many HIV-associated neoplasms, antiretroviral treatment (ART) for HIV-positive patients affords a better prognosis when used in addition to therapy directed at malignancy.⁷ The general approach is for concurrent ART with systemic therapies such as rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone for the rare CD20⁺ cases, and cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or dose-adjusted EPOCH therapy in the more common CD20⁻ PEL cases. Narkhede et al⁷ suggested avoidance of methotrexate in patients with effusions because of increased toxicity, but it is unclear if this recommendation is applicable in extracavitary PEL patients without an effusion. Additionally, second-line treatment modalities include radiation for solid PEL masses, HHV-8–targeted antivirals, and stem cell transplantation, though evidence is limited. Of note, there is a phase I-II trial (ClinicalTrials.gov identifier NCT02911142) ongoing for treatment-naïve PEL patients involving the experimental treatment DA-EPOCH-R plus lenalidomide, but the trial is ongoing.¹⁰

We report a case of cutaneous PEL in a patient with a history of Kaposi sarcoma. The patient’s deterioration and ultimate death despite initial treatment with EPOCH and bone marrow transplantation followed by final management with daratumumab and bortezomib confirm other reports that PEL has a poor prognosis and that optimal treatments are not well delineated for these patients. In general, the current approach is to utilize ART for HIV-positive patients and to then implement chemotherapy such as CHOP. Without continued research and careful planning of treatments, data will remain limited on how best to serve patients with PEL.

To the Editor:

A 47-year-old man presented to the dermatology service with an asymptomatic plaque on the right thigh of 2 months’ duration. He had a medical history of HIV and Kaposi sarcoma as well as a recently relapsed primary effusion lymphoma (PEL) subsequent to an allogeneic bone marrow transplant. He initially was diagnosed with PEL 3 years prior to the current presentation during a workup for fever and weight loss. Imaging at the time demonstrated a bladder mass, which was biopsied and demonstrated PEL. Further imaging demonstrated both sinus and bone marrow involvement. Prior to dermatologic consultation, he had been treated with 6 cycles of etoposide, prednisolone, vincristine, cyclophosphamide, and doxorubicin (EPOCH); 6 cycles of brentuximab; 4 cycles of rituximab with gemcitabine and oxaliplatin; and 2 cycles of ifosfamide, carboplatin, and etoposide. Despite these therapies, he had 3 relapses, and oncology determined the need for a matched unrelated donor allogeneic stem cell transplant for his PEL.

At the time of dermatology consultation, the patient was being managed on daratumumab and bortezomib. Physical examination revealed an infiltrative plaque on the right inferomedial thigh measuring approximately 6.0 cm (largest dimension) with a small amount of peripheral scale (Figure 1). An ultrasound revealed notable subcutaneous tissue edema and increased vascularity without a discrete mass or fluid collection. A 4-mm punch biopsy demonstrated a dense infiltrate comprised of collections of histiocytes admixed with scattered plasma cells and mature lymphoid aggregates. Additionally, rare enlarged plasmablastic cells with scant basophilic cytoplasm and slightly irregular nuclear contours were visualized (Figure 2A). Immunohistochemistry was positive for CD3 with a normal CD4:CD8 ratio, CD68-highlighted histiocytes within the lymphoid aggregates, and human herpesvirus 8 (HHV-8)(or Kaposi sarcoma–associated herpesvirus) demonstrated stippled nuclear staining within the scattered large cells (Figure 2B). Epstein-Barr virus–encoded RNA staining was negative, though the area of interest was lost on deeper sectioning of the tissue block. The histopathologic findings were consistent with cutaneous extracavitary PEL. Shortly after this diagnosis, he died from disease complications.

Primary effusion lymphoma is an aggressive non-Hodgkin B-cell lymphoma that was first described by Knowles et al¹ in 1989. Primary effusion lymphoma occurs exclusively in the setting of HHV-8 infection and typically is associated with chronic immunosuppression related to HIV/AIDS. Cases that are negative for HIV-1 are rare but have been reported in organ transplant recipients and elderly men from areas with a high prevalence of HHV-8 infections. Most HIV-associated cases show concurrent Epstein-Barr virus infection, though the pathogenic meaning of this co-infection remains unclear.^2,3

Primary effusion lymphoma classically presents as an isolated effusion of malignant lymphoid cells within body cavities in the absence of solid tumor masses. The pleural, peritoneal, and pericardial spaces most commonly are involved. Extracavitary PEL, a rare variant, may present as a solid mass without effusion. In general, extracavitary tumors may occur in the setting of de novo malignancy or recurrent PEL.⁴ Cutaneous manifestations associated with extracavitary PEL are rare; 4 cases have been described in which skin lesions were the heralding sign of the disease.³ Interestingly, despite obligatory underlying HHV-8 infection, a review by Pielasinski et al³ noted only 2 patients with cutaneous PEL who had prior or concurrent Kaposi sarcoma. This heterogeneity in HHV-8–related phenotypes may be related to differences in microRNA expression, but further study is needed.⁵

The diagnosis of PEL relies on histologic, immunophenotypic, and molecular analysis of the affected tissue. The malignant cells typically are large with round to irregular nuclei. These cells may demonstrate a variety of appearances, including anaplastic, plasmablastic, and immunoblastic morphologies.^6,7 The immunophenotype displays CD45 positivity and markers of lymphocyte activation (CD30, CD38, CD71), while typical B-cell (CD19, CD20, CD79a) and T-cell (CD3, CD4, CD8) markers often are absent.^6-8 Human herpesvirus 8 detection by polymerase chain reaction testing of the peripheral blood or by immunohistochemistry staining of the affected tissue is required for diagnosis.^6,7 Epstein-Barr virus infection may be detected via in situ hybridization, though it is not required for diagnosis.

The overall prognosis for PEL is poor; Brimo et al⁶ reported a median survival of less than 6 months, and Guillet et al⁹ reported 5-year overall survival (OS) for PEL vs extracavitary PEL to be 43% vs 39%. Another review noted variation in survival contingent on the number of body cavities involved; patients with a single body cavity involved experienced a median OS of 18 months, whereas patients with multiple involved cavities experienced a median OS of 4 months,⁷ possibly due to the limited study of treatment regimens or disease aggressiveness. Even in cases of successful initial treatment, relapse within 6 to 8 months is common. Extracavitary PEL may have improved disease-free survival relative to classic PEL, though the data were less clear for OS.⁹ Limitations of the Guillet et al⁹ study included a small sample size, the impossibility to randomize to disease type, and loss of power on the log-rank test for OS in the setting of possible nonproportional hazards (crossing survival curves). Overall, prognostic differences between the groups may be challenging to ascertain until further data are obtained.

