Case Reports

Macular telangiectasia type 2 (MacTel2) is an uncommon, bilateral, and asymmetric condition that typically presents between the ages of 40 and 60 years without sex predilection.^1-9 Its estimated prevalence ranges from 0.02 to 0.10%.^2,8 The disease can manifest in either a nonproliferative or proliferative phase; the latter is far less common. The etiology of MacTel2 is poorly understood, but it is believed to have neurodegenerative as well as vascular components.^1-6,8-10 We present a case of MacTel2 and highlight the role of diagnostic imaging in early diagnosis prior to development of classic funduscopic features.

Case Presentation

A 66-year-old White male with a 10-year history of type 2 diabetes mellitus (T2DM) presented to the eye clinic for an annual eye examination. The patient was taking metformin, and 6 months prior to presentation, his hemoglobin A_1c was 7.4%. He had a history of mild nonproliferative diabetic retinopathy in the left eye without diabetic macular edema. He reported no ocular concerns.

On examination, best-corrected visual acuity (VA) was 20/20 in each eye. Slit-lamp examination was notable only for bilateral mild nuclear sclerosis. Dilated fundus examination showed a blunted foveal reflex consistent with the appearance of a macular pseudo-hole in the right eye and was unremarkable in the left eye (Figure 1).

Discussion

This case highlights several important management considerations in MacTel2. These include symptoms, disease stage, and diagnostic imaging, which can allow more precise staging of the disease.

The etiology of MacTel2 is unknown.⁶ It is believed to be primarily a neurodegenerative condition that damages Müller cells and photoreceptors, leading to vascular changes.^1-6,8-10 Müller cells may play a role in creating and maintaining the integrity of the blood-retinal barrier, particularly in the deep capillary plexus where the vascular abnormalities begin.^6,10 These early changes in the deep capillary plexus may evolve to include the superficial capillary plexus in intermediate stages with anastomoses forming between the 2 layers.^2,6-10 Late proliferative stages show significant alterations of the juxtafoveal capillary network, subretinal neovascularization and retinochoroidal anastomoses.^6,7,9,11 In one cohort study, 81% of patients with MacTel2 were White, and a genetic link is still under investigation.^2,4-9

Presentation

The most common symptoms of MacTel2 include blurred vision, microscotoma, metamorphopsia, and difficulty reading, with missing or distorted letters a common concern.^1,2,4-8 Best-corrected VA at presentation is usually better than 20/30, and disease progression tends to be slow.^2,6 Microscotomata are best mapped with microperimetry.^1-3,5-7

There are several classic fundus findings (Table). In the early stages, these findings are subtle or entirely absent funduscopically.^1,2,4-10 In intermediate stages, fundus findings become apparent and include a loss of retinal clarity (grayish perifoveal sheen), telangiectatic macular vessels, retinal pigment epithelium hypertrophy, blunted right-angled vessels, and superficial retinal crystalline deposits.^2,4-11 Right-angled vessels may have a greater association with choroidal neovascularization, with growth into the outer retina in particular being a marker of disease progression.⁹ The crystalline deposits have been hypothesized to be the footplates of degenerated Müller cells.⁶

Diagnostic Testing

Diagnostic retinal imaging is invaluable in the diagnosis of MacTel2. The OCT can detect hyporeflectivity within the ellipsoid zone in early disease corresponding to ellipsoid zone loss, which increases as the disease progresses.^1-8,10 This loss most often begins in the temporal parafoveal region and correlates with the progression of both relative and absolute scotomas perceived by affected individuals.^2,3,5,8

Intraretinal foveal hyporeflective spaces on the OCT represent cavity formation after Müller cell and photoreceptor loss and do not correlate with increased thickness.^1,2,4,6,7 This is important in differentiating from diabetic macular edema, which will often show thickening.⁶ In most cases of MacTel2, foveal thickness is decreased.^4-6 The ILM remains intact overlying this space and is referred to as ILM drape.^6,7 This can cause blunting or absence of the foveal light reflex and mimic the appearance of a macular pseudohole.⁴

The OCT-A allows visualization of capillary changes through every layer of the retina, which could not otherwise be appreciated, allowing early detection as well as precise staging of the disease.^2,6-10 Anastomoses present in late-stage disease also can be imaged using OCT-A.^7,9 These anastomoses can be seen as hyperreflective vasculature present between the retinal layers where there is little to no vasculature visible in normal eyes.⁷

A lesser-known occurrence in MacTel2 is the depletion of macular luteal pigment, with many eyes possessing an abnormal distribution.^2,4,6-8,10 This depletion and abnormal distribution can be visualized with FAF. In particular, short wavelength fundus autofluorescence (SW-FAF) is the most effective at highlighting these changes.¹⁰ The characteristic finding is a hyperreflective halo surrounding the fovea.^2,6 Fluorescence life imaging ophthalmoscopy (FLIO) is a recent development in FAF that measures FAF lifetime, which is the duration of time a structure autofluoresces.⁸ A cross-sectional study published in 2018 showed prolonged FAF lifetime in the temporal fovea of patients with early and moderate stage MacTel2 when compared with normal patients.⁸ More advanced stages showed a ring encircling the entire fovea.⁸

Classic FA findings in MacTel2 include early hyperfluorescence of temporal foveal telangiectatic capillaries and late-stage leakage with sparing of the central fovea.^1,2,4,6,7,11

Management and Prognosis

Management of MacTel2 depends on the stage of the disease. In the absence of proven treatment, management in nonproliferative stages is conservative.^2,6 Intravitreal anti-VEGF does not offer any benefit in nonproliferative disease.^2,5,6 Indeed, as VEGF may have a neuroprotective effect on the retina, anti-VEGF may result in more harm than benefit in earlier disease stages.⁵ In proliferative stages, intravitreal anti-VEGF can help limit scarring and prevent vision loss.^2,5

Long-term prognosis of MacTel2 is variable with VA typically better than 20/100.² Vision loss in MacTel2 most often begins paracentrally; it can then progress centrally, leading to significant reduction in VA.¹² The progression of this functional vision loss and corresponding structural damage is typically slow.³ VA worse than 20/100 is usually a result of proliferative disease; in such cases, there is potential for severe central vision loss and legal blindness.¹

Conclusions

This case of MacTel2 underscores the subtle retinal findings in the earliest stages of the disease and the importance of a complete retinal examination and diagnostic imaging with macula OCT, OCT-A, and FAF to establish the correct diagnosis.

Macular telangiectasia type 2 (MacTel2) is an uncommon, bilateral, and asymmetric condition that typically presents between the ages of 40 and 60 years without sex predilection.^1-9 Its estimated prevalence ranges from 0.02 to 0.10%.^2,8 The disease can manifest in either a nonproliferative or proliferative phase; the latter is far less common. The etiology of MacTel2 is poorly understood, but it is believed to have neurodegenerative as well as vascular components.^1-6,8-10 We present a case of MacTel2 and highlight the role of diagnostic imaging in early diagnosis prior to development of classic funduscopic features.

Case Presentation

A 66-year-old White male with a 10-year history of type 2 diabetes mellitus (T2DM) presented to the eye clinic for an annual eye examination. The patient was taking metformin, and 6 months prior to presentation, his hemoglobin A_1c was 7.4%. He had a history of mild nonproliferative diabetic retinopathy in the left eye without diabetic macular edema. He reported no ocular concerns.

On examination, best-corrected visual acuity (VA) was 20/20 in each eye. Slit-lamp examination was notable only for bilateral mild nuclear sclerosis. Dilated fundus examination showed a blunted foveal reflex consistent with the appearance of a macular pseudo-hole in the right eye and was unremarkable in the left eye (Figure 1).

Discussion

This case highlights several important management considerations in MacTel2. These include symptoms, disease stage, and diagnostic imaging, which can allow more precise staging of the disease.

The etiology of MacTel2 is unknown.⁶ It is believed to be primarily a neurodegenerative condition that damages Müller cells and photoreceptors, leading to vascular changes.^1-6,8-10 Müller cells may play a role in creating and maintaining the integrity of the blood-retinal barrier, particularly in the deep capillary plexus where the vascular abnormalities begin.^6,10 These early changes in the deep capillary plexus may evolve to include the superficial capillary plexus in intermediate stages with anastomoses forming between the 2 layers.^2,6-10 Late proliferative stages show significant alterations of the juxtafoveal capillary network, subretinal neovascularization and retinochoroidal anastomoses.^6,7,9,11 In one cohort study, 81% of patients with MacTel2 were White, and a genetic link is still under investigation.^2,4-9

Presentation

The most common symptoms of MacTel2 include blurred vision, microscotoma, metamorphopsia, and difficulty reading, with missing or distorted letters a common concern.^1,2,4-8 Best-corrected VA at presentation is usually better than 20/30, and disease progression tends to be slow.^2,6 Microscotomata are best mapped with microperimetry.^1-3,5-7

There are several classic fundus findings (Table). In the early stages, these findings are subtle or entirely absent funduscopically.^1,2,4-10 In intermediate stages, fundus findings become apparent and include a loss of retinal clarity (grayish perifoveal sheen), telangiectatic macular vessels, retinal pigment epithelium hypertrophy, blunted right-angled vessels, and superficial retinal crystalline deposits.^2,4-11 Right-angled vessels may have a greater association with choroidal neovascularization, with growth into the outer retina in particular being a marker of disease progression.⁹ The crystalline deposits have been hypothesized to be the footplates of degenerated Müller cells.⁶

Diagnostic Testing

Diagnostic retinal imaging is invaluable in the diagnosis of MacTel2. The OCT can detect hyporeflectivity within the ellipsoid zone in early disease corresponding to ellipsoid zone loss, which increases as the disease progresses.^1-8,10 This loss most often begins in the temporal parafoveal region and correlates with the progression of both relative and absolute scotomas perceived by affected individuals.^2,3,5,8

Intraretinal foveal hyporeflective spaces on the OCT represent cavity formation after Müller cell and photoreceptor loss and do not correlate with increased thickness.^1,2,4,6,7 This is important in differentiating from diabetic macular edema, which will often show thickening.⁶ In most cases of MacTel2, foveal thickness is decreased.^4-6 The ILM remains intact overlying this space and is referred to as ILM drape.^6,7 This can cause blunting or absence of the foveal light reflex and mimic the appearance of a macular pseudohole.⁴

The OCT-A allows visualization of capillary changes through every layer of the retina, which could not otherwise be appreciated, allowing early detection as well as precise staging of the disease.^2,6-10 Anastomoses present in late-stage disease also can be imaged using OCT-A.^7,9 These anastomoses can be seen as hyperreflective vasculature present between the retinal layers where there is little to no vasculature visible in normal eyes.⁷

A lesser-known occurrence in MacTel2 is the depletion of macular luteal pigment, with many eyes possessing an abnormal distribution.^2,4,6-8,10 This depletion and abnormal distribution can be visualized with FAF. In particular, short wavelength fundus autofluorescence (SW-FAF) is the most effective at highlighting these changes.¹⁰ The characteristic finding is a hyperreflective halo surrounding the fovea.^2,6 Fluorescence life imaging ophthalmoscopy (FLIO) is a recent development in FAF that measures FAF lifetime, which is the duration of time a structure autofluoresces.⁸ A cross-sectional study published in 2018 showed prolonged FAF lifetime in the temporal fovea of patients with early and moderate stage MacTel2 when compared with normal patients.⁸ More advanced stages showed a ring encircling the entire fovea.⁸

Classic FA findings in MacTel2 include early hyperfluorescence of temporal foveal telangiectatic capillaries and late-stage leakage with sparing of the central fovea.^1,2,4,6,7,11

Management and Prognosis

Management of MacTel2 depends on the stage of the disease. In the absence of proven treatment, management in nonproliferative stages is conservative.^2,6 Intravitreal anti-VEGF does not offer any benefit in nonproliferative disease.^2,5,6 Indeed, as VEGF may have a neuroprotective effect on the retina, anti-VEGF may result in more harm than benefit in earlier disease stages.⁵ In proliferative stages, intravitreal anti-VEGF can help limit scarring and prevent vision loss.^2,5

Long-term prognosis of MacTel2 is variable with VA typically better than 20/100.² Vision loss in MacTel2 most often begins paracentrally; it can then progress centrally, leading to significant reduction in VA.¹² The progression of this functional vision loss and corresponding structural damage is typically slow.³ VA worse than 20/100 is usually a result of proliferative disease; in such cases, there is potential for severe central vision loss and legal blindness.¹

Conclusions

This case of MacTel2 underscores the subtle retinal findings in the earliest stages of the disease and the importance of a complete retinal examination and diagnostic imaging with macula OCT, OCT-A, and FAF to establish the correct diagnosis.

Macular telangiectasia type 2 (MacTel2) is an uncommon, bilateral, and asymmetric condition that typically presents between the ages of 40 and 60 years without sex predilection.^1-9 Its estimated prevalence ranges from 0.02 to 0.10%.^2,8 The disease can manifest in either a nonproliferative or proliferative phase; the latter is far less common. The etiology of MacTel2 is poorly understood, but it is believed to have neurodegenerative as well as vascular components.^1-6,8-10 We present a case of MacTel2 and highlight the role of diagnostic imaging in early diagnosis prior to development of classic funduscopic features.

Case Presentation

A 66-year-old White male with a 10-year history of type 2 diabetes mellitus (T2DM) presented to the eye clinic for an annual eye examination. The patient was taking metformin, and 6 months prior to presentation, his hemoglobin A_1c was 7.4%. He had a history of mild nonproliferative diabetic retinopathy in the left eye without diabetic macular edema. He reported no ocular concerns.

On examination, best-corrected visual acuity (VA) was 20/20 in each eye. Slit-lamp examination was notable only for bilateral mild nuclear sclerosis. Dilated fundus examination showed a blunted foveal reflex consistent with the appearance of a macular pseudo-hole in the right eye and was unremarkable in the left eye (Figure 1).

Discussion

This case highlights several important management considerations in MacTel2. These include symptoms, disease stage, and diagnostic imaging, which can allow more precise staging of the disease.

The etiology of MacTel2 is unknown.⁶ It is believed to be primarily a neurodegenerative condition that damages Müller cells and photoreceptors, leading to vascular changes.^1-6,8-10 Müller cells may play a role in creating and maintaining the integrity of the blood-retinal barrier, particularly in the deep capillary plexus where the vascular abnormalities begin.^6,10 These early changes in the deep capillary plexus may evolve to include the superficial capillary plexus in intermediate stages with anastomoses forming between the 2 layers.^2,6-10 Late proliferative stages show significant alterations of the juxtafoveal capillary network, subretinal neovascularization and retinochoroidal anastomoses.^6,7,9,11 In one cohort study, 81% of patients with MacTel2 were White, and a genetic link is still under investigation.^2,4-9

Presentation

The most common symptoms of MacTel2 include blurred vision, microscotoma, metamorphopsia, and difficulty reading, with missing or distorted letters a common concern.^1,2,4-8 Best-corrected VA at presentation is usually better than 20/30, and disease progression tends to be slow.^2,6 Microscotomata are best mapped with microperimetry.^1-3,5-7

There are several classic fundus findings (Table). In the early stages, these findings are subtle or entirely absent funduscopically.^1,2,4-10 In intermediate stages, fundus findings become apparent and include a loss of retinal clarity (grayish perifoveal sheen), telangiectatic macular vessels, retinal pigment epithelium hypertrophy, blunted right-angled vessels, and superficial retinal crystalline deposits.^2,4-11 Right-angled vessels may have a greater association with choroidal neovascularization, with growth into the outer retina in particular being a marker of disease progression.⁹ The crystalline deposits have been hypothesized to be the footplates of degenerated Müller cells.⁶

Diagnostic Testing

Diagnostic retinal imaging is invaluable in the diagnosis of MacTel2. The OCT can detect hyporeflectivity within the ellipsoid zone in early disease corresponding to ellipsoid zone loss, which increases as the disease progresses.^1-8,10 This loss most often begins in the temporal parafoveal region and correlates with the progression of both relative and absolute scotomas perceived by affected individuals.^2,3,5,8

Intraretinal foveal hyporeflective spaces on the OCT represent cavity formation after Müller cell and photoreceptor loss and do not correlate with increased thickness.^1,2,4,6,7 This is important in differentiating from diabetic macular edema, which will often show thickening.⁶ In most cases of MacTel2, foveal thickness is decreased.^4-6 The ILM remains intact overlying this space and is referred to as ILM drape.^6,7 This can cause blunting or absence of the foveal light reflex and mimic the appearance of a macular pseudohole.⁴

The OCT-A allows visualization of capillary changes through every layer of the retina, which could not otherwise be appreciated, allowing early detection as well as precise staging of the disease.^2,6-10 Anastomoses present in late-stage disease also can be imaged using OCT-A.^7,9 These anastomoses can be seen as hyperreflective vasculature present between the retinal layers where there is little to no vasculature visible in normal eyes.⁷

A lesser-known occurrence in MacTel2 is the depletion of macular luteal pigment, with many eyes possessing an abnormal distribution.^2,4,6-8,10 This depletion and abnormal distribution can be visualized with FAF. In particular, short wavelength fundus autofluorescence (SW-FAF) is the most effective at highlighting these changes.¹⁰ The characteristic finding is a hyperreflective halo surrounding the fovea.^2,6 Fluorescence life imaging ophthalmoscopy (FLIO) is a recent development in FAF that measures FAF lifetime, which is the duration of time a structure autofluoresces.⁸ A cross-sectional study published in 2018 showed prolonged FAF lifetime in the temporal fovea of patients with early and moderate stage MacTel2 when compared with normal patients.⁸ More advanced stages showed a ring encircling the entire fovea.⁸

Classic FA findings in MacTel2 include early hyperfluorescence of temporal foveal telangiectatic capillaries and late-stage leakage with sparing of the central fovea.^1,2,4,6,7,11

Management and Prognosis

Management of MacTel2 depends on the stage of the disease. In the absence of proven treatment, management in nonproliferative stages is conservative.^2,6 Intravitreal anti-VEGF does not offer any benefit in nonproliferative disease.^2,5,6 Indeed, as VEGF may have a neuroprotective effect on the retina, anti-VEGF may result in more harm than benefit in earlier disease stages.⁵ In proliferative stages, intravitreal anti-VEGF can help limit scarring and prevent vision loss.^2,5

Long-term prognosis of MacTel2 is variable with VA typically better than 20/100.² Vision loss in MacTel2 most often begins paracentrally; it can then progress centrally, leading to significant reduction in VA.¹² The progression of this functional vision loss and corresponding structural damage is typically slow.³ VA worse than 20/100 is usually a result of proliferative disease; in such cases, there is potential for severe central vision loss and legal blindness.¹

Conclusions

This case of MacTel2 underscores the subtle retinal findings in the earliest stages of the disease and the importance of a complete retinal examination and diagnostic imaging with macula OCT, OCT-A, and FAF to establish the correct diagnosis.