As with many HIV-associated neoplasms, antiretroviral treatment (ART) for HIV-positive patients affords a better prognosis when used in addition to therapy directed at malignancy.⁷ The general approach is for concurrent ART with systemic therapies such as rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone for the rare CD20⁺ cases, and cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or dose-adjusted EPOCH therapy in the more common CD20⁻ PEL cases. Narkhede et al⁷ suggested avoidance of methotrexate in patients with effusions because of increased toxicity, but it is unclear if this recommendation is applicable in extracavitary PEL patients without an effusion. Additionally, second-line treatment modalities include radiation for solid PEL masses, HHV-8–targeted antivirals, and stem cell transplantation, though evidence is limited. Of note, there is a phase I-II trial (ClinicalTrials.gov identifier NCT02911142) ongoing for treatment-naïve PEL patients involving the experimental treatment DA-EPOCH-R plus lenalidomide, but the trial is ongoing.¹⁰

We report a case of cutaneous PEL in a patient with a history of Kaposi sarcoma. The patient’s deterioration and ultimate death despite initial treatment with EPOCH and bone marrow transplantation followed by final management with daratumumab and bortezomib confirm other reports that PEL has a poor prognosis and that optimal treatments are not well delineated for these patients. In general, the current approach is to utilize ART for HIV-positive patients and to then implement chemotherapy such as CHOP. Without continued research and careful planning of treatments, data will remain limited on how best to serve patients with PEL.

To the Editor:

A 47-year-old man presented to the dermatology service with an asymptomatic plaque on the right thigh of 2 months’ duration. He had a medical history of HIV and Kaposi sarcoma as well as a recently relapsed primary effusion lymphoma (PEL) subsequent to an allogeneic bone marrow transplant. He initially was diagnosed with PEL 3 years prior to the current presentation during a workup for fever and weight loss. Imaging at the time demonstrated a bladder mass, which was biopsied and demonstrated PEL. Further imaging demonstrated both sinus and bone marrow involvement. Prior to dermatologic consultation, he had been treated with 6 cycles of etoposide, prednisolone, vincristine, cyclophosphamide, and doxorubicin (EPOCH); 6 cycles of brentuximab; 4 cycles of rituximab with gemcitabine and oxaliplatin; and 2 cycles of ifosfamide, carboplatin, and etoposide. Despite these therapies, he had 3 relapses, and oncology determined the need for a matched unrelated donor allogeneic stem cell transplant for his PEL.

At the time of dermatology consultation, the patient was being managed on daratumumab and bortezomib. Physical examination revealed an infiltrative plaque on the right inferomedial thigh measuring approximately 6.0 cm (largest dimension) with a small amount of peripheral scale (Figure 1). An ultrasound revealed notable subcutaneous tissue edema and increased vascularity without a discrete mass or fluid collection. A 4-mm punch biopsy demonstrated a dense infiltrate comprised of collections of histiocytes admixed with scattered plasma cells and mature lymphoid aggregates. Additionally, rare enlarged plasmablastic cells with scant basophilic cytoplasm and slightly irregular nuclear contours were visualized (Figure 2A). Immunohistochemistry was positive for CD3 with a normal CD4:CD8 ratio, CD68-highlighted histiocytes within the lymphoid aggregates, and human herpesvirus 8 (HHV-8)(or Kaposi sarcoma–associated herpesvirus) demonstrated stippled nuclear staining within the scattered large cells (Figure 2B). Epstein-Barr virus–encoded RNA staining was negative, though the area of interest was lost on deeper sectioning of the tissue block. The histopathologic findings were consistent with cutaneous extracavitary PEL. Shortly after this diagnosis, he died from disease complications.

Primary effusion lymphoma is an aggressive non-Hodgkin B-cell lymphoma that was first described by Knowles et al¹ in 1989. Primary effusion lymphoma occurs exclusively in the setting of HHV-8 infection and typically is associated with chronic immunosuppression related to HIV/AIDS. Cases that are negative for HIV-1 are rare but have been reported in organ transplant recipients and elderly men from areas with a high prevalence of HHV-8 infections. Most HIV-associated cases show concurrent Epstein-Barr virus infection, though the pathogenic meaning of this co-infection remains unclear.^2,3

Primary effusion lymphoma classically presents as an isolated effusion of malignant lymphoid cells within body cavities in the absence of solid tumor masses. The pleural, peritoneal, and pericardial spaces most commonly are involved. Extracavitary PEL, a rare variant, may present as a solid mass without effusion. In general, extracavitary tumors may occur in the setting of de novo malignancy or recurrent PEL.⁴ Cutaneous manifestations associated with extracavitary PEL are rare; 4 cases have been described in which skin lesions were the heralding sign of the disease.³ Interestingly, despite obligatory underlying HHV-8 infection, a review by Pielasinski et al³ noted only 2 patients with cutaneous PEL who had prior or concurrent Kaposi sarcoma. This heterogeneity in HHV-8–related phenotypes may be related to differences in microRNA expression, but further study is needed.⁵

The diagnosis of PEL relies on histologic, immunophenotypic, and molecular analysis of the affected tissue. The malignant cells typically are large with round to irregular nuclei. These cells may demonstrate a variety of appearances, including anaplastic, plasmablastic, and immunoblastic morphologies.^6,7 The immunophenotype displays CD45 positivity and markers of lymphocyte activation (CD30, CD38, CD71), while typical B-cell (CD19, CD20, CD79a) and T-cell (CD3, CD4, CD8) markers often are absent.^6-8 Human herpesvirus 8 detection by polymerase chain reaction testing of the peripheral blood or by immunohistochemistry staining of the affected tissue is required for diagnosis.^6,7 Epstein-Barr virus infection may be detected via in situ hybridization, though it is not required for diagnosis.

The overall prognosis for PEL is poor; Brimo et al⁶ reported a median survival of less than 6 months, and Guillet et al⁹ reported 5-year overall survival (OS) for PEL vs extracavitary PEL to be 43% vs 39%. Another review noted variation in survival contingent on the number of body cavities involved; patients with a single body cavity involved experienced a median OS of 18 months, whereas patients with multiple involved cavities experienced a median OS of 4 months,⁷ possibly due to the limited study of treatment regimens or disease aggressiveness. Even in cases of successful initial treatment, relapse within 6 to 8 months is common. Extracavitary PEL may have improved disease-free survival relative to classic PEL, though the data were less clear for OS.⁹ Limitations of the Guillet et al⁹ study included a small sample size, the impossibility to randomize to disease type, and loss of power on the log-rank test for OS in the setting of possible nonproportional hazards (crossing survival curves). Overall, prognostic differences between the groups may be challenging to ascertain until further data are obtained.

As with many HIV-associated neoplasms, antiretroviral treatment (ART) for HIV-positive patients affords a better prognosis when used in addition to therapy directed at malignancy.⁷ The general approach is for concurrent ART with systemic therapies such as rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone for the rare CD20⁺ cases, and cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or dose-adjusted EPOCH therapy in the more common CD20⁻ PEL cases. Narkhede et al⁷ suggested avoidance of methotrexate in patients with effusions because of increased toxicity, but it is unclear if this recommendation is applicable in extracavitary PEL patients without an effusion. Additionally, second-line treatment modalities include radiation for solid PEL masses, HHV-8–targeted antivirals, and stem cell transplantation, though evidence is limited. Of note, there is a phase I-II trial (ClinicalTrials.gov identifier NCT02911142) ongoing for treatment-naïve PEL patients involving the experimental treatment DA-EPOCH-R plus lenalidomide, but the trial is ongoing.¹⁰

We report a case of cutaneous PEL in a patient with a history of Kaposi sarcoma. The patient’s deterioration and ultimate death despite initial treatment with EPOCH and bone marrow transplantation followed by final management with daratumumab and bortezomib confirm other reports that PEL has a poor prognosis and that optimal treatments are not well delineated for these patients. In general, the current approach is to utilize ART for HIV-positive patients and to then implement chemotherapy such as CHOP. Without continued research and careful planning of treatments, data will remain limited on how best to serve patients with PEL.

To the Editor:

Squamous cell carcinoma (SCC) is the second most common cancer of the scalp.¹ Mohs micrographic surgery is used to treat SCC, and it commonly generates a 2.5×2.5-cm open wound with exposed bone.² Although Mohs micrographic surgery effectively treats cutaneous lesions, it carries a high risk for complications such as infection, wound dehiscence, and partial or full-thickness skin graft necrosis.³ Recommended therapies to decrease these complications include linear closures, flaps, and peripheral autograft tissue.⁴ However, these procedures do not come without risks and carry their own complications. Therefore, we suggest a safe, less-invasive initial approach using a synthetic extracellular matrix (ECM)–based collagen dressing for secondary wound closure.

A 76-year-old woman presented to the infectious disease clinic at Monument Health Rapid City Clinic (Rapid City, South Dakota) for evaluation of a dehisced scalp wound 3 months following Mohs micrographic surgery for scalp SCC. The wound underwent primary closure following surgery and dehisced shortly after (Figure 1A). Various oral antimicrobials were used by the dermatologist to assist with wound closure but without success. The patient was referred to the wound clinic for management. At the first appointment, all necrotic tissue was debrided and the cranium was exposed in the wound base (Figure 1B). The wound measured 2.3×2.3×0.2 cm. An ECM-containing collagen dressing (Endoform Natural Restorative Bioscaffold [Aroa Biosurgery Inc]) was used to provide a scaffold for wound closure (Figure 2A). It was dressed with the petroleum-based gauze Xeroform (Cardinal Health) and covered with dry gauze to prevent evaporation and provide moist wound healing. The wound developed some budding tissue islands 3 weeks after weekly ECM-based collagen dressing applications (Figure 3A). The wound continued to decrease in size and formed an isthmus by the second month of therapy (Figure 3B). The wound fully closed within 3 months and showed minimal scarring after 3 years (Figure 2B).

Chronic wounds usually get trapped in the inflammatory stage of wound healing due to destruction of growth factors and ECM by metalloproteases (MMPs), which creates a vicious cycle and wound stalling. Wound debridement converts a chronic wound back into an acute wound, which is the first step of healing. Following wound debridement, collagen-based dressings can assist with healing by binding the destructive MMPs, and ECM matrix promotes the building of new tissue. The 3 most commonly used ECM-based collagen dressings are Endoform, PuraPly AM (Organogenesis Inc), and Puracol Ultra ECM (Medline Industries, Inc).

Endoform is ovine-based collagen and provides a natural porous bioscaffold for rapid cell infiltration.⁵ It contains more than 150 ECM proteins along with residual vascular channels that help re-establish new vasculature. Ovine-based collagen contains collagen types I, III, and IV arranged as native fibers that retain the 3-dimensional architecture present in tissue ECM.⁵ Although MMPs are essential in normal healing, the elevated presence of MMPs has been linked to stalled wound healing. Clinical observation and assessment may not be sufficient to identify a wound with elevated protease activity that can break down ECM, affect wound fibroblasts, and impair growth factor response. Although collagen ECM itself does not contain any growth factors, it preserves the destruction of native ECM and growth factors by MMPs by functioning as a sacrificial substrate. The addition of 0.3% ionic silver to the ECM has been shown to decrease bacterial growth and prevent biofilm formation.⁶

PuraPly AM is a native, type I porcine collagen matrix embedded with the polyhexamethylene biguanide for the management of chronic wounds.⁷ The addition of polyhexamethylene biguanide to the ECM matrix provides bactericidal activity against biofilm formation.⁸ PuraPly AM reduced the counts of biofilm-producing pathogens such as Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida species, and Aspergillus niger in nonclinical studies. Use of polyhexamethylene biguanide has been seen within ECM grafts (PuraPly AM).

Puracol Ultra ECM is made of porcine mesothelium and is comprised of types I, III, and IV collagens; elastin; fibronectin; laminin; and proteoglycans. It also contains fibroblast growth factors, contributing to angiogenesis in the wound.⁹

Application of ECM-based collagen dressings on debrided wounds requires moisture for absorption. Because cranium wounds lack sufficient exudate production, dermal templates need to be hydrated with sterile normal saline before application and covered with a moisture-retaining dressing. Extracellular matrix–based dressings are biodegradable and can be reapplied every 5 to 7 days. For chronic wounds, application of collagen dressings, such as Endoform, is essential and could be considered as the first step prior to switching to more advanced wound care modalities.^6,10 Additional studies investigating ECM-containing may determine their comparative efficacy.