Cisplatin is a potent antineoplastic agent derived from platinum and commonly used in the treatment of head and neck, bladder, ovarian, and testicular malignancies.^1,2 Approximately 20% of all cancer patients are prescribed platinum-based chemotherapeutics.³ Although considered highly effective, cisplatin is also a dose-dependent nephrotoxin, inducing apoptosis in the proximal tubules of the nephron and reducing glomerular filtration rate. This nephron injury leads to inflammation and reduced medullary blood flow, causing further ischemic damage to the tubular cells.⁴ Given that the proximal tubule reabsorbs 67% of all sodium, cisplatin-induced nephron injuries can also lead to hyponatremia.⁵

The primary mechanisms of hyponatremia following cisplatin chemotherapy are syndrome of inappropriate antidiuretic hormone secretion (SIADH) and renal salt wasting syndrome (RSWS). Though these diagnoses have similar presentations, the treatment recommendations are different due to pathophysiologic differences. Fluid restriction is the hallmark of SIADH treatment, while increased sodium intake remains the hallmark of RSWS treatment.⁶ This patient presented with a combination of cisplatin-induced acute kidney injury (AKI) and hyponatremia secondary to RSWS. While RSWS and AKI are known complications of cisplatin chemotherapy, the combination is underreported in the literature. Therefore, this case report highlights the combination of these cisplatin-induced complications, emphasizes the clinical challenges in differentiating SIADH from RSWS, especially in the presence of a concomitant AKI, and suggests a treatment approach during diagnostic uncertainty.

Case Presentation

A 71-year-old man with a medical history of squamous cell carcinoma (SCC) of the left neck on cycle 1, day 8 of cisplatin-based chemotherapy and ongoing radiation therapy (720 cGy of 6300 cGy), lung adenocarcinoma status postresection, and hyperlipidemia presented to the emergency department (ED) at the request of his oncologist for abnormal laboratory values. In the ED, his metabolic panel showed a 131-mmol/L serum sodium, 3.3 mmol/L potassium, 83 mmol/L chloride, 29 mmol/L bicarbonate, 61 mg/dL blood urea nitrogen (BUN), and 8.8 mg/dL creatinine (baseline, 0.9 mg/dL). The patient reported throbbing headaches, persistent nausea, and multiple episodes of nonbloody emesis for several days that he attributed to his chemotherapy. He noted decreased urination without discomfort or changes in color or odor and no fatigue, fevers, chills, hematuria, flank, abdominal pain, thirst, or polydipsia. He reported no toxic ingestions or IV drug use. The patient had no relevant family history or additional social history. His outpatient medications included 10 mg cetirizine, 8 mg ondansetron, and 81 mg aspirin. On initial examination, his 137/66 mm Hg blood pressure was mildly elevated. The physical examination findings were notable for a 5-cm mass in the left neck that was firm and irregularly-shaped. His physical examination was otherwise unremarkable. He was admitted to the inpatient medicine service for an AKI complicated by symptomatic hyponatremia.

Investigations

We evaluated the patient’s AKI based on treatment responsiveness, imaging, and laboratory testing. Renal and bladder ultrasound showed no evidence of hydronephrosis or obstruction. He had a benign urinalysis with microscopy absent for protein, blood, ketones, leukocyte esterase, nitrites, and cellular casts. His urine pH was 5.5 (reference range, 5.0-9.0) and specific gravity was 1.011 (reference range, 1.005-1.030). His urine electrolytes revealed 45-mmol/L urine sodium (reference range, 40-220), 33-mmol/L urine chloride (reference range, 110-250), 10-mmol/L urine potassium (reference range, 25-120), 106.7-mg/dL urine creatinine (reference range, 10-400) and a calculated 2.7% fractional excretion of sodium (FE_Na) and 22.0-mEq/L elevated urine anion gap. As a fluid challenge, he was treated with IV 0.9% sodium chloride at 100-125 mL/h, receiving 3 liters over the first 48 hours of his hospitalization. His creatinine peaked at 9.2 mg/dL and stabilized before improving later in his hospitalization (Figure 1). The patient initially had oliguria (< 0.5 mL/kg/h), which slowly improved over his hospital course. Unfortunately, due to multiple system and clinical factors, accurate inputs and outputs were not adequately maintained during his hospitalization.

We evaluated hyponatremia with a combination of serum and urine laboratory tests. In addition to urine electrolytes, the initial evaluation focused on trending his clinical trajectory. We repeated a basic metabolic panel every 4 to 6 hours. He had 278-mOsm/kg serum osmolality (reference range, 285-295) with an effective 217-mOsm/kg serum tonicity. His urine osmolality was 270.5 mOsm/kg.

Despite administering 462 mEq sodium via crystalloid, his sodium worsened over the first 48 hours, reaching a nadir at 125 mmol/L on hospital day 3 (Figure 2). While he continued to appear euvolemic on physical examination, his blood pressure became difficult to control with 160- to 180-mm Hg systolic blood pressure readings. His thyroid stimulating hormone (TSH) was normal and aldosterone was low (4 ng/dL). Additional urine studies, including a 24-hour urine sample, were collected for further evaluation. His urine uric acid was 140 mg/d (reference range, 120-820); his serum uric acid level was 8.2 mg/dL (reference range, 3.0-9.0). His 24-hour urine creatinine was 0.57 g/d (reference range, 0.50-2.15) and uric acid to creatinine ratio was 246 mg/g (reference range, 60-580). His serum creatinine collected from the same day as his 24-hour urine sample was 7.3 mg/dL. His fractional excretion of uric acid (FE_urate) was 21.9%.

Differential Diagnosis

The patient’s recent administration of cisplatin raised clinical suspicion of cisplatin-induced AKI. To avoid premature diagnostic closure, we used a systematic approach for thinking about our patient’s AKI, considering prerenal, intrarenal, and postrenal etiologies. The unremarkable renal and bladder ultrasound made a postrenal etiology unlikely. The patient’s 2.7% FE_Na in the absence of a diuretic, limited responsiveness to crystalloid fluid resuscitation, 7.5 serum BUN/creatinine ratio, and 270.5 mOsm/kg urine osmolality suggested an intrarenal etiology, which can be further divided into problems with glomeruli, tubules, small vessels, or interstitial space. The patient’s normal urinary microscopy with no evidence of protein, blood, ketones, leukocyte esterase, nitrites, or cellular casts made a glomerular etiology less likely. The acute onset and lack of additional systemic features, other than hypertension, made a vascular etiology less likely. A tubular etiology, such as acute tubular necrosis (ATN), was highest on the differential and was followed by an interstitial etiology, such as acute interstitial nephritis (AIN).

Patients with drug-induced AIN commonly present with signs and symptoms of an allergic-type reaction, including fever, rash, hematuria, pyuria, and costovertebral angle tenderness. The patient lacked these symptoms. However, cisplatin is known to cause ATN in up to 20-30% of patients.⁷ Therefore, despite the lack of the classic muddy-brown, granular casts on urine microscopy, cisplatin-induced ATN remained the most likely etiology of his AKI. Moreover, ATN can cause hyponatremia. ATN is characterized by 3 phases: initiation, maintenance, and recovery phases.⁸ Hyponatremia occurs during the recovery phase, typically starting weeks after renal insult and associated with high urine output and diuresis. This patient presented 1 week after injury and had persistent oliguria, making ATN an unlikely culprit of his hyponatremia.

Our patient presented with hypotonic hyponatremia with a 131 mmol/L initial sodium level and an < 280 mOsm/kg effective serum osmolality, or serum tonicity. The serum tonicity is equivalent to the difference between the measured serum osmolality and the BUN. In the setting of profound AKI, this adjustment is essential for correctly categorizing a patient’s hyponatremia as hyper-, iso-, or hypotonic. The differential diagnosis for this patient’s hypotonic hyponatremia included dilutional effects of hypervolemia, SIADH, hyperthyroidism, adrenal insufficiency, and RSWS. The patient’s volume examination, lack of predisposing comorbidities or suggestive biomarkers, and > 20 mmol/L urinary sodium made hypervolemia unlikely. His urinary osmolality and specific gravity made primary polydipsia unlikely. We worked up his hyponatremia according to a diagnostic algorithm (eAppendix available at doi:10.12788/fp.0198).

The patient had a 217 mOsm/kg serum tonicity and a 270.5 mOsm/kg urine osmolality, consistent with impaired water excretion. His presentation, TSH, and concordant decrease in sodium and potassium made an endocrine etiology of his hyponatremia less likely. In hindsight, a serum cortisol would have been beneficial to more completely exclude adrenal insufficiency. His urine sodium was elevated at 45 mmol/L, raising concern for RSWS or SIADH. The FE_urate helped to distinguish between SIADH and RSWS. While FE_urate is often elevated in both SIADH and RSWS initially, the FE_urate normalizes in SIADH with normalization of the serum sodium. The ideal cutoff for posthyponatremia correction FE_urate is debated; however, a FE_urate value after sodium correction < 11% suggests SIADH while a value > 11% suggests RSWS.⁹ Our patient’s FE_urate following the sodium correction (serum sodium 134 mmol/L) was 21.9%, most suggestive of RSWS.

Treatment

Upon admission, initial treatment focused on resolving the patient’s AKI. The oncology team discontinued the cisplatin-based chemotherapy. His medication dosages were adjusted for his renal function and additional nephrotoxins avoided. In consultation, the nephrology service recommended 100 mL/h fluid resuscitation. After the patient received 3 L of 0.9% sodium chloride, his creatinine showed limited improvement and his sodium worsened, trending from 131 mmol/L to a nadir of 125 mmol/L. We initiated oral free-water restriction while continuing IV infusion of 0.9% sodium chloride at 125 mL/h.

We further augmented his sodium intake with 1-g sodium chloride tablets with each meal. By hospital day 6, the patient’s serum sodium, BUN, and creatinine improved to 130 mEq/L, 50 mg/dL, and 7.7 mg/dL, respectively. We then discontinued the oral sodium chloride tablets, fluid restriction, and IV fluids in a stepwise fashion prior to discharge. At discharge, the patient’s serum sodium was 136 mEq/L and creatinine, 4.8 mg/dL. The patient’s clinical course was complicated by symptomatic hypertension with systolic blood pressures about 180 mm Hg, requiring intermittent IV hydralazine, which was transitioned to daily nifedipine. Concerned that fluid resuscitation contributed to his hypertension, the patient also received several doses of furosemide. At time of discharge, the patient remained hypertensive and was discharged with nifedipine 90 mg daily.

Outcome and Follow-up

The patient has remained stable clinically since discharge. One week after discharge, his serum sodium and creatinine were 138 mmol/L and 3.8 mg/dL, respectively. More than 1 month after discharge, his sodium remains in the reference range and his creatinine was stable at about 3.5 mg/dL. He continues to follow-up with nephrology, oncology, and radiation oncology. He has restarted chemotherapy with a carboplatin-based regimen without recurrence of hyponatremia or AKI. His blood pressure has gradually improved to the point where he no longer requires nifedipine.

Discussion

The US Food and Drug Administration first approved the use of cisplatin, an alkylating agent that inhibits DNA replication, in 1978 for the treatment of testicular cancer.¹⁰ Since its approval, cisplatin has increased in popularity and is now considered one of the most effective antineoplastic agents for the treatment of solid tumors.¹ Unfortunately, cisplatin has a well-documented adverse effect profile that includes neurotoxicity, gastrointestinal toxicity, nephrotoxicity, and ototoxicity.⁴ Despite frequent nephrotoxicity, cisplatin only occasionally causes hyponatremia and rarely causes RSWS, a known but potentially fatal complication. Moreover, the combination of AKI and RSWS is unique. Our patient presented with the unique combination of AKI and hyponatremia, most consistent with RSWS, likely precipitated from cisplatin chemotherapy. Through this case, we review cisplatin-associated electrolyte abnormalities, highlight the challenge of differentiating SIADH and RSWS, and suggest a treatment approach for hyponatremia during the period of diagnostic uncertainty.

Blachley and colleagues first discussed renal and electrolyte disturbances, specifically magnesium wasting, secondary to cisplatin use in 1981. In 1984, Kurtzberg and colleagues noted salt wasting in 2 patients receiving cisplatin therapy. The authors suggested that cisplatin inhibits solute transport in the thick ascending limb, causing clinically significant electrolyte abnormalities, coining the term cisplatin-induced salt wasting.¹¹

The prevalence of cisplatin-induced salt wasting is unclear and likely underreported. In 1988, Hutchinson and colleagues conducted a prospective cohort study and noted 10% of patients (n = 70) developed RSWS at some point over 18 months of cisplatin therapy—a higher rate than previously estimated.¹² In 1992, another prospective cohort study evaluated the adverse effects of 47 patients with non-small cell lung cancer treated with cisplatin and reported hyponatremia in 43% of its 93 courses of chemotherapy. The authors did not report the etiology of these hyponatremia cases.¹³ Given the diagnostic challenge, RSWS may be underrepresented as a confirmed etiology of hyponatremia in cisplatin treatment.

Hyponatremia from cisplatin may present as either SIADH or RSWS, complicating treatment decisions. Both conditions lead to hypotonic hyponatremia with urine osmolality > 100 mOSm/kg and urine sodium levels > 40 mmol/L. However, pathophysiology behind SIADH and RSWS is different. In RSWS, proximal tubule damage causes hyponatremia, decreasing sodium reabsorption, and leading to impaired concentration gradient in every segment of the nephron. As a result, RSWS can lead to profound hyponatremia. Treatment typically consists of increasing sodium intake to correct serum sodium with salt tablets and hypertonic sodium chloride while treating the underlying etiology, in our case removing the offending agent, and waiting for proximal tubule function to recover.⁶ On the other hand, in SIADH, elevated antidiuretic hormone (ADH) increases water reabsorption in the collecting duct, which has no impact on concentration gradients of the other nephron segments.¹⁴ Free-water restriction is the hallmark of SIADH treatment. Severe SIADH may require sodium repletion and/or the initiation of vaptans, ADH antagonists that competitively inhibit V2 receptors in the collecting duct to prevent water reabsorption.¹⁵

Our patient had an uncertain etiology of his hyponatremia throughout most of his treatment course, complicating our treatment decision-making. Initially, his measured serum osmolality was 278 mOsm/kg; however, his effective tonicity was lower. His AKI elevated his BUN, which in turnrequired us to calculate his serum tonicity (217 mOsm/kg) that was consistent with hypotonic hyponatremia. His elevated urine osmolality and urine sodium levels made SIADH and RSWS the most likely etiologies of his hyponatremia. To confirm the etiology, we waited for correction of his serum sodium. Therefore, we treated him with a combination of sodium repletion with 0.9% sodium chloride (154 mEq/L), hypertonic relative to his serum sodium, sodium chloride tablets, and free-water restriction. In this approach, we attempted to harmonize the treatment strategies for both SIADH and RSWS and effectively corrected his serum sodium. We evaluated his response to our treatment with a basic metabolic panel every 6 to 8 hours. Had his serum sodium decreased < 120 mmol/L, we planned to transfer the patient to the intensive care unit for 3% sodium chloride and/or intensification of his fluid restriction. A significant worsening of his hyponatremia would have strongly suggested hyponatremia secondary to SIADH since isotonic saline can worsen hyponatremia due to increased free-water reabsorption in the collecting duct.¹⁶

To differentiate between SIADH and RSWS, we relied on the FE_urate after sodium correction. Multiple case reports from Japan have characterized the distinction between the processes through FE_urate and serum uric acid. While the optimal cut-off values for FE_urate require additional investigation, values < 11% after serum sodium correction suggests SIADH, while a value > 11% suggests RSWS.¹⁷ Prior cases have also emphasized serum hypouricemia as a distinguishing characteristic in RSWS. However, our case illustrates that serum hypouricemia is less reliable in the setting of AKI. Due to his severe AKI, our patient could not efficiently clear uric acid, likely contributing to his hyperuricemia.

Ultimately, our patient had an FE_urate > 20%, which was suggestive of RSWS. Nevertheless, we recognize limitations and confounders in our diagnosis and have reflected on our diagnostic and management choices. First, the sensitivity and specificity of postsodium correction FE_urate is unknown. Tracking the change in FE_urate with our interventions would have increased our diagnostic utility, as suggested by Maesaka and colleagues.¹⁴ Second, our patient’s serum sodium was still at the lower end of the reference range after treatment, which may decrease the specificity of FE_urate. Third, a plasma ADH collected during the initial phase of symptomatic hyponatremia would have helped differentiate between SIADH and RSWS.

Other diagnostic tests that could have excluded alternative diagnoses with even greater certainty include plasma adrenocorticotropic hormone, B-type natriuretic peptide, renin, cortisol, and thyroid function tests. From a practical standpoint, these laboratory results (excluding thyroid function test and brain natriuretic peptide) would have taken several weeks to result at our institution, limiting their clinical utility. Similarly, FE_urate also has limited clinical utility, requiring effective treatment as part of the diagnostic test. Therefore, we recommend focusing on optimal treatment for hyponatremia of uncertain etiology, especially where SIADH and RSWS are the leading diagnoses.

Conclusions

We described a rare case of concomitant cisplatin-induced severe AKI and RSWS. We have emphasized the diagnostic challenge of distinguishing between SIADH and RSWS, especially with concomitant AKI, and have acknowledged that optimal treatment relies on accurate differentiation. However, differentiation may not be clinically feasible. Therefore, we suggest a treatment strategy that incorporates both free-water restriction and sodium supplementation via IV and/or oral administration.

Cisplatin is a potent antineoplastic agent derived from platinum and commonly used in the treatment of head and neck, bladder, ovarian, and testicular malignancies.^1,2 Approximately 20% of all cancer patients are prescribed platinum-based chemotherapeutics.³ Although considered highly effective, cisplatin is also a dose-dependent nephrotoxin, inducing apoptosis in the proximal tubules of the nephron and reducing glomerular filtration rate. This nephron injury leads to inflammation and reduced medullary blood flow, causing further ischemic damage to the tubular cells.⁴ Given that the proximal tubule reabsorbs 67% of all sodium, cisplatin-induced nephron injuries can also lead to hyponatremia.⁵

The primary mechanisms of hyponatremia following cisplatin chemotherapy are syndrome of inappropriate antidiuretic hormone secretion (SIADH) and renal salt wasting syndrome (RSWS). Though these diagnoses have similar presentations, the treatment recommendations are different due to pathophysiologic differences. Fluid restriction is the hallmark of SIADH treatment, while increased sodium intake remains the hallmark of RSWS treatment.⁶ This patient presented with a combination of cisplatin-induced acute kidney injury (AKI) and hyponatremia secondary to RSWS. While RSWS and AKI are known complications of cisplatin chemotherapy, the combination is underreported in the literature. Therefore, this case report highlights the combination of these cisplatin-induced complications, emphasizes the clinical challenges in differentiating SIADH from RSWS, especially in the presence of a concomitant AKI, and suggests a treatment approach during diagnostic uncertainty.