To the Editor:

Squamous cell carcinoma (SCC) is the second most common cancer of the scalp.¹ Mohs micrographic surgery is used to treat SCC, and it commonly generates a 2.5×2.5-cm open wound with exposed bone.² Although Mohs micrographic surgery effectively treats cutaneous lesions, it carries a high risk for complications such as infection, wound dehiscence, and partial or full-thickness skin graft necrosis.³ Recommended therapies to decrease these complications include linear closures, flaps, and peripheral autograft tissue.⁴ However, these procedures do not come without risks and carry their own complications. Therefore, we suggest a safe, less-invasive initial approach using a synthetic extracellular matrix (ECM)–based collagen dressing for secondary wound closure.

A 76-year-old woman presented to the infectious disease clinic at Monument Health Rapid City Clinic (Rapid City, South Dakota) for evaluation of a dehisced scalp wound 3 months following Mohs micrographic surgery for scalp SCC. The wound underwent primary closure following surgery and dehisced shortly after (Figure 1A). Various oral antimicrobials were used by the dermatologist to assist with wound closure but without success. The patient was referred to the wound clinic for management. At the first appointment, all necrotic tissue was debrided and the cranium was exposed in the wound base (Figure 1B). The wound measured 2.3×2.3×0.2 cm. An ECM-containing collagen dressing (Endoform Natural Restorative Bioscaffold [Aroa Biosurgery Inc]) was used to provide a scaffold for wound closure (Figure 2A). It was dressed with the petroleum-based gauze Xeroform (Cardinal Health) and covered with dry gauze to prevent evaporation and provide moist wound healing. The wound developed some budding tissue islands 3 weeks after weekly ECM-based collagen dressing applications (Figure 3A). The wound continued to decrease in size and formed an isthmus by the second month of therapy (Figure 3B). The wound fully closed within 3 months and showed minimal scarring after 3 years (Figure 2B).

Chronic wounds usually get trapped in the inflammatory stage of wound healing due to destruction of growth factors and ECM by metalloproteases (MMPs), which creates a vicious cycle and wound stalling. Wound debridement converts a chronic wound back into an acute wound, which is the first step of healing. Following wound debridement, collagen-based dressings can assist with healing by binding the destructive MMPs, and ECM matrix promotes the building of new tissue. The 3 most commonly used ECM-based collagen dressings are Endoform, PuraPly AM (Organogenesis Inc), and Puracol Ultra ECM (Medline Industries, Inc).

Endoform is ovine-based collagen and provides a natural porous bioscaffold for rapid cell infiltration.⁵ It contains more than 150 ECM proteins along with residual vascular channels that help re-establish new vasculature. Ovine-based collagen contains collagen types I, III, and IV arranged as native fibers that retain the 3-dimensional architecture present in tissue ECM.⁵ Although MMPs are essential in normal healing, the elevated presence of MMPs has been linked to stalled wound healing. Clinical observation and assessment may not be sufficient to identify a wound with elevated protease activity that can break down ECM, affect wound fibroblasts, and impair growth factor response. Although collagen ECM itself does not contain any growth factors, it preserves the destruction of native ECM and growth factors by MMPs by functioning as a sacrificial substrate. The addition of 0.3% ionic silver to the ECM has been shown to decrease bacterial growth and prevent biofilm formation.⁶

PuraPly AM is a native, type I porcine collagen matrix embedded with the polyhexamethylene biguanide for the management of chronic wounds.⁷ The addition of polyhexamethylene biguanide to the ECM matrix provides bactericidal activity against biofilm formation.⁸ PuraPly AM reduced the counts of biofilm-producing pathogens such as Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida species, and Aspergillus niger in nonclinical studies. Use of polyhexamethylene biguanide has been seen within ECM grafts (PuraPly AM).

Puracol Ultra ECM is made of porcine mesothelium and is comprised of types I, III, and IV collagens; elastin; fibronectin; laminin; and proteoglycans. It also contains fibroblast growth factors, contributing to angiogenesis in the wound.⁹

Application of ECM-based collagen dressings on debrided wounds requires moisture for absorption. Because cranium wounds lack sufficient exudate production, dermal templates need to be hydrated with sterile normal saline before application and covered with a moisture-retaining dressing. Extracellular matrix–based dressings are biodegradable and can be reapplied every 5 to 7 days. For chronic wounds, application of collagen dressings, such as Endoform, is essential and could be considered as the first step prior to switching to more advanced wound care modalities.^6,10 Additional studies investigating ECM-containing may determine their comparative efficacy.

To the Editor:

Squamous cell carcinoma (SCC) is the second most common cancer of the scalp.¹ Mohs micrographic surgery is used to treat SCC, and it commonly generates a 2.5×2.5-cm open wound with exposed bone.² Although Mohs micrographic surgery effectively treats cutaneous lesions, it carries a high risk for complications such as infection, wound dehiscence, and partial or full-thickness skin graft necrosis.³ Recommended therapies to decrease these complications include linear closures, flaps, and peripheral autograft tissue.⁴ However, these procedures do not come without risks and carry their own complications. Therefore, we suggest a safe, less-invasive initial approach using a synthetic extracellular matrix (ECM)–based collagen dressing for secondary wound closure.

A 76-year-old woman presented to the infectious disease clinic at Monument Health Rapid City Clinic (Rapid City, South Dakota) for evaluation of a dehisced scalp wound 3 months following Mohs micrographic surgery for scalp SCC. The wound underwent primary closure following surgery and dehisced shortly after (Figure 1A). Various oral antimicrobials were used by the dermatologist to assist with wound closure but without success. The patient was referred to the wound clinic for management. At the first appointment, all necrotic tissue was debrided and the cranium was exposed in the wound base (Figure 1B). The wound measured 2.3×2.3×0.2 cm. An ECM-containing collagen dressing (Endoform Natural Restorative Bioscaffold [Aroa Biosurgery Inc]) was used to provide a scaffold for wound closure (Figure 2A). It was dressed with the petroleum-based gauze Xeroform (Cardinal Health) and covered with dry gauze to prevent evaporation and provide moist wound healing. The wound developed some budding tissue islands 3 weeks after weekly ECM-based collagen dressing applications (Figure 3A). The wound continued to decrease in size and formed an isthmus by the second month of therapy (Figure 3B). The wound fully closed within 3 months and showed minimal scarring after 3 years (Figure 2B).