Case Presentation

A 71-year-old man with a medical history of squamous cell carcinoma (SCC) of the left neck on cycle 1, day 8 of cisplatin-based chemotherapy and ongoing radiation therapy (720 cGy of 6300 cGy), lung adenocarcinoma status postresection, and hyperlipidemia presented to the emergency department (ED) at the request of his oncologist for abnormal laboratory values. In the ED, his metabolic panel showed a 131-mmol/L serum sodium, 3.3 mmol/L potassium, 83 mmol/L chloride, 29 mmol/L bicarbonate, 61 mg/dL blood urea nitrogen (BUN), and 8.8 mg/dL creatinine (baseline, 0.9 mg/dL). The patient reported throbbing headaches, persistent nausea, and multiple episodes of nonbloody emesis for several days that he attributed to his chemotherapy. He noted decreased urination without discomfort or changes in color or odor and no fatigue, fevers, chills, hematuria, flank, abdominal pain, thirst, or polydipsia. He reported no toxic ingestions or IV drug use. The patient had no relevant family history or additional social history. His outpatient medications included 10 mg cetirizine, 8 mg ondansetron, and 81 mg aspirin. On initial examination, his 137/66 mm Hg blood pressure was mildly elevated. The physical examination findings were notable for a 5-cm mass in the left neck that was firm and irregularly-shaped. His physical examination was otherwise unremarkable. He was admitted to the inpatient medicine service for an AKI complicated by symptomatic hyponatremia.

Investigations

We evaluated the patient’s AKI based on treatment responsiveness, imaging, and laboratory testing. Renal and bladder ultrasound showed no evidence of hydronephrosis or obstruction. He had a benign urinalysis with microscopy absent for protein, blood, ketones, leukocyte esterase, nitrites, and cellular casts. His urine pH was 5.5 (reference range, 5.0-9.0) and specific gravity was 1.011 (reference range, 1.005-1.030). His urine electrolytes revealed 45-mmol/L urine sodium (reference range, 40-220), 33-mmol/L urine chloride (reference range, 110-250), 10-mmol/L urine potassium (reference range, 25-120), 106.7-mg/dL urine creatinine (reference range, 10-400) and a calculated 2.7% fractional excretion of sodium (FE_Na) and 22.0-mEq/L elevated urine anion gap. As a fluid challenge, he was treated with IV 0.9% sodium chloride at 100-125 mL/h, receiving 3 liters over the first 48 hours of his hospitalization. His creatinine peaked at 9.2 mg/dL and stabilized before improving later in his hospitalization (Figure 1). The patient initially had oliguria (< 0.5 mL/kg/h), which slowly improved over his hospital course. Unfortunately, due to multiple system and clinical factors, accurate inputs and outputs were not adequately maintained during his hospitalization.

We evaluated hyponatremia with a combination of serum and urine laboratory tests. In addition to urine electrolytes, the initial evaluation focused on trending his clinical trajectory. We repeated a basic metabolic panel every 4 to 6 hours. He had 278-mOsm/kg serum osmolality (reference range, 285-295) with an effective 217-mOsm/kg serum tonicity. His urine osmolality was 270.5 mOsm/kg.

Despite administering 462 mEq sodium via crystalloid, his sodium worsened over the first 48 hours, reaching a nadir at 125 mmol/L on hospital day 3 (Figure 2). While he continued to appear euvolemic on physical examination, his blood pressure became difficult to control with 160- to 180-mm Hg systolic blood pressure readings. His thyroid stimulating hormone (TSH) was normal and aldosterone was low (4 ng/dL). Additional urine studies, including a 24-hour urine sample, were collected for further evaluation. His urine uric acid was 140 mg/d (reference range, 120-820); his serum uric acid level was 8.2 mg/dL (reference range, 3.0-9.0). His 24-hour urine creatinine was 0.57 g/d (reference range, 0.50-2.15) and uric acid to creatinine ratio was 246 mg/g (reference range, 60-580). His serum creatinine collected from the same day as his 24-hour urine sample was 7.3 mg/dL. His fractional excretion of uric acid (FE_urate) was 21.9%.

Differential Diagnosis

The patient’s recent administration of cisplatin raised clinical suspicion of cisplatin-induced AKI. To avoid premature diagnostic closure, we used a systematic approach for thinking about our patient’s AKI, considering prerenal, intrarenal, and postrenal etiologies. The unremarkable renal and bladder ultrasound made a postrenal etiology unlikely. The patient’s 2.7% FE_Na in the absence of a diuretic, limited responsiveness to crystalloid fluid resuscitation, 7.5 serum BUN/creatinine ratio, and 270.5 mOsm/kg urine osmolality suggested an intrarenal etiology, which can be further divided into problems with glomeruli, tubules, small vessels, or interstitial space. The patient’s normal urinary microscopy with no evidence of protein, blood, ketones, leukocyte esterase, nitrites, or cellular casts made a glomerular etiology less likely. The acute onset and lack of additional systemic features, other than hypertension, made a vascular etiology less likely. A tubular etiology, such as acute tubular necrosis (ATN), was highest on the differential and was followed by an interstitial etiology, such as acute interstitial nephritis (AIN).

Patients with drug-induced AIN commonly present with signs and symptoms of an allergic-type reaction, including fever, rash, hematuria, pyuria, and costovertebral angle tenderness. The patient lacked these symptoms. However, cisplatin is known to cause ATN in up to 20-30% of patients.⁷ Therefore, despite the lack of the classic muddy-brown, granular casts on urine microscopy, cisplatin-induced ATN remained the most likely etiology of his AKI. Moreover, ATN can cause hyponatremia. ATN is characterized by 3 phases: initiation, maintenance, and recovery phases.⁸ Hyponatremia occurs during the recovery phase, typically starting weeks after renal insult and associated with high urine output and diuresis. This patient presented 1 week after injury and had persistent oliguria, making ATN an unlikely culprit of his hyponatremia.

Our patient presented with hypotonic hyponatremia with a 131 mmol/L initial sodium level and an < 280 mOsm/kg effective serum osmolality, or serum tonicity. The serum tonicity is equivalent to the difference between the measured serum osmolality and the BUN. In the setting of profound AKI, this adjustment is essential for correctly categorizing a patient’s hyponatremia as hyper-, iso-, or hypotonic. The differential diagnosis for this patient’s hypotonic hyponatremia included dilutional effects of hypervolemia, SIADH, hyperthyroidism, adrenal insufficiency, and RSWS. The patient’s volume examination, lack of predisposing comorbidities or suggestive biomarkers, and > 20 mmol/L urinary sodium made hypervolemia unlikely. His urinary osmolality and specific gravity made primary polydipsia unlikely. We worked up his hyponatremia according to a diagnostic algorithm (eAppendix available at doi:10.12788/fp.0198).

The patient had a 217 mOsm/kg serum tonicity and a 270.5 mOsm/kg urine osmolality, consistent with impaired water excretion. His presentation, TSH, and concordant decrease in sodium and potassium made an endocrine etiology of his hyponatremia less likely. In hindsight, a serum cortisol would have been beneficial to more completely exclude adrenal insufficiency. His urine sodium was elevated at 45 mmol/L, raising concern for RSWS or SIADH. The FE_urate helped to distinguish between SIADH and RSWS. While FE_urate is often elevated in both SIADH and RSWS initially, the FE_urate normalizes in SIADH with normalization of the serum sodium. The ideal cutoff for posthyponatremia correction FE_urate is debated; however, a FE_urate value after sodium correction < 11% suggests SIADH while a value > 11% suggests RSWS.⁹ Our patient’s FE_urate following the sodium correction (serum sodium 134 mmol/L) was 21.9%, most suggestive of RSWS.

Treatment

Upon admission, initial treatment focused on resolving the patient’s AKI. The oncology team discontinued the cisplatin-based chemotherapy. His medication dosages were adjusted for his renal function and additional nephrotoxins avoided. In consultation, the nephrology service recommended 100 mL/h fluid resuscitation. After the patient received 3 L of 0.9% sodium chloride, his creatinine showed limited improvement and his sodium worsened, trending from 131 mmol/L to a nadir of 125 mmol/L. We initiated oral free-water restriction while continuing IV infusion of 0.9% sodium chloride at 125 mL/h.

We further augmented his sodium intake with 1-g sodium chloride tablets with each meal. By hospital day 6, the patient’s serum sodium, BUN, and creatinine improved to 130 mEq/L, 50 mg/dL, and 7.7 mg/dL, respectively. We then discontinued the oral sodium chloride tablets, fluid restriction, and IV fluids in a stepwise fashion prior to discharge. At discharge, the patient’s serum sodium was 136 mEq/L and creatinine, 4.8 mg/dL. The patient’s clinical course was complicated by symptomatic hypertension with systolic blood pressures about 180 mm Hg, requiring intermittent IV hydralazine, which was transitioned to daily nifedipine. Concerned that fluid resuscitation contributed to his hypertension, the patient also received several doses of furosemide. At time of discharge, the patient remained hypertensive and was discharged with nifedipine 90 mg daily.

Outcome and Follow-up

The patient has remained stable clinically since discharge. One week after discharge, his serum sodium and creatinine were 138 mmol/L and 3.8 mg/dL, respectively. More than 1 month after discharge, his sodium remains in the reference range and his creatinine was stable at about 3.5 mg/dL. He continues to follow-up with nephrology, oncology, and radiation oncology. He has restarted chemotherapy with a carboplatin-based regimen without recurrence of hyponatremia or AKI. His blood pressure has gradually improved to the point where he no longer requires nifedipine.

Discussion

The US Food and Drug Administration first approved the use of cisplatin, an alkylating agent that inhibits DNA replication, in 1978 for the treatment of testicular cancer.¹⁰ Since its approval, cisplatin has increased in popularity and is now considered one of the most effective antineoplastic agents for the treatment of solid tumors.¹ Unfortunately, cisplatin has a well-documented adverse effect profile that includes neurotoxicity, gastrointestinal toxicity, nephrotoxicity, and ototoxicity.⁴ Despite frequent nephrotoxicity, cisplatin only occasionally causes hyponatremia and rarely causes RSWS, a known but potentially fatal complication. Moreover, the combination of AKI and RSWS is unique. Our patient presented with the unique combination of AKI and hyponatremia, most consistent with RSWS, likely precipitated from cisplatin chemotherapy. Through this case, we review cisplatin-associated electrolyte abnormalities, highlight the challenge of differentiating SIADH and RSWS, and suggest a treatment approach for hyponatremia during the period of diagnostic uncertainty.

Blachley and colleagues first discussed renal and electrolyte disturbances, specifically magnesium wasting, secondary to cisplatin use in 1981. In 1984, Kurtzberg and colleagues noted salt wasting in 2 patients receiving cisplatin therapy. The authors suggested that cisplatin inhibits solute transport in the thick ascending limb, causing clinically significant electrolyte abnormalities, coining the term cisplatin-induced salt wasting.¹¹

The prevalence of cisplatin-induced salt wasting is unclear and likely underreported. In 1988, Hutchinson and colleagues conducted a prospective cohort study and noted 10% of patients (n = 70) developed RSWS at some point over 18 months of cisplatin therapy—a higher rate than previously estimated.¹² In 1992, another prospective cohort study evaluated the adverse effects of 47 patients with non-small cell lung cancer treated with cisplatin and reported hyponatremia in 43% of its 93 courses of chemotherapy. The authors did not report the etiology of these hyponatremia cases.¹³ Given the diagnostic challenge, RSWS may be underrepresented as a confirmed etiology of hyponatremia in cisplatin treatment.

Hyponatremia from cisplatin may present as either SIADH or RSWS, complicating treatment decisions. Both conditions lead to hypotonic hyponatremia with urine osmolality > 100 mOSm/kg and urine sodium levels > 40 mmol/L. However, pathophysiology behind SIADH and RSWS is different. In RSWS, proximal tubule damage causes hyponatremia, decreasing sodium reabsorption, and leading to impaired concentration gradient in every segment of the nephron. As a result, RSWS can lead to profound hyponatremia. Treatment typically consists of increasing sodium intake to correct serum sodium with salt tablets and hypertonic sodium chloride while treating the underlying etiology, in our case removing the offending agent, and waiting for proximal tubule function to recover.⁶ On the other hand, in SIADH, elevated antidiuretic hormone (ADH) increases water reabsorption in the collecting duct, which has no impact on concentration gradients of the other nephron segments.¹⁴ Free-water restriction is the hallmark of SIADH treatment. Severe SIADH may require sodium repletion and/or the initiation of vaptans, ADH antagonists that competitively inhibit V2 receptors in the collecting duct to prevent water reabsorption.¹⁵

Our patient had an uncertain etiology of his hyponatremia throughout most of his treatment course, complicating our treatment decision-making. Initially, his measured serum osmolality was 278 mOsm/kg; however, his effective tonicity was lower. His AKI elevated his BUN, which in turnrequired us to calculate his serum tonicity (217 mOsm/kg) that was consistent with hypotonic hyponatremia. His elevated urine osmolality and urine sodium levels made SIADH and RSWS the most likely etiologies of his hyponatremia. To confirm the etiology, we waited for correction of his serum sodium. Therefore, we treated him with a combination of sodium repletion with 0.9% sodium chloride (154 mEq/L), hypertonic relative to his serum sodium, sodium chloride tablets, and free-water restriction. In this approach, we attempted to harmonize the treatment strategies for both SIADH and RSWS and effectively corrected his serum sodium. We evaluated his response to our treatment with a basic metabolic panel every 6 to 8 hours. Had his serum sodium decreased < 120 mmol/L, we planned to transfer the patient to the intensive care unit for 3% sodium chloride and/or intensification of his fluid restriction. A significant worsening of his hyponatremia would have strongly suggested hyponatremia secondary to SIADH since isotonic saline can worsen hyponatremia due to increased free-water reabsorption in the collecting duct.¹⁶

To differentiate between SIADH and RSWS, we relied on the FE_urate after sodium correction. Multiple case reports from Japan have characterized the distinction between the processes through FE_urate and serum uric acid. While the optimal cut-off values for FE_urate require additional investigation, values < 11% after serum sodium correction suggests SIADH, while a value > 11% suggests RSWS.¹⁷ Prior cases have also emphasized serum hypouricemia as a distinguishing characteristic in RSWS. However, our case illustrates that serum hypouricemia is less reliable in the setting of AKI. Due to his severe AKI, our patient could not efficiently clear uric acid, likely contributing to his hyperuricemia.

Ultimately, our patient had an FE_urate > 20%, which was suggestive of RSWS. Nevertheless, we recognize limitations and confounders in our diagnosis and have reflected on our diagnostic and management choices. First, the sensitivity and specificity of postsodium correction FE_urate is unknown. Tracking the change in FE_urate with our interventions would have increased our diagnostic utility, as suggested by Maesaka and colleagues.¹⁴ Second, our patient’s serum sodium was still at the lower end of the reference range after treatment, which may decrease the specificity of FE_urate. Third, a plasma ADH collected during the initial phase of symptomatic hyponatremia would have helped differentiate between SIADH and RSWS.

Other diagnostic tests that could have excluded alternative diagnoses with even greater certainty include plasma adrenocorticotropic hormone, B-type natriuretic peptide, renin, cortisol, and thyroid function tests. From a practical standpoint, these laboratory results (excluding thyroid function test and brain natriuretic peptide) would have taken several weeks to result at our institution, limiting their clinical utility. Similarly, FE_urate also has limited clinical utility, requiring effective treatment as part of the diagnostic test. Therefore, we recommend focusing on optimal treatment for hyponatremia of uncertain etiology, especially where SIADH and RSWS are the leading diagnoses.

Conclusions

We described a rare case of concomitant cisplatin-induced severe AKI and RSWS. We have emphasized the diagnostic challenge of distinguishing between SIADH and RSWS, especially with concomitant AKI, and have acknowledged that optimal treatment relies on accurate differentiation. However, differentiation may not be clinically feasible. Therefore, we suggest a treatment strategy that incorporates both free-water restriction and sodium supplementation via IV and/or oral administration.

Cisplatin is a potent antineoplastic agent derived from platinum and commonly used in the treatment of head and neck, bladder, ovarian, and testicular malignancies.^1,2 Approximately 20% of all cancer patients are prescribed platinum-based chemotherapeutics.³ Although considered highly effective, cisplatin is also a dose-dependent nephrotoxin, inducing apoptosis in the proximal tubules of the nephron and reducing glomerular filtration rate. This nephron injury leads to inflammation and reduced medullary blood flow, causing further ischemic damage to the tubular cells.⁴ Given that the proximal tubule reabsorbs 67% of all sodium, cisplatin-induced nephron injuries can also lead to hyponatremia.⁵

The primary mechanisms of hyponatremia following cisplatin chemotherapy are syndrome of inappropriate antidiuretic hormone secretion (SIADH) and renal salt wasting syndrome (RSWS). Though these diagnoses have similar presentations, the treatment recommendations are different due to pathophysiologic differences. Fluid restriction is the hallmark of SIADH treatment, while increased sodium intake remains the hallmark of RSWS treatment.⁶ This patient presented with a combination of cisplatin-induced acute kidney injury (AKI) and hyponatremia secondary to RSWS. While RSWS and AKI are known complications of cisplatin chemotherapy, the combination is underreported in the literature. Therefore, this case report highlights the combination of these cisplatin-induced complications, emphasizes the clinical challenges in differentiating SIADH from RSWS, especially in the presence of a concomitant AKI, and suggests a treatment approach during diagnostic uncertainty.

Case Presentation

A 71-year-old man with a medical history of squamous cell carcinoma (SCC) of the left neck on cycle 1, day 8 of cisplatin-based chemotherapy and ongoing radiation therapy (720 cGy of 6300 cGy), lung adenocarcinoma status postresection, and hyperlipidemia presented to the emergency department (ED) at the request of his oncologist for abnormal laboratory values. In the ED, his metabolic panel showed a 131-mmol/L serum sodium, 3.3 mmol/L potassium, 83 mmol/L chloride, 29 mmol/L bicarbonate, 61 mg/dL blood urea nitrogen (BUN), and 8.8 mg/dL creatinine (baseline, 0.9 mg/dL). The patient reported throbbing headaches, persistent nausea, and multiple episodes of nonbloody emesis for several days that he attributed to his chemotherapy. He noted decreased urination without discomfort or changes in color or odor and no fatigue, fevers, chills, hematuria, flank, abdominal pain, thirst, or polydipsia. He reported no toxic ingestions or IV drug use. The patient had no relevant family history or additional social history. His outpatient medications included 10 mg cetirizine, 8 mg ondansetron, and 81 mg aspirin. On initial examination, his 137/66 mm Hg blood pressure was mildly elevated. The physical examination findings were notable for a 5-cm mass in the left neck that was firm and irregularly-shaped. His physical examination was otherwise unremarkable. He was admitted to the inpatient medicine service for an AKI complicated by symptomatic hyponatremia.