Chronic wounds usually get trapped in the inflammatory stage of wound healing due to destruction of growth factors and ECM by metalloproteases (MMPs), which creates a vicious cycle and wound stalling. Wound debridement converts a chronic wound back into an acute wound, which is the first step of healing. Following wound debridement, collagen-based dressings can assist with healing by binding the destructive MMPs, and ECM matrix promotes the building of new tissue. The 3 most commonly used ECM-based collagen dressings are Endoform, PuraPly AM (Organogenesis Inc), and Puracol Ultra ECM (Medline Industries, Inc).

Endoform is ovine-based collagen and provides a natural porous bioscaffold for rapid cell infiltration.⁵ It contains more than 150 ECM proteins along with residual vascular channels that help re-establish new vasculature. Ovine-based collagen contains collagen types I, III, and IV arranged as native fibers that retain the 3-dimensional architecture present in tissue ECM.⁵ Although MMPs are essential in normal healing, the elevated presence of MMPs has been linked to stalled wound healing. Clinical observation and assessment may not be sufficient to identify a wound with elevated protease activity that can break down ECM, affect wound fibroblasts, and impair growth factor response. Although collagen ECM itself does not contain any growth factors, it preserves the destruction of native ECM and growth factors by MMPs by functioning as a sacrificial substrate. The addition of 0.3% ionic silver to the ECM has been shown to decrease bacterial growth and prevent biofilm formation.⁶

PuraPly AM is a native, type I porcine collagen matrix embedded with the polyhexamethylene biguanide for the management of chronic wounds.⁷ The addition of polyhexamethylene biguanide to the ECM matrix provides bactericidal activity against biofilm formation.⁸ PuraPly AM reduced the counts of biofilm-producing pathogens such as Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida species, and Aspergillus niger in nonclinical studies. Use of polyhexamethylene biguanide has been seen within ECM grafts (PuraPly AM).

Puracol Ultra ECM is made of porcine mesothelium and is comprised of types I, III, and IV collagens; elastin; fibronectin; laminin; and proteoglycans. It also contains fibroblast growth factors, contributing to angiogenesis in the wound.⁹

Application of ECM-based collagen dressings on debrided wounds requires moisture for absorption. Because cranium wounds lack sufficient exudate production, dermal templates need to be hydrated with sterile normal saline before application and covered with a moisture-retaining dressing. Extracellular matrix–based dressings are biodegradable and can be reapplied every 5 to 7 days. For chronic wounds, application of collagen dressings, such as Endoform, is essential and could be considered as the first step prior to switching to more advanced wound care modalities.^6,10 Additional studies investigating ECM-containing may determine their comparative efficacy.

To the Editor:

A 12-year-old girl presented to the dermatology clinic for evaluation of a congenital scalp lesion. The patient was diagnosed with alopecia areata by a dermatologist at 4 years of age, and she was treated with topical corticosteroids and minoxidil, which failed to resolve her condition. Physical examination revealed an 8×10-cm, well-demarcated, yellowish-pink plaque located over the vertex and right parietal scalp (Figure 1A), extending down to the right preauricular cheek (Figure 1B) in a linear configuration with blaschkoid features. The scalp plaque appeared bald and completely lacking in terminal hairs but contained numerous fine vellus hairs (Figure 1A). A 6-mm, oval-appearing, pigmented papule was present in the plaque, and a few smaller, scattered, pigmented papules were noted in the vertex region (Figure 1A).

The cutaneous examination was otherwise unremarkable. A review of systems was negative, except for a history of attention-deficit/hyperactivity disorder. There was no history of seizures or other neurocognitive developmental abnormalities.

A 4-mm punch biopsy of the vertex scalp included the pigmented lesion but excluded an adnexal neoplasm. Epidermal acanthosis and mild papillomatosis were reported on microscopic examination. Multiple prominent sebaceous glands without associated hair follicles, which emptied directly onto the epidermal surface, were noted in the dermis (Figure 2). Several apocrine glands were observed (Figure 3). Epidermal and dermal melanocytic nests were highlighted with SOX-10 and Melan-A immunohistochemical stains, confirming the presence of a benign compound nevus. The punch biopsy analysis confirmed the diagnosis of a nevus sebaceus (NS) of Jadassohn (organoid nevus) with incidental compound nevus. Additional 4-mm punch biopsies were obtained for genetic testing, performed by the Genomics and Pathology Services at Washington University (St. Louis, Missouri). A missense HRAS p.G12V variant was observed in the tissue. A negative blood test result ruled out a germline mutation. The patient was managed with active observation of the lesion to evaluate for potential formation of neoplasms, as well as continuity of care with the dermatology clinic, considering the extent of the lesions, to monitor the development of any new medical conditions that would be concerning for syndromes associated with NS.

Nevus sebaceus is a benign skin hamartoma caused by a congenital defect in the pilosebaceous follicular unit and consists of epidermal, sebaceous, and apocrine elements.^1,2 In dermatology patients, the prevalence of NS ranges from 0.05% to 1%.¹ In 90% of cases, NS presents at birth as a 1- to 10-cm, round or linear, yellowish-orange, hairless plaque located on the scalp. It also may appear on the face, neck, trunk, oral mucosa, or labia minora.^1,3 Although NS is a benign condition, secondary tumors may form within the lesion.³

The physical and histologic characteristics of NS evolve as the patient ages. In childhood, NS typically appears as a yellow-pink macule or patch with mild to moderate epidermal hyperplasia. Patients exhibit underdeveloped sebaceous glands, immature hair follicles, hyperkeratosis, and acanthosis.^1,3,4 The development of early lesions can be quite subtle and can lead to diagnostic uncertainty, as described in our patient. During puberty, lesions thicken due to papillomatous hyperplasia in the epidermis, and the number and size of sebaceous and apocrine glands increase.⁴ In adults, the risk for secondary tumor formation increases. These physical and histologic transformations, including secondary tumor formation, are thought to be stimulated by the action of postpubertal androgens.¹

Nevus sebaceus is associated with both benign and malignant secondary tumor formation; however, fewer than 1% of tumors are malignant.¹ In a retrospective analysis, Idriss and Elston⁵ (N=707) reported that 21.4% of patients with NS had secondary neoplasms; 18.9% of the secondary neoplasms were benign, and 2.5% were malignant. Additionally, this study showed that secondary tumor formation can occur in children, though it typically occurs in adults. Benign neoplasms were reported in 5 children in the subset aged 0 to 10 years and 10 children in the subset aged 11 to 17 years; 1 child developed a malignant neoplasm in the latter subset.⁵ The most common NS-associated benign neoplasms include trichoblastoma and syringocystadenoma papilliferum. Others include trichilemmoma, apocrine/eccrine adenoma, and sebaceoma.¹ Nevus sebaceus–associated malignant neoplasms include basal cell carcinoma, squamous cell carcinoma, adenocarcinoma, carcinosarcoma, and sebaceous carcinoma.³

Our patient was incorrectly diagnosed and treated for alopecia areata before an eventual diagnosis of NS was confirmed by biopsy. Additional genetic studies revealed a novel mutation in the HRAS gene, the most commonly affected gene in NS. The most common mutation location seen in more than 90% of NS lesions is HRAS c.37G>C (p.G13R), while KRAS mutations account for almost all the remaining cases.³ In our patient, a pathogenic missense HRAS p.G12V variant of somatic origin was detected with DNA extraction and sequencing from a fresh tissue sample acquired from two 4-mm punch biopsies performed on the lesion. The following genes were sequenced and found to be uninvolved: BRAF, FGFR1, FGFR2, FGFR3, GNA11, GNAQ, KRAS, MAP3K3, NRAS, PIK3CA, and TEK. The Sanger sequencing method for comparative analysis performed on peripheral blood was negative.

Nevus sebaceus typically is caused by a sporadic mutation, though familial cases have been reported.¹ Additionally, germline HRAS mutations can lead to Costello syndrome, an autosomal-dominant disorder characterized by short stature; intellectual disabilities; coarse facial features; facial and perianal papillomata; cardiac defects; loose skin; joint hyperflexibility; and an increased risk for malignant tumors including rhabdomyosarcoma, neuroblastoma, and transitional cell carcinoma of the bladder.⁶

The diagnosis of NS often can be made clinically but can be difficult to confirm in underdeveloped lesions in young children. The differential diagnosis can include alopecia areata, aplasia cutis congenita, juvenile xanthogranuloma, epidermal nevus, de novo syringocystadenoma papilliferum, and solitary mastocytoma.¹ Nevus sebaceus can be associated with 4 additional syndromes: Schimmelpenning syndrome; phacomatosis pigmentokeratotica; didymosis aplasticosebacea; and SCALP (sebaceus nevus, central nervous system malformations, aplasia cutis congenital, limbal dermoid, pigmented nevus) syndrome.¹ Approximately 7% of NS cases may be associated with Schimmelpenning-Feuerstein-Mims (SFM) syndrome, a more severe condition that leads to systemic involvement and abnormalities in the neurological, ophthalmological, cardiovascular, genitourological, and skeletal systems.^1,3 Phacomatosis pigmentokeratotica has speckled lentiginous nevi, as well as abnormalities in the neurological, ophthalmological, cardiovascular, genitourological, and skeletal systems.¹ Didymosis aplasticosebacea is the concurrence of NS and aplasia cutis congenita.

The definitive treatment of NS is surgical excision. Alternative therapies include photodynamic therapy, fractional laser resurfacing, and dermabrasion; these are not definitive treatments, and patients must be monitored for the development of secondary neoplasms. Multiple variables must be considered when determining treatment, including patient age, risk potential for malignancy, and surgery-associated risks.¹ In our patient, given the extent of the lesions, active observation and follow-up was agreed upon for management.

This case demonstrates the importance of considering NS as an alternative diagnosis when alopecia areata has been diagnosed in a child who is unresponsive to treatments. After the diagnosis of NS is confirmed, more serious associated syndromes should be ruled out, and treatment should be tailored to each case.

To the Editor:

A 12-year-old girl presented to the dermatology clinic for evaluation of a congenital scalp lesion. The patient was diagnosed with alopecia areata by a dermatologist at 4 years of age, and she was treated with topical corticosteroids and minoxidil, which failed to resolve her condition. Physical examination revealed an 8×10-cm, well-demarcated, yellowish-pink plaque located over the vertex and right parietal scalp (Figure 1A), extending down to the right preauricular cheek (Figure 1B) in a linear configuration with blaschkoid features. The scalp plaque appeared bald and completely lacking in terminal hairs but contained numerous fine vellus hairs (Figure 1A). A 6-mm, oval-appearing, pigmented papule was present in the plaque, and a few smaller, scattered, pigmented papules were noted in the vertex region (Figure 1A).

The cutaneous examination was otherwise unremarkable. A review of systems was negative, except for a history of attention-deficit/hyperactivity disorder. There was no history of seizures or other neurocognitive developmental abnormalities.

A 4-mm punch biopsy of the vertex scalp included the pigmented lesion but excluded an adnexal neoplasm. Epidermal acanthosis and mild papillomatosis were reported on microscopic examination. Multiple prominent sebaceous glands without associated hair follicles, which emptied directly onto the epidermal surface, were noted in the dermis (Figure 2). Several apocrine glands were observed (Figure 3). Epidermal and dermal melanocytic nests were highlighted with SOX-10 and Melan-A immunohistochemical stains, confirming the presence of a benign compound nevus. The punch biopsy analysis confirmed the diagnosis of a nevus sebaceus (NS) of Jadassohn (organoid nevus) with incidental compound nevus. Additional 4-mm punch biopsies were obtained for genetic testing, performed by the Genomics and Pathology Services at Washington University (St. Louis, Missouri). A missense HRAS p.G12V variant was observed in the tissue. A negative blood test result ruled out a germline mutation. The patient was managed with active observation of the lesion to evaluate for potential formation of neoplasms, as well as continuity of care with the dermatology clinic, considering the extent of the lesions, to monitor the development of any new medical conditions that would be concerning for syndromes associated with NS.