Investigations

We evaluated the patient’s AKI based on treatment responsiveness, imaging, and laboratory testing. Renal and bladder ultrasound showed no evidence of hydronephrosis or obstruction. He had a benign urinalysis with microscopy absent for protein, blood, ketones, leukocyte esterase, nitrites, and cellular casts. His urine pH was 5.5 (reference range, 5.0-9.0) and specific gravity was 1.011 (reference range, 1.005-1.030). His urine electrolytes revealed 45-mmol/L urine sodium (reference range, 40-220), 33-mmol/L urine chloride (reference range, 110-250), 10-mmol/L urine potassium (reference range, 25-120), 106.7-mg/dL urine creatinine (reference range, 10-400) and a calculated 2.7% fractional excretion of sodium (FE_Na) and 22.0-mEq/L elevated urine anion gap. As a fluid challenge, he was treated with IV 0.9% sodium chloride at 100-125 mL/h, receiving 3 liters over the first 48 hours of his hospitalization. His creatinine peaked at 9.2 mg/dL and stabilized before improving later in his hospitalization (Figure 1). The patient initially had oliguria (< 0.5 mL/kg/h), which slowly improved over his hospital course. Unfortunately, due to multiple system and clinical factors, accurate inputs and outputs were not adequately maintained during his hospitalization.

We evaluated hyponatremia with a combination of serum and urine laboratory tests. In addition to urine electrolytes, the initial evaluation focused on trending his clinical trajectory. We repeated a basic metabolic panel every 4 to 6 hours. He had 278-mOsm/kg serum osmolality (reference range, 285-295) with an effective 217-mOsm/kg serum tonicity. His urine osmolality was 270.5 mOsm/kg.

Despite administering 462 mEq sodium via crystalloid, his sodium worsened over the first 48 hours, reaching a nadir at 125 mmol/L on hospital day 3 (Figure 2). While he continued to appear euvolemic on physical examination, his blood pressure became difficult to control with 160- to 180-mm Hg systolic blood pressure readings. His thyroid stimulating hormone (TSH) was normal and aldosterone was low (4 ng/dL). Additional urine studies, including a 24-hour urine sample, were collected for further evaluation. His urine uric acid was 140 mg/d (reference range, 120-820); his serum uric acid level was 8.2 mg/dL (reference range, 3.0-9.0). His 24-hour urine creatinine was 0.57 g/d (reference range, 0.50-2.15) and uric acid to creatinine ratio was 246 mg/g (reference range, 60-580). His serum creatinine collected from the same day as his 24-hour urine sample was 7.3 mg/dL. His fractional excretion of uric acid (FE_urate) was 21.9%.

Differential Diagnosis

The patient’s recent administration of cisplatin raised clinical suspicion of cisplatin-induced AKI. To avoid premature diagnostic closure, we used a systematic approach for thinking about our patient’s AKI, considering prerenal, intrarenal, and postrenal etiologies. The unremarkable renal and bladder ultrasound made a postrenal etiology unlikely. The patient’s 2.7% FE_Na in the absence of a diuretic, limited responsiveness to crystalloid fluid resuscitation, 7.5 serum BUN/creatinine ratio, and 270.5 mOsm/kg urine osmolality suggested an intrarenal etiology, which can be further divided into problems with glomeruli, tubules, small vessels, or interstitial space. The patient’s normal urinary microscopy with no evidence of protein, blood, ketones, leukocyte esterase, nitrites, or cellular casts made a glomerular etiology less likely. The acute onset and lack of additional systemic features, other than hypertension, made a vascular etiology less likely. A tubular etiology, such as acute tubular necrosis (ATN), was highest on the differential and was followed by an interstitial etiology, such as acute interstitial nephritis (AIN).

Patients with drug-induced AIN commonly present with signs and symptoms of an allergic-type reaction, including fever, rash, hematuria, pyuria, and costovertebral angle tenderness. The patient lacked these symptoms. However, cisplatin is known to cause ATN in up to 20-30% of patients.⁷ Therefore, despite the lack of the classic muddy-brown, granular casts on urine microscopy, cisplatin-induced ATN remained the most likely etiology of his AKI. Moreover, ATN can cause hyponatremia. ATN is characterized by 3 phases: initiation, maintenance, and recovery phases.⁸ Hyponatremia occurs during the recovery phase, typically starting weeks after renal insult and associated with high urine output and diuresis. This patient presented 1 week after injury and had persistent oliguria, making ATN an unlikely culprit of his hyponatremia.

Our patient presented with hypotonic hyponatremia with a 131 mmol/L initial sodium level and an < 280 mOsm/kg effective serum osmolality, or serum tonicity. The serum tonicity is equivalent to the difference between the measured serum osmolality and the BUN. In the setting of profound AKI, this adjustment is essential for correctly categorizing a patient’s hyponatremia as hyper-, iso-, or hypotonic. The differential diagnosis for this patient’s hypotonic hyponatremia included dilutional effects of hypervolemia, SIADH, hyperthyroidism, adrenal insufficiency, and RSWS. The patient’s volume examination, lack of predisposing comorbidities or suggestive biomarkers, and > 20 mmol/L urinary sodium made hypervolemia unlikely. His urinary osmolality and specific gravity made primary polydipsia unlikely. We worked up his hyponatremia according to a diagnostic algorithm (eAppendix available at doi:10.12788/fp.0198).

The patient had a 217 mOsm/kg serum tonicity and a 270.5 mOsm/kg urine osmolality, consistent with impaired water excretion. His presentation, TSH, and concordant decrease in sodium and potassium made an endocrine etiology of his hyponatremia less likely. In hindsight, a serum cortisol would have been beneficial to more completely exclude adrenal insufficiency. His urine sodium was elevated at 45 mmol/L, raising concern for RSWS or SIADH. The FE_urate helped to distinguish between SIADH and RSWS. While FE_urate is often elevated in both SIADH and RSWS initially, the FE_urate normalizes in SIADH with normalization of the serum sodium. The ideal cutoff for posthyponatremia correction FE_urate is debated; however, a FE_urate value after sodium correction < 11% suggests SIADH while a value > 11% suggests RSWS.⁹ Our patient’s FE_urate following the sodium correction (serum sodium 134 mmol/L) was 21.9%, most suggestive of RSWS.

Treatment

Upon admission, initial treatment focused on resolving the patient’s AKI. The oncology team discontinued the cisplatin-based chemotherapy. His medication dosages were adjusted for his renal function and additional nephrotoxins avoided. In consultation, the nephrology service recommended 100 mL/h fluid resuscitation. After the patient received 3 L of 0.9% sodium chloride, his creatinine showed limited improvement and his sodium worsened, trending from 131 mmol/L to a nadir of 125 mmol/L. We initiated oral free-water restriction while continuing IV infusion of 0.9% sodium chloride at 125 mL/h.

We further augmented his sodium intake with 1-g sodium chloride tablets with each meal. By hospital day 6, the patient’s serum sodium, BUN, and creatinine improved to 130 mEq/L, 50 mg/dL, and 7.7 mg/dL, respectively. We then discontinued the oral sodium chloride tablets, fluid restriction, and IV fluids in a stepwise fashion prior to discharge. At discharge, the patient’s serum sodium was 136 mEq/L and creatinine, 4.8 mg/dL. The patient’s clinical course was complicated by symptomatic hypertension with systolic blood pressures about 180 mm Hg, requiring intermittent IV hydralazine, which was transitioned to daily nifedipine. Concerned that fluid resuscitation contributed to his hypertension, the patient also received several doses of furosemide. At time of discharge, the patient remained hypertensive and was discharged with nifedipine 90 mg daily.

Outcome and Follow-up

The patient has remained stable clinically since discharge. One week after discharge, his serum sodium and creatinine were 138 mmol/L and 3.8 mg/dL, respectively. More than 1 month after discharge, his sodium remains in the reference range and his creatinine was stable at about 3.5 mg/dL. He continues to follow-up with nephrology, oncology, and radiation oncology. He has restarted chemotherapy with a carboplatin-based regimen without recurrence of hyponatremia or AKI. His blood pressure has gradually improved to the point where he no longer requires nifedipine.

Discussion

The US Food and Drug Administration first approved the use of cisplatin, an alkylating agent that inhibits DNA replication, in 1978 for the treatment of testicular cancer.¹⁰ Since its approval, cisplatin has increased in popularity and is now considered one of the most effective antineoplastic agents for the treatment of solid tumors.¹ Unfortunately, cisplatin has a well-documented adverse effect profile that includes neurotoxicity, gastrointestinal toxicity, nephrotoxicity, and ototoxicity.⁴ Despite frequent nephrotoxicity, cisplatin only occasionally causes hyponatremia and rarely causes RSWS, a known but potentially fatal complication. Moreover, the combination of AKI and RSWS is unique. Our patient presented with the unique combination of AKI and hyponatremia, most consistent with RSWS, likely precipitated from cisplatin chemotherapy. Through this case, we review cisplatin-associated electrolyte abnormalities, highlight the challenge of differentiating SIADH and RSWS, and suggest a treatment approach for hyponatremia during the period of diagnostic uncertainty.

Blachley and colleagues first discussed renal and electrolyte disturbances, specifically magnesium wasting, secondary to cisplatin use in 1981. In 1984, Kurtzberg and colleagues noted salt wasting in 2 patients receiving cisplatin therapy. The authors suggested that cisplatin inhibits solute transport in the thick ascending limb, causing clinically significant electrolyte abnormalities, coining the term cisplatin-induced salt wasting.¹¹

The prevalence of cisplatin-induced salt wasting is unclear and likely underreported. In 1988, Hutchinson and colleagues conducted a prospective cohort study and noted 10% of patients (n = 70) developed RSWS at some point over 18 months of cisplatin therapy—a higher rate than previously estimated.¹² In 1992, another prospective cohort study evaluated the adverse effects of 47 patients with non-small cell lung cancer treated with cisplatin and reported hyponatremia in 43% of its 93 courses of chemotherapy. The authors did not report the etiology of these hyponatremia cases.¹³ Given the diagnostic challenge, RSWS may be underrepresented as a confirmed etiology of hyponatremia in cisplatin treatment.

Hyponatremia from cisplatin may present as either SIADH or RSWS, complicating treatment decisions. Both conditions lead to hypotonic hyponatremia with urine osmolality > 100 mOSm/kg and urine sodium levels > 40 mmol/L. However, pathophysiology behind SIADH and RSWS is different. In RSWS, proximal tubule damage causes hyponatremia, decreasing sodium reabsorption, and leading to impaired concentration gradient in every segment of the nephron. As a result, RSWS can lead to profound hyponatremia. Treatment typically consists of increasing sodium intake to correct serum sodium with salt tablets and hypertonic sodium chloride while treating the underlying etiology, in our case removing the offending agent, and waiting for proximal tubule function to recover.⁶ On the other hand, in SIADH, elevated antidiuretic hormone (ADH) increases water reabsorption in the collecting duct, which has no impact on concentration gradients of the other nephron segments.¹⁴ Free-water restriction is the hallmark of SIADH treatment. Severe SIADH may require sodium repletion and/or the initiation of vaptans, ADH antagonists that competitively inhibit V2 receptors in the collecting duct to prevent water reabsorption.¹⁵

Our patient had an uncertain etiology of his hyponatremia throughout most of his treatment course, complicating our treatment decision-making. Initially, his measured serum osmolality was 278 mOsm/kg; however, his effective tonicity was lower. His AKI elevated his BUN, which in turnrequired us to calculate his serum tonicity (217 mOsm/kg) that was consistent with hypotonic hyponatremia. His elevated urine osmolality and urine sodium levels made SIADH and RSWS the most likely etiologies of his hyponatremia. To confirm the etiology, we waited for correction of his serum sodium. Therefore, we treated him with a combination of sodium repletion with 0.9% sodium chloride (154 mEq/L), hypertonic relative to his serum sodium, sodium chloride tablets, and free-water restriction. In this approach, we attempted to harmonize the treatment strategies for both SIADH and RSWS and effectively corrected his serum sodium. We evaluated his response to our treatment with a basic metabolic panel every 6 to 8 hours. Had his serum sodium decreased < 120 mmol/L, we planned to transfer the patient to the intensive care unit for 3% sodium chloride and/or intensification of his fluid restriction. A significant worsening of his hyponatremia would have strongly suggested hyponatremia secondary to SIADH since isotonic saline can worsen hyponatremia due to increased free-water reabsorption in the collecting duct.¹⁶

To differentiate between SIADH and RSWS, we relied on the FE_urate after sodium correction. Multiple case reports from Japan have characterized the distinction between the processes through FE_urate and serum uric acid. While the optimal cut-off values for FE_urate require additional investigation, values < 11% after serum sodium correction suggests SIADH, while a value > 11% suggests RSWS.¹⁷ Prior cases have also emphasized serum hypouricemia as a distinguishing characteristic in RSWS. However, our case illustrates that serum hypouricemia is less reliable in the setting of AKI. Due to his severe AKI, our patient could not efficiently clear uric acid, likely contributing to his hyperuricemia.

Ultimately, our patient had an FE_urate > 20%, which was suggestive of RSWS. Nevertheless, we recognize limitations and confounders in our diagnosis and have reflected on our diagnostic and management choices. First, the sensitivity and specificity of postsodium correction FE_urate is unknown. Tracking the change in FE_urate with our interventions would have increased our diagnostic utility, as suggested by Maesaka and colleagues.¹⁴ Second, our patient’s serum sodium was still at the lower end of the reference range after treatment, which may decrease the specificity of FE_urate. Third, a plasma ADH collected during the initial phase of symptomatic hyponatremia would have helped differentiate between SIADH and RSWS.

Other diagnostic tests that could have excluded alternative diagnoses with even greater certainty include plasma adrenocorticotropic hormone, B-type natriuretic peptide, renin, cortisol, and thyroid function tests. From a practical standpoint, these laboratory results (excluding thyroid function test and brain natriuretic peptide) would have taken several weeks to result at our institution, limiting their clinical utility. Similarly, FE_urate also has limited clinical utility, requiring effective treatment as part of the diagnostic test. Therefore, we recommend focusing on optimal treatment for hyponatremia of uncertain etiology, especially where SIADH and RSWS are the leading diagnoses.

Conclusions

We described a rare case of concomitant cisplatin-induced severe AKI and RSWS. We have emphasized the diagnostic challenge of distinguishing between SIADH and RSWS, especially with concomitant AKI, and have acknowledged that optimal treatment relies on accurate differentiation. However, differentiation may not be clinically feasible. Therefore, we suggest a treatment strategy that incorporates both free-water restriction and sodium supplementation via IV and/or oral administration.

THE CASE

A 25-year-old woman presented to an infectious diseases (ID) physician with a 4-day history of symptoms following receipt of a quadrivalent influenza vaccine. Two hours after receiving the vaccine, the patient experienced abdominal pain. One hour later, she felt warm and developed diffuse urticaria and rigors. Because of her worsening condition, she presented to the emergency department, where she was given intravenous methylprednisolone 40 mg, ondansetron 8 mg, diphenhydramine 25 mg, and normal saline. Her urticarial rash resolved within 45 minutes, and she was discharged home.

Three days later, she sought additional medical care because of persistent chest tightness, new-onset bronchospasm, pleuritic chest pain, nausea, diarrhea, facial swelling, urticaria, and anorexia. The patient’s vital signs were within normal limits. The oropharynx lacked erythema or obstruction. The lungs were clear to auscultation bilaterally, and heart sounds were regular, with no ectopy or murmurs. Her abdomen was soft, nontender, and nondistended. The patient demonstrated dermatographism on her back.

Historically, the patient had received the influenza vaccine without difficulty. She tolerated latex but had concerns about egg allergy due to vomiting with egg-yolk exposure.

THE DIAGNOSIS

The ID physician, suspecting anaphylaxis and sustained allergic response to the influenza vaccine, arranged for immediate follow-up with an allergist. Multiple tests were done. A negative result on epicutaneous testing to egg was inconsistent with an immunoglobulin (Ig) E-mediated food allergy.

Intradermal testing with the flu vaccine (diluted 1:100) was subsequently performed with appropriate controls. A positive intradermal result is typically a wheal ≥ 5 mm larger than the control. The patient had a 5-mm/15-mm wheal-and-flare response to the flu vaccine, compared to a negative response to saline (FIGURE). (Since the vaccine did not contain gelatin, this was not tested.)

Based on the positive response to flu vaccine and negative response to egg, it was determined that the patient had experienced an anaphylactic reaction to the vaccine itself.

DISCUSSION

In adults, the most common adverse reactions to quadrivalent flu vaccine include pain, headache, and fatigue. IgE-mediated reactions to the influenza vaccine, especially anaphylactic reactions, are rare. A Vaccine Safety Datalink study found 10 cases of anaphylaxis after more than 7.4 million doses of inactivated flu vaccine were given, for a rate of 1.35 per 1 million doses.¹

Continue to: Don't blame eggs

Don’t blame eggs. It was previously believed that reactions to the flu vaccine were due to egg allergies, because the vaccine may contain a tiny amount of ovalbumin, a protein found in egg. However, multiple studies have supported the safety of injectable influenza vaccine in patients with an egg allergy because the amount of ovalbumin contained in each dose is very low and thus not likely to evoke an allergic response.^2,3

How and when to test for allergy. For patients who have a severe allergic reaction or anaphylaxis after immunization, immediate-type allergy skin testing should be performed by an allergist to establish whether the reaction was IgE mediated and to determine the causative agent.

Wait 4 to 6 weeks after an anaphylactic reaction before doing skin testing, as earlier testing can lead to false-negative results.

It’s best to wait 4 to 6 weeks after an anaphylactic reaction before doing skin testing, as earlier testing can lead to false-negative results.⁴ The vaccine should first be tested by using the prick method. If this test is negative, an intradermal test with the vaccine diluted 1:100 should be performed with appropriate controls.⁵

Should the patient receive future vaccinations?

If skin testing is positive, there are several ways to proceed. A vaccine to which the patient has previously had an allergic reaction and positive skin test can still be administered, with caution.⁵ With emergency supplies, medication, and equipment immediately available, medical personnel can administer the influenza vaccine in titrated doses. If the full vaccine dose is normally a volume of 0.5 mL, the patient is first given 0.05 mL of a 1:10 dilution and then, at 15-minute intervals, given full-strength vaccine at doses of 0.05, 0.1, 0.15, and finally 0.2 mL, for a cumulative dose of 0.5 mL.⁵

Alternatively, the patient can forego the vaccination, although this decision has its own risks. In a patient who has previously had an anaphylactic reaction but has negative skin tests—meaning it is unlikely that the patient has IgE antibody to the vaccine—the vaccine can be administered and followed with an observation period of at least 30 minutes.⁵z Our patient was counseled on both options and decided to forego the vaccine.

THE TAKEAWAY

Anaphylaxis is a life-threatening allergic reaction requiring immediate treatment. Anaphylaxis after vaccine receipt is exceedingly rare.⁶ Most IgE-mediated allergic reactions post vaccination are attributed to added or residual substances in the vaccine, rather than the immunizing agent itself.⁶ While common local reactions and fever post vaccination do not contraindicate future vaccination, rare anaphylactic reactions need to be further evaluated, with a referral to an allergist to determine if the patient is, in fact, allergic to additive ingredients within the vaccine vs allergic to the vaccine itself.