Nevus sebaceus is a benign skin hamartoma caused by a congenital defect in the pilosebaceous follicular unit and consists of epidermal, sebaceous, and apocrine elements.^1,2 In dermatology patients, the prevalence of NS ranges from 0.05% to 1%.¹ In 90% of cases, NS presents at birth as a 1- to 10-cm, round or linear, yellowish-orange, hairless plaque located on the scalp. It also may appear on the face, neck, trunk, oral mucosa, or labia minora.^1,3 Although NS is a benign condition, secondary tumors may form within the lesion.³

The physical and histologic characteristics of NS evolve as the patient ages. In childhood, NS typically appears as a yellow-pink macule or patch with mild to moderate epidermal hyperplasia. Patients exhibit underdeveloped sebaceous glands, immature hair follicles, hyperkeratosis, and acanthosis.^1,3,4 The development of early lesions can be quite subtle and can lead to diagnostic uncertainty, as described in our patient. During puberty, lesions thicken due to papillomatous hyperplasia in the epidermis, and the number and size of sebaceous and apocrine glands increase.⁴ In adults, the risk for secondary tumor formation increases. These physical and histologic transformations, including secondary tumor formation, are thought to be stimulated by the action of postpubertal androgens.¹

Nevus sebaceus is associated with both benign and malignant secondary tumor formation; however, fewer than 1% of tumors are malignant.¹ In a retrospective analysis, Idriss and Elston⁵ (N=707) reported that 21.4% of patients with NS had secondary neoplasms; 18.9% of the secondary neoplasms were benign, and 2.5% were malignant. Additionally, this study showed that secondary tumor formation can occur in children, though it typically occurs in adults. Benign neoplasms were reported in 5 children in the subset aged 0 to 10 years and 10 children in the subset aged 11 to 17 years; 1 child developed a malignant neoplasm in the latter subset.⁵ The most common NS-associated benign neoplasms include trichoblastoma and syringocystadenoma papilliferum. Others include trichilemmoma, apocrine/eccrine adenoma, and sebaceoma.¹ Nevus sebaceus–associated malignant neoplasms include basal cell carcinoma, squamous cell carcinoma, adenocarcinoma, carcinosarcoma, and sebaceous carcinoma.³

Our patient was incorrectly diagnosed and treated for alopecia areata before an eventual diagnosis of NS was confirmed by biopsy. Additional genetic studies revealed a novel mutation in the HRAS gene, the most commonly affected gene in NS. The most common mutation location seen in more than 90% of NS lesions is HRAS c.37G>C (p.G13R), while KRAS mutations account for almost all the remaining cases.³ In our patient, a pathogenic missense HRAS p.G12V variant of somatic origin was detected with DNA extraction and sequencing from a fresh tissue sample acquired from two 4-mm punch biopsies performed on the lesion. The following genes were sequenced and found to be uninvolved: BRAF, FGFR1, FGFR2, FGFR3, GNA11, GNAQ, KRAS, MAP3K3, NRAS, PIK3CA, and TEK. The Sanger sequencing method for comparative analysis performed on peripheral blood was negative.

Nevus sebaceus typically is caused by a sporadic mutation, though familial cases have been reported.¹ Additionally, germline HRAS mutations can lead to Costello syndrome, an autosomal-dominant disorder characterized by short stature; intellectual disabilities; coarse facial features; facial and perianal papillomata; cardiac defects; loose skin; joint hyperflexibility; and an increased risk for malignant tumors including rhabdomyosarcoma, neuroblastoma, and transitional cell carcinoma of the bladder.⁶

The diagnosis of NS often can be made clinically but can be difficult to confirm in underdeveloped lesions in young children. The differential diagnosis can include alopecia areata, aplasia cutis congenita, juvenile xanthogranuloma, epidermal nevus, de novo syringocystadenoma papilliferum, and solitary mastocytoma.¹ Nevus sebaceus can be associated with 4 additional syndromes: Schimmelpenning syndrome; phacomatosis pigmentokeratotica; didymosis aplasticosebacea; and SCALP (sebaceus nevus, central nervous system malformations, aplasia cutis congenital, limbal dermoid, pigmented nevus) syndrome.¹ Approximately 7% of NS cases may be associated with Schimmelpenning-Feuerstein-Mims (SFM) syndrome, a more severe condition that leads to systemic involvement and abnormalities in the neurological, ophthalmological, cardiovascular, genitourological, and skeletal systems.^1,3 Phacomatosis pigmentokeratotica has speckled lentiginous nevi, as well as abnormalities in the neurological, ophthalmological, cardiovascular, genitourological, and skeletal systems.¹ Didymosis aplasticosebacea is the concurrence of NS and aplasia cutis congenita.

The definitive treatment of NS is surgical excision. Alternative therapies include photodynamic therapy, fractional laser resurfacing, and dermabrasion; these are not definitive treatments, and patients must be monitored for the development of secondary neoplasms. Multiple variables must be considered when determining treatment, including patient age, risk potential for malignancy, and surgery-associated risks.¹ In our patient, given the extent of the lesions, active observation and follow-up was agreed upon for management.

This case demonstrates the importance of considering NS as an alternative diagnosis when alopecia areata has been diagnosed in a child who is unresponsive to treatments. After the diagnosis of NS is confirmed, more serious associated syndromes should be ruled out, and treatment should be tailored to each case.

To the Editor:

A 12-year-old girl presented to the dermatology clinic for evaluation of a congenital scalp lesion. The patient was diagnosed with alopecia areata by a dermatologist at 4 years of age, and she was treated with topical corticosteroids and minoxidil, which failed to resolve her condition. Physical examination revealed an 8×10-cm, well-demarcated, yellowish-pink plaque located over the vertex and right parietal scalp (Figure 1A), extending down to the right preauricular cheek (Figure 1B) in a linear configuration with blaschkoid features. The scalp plaque appeared bald and completely lacking in terminal hairs but contained numerous fine vellus hairs (Figure 1A). A 6-mm, oval-appearing, pigmented papule was present in the plaque, and a few smaller, scattered, pigmented papules were noted in the vertex region (Figure 1A).

The cutaneous examination was otherwise unremarkable. A review of systems was negative, except for a history of attention-deficit/hyperactivity disorder. There was no history of seizures or other neurocognitive developmental abnormalities.