CORRESPONDENCE
Kathleen Dass, MD, 24601 Coolidge Highway, Oak Park, MI 48237; [email protected]

THE CASE

A 25-year-old woman presented to an infectious diseases (ID) physician with a 4-day history of symptoms following receipt of a quadrivalent influenza vaccine. Two hours after receiving the vaccine, the patient experienced abdominal pain. One hour later, she felt warm and developed diffuse urticaria and rigors. Because of her worsening condition, she presented to the emergency department, where she was given intravenous methylprednisolone 40 mg, ondansetron 8 mg, diphenhydramine 25 mg, and normal saline. Her urticarial rash resolved within 45 minutes, and she was discharged home.

Three days later, she sought additional medical care because of persistent chest tightness, new-onset bronchospasm, pleuritic chest pain, nausea, diarrhea, facial swelling, urticaria, and anorexia. The patient’s vital signs were within normal limits. The oropharynx lacked erythema or obstruction. The lungs were clear to auscultation bilaterally, and heart sounds were regular, with no ectopy or murmurs. Her abdomen was soft, nontender, and nondistended. The patient demonstrated dermatographism on her back.

Historically, the patient had received the influenza vaccine without difficulty. She tolerated latex but had concerns about egg allergy due to vomiting with egg-yolk exposure.

THE DIAGNOSIS

The ID physician, suspecting anaphylaxis and sustained allergic response to the influenza vaccine, arranged for immediate follow-up with an allergist. Multiple tests were done. A negative result on epicutaneous testing to egg was inconsistent with an immunoglobulin (Ig) E-mediated food allergy.

Intradermal testing with the flu vaccine (diluted 1:100) was subsequently performed with appropriate controls. A positive intradermal result is typically a wheal ≥ 5 mm larger than the control. The patient had a 5-mm/15-mm wheal-and-flare response to the flu vaccine, compared to a negative response to saline (FIGURE). (Since the vaccine did not contain gelatin, this was not tested.)

Based on the positive response to flu vaccine and negative response to egg, it was determined that the patient had experienced an anaphylactic reaction to the vaccine itself.

DISCUSSION

In adults, the most common adverse reactions to quadrivalent flu vaccine include pain, headache, and fatigue. IgE-mediated reactions to the influenza vaccine, especially anaphylactic reactions, are rare. A Vaccine Safety Datalink study found 10 cases of anaphylaxis after more than 7.4 million doses of inactivated flu vaccine were given, for a rate of 1.35 per 1 million doses.¹

Continue to: Don't blame eggs

Don’t blame eggs. It was previously believed that reactions to the flu vaccine were due to egg allergies, because the vaccine may contain a tiny amount of ovalbumin, a protein found in egg. However, multiple studies have supported the safety of injectable influenza vaccine in patients with an egg allergy because the amount of ovalbumin contained in each dose is very low and thus not likely to evoke an allergic response.^2,3

How and when to test for allergy. For patients who have a severe allergic reaction or anaphylaxis after immunization, immediate-type allergy skin testing should be performed by an allergist to establish whether the reaction was IgE mediated and to determine the causative agent.

Wait 4 to 6 weeks after an anaphylactic reaction before doing skin testing, as earlier testing can lead to false-negative results.

It’s best to wait 4 to 6 weeks after an anaphylactic reaction before doing skin testing, as earlier testing can lead to false-negative results.⁴ The vaccine should first be tested by using the prick method. If this test is negative, an intradermal test with the vaccine diluted 1:100 should be performed with appropriate controls.⁵

Should the patient receive future vaccinations?

If skin testing is positive, there are several ways to proceed. A vaccine to which the patient has previously had an allergic reaction and positive skin test can still be administered, with caution.⁵ With emergency supplies, medication, and equipment immediately available, medical personnel can administer the influenza vaccine in titrated doses. If the full vaccine dose is normally a volume of 0.5 mL, the patient is first given 0.05 mL of a 1:10 dilution and then, at 15-minute intervals, given full-strength vaccine at doses of 0.05, 0.1, 0.15, and finally 0.2 mL, for a cumulative dose of 0.5 mL.⁵

Alternatively, the patient can forego the vaccination, although this decision has its own risks. In a patient who has previously had an anaphylactic reaction but has negative skin tests—meaning it is unlikely that the patient has IgE antibody to the vaccine—the vaccine can be administered and followed with an observation period of at least 30 minutes.⁵z Our patient was counseled on both options and decided to forego the vaccine.

THE TAKEAWAY

Anaphylaxis is a life-threatening allergic reaction requiring immediate treatment. Anaphylaxis after vaccine receipt is exceedingly rare.⁶ Most IgE-mediated allergic reactions post vaccination are attributed to added or residual substances in the vaccine, rather than the immunizing agent itself.⁶ While common local reactions and fever post vaccination do not contraindicate future vaccination, rare anaphylactic reactions need to be further evaluated, with a referral to an allergist to determine if the patient is, in fact, allergic to additive ingredients within the vaccine vs allergic to the vaccine itself.

CORRESPONDENCE
Kathleen Dass, MD, 24601 Coolidge Highway, Oak Park, MI 48237; [email protected]

THE CASE

A 25-year-old woman presented to an infectious diseases (ID) physician with a 4-day history of symptoms following receipt of a quadrivalent influenza vaccine. Two hours after receiving the vaccine, the patient experienced abdominal pain. One hour later, she felt warm and developed diffuse urticaria and rigors. Because of her worsening condition, she presented to the emergency department, where she was given intravenous methylprednisolone 40 mg, ondansetron 8 mg, diphenhydramine 25 mg, and normal saline. Her urticarial rash resolved within 45 minutes, and she was discharged home.

Three days later, she sought additional medical care because of persistent chest tightness, new-onset bronchospasm, pleuritic chest pain, nausea, diarrhea, facial swelling, urticaria, and anorexia. The patient’s vital signs were within normal limits. The oropharynx lacked erythema or obstruction. The lungs were clear to auscultation bilaterally, and heart sounds were regular, with no ectopy or murmurs. Her abdomen was soft, nontender, and nondistended. The patient demonstrated dermatographism on her back.

Historically, the patient had received the influenza vaccine without difficulty. She tolerated latex but had concerns about egg allergy due to vomiting with egg-yolk exposure.

THE DIAGNOSIS

The ID physician, suspecting anaphylaxis and sustained allergic response to the influenza vaccine, arranged for immediate follow-up with an allergist. Multiple tests were done. A negative result on epicutaneous testing to egg was inconsistent with an immunoglobulin (Ig) E-mediated food allergy.

Intradermal testing with the flu vaccine (diluted 1:100) was subsequently performed with appropriate controls. A positive intradermal result is typically a wheal ≥ 5 mm larger than the control. The patient had a 5-mm/15-mm wheal-and-flare response to the flu vaccine, compared to a negative response to saline (FIGURE). (Since the vaccine did not contain gelatin, this was not tested.)

Based on the positive response to flu vaccine and negative response to egg, it was determined that the patient had experienced an anaphylactic reaction to the vaccine itself.

DISCUSSION

In adults, the most common adverse reactions to quadrivalent flu vaccine include pain, headache, and fatigue. IgE-mediated reactions to the influenza vaccine, especially anaphylactic reactions, are rare. A Vaccine Safety Datalink study found 10 cases of anaphylaxis after more than 7.4 million doses of inactivated flu vaccine were given, for a rate of 1.35 per 1 million doses.¹

Continue to: Don't blame eggs

Don’t blame eggs. It was previously believed that reactions to the flu vaccine were due to egg allergies, because the vaccine may contain a tiny amount of ovalbumin, a protein found in egg. However, multiple studies have supported the safety of injectable influenza vaccine in patients with an egg allergy because the amount of ovalbumin contained in each dose is very low and thus not likely to evoke an allergic response.^2,3

How and when to test for allergy. For patients who have a severe allergic reaction or anaphylaxis after immunization, immediate-type allergy skin testing should be performed by an allergist to establish whether the reaction was IgE mediated and to determine the causative agent.

Wait 4 to 6 weeks after an anaphylactic reaction before doing skin testing, as earlier testing can lead to false-negative results.

It’s best to wait 4 to 6 weeks after an anaphylactic reaction before doing skin testing, as earlier testing can lead to false-negative results.⁴ The vaccine should first be tested by using the prick method. If this test is negative, an intradermal test with the vaccine diluted 1:100 should be performed with appropriate controls.⁵

Should the patient receive future vaccinations?

If skin testing is positive, there are several ways to proceed. A vaccine to which the patient has previously had an allergic reaction and positive skin test can still be administered, with caution.⁵ With emergency supplies, medication, and equipment immediately available, medical personnel can administer the influenza vaccine in titrated doses. If the full vaccine dose is normally a volume of 0.5 mL, the patient is first given 0.05 mL of a 1:10 dilution and then, at 15-minute intervals, given full-strength vaccine at doses of 0.05, 0.1, 0.15, and finally 0.2 mL, for a cumulative dose of 0.5 mL.⁵

Alternatively, the patient can forego the vaccination, although this decision has its own risks. In a patient who has previously had an anaphylactic reaction but has negative skin tests—meaning it is unlikely that the patient has IgE antibody to the vaccine—the vaccine can be administered and followed with an observation period of at least 30 minutes.⁵z Our patient was counseled on both options and decided to forego the vaccine.

THE TAKEAWAY

Anaphylaxis is a life-threatening allergic reaction requiring immediate treatment. Anaphylaxis after vaccine receipt is exceedingly rare.⁶ Most IgE-mediated allergic reactions post vaccination are attributed to added or residual substances in the vaccine, rather than the immunizing agent itself.⁶ While common local reactions and fever post vaccination do not contraindicate future vaccination, rare anaphylactic reactions need to be further evaluated, with a referral to an allergist to determine if the patient is, in fact, allergic to additive ingredients within the vaccine vs allergic to the vaccine itself.

CORRESPONDENCE
Kathleen Dass, MD, 24601 Coolidge Highway, Oak Park, MI 48237; [email protected]

Nephrogenic systemic fibrosis (NSF) is a rare debilitating disorder characterized by dermal plaques, joint contractures, and fibrosis of the skin with possible involvement of muscles and internal organs.^1-3 Originally identified in 1997 as nephrogenic fibrosing dermopathy to describe its characteristic cutaneous thickening and hardening, the name was changed to NSF to more accurately reflect the noncutaneous manifestations present in other organ tissues.^2,4,5 Nephrogenic systemic fibrosis occurs in patients with a history of renal insufficiency and exposure to gadolinium-based contrast agents (GBCAs) used in magnetic resonance angiography and magnetic resonance imaging. There is no predilection for age, sex, or ethnicity.

Nephrogenic systemic fibrosis may develop over a period of days to several weeks. However, there have been cases of NSF developing 10 years after gadolinium exposure.² In most cases, patients have a history of severe chronic renal disease requiring hemodialysis. There have been a few reported cases of NSF occurring in patients with resolved acute kidney injury or resolved acute on chronic renal disease.^1,6-10 We present a case of NSF occurring in a patient with resolved transient renal insufficiency and no history of chronic renal disease.

Case Report

A 68-year-old woman presented with new dark, painless, pink plaques on the right thigh and calf. The patient stated the condition started and got worse after she was hospitalized 12 years prior for lower extremity cellulitis, sepsis, and acute renal failure. The patient developed complications during that hospital stay and underwent a renal biopsy and renal artery embolization requiring use of a GBCA. After the procedure, she noticed skin hardening in the extremities and decreased mobility in both legs while she was still in the hospital. It was thought that the lower leg changes were due to cellulitis. Therefore, when the renal issues resolved, she was discharged. Her skin and joint changes remained stable until 6 years later when she noticed new pink plaques appearing. Her medical history was positive for breast cancer, which was surgically and medically treated 16 years prior to presentation.

On presentation, physical examination revealed dark pink, hyperpigmented plaques on the right leg and a firm hypopigmented broad linear plaque on the right forearm. Palpation of the legs revealed thickened sclerotic plaques from the thighs down to the ankles (Figure 1). The plaques were not tender to palpation. She did have a decreased range of motion with eversion and inversion of the feet and ankles.

Biopsies from the right medial leg and right volar forearm showed increased bland dermal spindle cellularity associated with numerous round to ovoid osteoid aggregates encircling elastic fibers and surrounded by osteoblasts (Figure 2). CD34 immunohistochemistry showed general retention of staining within the dermal fibroblast population, and elastin stain showed general retention of elastic fiber bundles and thickening.

Laboratory workup included a complete blood cell count, comprehensive metabolic panel, thyroid-stimulating hormone level, and serum protein electrophoresis; results were all within reference range. The patient also had a urine element profile from an outside provider 1 month after presenting to our office that showed an elevated urine gadolinium level of 4.146 μg/g (reference range, 0–0.019 μg/g). The patient’s skin lesions have remained stable, and she is now working with physical therapy to help with her range of motion.

Comment

Gadolinium Causing Fibrosis—The incidence of NSF varies according to the severity of renal impairment, dosage level of GBCA used, and the history of GBCA use. In patients with normal renal function, gadolinium is excreted within 90 minutes. In patients with severe renal disease, the half-life can increase to up to 34.3 hours.¹¹ Reduced renal clearance and increased half-life of gadolinium lead to prolonged excretion, causing the GBCA to become unstable and dissociate into its constituents, leading to tissue deposition of Gd³⁺ cations. This dissociation is thought to be due to differences in the stability of the various chelation complexes among the different formulations of GBCAs.¹² The mechanism by which the dissociated gadolinium causes the fibrosis in the skin or other organs of the body is still unknown. Furthermore, even patients with normal renal function who undergo repeated administration of GBCA have been found to have higher levels of Gd³⁺ in their tissues, even in the absence of symptoms.¹³

Diagnosing NSF—In 2011, Girardi et al¹⁴ created a clinical and histopathological scoring system to help diagnose NSF. Clinical findings can be broken down into major criteria and minor criteria. Major criteria consist of patterned plaques, joint contractures, cobblestoning, marked induration, or peau d’orange change. Minor criteria consist of puckering, linear banding, superficial plaques or patches, dermal papules, and scleral plaques. Histopathologic findings include increased dermal cellularity (score +1), CD34⁺ cells with tram tracking (score +1), thickened or thin collagen bundles (score +1), preserved elastic fibers (score −1), septal involvement (score +1), and osseous metaplasia (score +3)(eTable).¹⁴

Differential Diagnosis—The differential diagnosis of NSF includes scleromyxedema, scleroderma, eosinophilic fasciitis, eosinophilia-myalgia syndrome, lipodermatosclerosis, morphea, and chronic graft-vs-host disease. Histopathologic examination of scleromyxedema can look identical to NSF. Therefore, a review of the patient’s medical history, prior hospitalizations, and prior gadolinium exposure is important. Appropriate laboratory workups should be ordered to rule out the other differential diagnoses.

NSF and Kidney Injury—A PubMed search of articles indexed for MEDLINE using the terms NSF with kidney injury revealed 7 cases of NSF occurring in patients who either had resolved acute kidney injury or resolved acute on chronic kidney disease.^1,6-10 Of those cases, 3 reported NSF occurring in patients with completely resolved acute kidney injury.^6,7,10 One of those cases involved a 65-year-old man who developed acute renal failure due to acute tubular necrosis.⁷ He had no history of renal disease prior to hospitalization. His skin lesions continued to improve as his renal function normalized back to baseline after discharge.⁷ The second case involved a 42-year-old man who had repeated exposure to GBCAs during a brief period of acute kidney injury.⁶ Nephrogenic systemic fibrosis developed after his renal function normalized. The authors did not mention if there was clinical improvement.⁶ The third case involved a 22-year-old man who developed acute renal failure after ingestion of hair dye. He did not have a history of chronic renal disease, and as he recovered from the acute kidney injury, almost all of the skin lesions cleared after 1 year.¹⁰

Our patient did not have a history of chronic renal disease when she presented to the hospital for sepsis and acute tubular necrosis. Unlike 2 of the prior cases, she did not notice improvement of the skin lesions as the renal function returned to baseline. She continued to experience changes in the skin, even up to 5 years after, and then stabilized. Throughout that time, her renal function was normal. Interestingly, despite having a normal creatinine level, the patient had an elevated gadolinium level on the urine gadolinium test, which typically is not a standard test for NSF. However, the elevated value does shed light on the persistence of gadolinium in the patient despite her exposure having been more than 10 years earlier.

Treatment of NSF—There is no gold standard treatment of NSF, and reversing the fibrosis has proven to be difficult. Avoidance of GBCAs in acute kidney injury or chronic severe renal disease, as recommended by the US Food and Drug Administration, is key to preventing this debilitating disease.¹⁵ Restoration of renal function is essential for excreting the gadolinium and improvement in NSF.¹² Physical and occupational therapy can improve joint mobility. Therapies such as extracorporeal photopheresis, sodium thiosulfate, pentoxifylline, glucocorticoids, plasmapheresis, intravenous immunoglobulin, cyclophosphamide, imatinib mesylate, intralesional interferon alfa, topical calcipotriene, corticosteroids, and UVA1 light therapy have been used with varying results.¹² It has been suggested that renal transplantation can stop the progression of NSF. However, in the cases we reviewed, renal transplantation would not have benefited those patients because their renal function normalized.^6,7,10 Additionally, even though our patient’s renal function normalized after discharge from the hospital, she continued to see more skin lesions developing, likely due to the accumulated gadolinium that was already in her tissue. The possibility of chelation therapy to remove the gadolinium has been proposed. In 1 case study involving deferoxamine injected intramuscularly in a patient with NSF, the urine excretion of gadolinium increased almost 2-fold, but there was no change in the serum concentration level of gadolinium or improvement in the patient’s clinical symptoms.¹⁶ We anticipate that our patient’s symptoms will slowly improve, as her body is still excreting the gadolinium. Our patient also was added to the International NSF Registry that was created by Dr. Shawn E. Cowper at the Yale School of Medicine (New Haven, Connecticut).

Conclusion

We report a rare case of NSF occurring in a patient with resolved acute kidney injury and no history of chronic renal disease. Our patient initially did not improve after her renal function normalized, as she continued to develop lesions 10 years after the exposure. Her elevated urine gadolinium excretion level also sheds light on the persistence of gadolinium in her body despite her normal renal function 10 years after her exposure. Although her clinical symptoms have stabilized, our case reiterates the complex pathology of this entity and challenge regarding treatment options. Physicians should be aware that NSF can still occur in healthy patients with no chronic renal disease who have had an episode of acute renal insufficiency along with exposure to a GBCA.

Nephrogenic systemic fibrosis (NSF) is a rare debilitating disorder characterized by dermal plaques, joint contractures, and fibrosis of the skin with possible involvement of muscles and internal organs.^1-3 Originally identified in 1997 as nephrogenic fibrosing dermopathy to describe its characteristic cutaneous thickening and hardening, the name was changed to NSF to more accurately reflect the noncutaneous manifestations present in other organ tissues.^2,4,5 Nephrogenic systemic fibrosis occurs in patients with a history of renal insufficiency and exposure to gadolinium-based contrast agents (GBCAs) used in magnetic resonance angiography and magnetic resonance imaging. There is no predilection for age, sex, or ethnicity.

Nephrogenic systemic fibrosis may develop over a period of days to several weeks. However, there have been cases of NSF developing 10 years after gadolinium exposure.² In most cases, patients have a history of severe chronic renal disease requiring hemodialysis. There have been a few reported cases of NSF occurring in patients with resolved acute kidney injury or resolved acute on chronic renal disease.^1,6-10 We present a case of NSF occurring in a patient with resolved transient renal insufficiency and no history of chronic renal disease.

Case Report

A 68-year-old woman presented with new dark, painless, pink plaques on the right thigh and calf. The patient stated the condition started and got worse after she was hospitalized 12 years prior for lower extremity cellulitis, sepsis, and acute renal failure. The patient developed complications during that hospital stay and underwent a renal biopsy and renal artery embolization requiring use of a GBCA. After the procedure, she noticed skin hardening in the extremities and decreased mobility in both legs while she was still in the hospital. It was thought that the lower leg changes were due to cellulitis. Therefore, when the renal issues resolved, she was discharged. Her skin and joint changes remained stable until 6 years later when she noticed new pink plaques appearing. Her medical history was positive for breast cancer, which was surgically and medically treated 16 years prior to presentation.

On presentation, physical examination revealed dark pink, hyperpigmented plaques on the right leg and a firm hypopigmented broad linear plaque on the right forearm. Palpation of the legs revealed thickened sclerotic plaques from the thighs down to the ankles (Figure 1). The plaques were not tender to palpation. She did have a decreased range of motion with eversion and inversion of the feet and ankles.

Biopsies from the right medial leg and right volar forearm showed increased bland dermal spindle cellularity associated with numerous round to ovoid osteoid aggregates encircling elastic fibers and surrounded by osteoblasts (Figure 2). CD34 immunohistochemistry showed general retention of staining within the dermal fibroblast population, and elastin stain showed general retention of elastic fiber bundles and thickening.

Laboratory workup included a complete blood cell count, comprehensive metabolic panel, thyroid-stimulating hormone level, and serum protein electrophoresis; results were all within reference range. The patient also had a urine element profile from an outside provider 1 month after presenting to our office that showed an elevated urine gadolinium level of 4.146 μg/g (reference range, 0–0.019 μg/g). The patient’s skin lesions have remained stable, and she is now working with physical therapy to help with her range of motion.

Comment

Gadolinium Causing Fibrosis—The incidence of NSF varies according to the severity of renal impairment, dosage level of GBCA used, and the history of GBCA use. In patients with normal renal function, gadolinium is excreted within 90 minutes. In patients with severe renal disease, the half-life can increase to up to 34.3 hours.¹¹ Reduced renal clearance and increased half-life of gadolinium lead to prolonged excretion, causing the GBCA to become unstable and dissociate into its constituents, leading to tissue deposition of Gd³⁺ cations. This dissociation is thought to be due to differences in the stability of the various chelation complexes among the different formulations of GBCAs.¹² The mechanism by which the dissociated gadolinium causes the fibrosis in the skin or other organs of the body is still unknown. Furthermore, even patients with normal renal function who undergo repeated administration of GBCA have been found to have higher levels of Gd³⁺ in their tissues, even in the absence of symptoms.¹³

Diagnosing NSF—In 2011, Girardi et al¹⁴ created a clinical and histopathological scoring system to help diagnose NSF. Clinical findings can be broken down into major criteria and minor criteria. Major criteria consist of patterned plaques, joint contractures, cobblestoning, marked induration, or peau d’orange change. Minor criteria consist of puckering, linear banding, superficial plaques or patches, dermal papules, and scleral plaques. Histopathologic findings include increased dermal cellularity (score +1), CD34⁺ cells with tram tracking (score +1), thickened or thin collagen bundles (score +1), preserved elastic fibers (score −1), septal involvement (score +1), and osseous metaplasia (score +3)(eTable).¹⁴

Differential Diagnosis—The differential diagnosis of NSF includes scleromyxedema, scleroderma, eosinophilic fasciitis, eosinophilia-myalgia syndrome, lipodermatosclerosis, morphea, and chronic graft-vs-host disease. Histopathologic examination of scleromyxedema can look identical to NSF. Therefore, a review of the patient’s medical history, prior hospitalizations, and prior gadolinium exposure is important. Appropriate laboratory workups should be ordered to rule out the other differential diagnoses.

NSF and Kidney Injury—A PubMed search of articles indexed for MEDLINE using the terms NSF with kidney injury revealed 7 cases of NSF occurring in patients who either had resolved acute kidney injury or resolved acute on chronic kidney disease.^1,6-10 Of those cases, 3 reported NSF occurring in patients with completely resolved acute kidney injury.^6,7,10 One of those cases involved a 65-year-old man who developed acute renal failure due to acute tubular necrosis.⁷ He had no history of renal disease prior to hospitalization. His skin lesions continued to improve as his renal function normalized back to baseline after discharge.⁷ The second case involved a 42-year-old man who had repeated exposure to GBCAs during a brief period of acute kidney injury.⁶ Nephrogenic systemic fibrosis developed after his renal function normalized. The authors did not mention if there was clinical improvement.⁶ The third case involved a 22-year-old man who developed acute renal failure after ingestion of hair dye. He did not have a history of chronic renal disease, and as he recovered from the acute kidney injury, almost all of the skin lesions cleared after 1 year.¹⁰

Our patient did not have a history of chronic renal disease when she presented to the hospital for sepsis and acute tubular necrosis. Unlike 2 of the prior cases, she did not notice improvement of the skin lesions as the renal function returned to baseline. She continued to experience changes in the skin, even up to 5 years after, and then stabilized. Throughout that time, her renal function was normal. Interestingly, despite having a normal creatinine level, the patient had an elevated gadolinium level on the urine gadolinium test, which typically is not a standard test for NSF. However, the elevated value does shed light on the persistence of gadolinium in the patient despite her exposure having been more than 10 years earlier.

Treatment of NSF—There is no gold standard treatment of NSF, and reversing the fibrosis has proven to be difficult. Avoidance of GBCAs in acute kidney injury or chronic severe renal disease, as recommended by the US Food and Drug Administration, is key to preventing this debilitating disease.¹⁵ Restoration of renal function is essential for excreting the gadolinium and improvement in NSF.¹² Physical and occupational therapy can improve joint mobility. Therapies such as extracorporeal photopheresis, sodium thiosulfate, pentoxifylline, glucocorticoids, plasmapheresis, intravenous immunoglobulin, cyclophosphamide, imatinib mesylate, intralesional interferon alfa, topical calcipotriene, corticosteroids, and UVA1 light therapy have been used with varying results.¹² It has been suggested that renal transplantation can stop the progression of NSF. However, in the cases we reviewed, renal transplantation would not have benefited those patients because their renal function normalized.^6,7,10 Additionally, even though our patient’s renal function normalized after discharge from the hospital, she continued to see more skin lesions developing, likely due to the accumulated gadolinium that was already in her tissue. The possibility of chelation therapy to remove the gadolinium has been proposed. In 1 case study involving deferoxamine injected intramuscularly in a patient with NSF, the urine excretion of gadolinium increased almost 2-fold, but there was no change in the serum concentration level of gadolinium or improvement in the patient’s clinical symptoms.¹⁶ We anticipate that our patient’s symptoms will slowly improve, as her body is still excreting the gadolinium. Our patient also was added to the International NSF Registry that was created by Dr. Shawn E. Cowper at the Yale School of Medicine (New Haven, Connecticut).

Conclusion

We report a rare case of NSF occurring in a patient with resolved acute kidney injury and no history of chronic renal disease. Our patient initially did not improve after her renal function normalized, as she continued to develop lesions 10 years after the exposure. Her elevated urine gadolinium excretion level also sheds light on the persistence of gadolinium in her body despite her normal renal function 10 years after her exposure. Although her clinical symptoms have stabilized, our case reiterates the complex pathology of this entity and challenge regarding treatment options. Physicians should be aware that NSF can still occur in healthy patients with no chronic renal disease who have had an episode of acute renal insufficiency along with exposure to a GBCA.

Nephrogenic systemic fibrosis (NSF) is a rare debilitating disorder characterized by dermal plaques, joint contractures, and fibrosis of the skin with possible involvement of muscles and internal organs.^1-3 Originally identified in 1997 as nephrogenic fibrosing dermopathy to describe its characteristic cutaneous thickening and hardening, the name was changed to NSF to more accurately reflect the noncutaneous manifestations present in other organ tissues.^2,4,5 Nephrogenic systemic fibrosis occurs in patients with a history of renal insufficiency and exposure to gadolinium-based contrast agents (GBCAs) used in magnetic resonance angiography and magnetic resonance imaging. There is no predilection for age, sex, or ethnicity.

Nephrogenic systemic fibrosis may develop over a period of days to several weeks. However, there have been cases of NSF developing 10 years after gadolinium exposure.² In most cases, patients have a history of severe chronic renal disease requiring hemodialysis. There have been a few reported cases of NSF occurring in patients with resolved acute kidney injury or resolved acute on chronic renal disease.^1,6-10 We present a case of NSF occurring in a patient with resolved transient renal insufficiency and no history of chronic renal disease.

Case Report

A 68-year-old woman presented with new dark, painless, pink plaques on the right thigh and calf. The patient stated the condition started and got worse after she was hospitalized 12 years prior for lower extremity cellulitis, sepsis, and acute renal failure. The patient developed complications during that hospital stay and underwent a renal biopsy and renal artery embolization requiring use of a GBCA. After the procedure, she noticed skin hardening in the extremities and decreased mobility in both legs while she was still in the hospital. It was thought that the lower leg changes were due to cellulitis. Therefore, when the renal issues resolved, she was discharged. Her skin and joint changes remained stable until 6 years later when she noticed new pink plaques appearing. Her medical history was positive for breast cancer, which was surgically and medically treated 16 years prior to presentation.

On presentation, physical examination revealed dark pink, hyperpigmented plaques on the right leg and a firm hypopigmented broad linear plaque on the right forearm. Palpation of the legs revealed thickened sclerotic plaques from the thighs down to the ankles (Figure 1). The plaques were not tender to palpation. She did have a decreased range of motion with eversion and inversion of the feet and ankles.

Biopsies from the right medial leg and right volar forearm showed increased bland dermal spindle cellularity associated with numerous round to ovoid osteoid aggregates encircling elastic fibers and surrounded by osteoblasts (Figure 2). CD34 immunohistochemistry showed general retention of staining within the dermal fibroblast population, and elastin stain showed general retention of elastic fiber bundles and thickening.

Laboratory workup included a complete blood cell count, comprehensive metabolic panel, thyroid-stimulating hormone level, and serum protein electrophoresis; results were all within reference range. The patient also had a urine element profile from an outside provider 1 month after presenting to our office that showed an elevated urine gadolinium level of 4.146 μg/g (reference range, 0–0.019 μg/g). The patient’s skin lesions have remained stable, and she is now working with physical therapy to help with her range of motion.

Comment

Gadolinium Causing Fibrosis—The incidence of NSF varies according to the severity of renal impairment, dosage level of GBCA used, and the history of GBCA use. In patients with normal renal function, gadolinium is excreted within 90 minutes. In patients with severe renal disease, the half-life can increase to up to 34.3 hours.¹¹ Reduced renal clearance and increased half-life of gadolinium lead to prolonged excretion, causing the GBCA to become unstable and dissociate into its constituents, leading to tissue deposition of Gd³⁺ cations. This dissociation is thought to be due to differences in the stability of the various chelation complexes among the different formulations of GBCAs.¹² The mechanism by which the dissociated gadolinium causes the fibrosis in the skin or other organs of the body is still unknown. Furthermore, even patients with normal renal function who undergo repeated administration of GBCA have been found to have higher levels of Gd³⁺ in their tissues, even in the absence of symptoms.¹³

Diagnosing NSF—In 2011, Girardi et al¹⁴ created a clinical and histopathological scoring system to help diagnose NSF. Clinical findings can be broken down into major criteria and minor criteria. Major criteria consist of patterned plaques, joint contractures, cobblestoning, marked induration, or peau d’orange change. Minor criteria consist of puckering, linear banding, superficial plaques or patches, dermal papules, and scleral plaques. Histopathologic findings include increased dermal cellularity (score +1), CD34⁺ cells with tram tracking (score +1), thickened or thin collagen bundles (score +1), preserved elastic fibers (score −1), septal involvement (score +1), and osseous metaplasia (score +3)(eTable).¹⁴

Differential Diagnosis—The differential diagnosis of NSF includes scleromyxedema, scleroderma, eosinophilic fasciitis, eosinophilia-myalgia syndrome, lipodermatosclerosis, morphea, and chronic graft-vs-host disease. Histopathologic examination of scleromyxedema can look identical to NSF. Therefore, a review of the patient’s medical history, prior hospitalizations, and prior gadolinium exposure is important. Appropriate laboratory workups should be ordered to rule out the other differential diagnoses.

NSF and Kidney Injury—A PubMed search of articles indexed for MEDLINE using the terms NSF with kidney injury revealed 7 cases of NSF occurring in patients who either had resolved acute kidney injury or resolved acute on chronic kidney disease.^1,6-10 Of those cases, 3 reported NSF occurring in patients with completely resolved acute kidney injury.^6,7,10 One of those cases involved a 65-year-old man who developed acute renal failure due to acute tubular necrosis.⁷ He had no history of renal disease prior to hospitalization. His skin lesions continued to improve as his renal function normalized back to baseline after discharge.⁷ The second case involved a 42-year-old man who had repeated exposure to GBCAs during a brief period of acute kidney injury.⁶ Nephrogenic systemic fibrosis developed after his renal function normalized. The authors did not mention if there was clinical improvement.⁶ The third case involved a 22-year-old man who developed acute renal failure after ingestion of hair dye. He did not have a history of chronic renal disease, and as he recovered from the acute kidney injury, almost all of the skin lesions cleared after 1 year.¹⁰

Our patient did not have a history of chronic renal disease when she presented to the hospital for sepsis and acute tubular necrosis. Unlike 2 of the prior cases, she did not notice improvement of the skin lesions as the renal function returned to baseline. She continued to experience changes in the skin, even up to 5 years after, and then stabilized. Throughout that time, her renal function was normal. Interestingly, despite having a normal creatinine level, the patient had an elevated gadolinium level on the urine gadolinium test, which typically is not a standard test for NSF. However, the elevated value does shed light on the persistence of gadolinium in the patient despite her exposure having been more than 10 years earlier.

Treatment of NSF—There is no gold standard treatment of NSF, and reversing the fibrosis has proven to be difficult. Avoidance of GBCAs in acute kidney injury or chronic severe renal disease, as recommended by the US Food and Drug Administration, is key to preventing this debilitating disease.¹⁵ Restoration of renal function is essential for excreting the gadolinium and improvement in NSF.¹² Physical and occupational therapy can improve joint mobility. Therapies such as extracorporeal photopheresis, sodium thiosulfate, pentoxifylline, glucocorticoids, plasmapheresis, intravenous immunoglobulin, cyclophosphamide, imatinib mesylate, intralesional interferon alfa, topical calcipotriene, corticosteroids, and UVA1 light therapy have been used with varying results.¹² It has been suggested that renal transplantation can stop the progression of NSF. However, in the cases we reviewed, renal transplantation would not have benefited those patients because their renal function normalized.^6,7,10 Additionally, even though our patient’s renal function normalized after discharge from the hospital, she continued to see more skin lesions developing, likely due to the accumulated gadolinium that was already in her tissue. The possibility of chelation therapy to remove the gadolinium has been proposed. In 1 case study involving deferoxamine injected intramuscularly in a patient with NSF, the urine excretion of gadolinium increased almost 2-fold, but there was no change in the serum concentration level of gadolinium or improvement in the patient’s clinical symptoms.¹⁶ We anticipate that our patient’s symptoms will slowly improve, as her body is still excreting the gadolinium. Our patient also was added to the International NSF Registry that was created by Dr. Shawn E. Cowper at the Yale School of Medicine (New Haven, Connecticut).

Conclusion

We report a rare case of NSF occurring in a patient with resolved acute kidney injury and no history of chronic renal disease. Our patient initially did not improve after her renal function normalized, as she continued to develop lesions 10 years after the exposure. Her elevated urine gadolinium excretion level also sheds light on the persistence of gadolinium in her body despite her normal renal function 10 years after her exposure. Although her clinical symptoms have stabilized, our case reiterates the complex pathology of this entity and challenge regarding treatment options. Physicians should be aware that NSF can still occur in healthy patients with no chronic renal disease who have had an episode of acute renal insufficiency along with exposure to a GBCA.

Pityriasis rosea is a papulosquamous eruption that favors the trunk and proximal extremities. It occurs most commonly in adolescents and young adults.¹ The rash typically presents with a solitary lesion, known as a “herald patch,” which is followed by a scaly erythematous eruption along the cleavage lines of the skin. The condition is self-limited and often resolves in 6 to 8 weeks. Recent evidence suggests that viral reactivation of human herpesvirus 6 and human herpesvirus 7 may play a role in the development of skin lesions.² Pityriasis rosea also has been reported following the administration of new medications and vaccinations.^1-3 We report a case of a 30-year-old woman who developed pityriasis rosea 3 days after receiving the second dose of the COVID-19 vaccine.

Case Report

A 30-year-old woman presented to the dermatology office for evaluation of a rash on the trunk and upper extremities that had been present for 5 days. She reported an initial solitary lesion on the left upper back, subsequently followed by the appearance of a mildly pruritic rash on the trunk and upper extremities. The rash first appeared 3 days after she received the second dose of the Pfizer-BioNTech COVID-19 vaccine. She was otherwise asymptomatic after vaccination and denied fever, chills, headache, and myalgia. She denied any rash following her first dose of the COVID-19 vaccine, history of known COVID-19 infection or exposures, or new medications. Notably, the patient worked in health care.

Physical examination revealed a 2-cm, erythematous, thin, scaly plaque over the left side of the upper back (Figure, A). Erythematous, scaly, thin papules of varying sizes were distributed along the cleavage lines of the trunk and upper extremities (Figure, B). No biopsy was performed because of the classic clinical presentation of this self-limited condition and the patient’s history of hypertrophic scarring. No additional laboratory workup was performed. She was prescribed triamcinolone cream 0.1% as needed for pruritus and was reassured about the benign nature of this cutaneous eruption.

Comment

A broad spectrum of cutaneous manifestations has been reported in association with acute COVID-19 infection, including a papulovesicular rash, perniolike eruptions, urticaria, livedo reticularis, and petechiae.⁴ Several cases of pityriasis rosea in association with acute COVID-19 infection also have been reported.⁵ COVID-19 infection has been linked to reactivation of the herpesvirus, which may explain the connection between acute COVID-19 infection and the development of pityriasis rosea.⁶ Pityriasis rosea associated with administration of the COVID-19 vaccine is a rare complication with few reports in the literature.⁷ Similar to our patient, there are reports of pityriasis rosea developing after the second dose of the vaccine, with some patients reporting a reactivation of skin lesions.⁸ There is a paucity of reports describing pityriasis rosea associated with the influenza vaccine, hepatitis B vaccine, and human papillomavirus vaccine.³ In such cases, the onset of skin lesions was thought to be related to vaccine-induced stimulation of the immune system or a component of the vaccine.