A 4-mm punch biopsy of the vertex scalp included the pigmented lesion but excluded an adnexal neoplasm. Epidermal acanthosis and mild papillomatosis were reported on microscopic examination. Multiple prominent sebaceous glands without associated hair follicles, which emptied directly onto the epidermal surface, were noted in the dermis (Figure 2). Several apocrine glands were observed (Figure 3). Epidermal and dermal melanocytic nests were highlighted with SOX-10 and Melan-A immunohistochemical stains, confirming the presence of a benign compound nevus. The punch biopsy analysis confirmed the diagnosis of a nevus sebaceus (NS) of Jadassohn (organoid nevus) with incidental compound nevus. Additional 4-mm punch biopsies were obtained for genetic testing, performed by the Genomics and Pathology Services at Washington University (St. Louis, Missouri). A missense HRAS p.G12V variant was observed in the tissue. A negative blood test result ruled out a germline mutation. The patient was managed with active observation of the lesion to evaluate for potential formation of neoplasms, as well as continuity of care with the dermatology clinic, considering the extent of the lesions, to monitor the development of any new medical conditions that would be concerning for syndromes associated with NS.

Nevus sebaceus is a benign skin hamartoma caused by a congenital defect in the pilosebaceous follicular unit and consists of epidermal, sebaceous, and apocrine elements.^1,2 In dermatology patients, the prevalence of NS ranges from 0.05% to 1%.¹ In 90% of cases, NS presents at birth as a 1- to 10-cm, round or linear, yellowish-orange, hairless plaque located on the scalp. It also may appear on the face, neck, trunk, oral mucosa, or labia minora.^1,3 Although NS is a benign condition, secondary tumors may form within the lesion.³

The physical and histologic characteristics of NS evolve as the patient ages. In childhood, NS typically appears as a yellow-pink macule or patch with mild to moderate epidermal hyperplasia. Patients exhibit underdeveloped sebaceous glands, immature hair follicles, hyperkeratosis, and acanthosis.^1,3,4 The development of early lesions can be quite subtle and can lead to diagnostic uncertainty, as described in our patient. During puberty, lesions thicken due to papillomatous hyperplasia in the epidermis, and the number and size of sebaceous and apocrine glands increase.⁴ In adults, the risk for secondary tumor formation increases. These physical and histologic transformations, including secondary tumor formation, are thought to be stimulated by the action of postpubertal androgens.¹

Nevus sebaceus is associated with both benign and malignant secondary tumor formation; however, fewer than 1% of tumors are malignant.¹ In a retrospective analysis, Idriss and Elston⁵ (N=707) reported that 21.4% of patients with NS had secondary neoplasms; 18.9% of the secondary neoplasms were benign, and 2.5% were malignant. Additionally, this study showed that secondary tumor formation can occur in children, though it typically occurs in adults. Benign neoplasms were reported in 5 children in the subset aged 0 to 10 years and 10 children in the subset aged 11 to 17 years; 1 child developed a malignant neoplasm in the latter subset.⁵ The most common NS-associated benign neoplasms include trichoblastoma and syringocystadenoma papilliferum. Others include trichilemmoma, apocrine/eccrine adenoma, and sebaceoma.¹ Nevus sebaceus–associated malignant neoplasms include basal cell carcinoma, squamous cell carcinoma, adenocarcinoma, carcinosarcoma, and sebaceous carcinoma.³

Our patient was incorrectly diagnosed and treated for alopecia areata before an eventual diagnosis of NS was confirmed by biopsy. Additional genetic studies revealed a novel mutation in the HRAS gene, the most commonly affected gene in NS. The most common mutation location seen in more than 90% of NS lesions is HRAS c.37G>C (p.G13R), while KRAS mutations account for almost all the remaining cases.³ In our patient, a pathogenic missense HRAS p.G12V variant of somatic origin was detected with DNA extraction and sequencing from a fresh tissue sample acquired from two 4-mm punch biopsies performed on the lesion. The following genes were sequenced and found to be uninvolved: BRAF, FGFR1, FGFR2, FGFR3, GNA11, GNAQ, KRAS, MAP3K3, NRAS, PIK3CA, and TEK. The Sanger sequencing method for comparative analysis performed on peripheral blood was negative.

Nevus sebaceus typically is caused by a sporadic mutation, though familial cases have been reported.¹ Additionally, germline HRAS mutations can lead to Costello syndrome, an autosomal-dominant disorder characterized by short stature; intellectual disabilities; coarse facial features; facial and perianal papillomata; cardiac defects; loose skin; joint hyperflexibility; and an increased risk for malignant tumors including rhabdomyosarcoma, neuroblastoma, and transitional cell carcinoma of the bladder.⁶

The diagnosis of NS often can be made clinically but can be difficult to confirm in underdeveloped lesions in young children. The differential diagnosis can include alopecia areata, aplasia cutis congenita, juvenile xanthogranuloma, epidermal nevus, de novo syringocystadenoma papilliferum, and solitary mastocytoma.¹ Nevus sebaceus can be associated with 4 additional syndromes: Schimmelpenning syndrome; phacomatosis pigmentokeratotica; didymosis aplasticosebacea; and SCALP (sebaceus nevus, central nervous system malformations, aplasia cutis congenital, limbal dermoid, pigmented nevus) syndrome.¹ Approximately 7% of NS cases may be associated with Schimmelpenning-Feuerstein-Mims (SFM) syndrome, a more severe condition that leads to systemic involvement and abnormalities in the neurological, ophthalmological, cardiovascular, genitourological, and skeletal systems.^1,3 Phacomatosis pigmentokeratotica has speckled lentiginous nevi, as well as abnormalities in the neurological, ophthalmological, cardiovascular, genitourological, and skeletal systems.¹ Didymosis aplasticosebacea is the concurrence of NS and aplasia cutis congenita.

The definitive treatment of NS is surgical excision. Alternative therapies include photodynamic therapy, fractional laser resurfacing, and dermabrasion; these are not definitive treatments, and patients must be monitored for the development of secondary neoplasms. Multiple variables must be considered when determining treatment, including patient age, risk potential for malignancy, and surgery-associated risks.¹ In our patient, given the extent of the lesions, active observation and follow-up was agreed upon for management.

This case demonstrates the importance of considering NS as an alternative diagnosis when alopecia areata has been diagnosed in a child who is unresponsive to treatments. After the diagnosis of NS is confirmed, more serious associated syndromes should be ruled out, and treatment should be tailored to each case.