Conclusion

We presented a unique case of pityriasis rosea following COVID-19 vaccination. Because additional laboratory workup and a skin biopsy were not performed, we are unable to infer causation. However, the classic clinical presentation, rash development within 3 days of vaccination, and prior reports of vaccine-associated pityriasis rosea strengthen the aforementioned association. We hope this case adds to the growing understanding of the novel COVID-19 vaccine. As more individuals become vaccinated, both clinicians and patients should be aware of this benign cutaneous eruption that can develop following COVID-19 vaccination.

Pityriasis rosea is a papulosquamous eruption that favors the trunk and proximal extremities. It occurs most commonly in adolescents and young adults.¹ The rash typically presents with a solitary lesion, known as a “herald patch,” which is followed by a scaly erythematous eruption along the cleavage lines of the skin. The condition is self-limited and often resolves in 6 to 8 weeks. Recent evidence suggests that viral reactivation of human herpesvirus 6 and human herpesvirus 7 may play a role in the development of skin lesions.² Pityriasis rosea also has been reported following the administration of new medications and vaccinations.^1-3 We report a case of a 30-year-old woman who developed pityriasis rosea 3 days after receiving the second dose of the COVID-19 vaccine.

Case Report

A 30-year-old woman presented to the dermatology office for evaluation of a rash on the trunk and upper extremities that had been present for 5 days. She reported an initial solitary lesion on the left upper back, subsequently followed by the appearance of a mildly pruritic rash on the trunk and upper extremities. The rash first appeared 3 days after she received the second dose of the Pfizer-BioNTech COVID-19 vaccine. She was otherwise asymptomatic after vaccination and denied fever, chills, headache, and myalgia. She denied any rash following her first dose of the COVID-19 vaccine, history of known COVID-19 infection or exposures, or new medications. Notably, the patient worked in health care.

Physical examination revealed a 2-cm, erythematous, thin, scaly plaque over the left side of the upper back (Figure, A). Erythematous, scaly, thin papules of varying sizes were distributed along the cleavage lines of the trunk and upper extremities (Figure, B). No biopsy was performed because of the classic clinical presentation of this self-limited condition and the patient’s history of hypertrophic scarring. No additional laboratory workup was performed. She was prescribed triamcinolone cream 0.1% as needed for pruritus and was reassured about the benign nature of this cutaneous eruption.

Comment

A broad spectrum of cutaneous manifestations has been reported in association with acute COVID-19 infection, including a papulovesicular rash, perniolike eruptions, urticaria, livedo reticularis, and petechiae.⁴ Several cases of pityriasis rosea in association with acute COVID-19 infection also have been reported.⁵ COVID-19 infection has been linked to reactivation of the herpesvirus, which may explain the connection between acute COVID-19 infection and the development of pityriasis rosea.⁶ Pityriasis rosea associated with administration of the COVID-19 vaccine is a rare complication with few reports in the literature.⁷ Similar to our patient, there are reports of pityriasis rosea developing after the second dose of the vaccine, with some patients reporting a reactivation of skin lesions.⁸ There is a paucity of reports describing pityriasis rosea associated with the influenza vaccine, hepatitis B vaccine, and human papillomavirus vaccine.³ In such cases, the onset of skin lesions was thought to be related to vaccine-induced stimulation of the immune system or a component of the vaccine.

Conclusion

We presented a unique case of pityriasis rosea following COVID-19 vaccination. Because additional laboratory workup and a skin biopsy were not performed, we are unable to infer causation. However, the classic clinical presentation, rash development within 3 days of vaccination, and prior reports of vaccine-associated pityriasis rosea strengthen the aforementioned association. We hope this case adds to the growing understanding of the novel COVID-19 vaccine. As more individuals become vaccinated, both clinicians and patients should be aware of this benign cutaneous eruption that can develop following COVID-19 vaccination.

Pityriasis rosea is a papulosquamous eruption that favors the trunk and proximal extremities. It occurs most commonly in adolescents and young adults.¹ The rash typically presents with a solitary lesion, known as a “herald patch,” which is followed by a scaly erythematous eruption along the cleavage lines of the skin. The condition is self-limited and often resolves in 6 to 8 weeks. Recent evidence suggests that viral reactivation of human herpesvirus 6 and human herpesvirus 7 may play a role in the development of skin lesions.² Pityriasis rosea also has been reported following the administration of new medications and vaccinations.^1-3 We report a case of a 30-year-old woman who developed pityriasis rosea 3 days after receiving the second dose of the COVID-19 vaccine.

Case Report

A 30-year-old woman presented to the dermatology office for evaluation of a rash on the trunk and upper extremities that had been present for 5 days. She reported an initial solitary lesion on the left upper back, subsequently followed by the appearance of a mildly pruritic rash on the trunk and upper extremities. The rash first appeared 3 days after she received the second dose of the Pfizer-BioNTech COVID-19 vaccine. She was otherwise asymptomatic after vaccination and denied fever, chills, headache, and myalgia. She denied any rash following her first dose of the COVID-19 vaccine, history of known COVID-19 infection or exposures, or new medications. Notably, the patient worked in health care.

Physical examination revealed a 2-cm, erythematous, thin, scaly plaque over the left side of the upper back (Figure, A). Erythematous, scaly, thin papules of varying sizes were distributed along the cleavage lines of the trunk and upper extremities (Figure, B). No biopsy was performed because of the classic clinical presentation of this self-limited condition and the patient’s history of hypertrophic scarring. No additional laboratory workup was performed. She was prescribed triamcinolone cream 0.1% as needed for pruritus and was reassured about the benign nature of this cutaneous eruption.

Comment

A broad spectrum of cutaneous manifestations has been reported in association with acute COVID-19 infection, including a papulovesicular rash, perniolike eruptions, urticaria, livedo reticularis, and petechiae.⁴ Several cases of pityriasis rosea in association with acute COVID-19 infection also have been reported.⁵ COVID-19 infection has been linked to reactivation of the herpesvirus, which may explain the connection between acute COVID-19 infection and the development of pityriasis rosea.⁶ Pityriasis rosea associated with administration of the COVID-19 vaccine is a rare complication with few reports in the literature.⁷ Similar to our patient, there are reports of pityriasis rosea developing after the second dose of the vaccine, with some patients reporting a reactivation of skin lesions.⁸ There is a paucity of reports describing pityriasis rosea associated with the influenza vaccine, hepatitis B vaccine, and human papillomavirus vaccine.³ In such cases, the onset of skin lesions was thought to be related to vaccine-induced stimulation of the immune system or a component of the vaccine.

Conclusion

We presented a unique case of pityriasis rosea following COVID-19 vaccination. Because additional laboratory workup and a skin biopsy were not performed, we are unable to infer causation. However, the classic clinical presentation, rash development within 3 days of vaccination, and prior reports of vaccine-associated pityriasis rosea strengthen the aforementioned association. We hope this case adds to the growing understanding of the novel COVID-19 vaccine. As more individuals become vaccinated, both clinicians and patients should be aware of this benign cutaneous eruption that can develop following COVID-19 vaccination.

THE CASE

A 49-year-old man with chronic insomnia was referred to the pharmacist authors (LF and DP) to initiate and manage the tapering of nightly zolpidem use. Per chart review, the patient had complaints of insomnia for more than 30 years. His care had been transferred to a Nebraska clinic 5 years earlier, with a medication list that included zolpidem controlled release (CR) 12.5 mg nightly. Since then, multiple interventions to achieve cessation had been tried, including counseling on sleep hygiene, adjunct antidepressant use, and abrupt discontinuation. Each of these methods was unsuccessful. So, his family physician (SS) reached out to the pharmacist authors (LF and DP).

THE APPROACH

Due to the patient’s long history of zolpidem use, a lack of literature on the topic, and worry for withdrawal symptoms, a taper schedule was designed utilizing various benzodiazepine taper resources for guidance. The proposed taper utilized 5-mg immediate release (IR) tablets to ensure ease of tapering. The taper ranged from 20% to 43% weekly reductions based on the ability to split the zolpidem tablet in half.

DISCUSSION

Zolpidem is a sedative-hypnotic medication indicated for the treatment of insomnia when used at therapeutic dosing (ie, 5 to 10 mg nightly). Anecdotal efficacy, accompanied by weak chronic insomnia guideline recommendations, has led prescribers to use zolpidem as a chronic medication to treat insomnia.^1,2 There is evidence of dependence and possible seizures from supratherapeutic zolpidem doses in the hundreds of milligrams, raising safety concerns regarding abuse, dependence, and withdrawal seizures in chronic use.^2,3

Additionally, there is limited evidence regarding the appropriate process of discontinuing zolpidem after chronic use.² Often a taper schedule—similar to those used with benzodiazepine medications—is used as a reference for discontinuation.¹ The hypothetical goal of a taper is to prevent withdrawal effects such as rebound insomnia, anxiety, palpitations, and seizures.³ However, an extended taper may not actually be necessary with chronic zolpidem patients.

Tapering with minimal adverse effects

Pharmacokinetic and pharmacodynamic studies have suggested minimal, if not complete, absence of rebound or withdrawal effects with short-term zolpidem use.⁴ The same appears to be true of patients with long-term use. In a study, Roehrs and colleagues⁵ explored whether long-term treatment (defined as 8 months) caused rebound insomnia upon abrupt withdrawal. The investigators concluded that people with primary insomnia do not experience rebound insomnia or withdrawal symptoms with chronic, therapeutic dosing.

This case documents a successfully accelerated taper for a patient with a chronic history (> 5 years) of zolpidem use.

Another study involving 92 elderly patients on long-term treatment of zolpidem (defined as > 1 month, with average around 9.9 ± 6.2 years) experienced only 1 or 2 nights of rebound insomnia during a month-long taper.^1,6 Following that, they experienced improvements in initiation and staying asleep.

A possible explanation for the lack of dependence or withdrawal symptoms in patients chronically treated with zolpidem is the pharmacokinetic profile. While the selectivity of the binding sites differentiates this medication from benzodiazepines, the additional fact of a short half-life, and no repeated dosing throughout the day, likely limit the risk of experiencing withdrawal symptoms.¹ The daily periods of minimal zolpidem exposure in the body may limit the amount of physical dependence.

Continue to: Discontinuation of zolpidem

Discontinuation of zolpidem

The 49-year-old man had a history of failed abrupt discontinuation of zolpidem in the past (without noted withdrawal symptoms). Thus, various benzodiazepine taper resources were consulted to develop a taper schedule.

We switched our patient from the zolpidem CR 12.5 mg nightly to 10 mg of the IR formulation, and the pharmacists proposed 20% to 43% weekly decreases in dosing based on dosage strengths. At the initial 3-day follow-up (having taken 10 mg nightly for 3 days), the patient reported a quicker onset of sleep but an inability to sleep through the night. The patient denied withdrawal symptoms or any significant impact to his daily routines. These results encouraged a progression to the next step of the taper. For the next 9 days, the patient took 5 mg nightly, rather than the pharmacist-advised dosing of alternating 5 mg and 10 mg nightly, and reported similar outcomes at his next visit.

This success led to the discontinuation of scheduled zolpidem. The patient was also given a prescription of 2.5 mg, as needed, if insomnia rebounded. No adverse effects were noted despite the accelerated taper. Based on patient response and motivation, the taper had progressed more quickly than scheduled, resulting in 3 days of 10 mg, 9 days of 5 mg, and 1 final day of 2.5 mg that was used when the patient had trouble falling asleep. At the 6-month follow-up, the patient informed the physician that he had neither experienced insomnia nor used any further medication.

THE TAKEAWAY

This case documents a successfully accelerated taper for a patient with a chronic history (> 5 years) of zolpidem use. Although withdrawal is often patient specific, this case suggests the risk is low despite the chronic usage. This further adds to the literature suggesting against the need for an extended taper, and possibly a taper at all, when using recommended doses of chronic zolpidem. This is a significant difference compared to past practices that drew from literature-based benzodiazepine tapers.⁶ This case serves as an observational point of reference for clinicians who are assisting patients with chronic zolpidem tapers.

CORRESPONDENCE
Logan Franck, PharmD, 986145 Nebraska Medical Center, Omaha, NE 68198-6145; [email protected]

THE CASE

A 49-year-old man with chronic insomnia was referred to the pharmacist authors (LF and DP) to initiate and manage the tapering of nightly zolpidem use. Per chart review, the patient had complaints of insomnia for more than 30 years. His care had been transferred to a Nebraska clinic 5 years earlier, with a medication list that included zolpidem controlled release (CR) 12.5 mg nightly. Since then, multiple interventions to achieve cessation had been tried, including counseling on sleep hygiene, adjunct antidepressant use, and abrupt discontinuation. Each of these methods was unsuccessful. So, his family physician (SS) reached out to the pharmacist authors (LF and DP).

THE APPROACH

Due to the patient’s long history of zolpidem use, a lack of literature on the topic, and worry for withdrawal symptoms, a taper schedule was designed utilizing various benzodiazepine taper resources for guidance. The proposed taper utilized 5-mg immediate release (IR) tablets to ensure ease of tapering. The taper ranged from 20% to 43% weekly reductions based on the ability to split the zolpidem tablet in half.

DISCUSSION

Zolpidem is a sedative-hypnotic medication indicated for the treatment of insomnia when used at therapeutic dosing (ie, 5 to 10 mg nightly). Anecdotal efficacy, accompanied by weak chronic insomnia guideline recommendations, has led prescribers to use zolpidem as a chronic medication to treat insomnia.^1,2 There is evidence of dependence and possible seizures from supratherapeutic zolpidem doses in the hundreds of milligrams, raising safety concerns regarding abuse, dependence, and withdrawal seizures in chronic use.^2,3

Additionally, there is limited evidence regarding the appropriate process of discontinuing zolpidem after chronic use.² Often a taper schedule—similar to those used with benzodiazepine medications—is used as a reference for discontinuation.¹ The hypothetical goal of a taper is to prevent withdrawal effects such as rebound insomnia, anxiety, palpitations, and seizures.³ However, an extended taper may not actually be necessary with chronic zolpidem patients.

Tapering with minimal adverse effects

Pharmacokinetic and pharmacodynamic studies have suggested minimal, if not complete, absence of rebound or withdrawal effects with short-term zolpidem use.⁴ The same appears to be true of patients with long-term use. In a study, Roehrs and colleagues⁵ explored whether long-term treatment (defined as 8 months) caused rebound insomnia upon abrupt withdrawal. The investigators concluded that people with primary insomnia do not experience rebound insomnia or withdrawal symptoms with chronic, therapeutic dosing.

This case documents a successfully accelerated taper for a patient with a chronic history (> 5 years) of zolpidem use.

Another study involving 92 elderly patients on long-term treatment of zolpidem (defined as > 1 month, with average around 9.9 ± 6.2 years) experienced only 1 or 2 nights of rebound insomnia during a month-long taper.^1,6 Following that, they experienced improvements in initiation and staying asleep.

A possible explanation for the lack of dependence or withdrawal symptoms in patients chronically treated with zolpidem is the pharmacokinetic profile. While the selectivity of the binding sites differentiates this medication from benzodiazepines, the additional fact of a short half-life, and no repeated dosing throughout the day, likely limit the risk of experiencing withdrawal symptoms.¹ The daily periods of minimal zolpidem exposure in the body may limit the amount of physical dependence.

Continue to: Discontinuation of zolpidem

Discontinuation of zolpidem

The 49-year-old man had a history of failed abrupt discontinuation of zolpidem in the past (without noted withdrawal symptoms). Thus, various benzodiazepine taper resources were consulted to develop a taper schedule.

We switched our patient from the zolpidem CR 12.5 mg nightly to 10 mg of the IR formulation, and the pharmacists proposed 20% to 43% weekly decreases in dosing based on dosage strengths. At the initial 3-day follow-up (having taken 10 mg nightly for 3 days), the patient reported a quicker onset of sleep but an inability to sleep through the night. The patient denied withdrawal symptoms or any significant impact to his daily routines. These results encouraged a progression to the next step of the taper. For the next 9 days, the patient took 5 mg nightly, rather than the pharmacist-advised dosing of alternating 5 mg and 10 mg nightly, and reported similar outcomes at his next visit.

This success led to the discontinuation of scheduled zolpidem. The patient was also given a prescription of 2.5 mg, as needed, if insomnia rebounded. No adverse effects were noted despite the accelerated taper. Based on patient response and motivation, the taper had progressed more quickly than scheduled, resulting in 3 days of 10 mg, 9 days of 5 mg, and 1 final day of 2.5 mg that was used when the patient had trouble falling asleep. At the 6-month follow-up, the patient informed the physician that he had neither experienced insomnia nor used any further medication.

THE TAKEAWAY

This case documents a successfully accelerated taper for a patient with a chronic history (> 5 years) of zolpidem use. Although withdrawal is often patient specific, this case suggests the risk is low despite the chronic usage. This further adds to the literature suggesting against the need for an extended taper, and possibly a taper at all, when using recommended doses of chronic zolpidem. This is a significant difference compared to past practices that drew from literature-based benzodiazepine tapers.⁶ This case serves as an observational point of reference for clinicians who are assisting patients with chronic zolpidem tapers.

CORRESPONDENCE
Logan Franck, PharmD, 986145 Nebraska Medical Center, Omaha, NE 68198-6145; [email protected]

THE CASE

A 49-year-old man with chronic insomnia was referred to the pharmacist authors (LF and DP) to initiate and manage the tapering of nightly zolpidem use. Per chart review, the patient had complaints of insomnia for more than 30 years. His care had been transferred to a Nebraska clinic 5 years earlier, with a medication list that included zolpidem controlled release (CR) 12.5 mg nightly. Since then, multiple interventions to achieve cessation had been tried, including counseling on sleep hygiene, adjunct antidepressant use, and abrupt discontinuation. Each of these methods was unsuccessful. So, his family physician (SS) reached out to the pharmacist authors (LF and DP).

THE APPROACH

Due to the patient’s long history of zolpidem use, a lack of literature on the topic, and worry for withdrawal symptoms, a taper schedule was designed utilizing various benzodiazepine taper resources for guidance. The proposed taper utilized 5-mg immediate release (IR) tablets to ensure ease of tapering. The taper ranged from 20% to 43% weekly reductions based on the ability to split the zolpidem tablet in half.

DISCUSSION

Zolpidem is a sedative-hypnotic medication indicated for the treatment of insomnia when used at therapeutic dosing (ie, 5 to 10 mg nightly). Anecdotal efficacy, accompanied by weak chronic insomnia guideline recommendations, has led prescribers to use zolpidem as a chronic medication to treat insomnia.^1,2 There is evidence of dependence and possible seizures from supratherapeutic zolpidem doses in the hundreds of milligrams, raising safety concerns regarding abuse, dependence, and withdrawal seizures in chronic use.^2,3

Additionally, there is limited evidence regarding the appropriate process of discontinuing zolpidem after chronic use.² Often a taper schedule—similar to those used with benzodiazepine medications—is used as a reference for discontinuation.¹ The hypothetical goal of a taper is to prevent withdrawal effects such as rebound insomnia, anxiety, palpitations, and seizures.³ However, an extended taper may not actually be necessary with chronic zolpidem patients.

Tapering with minimal adverse effects

Pharmacokinetic and pharmacodynamic studies have suggested minimal, if not complete, absence of rebound or withdrawal effects with short-term zolpidem use.⁴ The same appears to be true of patients with long-term use. In a study, Roehrs and colleagues⁵ explored whether long-term treatment (defined as 8 months) caused rebound insomnia upon abrupt withdrawal. The investigators concluded that people with primary insomnia do not experience rebound insomnia or withdrawal symptoms with chronic, therapeutic dosing.

This case documents a successfully accelerated taper for a patient with a chronic history (> 5 years) of zolpidem use.

Another study involving 92 elderly patients on long-term treatment of zolpidem (defined as > 1 month, with average around 9.9 ± 6.2 years) experienced only 1 or 2 nights of rebound insomnia during a month-long taper.^1,6 Following that, they experienced improvements in initiation and staying asleep.

A possible explanation for the lack of dependence or withdrawal symptoms in patients chronically treated with zolpidem is the pharmacokinetic profile. While the selectivity of the binding sites differentiates this medication from benzodiazepines, the additional fact of a short half-life, and no repeated dosing throughout the day, likely limit the risk of experiencing withdrawal symptoms.¹ The daily periods of minimal zolpidem exposure in the body may limit the amount of physical dependence.

Continue to: Discontinuation of zolpidem

Discontinuation of zolpidem

The 49-year-old man had a history of failed abrupt discontinuation of zolpidem in the past (without noted withdrawal symptoms). Thus, various benzodiazepine taper resources were consulted to develop a taper schedule.

We switched our patient from the zolpidem CR 12.5 mg nightly to 10 mg of the IR formulation, and the pharmacists proposed 20% to 43% weekly decreases in dosing based on dosage strengths. At the initial 3-day follow-up (having taken 10 mg nightly for 3 days), the patient reported a quicker onset of sleep but an inability to sleep through the night. The patient denied withdrawal symptoms or any significant impact to his daily routines. These results encouraged a progression to the next step of the taper. For the next 9 days, the patient took 5 mg nightly, rather than the pharmacist-advised dosing of alternating 5 mg and 10 mg nightly, and reported similar outcomes at his next visit.

This success led to the discontinuation of scheduled zolpidem. The patient was also given a prescription of 2.5 mg, as needed, if insomnia rebounded. No adverse effects were noted despite the accelerated taper. Based on patient response and motivation, the taper had progressed more quickly than scheduled, resulting in 3 days of 10 mg, 9 days of 5 mg, and 1 final day of 2.5 mg that was used when the patient had trouble falling asleep. At the 6-month follow-up, the patient informed the physician that he had neither experienced insomnia nor used any further medication.

THE TAKEAWAY

This case documents a successfully accelerated taper for a patient with a chronic history (> 5 years) of zolpidem use. Although withdrawal is often patient specific, this case suggests the risk is low despite the chronic usage. This further adds to the literature suggesting against the need for an extended taper, and possibly a taper at all, when using recommended doses of chronic zolpidem. This is a significant difference compared to past practices that drew from literature-based benzodiazepine tapers.⁶ This case serves as an observational point of reference for clinicians who are assisting patients with chronic zolpidem tapers.

CORRESPONDENCE
Logan Franck, PharmD, 986145 Nebraska Medical Center, Omaha, NE 68198-6145; [email protected]

Abnormalities in the T-wave morphology of an electrocardiogram (ECG) are classically attributed to ischemic cardiac disease. However, these changes can be seen in a variety of other etiologies, including noncardiac pathology, which should be considered whenever reviewing an ECG: central nervous system disease, including stroke and subarachnoid hemorrhage; hypothermia; pulmonary disease, such as pulmonary embolism or chronic obstructive pulmonary disease; myopericarditis; drug effects; and electrolyte abnormalities.

Prolongation of the QT interval, on the other hand, can be precipitated by medications, metabolic derangements, or genetic phenotypes. The QT interval is measured from the beginning of the QRS complex to the termination of the T wave and represents the total time for ventricular depolarization and repolarization. The QT interval must be corrected based on the patient’s heart rate, known as the QTc. As the QTc interval lengthens, there is increased risk of R-on-T phenomena, which may result in Torsades de Pointes (TdP). Typical features of TdP include an antecedent prolonged QTc, cyclic polymorphic ventricular tachycardia on the surface ECG, and either a short-lived spontaneously terminating course or degeneration into ventricular fibrillation (VF) and sudden cardiac death.¹ These dysrhythmias become more likely as the QTc interval exceeds 500 msec.²

The combination of new-onset global T-wave inversions with prolongation of the QT interval has been reported in only a few limited conditions. Some known causes of these QT T changes include cardiac ischemia, status epilepticus, pheochromocytoma, and acute cocaine intoxication.³ One uncommon and rarely reported cause of extreme QT prolongation and T-wave inversion is acute pulmonary edema. The ECG findings are not present on initial patient presentation; rather the dynamic changes occur after resolution of the pulmonary symptoms. Despite significant ECG changes, all prior reported cases describe ECG normalization without significant morbidity.^4,5 We report a case of extreme QT prolongation following acute pulmonary edema that resulted in cardiac arrest secondary to VF.

Case Presentation

A 72-year-old male with medical history of combined systolic and diastolic heart failure, ischemic cardiomyopathy, coronary artery disease, cerebral vascular accident, hypertension, hyperlipidemia, type 2 diabetes mellitus, and tobacco dependence presented to the emergency department (ED) by emergency medical services after awaking with acute onset of dyspnea and diaphoresis. On arrival at the ED, the patient was noted to be in respiratory distress (ie, unable to speak single words) and was extremely diaphoretic. His initial vital signs included blood pressure, 186/113 mm Hg, heart rate, 104 beats per minute, respiratory rate, 40 breaths per minute, and temperature, 36.4 °C. The patient was quickly placed on bilevel positive airway pressure and given sublingual nitroglycerin followed by transdermal nitroglycerin with a single dose of 40 mg IV furosemide, which improved his respiratory status. A chest X-ray was consistent with pulmonary edema, and his brain natriuretic peptide was 1654 pg/mL. An ECG demonstrated new T-wave inversions, and his troponin increased from 0.04 to 0.24 ng/mL during his ED stay (Figure 1). He was started on a heparin infusion and admitted to the hospital for hypertensive emergency with presumed acute decompensated heart failure and non-ST-elevated myocardial infarction.

Throughout the patient’s first night, the troponin level started to down-trend after peaking at 0.24 ng/mL, and his oxygen requirements decreased allowing transition to nasal cannula. However, his repeat ECGs demonstrated significant T-wave abnormalities, new premature ventricular contractions, bradycardia, and a prolonging QTc interval to 703 msec (Figure 2). At this time, the patient’s electrolytes were normal, specifically a potassium level of 4.4 mEq/L, calcium 8.8 mg/dL, magnesium 2.0 mg/dL, and phosphorus 2.6 mg/dL. Given the worsening ECG changes, a computed tomography scan of his head was ordered to rule out intracranial pathology. While in the scanner, the patient went into pulseless VF, prompting defibrillation with 200 J. In addition, he was given 75 mg IV lidocaine, 2 g IV magnesium, and 1 ampule of both calcium chloride and sodium bicarbonate. With treatment, he had return of spontaneous circulation and was taken promptly to cardiac catheterization. The catheterization showed no significant obstructive coronary artery disease, and no interventions were performed. The patient was transferred to the cardiac intensive care unit for continued care.

During his course in the intensive care unit, the patient’s potassium and magnesium levels were maintained at high-normal levels. The patient was started on a dobutamine infusion to increase his heart rate and attempt to decrease his QTc. The patient also underwent cardiac magnetic resonance imaging (MRI) to evaluate for possible myocarditis, which showed no evidence of acute inflammation. Echocardiogram demonstrated an ejection fraction of 40% and global hypokinesis but no specific regional abnormalities and no change from prior echocardiogram performed 1 year earlier. Over the course of 3 days, his ECG normalized and his QTc shortened to 477 msec. Genetic testing was performed and did not reveal any mutations associated with long QT syndrome. Ultimately, an automated internal cardiac defibrillator (AICD) was placed, and the patient was discharged home.

Over the 2 years since his initial event, the patient has not experienced recurrent VF and his AICD has not fired. The patient continues to have ED presentations for heart-failure symptoms, though he has been stable from an electrophysiologic standpoint and his QTc remains less than 500 msec.

Discussion

Prolongation of the QT interval as a result of deep, global T-wave inversions after resolution of acute pulmonary edema has been minimally reported.^4,5 This phenomenon has been described in the cardiology literature but has not been discussed in the emergency medicine literature and bears consideration in this case.^4,5 As noted, an extensive evaluation did not reveal another cause of QTc prolongation. The patient had normal electrolytes and temperature, his neurologic examination and computed tomography were not remarkable. The patient had no obstructive coronary artery disease on catheterization, no evidence of acute myocarditis on cardiac MRI, no prescribed medications associated with QT prolongation, and no evidence of genetic mutations associated with QT prolongation on testing. The minimal troponin elevation was felt to represent a type II myocardial infarction related to ischemia due to supply-demand mismatch rather than acute plaque rupture.

Littmann published a case series of 9 cases of delayed onset T-wave inversion and extreme QTc prolongation in the 24 to 48 hours following treatment and symptomatic improvement in acute pulmonary edema.⁴ In each of his patients, an ischemic cardiac insult was ruled out as the etiology of the pulmonary edema by laboratory assessment, echocardiography, and left heart catheterization.All of the patients in this case series recovered without incident and with normalization of the QTc interval.⁴ Similarly, in our patient, significant QT T changes occurred approximately 22 hours after presentation and with resolution of symptoms of pulmonary edema. Pascale and colleagues also published a series of 3 patients developing similar ECG patterns following a hypertensive crisis with resolution of ECG findings and without any morbidity.⁵ In contrast, our patient experienced significant morbidity secondary to the extreme QTc prolongation.

Conclusions

We believe this is the first reported case of excessive prolongation of the QTc with VF arrest secondary to resolution of acute pulmonary edema. The pattern observed in our patient follows the patterns outlined in the previous case series—patients present with acute pulmonary edema and hypertensive crisis but develop significant ECG abnormalities about 24 hours after the resolution of the high catecholamine state. Our patient did have a history of prior cardiac insult, given the QTc changes developed acutely, with frequent premature ventricular contractions, and the cardiac arrest occurred at maximal QTc prolongation, yet after resolution of the high catecholamine state, the treatment team felt there was likely an uncaptured and short-lived episode of TdP that degenerated into VF. This theory is further supported by the lack of recurrent VF episodes, confirmed by AICD interrogation, after normalization of the QTc in our patient.

Abnormalities in the T-wave morphology of an electrocardiogram (ECG) are classically attributed to ischemic cardiac disease. However, these changes can be seen in a variety of other etiologies, including noncardiac pathology, which should be considered whenever reviewing an ECG: central nervous system disease, including stroke and subarachnoid hemorrhage; hypothermia; pulmonary disease, such as pulmonary embolism or chronic obstructive pulmonary disease; myopericarditis; drug effects; and electrolyte abnormalities.

Prolongation of the QT interval, on the other hand, can be precipitated by medications, metabolic derangements, or genetic phenotypes. The QT interval is measured from the beginning of the QRS complex to the termination of the T wave and represents the total time for ventricular depolarization and repolarization. The QT interval must be corrected based on the patient’s heart rate, known as the QTc. As the QTc interval lengthens, there is increased risk of R-on-T phenomena, which may result in Torsades de Pointes (TdP). Typical features of TdP include an antecedent prolonged QTc, cyclic polymorphic ventricular tachycardia on the surface ECG, and either a short-lived spontaneously terminating course or degeneration into ventricular fibrillation (VF) and sudden cardiac death.¹ These dysrhythmias become more likely as the QTc interval exceeds 500 msec.²

The combination of new-onset global T-wave inversions with prolongation of the QT interval has been reported in only a few limited conditions. Some known causes of these QT T changes include cardiac ischemia, status epilepticus, pheochromocytoma, and acute cocaine intoxication.³ One uncommon and rarely reported cause of extreme QT prolongation and T-wave inversion is acute pulmonary edema. The ECG findings are not present on initial patient presentation; rather the dynamic changes occur after resolution of the pulmonary symptoms. Despite significant ECG changes, all prior reported cases describe ECG normalization without significant morbidity.^4,5 We report a case of extreme QT prolongation following acute pulmonary edema that resulted in cardiac arrest secondary to VF.

Case Presentation

A 72-year-old male with medical history of combined systolic and diastolic heart failure, ischemic cardiomyopathy, coronary artery disease, cerebral vascular accident, hypertension, hyperlipidemia, type 2 diabetes mellitus, and tobacco dependence presented to the emergency department (ED) by emergency medical services after awaking with acute onset of dyspnea and diaphoresis. On arrival at the ED, the patient was noted to be in respiratory distress (ie, unable to speak single words) and was extremely diaphoretic. His initial vital signs included blood pressure, 186/113 mm Hg, heart rate, 104 beats per minute, respiratory rate, 40 breaths per minute, and temperature, 36.4 °C. The patient was quickly placed on bilevel positive airway pressure and given sublingual nitroglycerin followed by transdermal nitroglycerin with a single dose of 40 mg IV furosemide, which improved his respiratory status. A chest X-ray was consistent with pulmonary edema, and his brain natriuretic peptide was 1654 pg/mL. An ECG demonstrated new T-wave inversions, and his troponin increased from 0.04 to 0.24 ng/mL during his ED stay (Figure 1). He was started on a heparin infusion and admitted to the hospital for hypertensive emergency with presumed acute decompensated heart failure and non-ST-elevated myocardial infarction.

Throughout the patient’s first night, the troponin level started to down-trend after peaking at 0.24 ng/mL, and his oxygen requirements decreased allowing transition to nasal cannula. However, his repeat ECGs demonstrated significant T-wave abnormalities, new premature ventricular contractions, bradycardia, and a prolonging QTc interval to 703 msec (Figure 2). At this time, the patient’s electrolytes were normal, specifically a potassium level of 4.4 mEq/L, calcium 8.8 mg/dL, magnesium 2.0 mg/dL, and phosphorus 2.6 mg/dL. Given the worsening ECG changes, a computed tomography scan of his head was ordered to rule out intracranial pathology. While in the scanner, the patient went into pulseless VF, prompting defibrillation with 200 J. In addition, he was given 75 mg IV lidocaine, 2 g IV magnesium, and 1 ampule of both calcium chloride and sodium bicarbonate. With treatment, he had return of spontaneous circulation and was taken promptly to cardiac catheterization. The catheterization showed no significant obstructive coronary artery disease, and no interventions were performed. The patient was transferred to the cardiac intensive care unit for continued care.

During his course in the intensive care unit, the patient’s potassium and magnesium levels were maintained at high-normal levels. The patient was started on a dobutamine infusion to increase his heart rate and attempt to decrease his QTc. The patient also underwent cardiac magnetic resonance imaging (MRI) to evaluate for possible myocarditis, which showed no evidence of acute inflammation. Echocardiogram demonstrated an ejection fraction of 40% and global hypokinesis but no specific regional abnormalities and no change from prior echocardiogram performed 1 year earlier. Over the course of 3 days, his ECG normalized and his QTc shortened to 477 msec. Genetic testing was performed and did not reveal any mutations associated with long QT syndrome. Ultimately, an automated internal cardiac defibrillator (AICD) was placed, and the patient was discharged home.

Over the 2 years since his initial event, the patient has not experienced recurrent VF and his AICD has not fired. The patient continues to have ED presentations for heart-failure symptoms, though he has been stable from an electrophysiologic standpoint and his QTc remains less than 500 msec.

Discussion

Prolongation of the QT interval as a result of deep, global T-wave inversions after resolution of acute pulmonary edema has been minimally reported.^4,5 This phenomenon has been described in the cardiology literature but has not been discussed in the emergency medicine literature and bears consideration in this case.^4,5 As noted, an extensive evaluation did not reveal another cause of QTc prolongation. The patient had normal electrolytes and temperature, his neurologic examination and computed tomography were not remarkable. The patient had no obstructive coronary artery disease on catheterization, no evidence of acute myocarditis on cardiac MRI, no prescribed medications associated with QT prolongation, and no evidence of genetic mutations associated with QT prolongation on testing. The minimal troponin elevation was felt to represent a type II myocardial infarction related to ischemia due to supply-demand mismatch rather than acute plaque rupture.

Littmann published a case series of 9 cases of delayed onset T-wave inversion and extreme QTc prolongation in the 24 to 48 hours following treatment and symptomatic improvement in acute pulmonary edema.⁴ In each of his patients, an ischemic cardiac insult was ruled out as the etiology of the pulmonary edema by laboratory assessment, echocardiography, and left heart catheterization.All of the patients in this case series recovered without incident and with normalization of the QTc interval.⁴ Similarly, in our patient, significant QT T changes occurred approximately 22 hours after presentation and with resolution of symptoms of pulmonary edema. Pascale and colleagues also published a series of 3 patients developing similar ECG patterns following a hypertensive crisis with resolution of ECG findings and without any morbidity.⁵ In contrast, our patient experienced significant morbidity secondary to the extreme QTc prolongation.

Conclusions

We believe this is the first reported case of excessive prolongation of the QTc with VF arrest secondary to resolution of acute pulmonary edema. The pattern observed in our patient follows the patterns outlined in the previous case series—patients present with acute pulmonary edema and hypertensive crisis but develop significant ECG abnormalities about 24 hours after the resolution of the high catecholamine state. Our patient did have a history of prior cardiac insult, given the QTc changes developed acutely, with frequent premature ventricular contractions, and the cardiac arrest occurred at maximal QTc prolongation, yet after resolution of the high catecholamine state, the treatment team felt there was likely an uncaptured and short-lived episode of TdP that degenerated into VF. This theory is further supported by the lack of recurrent VF episodes, confirmed by AICD interrogation, after normalization of the QTc in our patient.

Abnormalities in the T-wave morphology of an electrocardiogram (ECG) are classically attributed to ischemic cardiac disease. However, these changes can be seen in a variety of other etiologies, including noncardiac pathology, which should be considered whenever reviewing an ECG: central nervous system disease, including stroke and subarachnoid hemorrhage; hypothermia; pulmonary disease, such as pulmonary embolism or chronic obstructive pulmonary disease; myopericarditis; drug effects; and electrolyte abnormalities.

Prolongation of the QT interval, on the other hand, can be precipitated by medications, metabolic derangements, or genetic phenotypes. The QT interval is measured from the beginning of the QRS complex to the termination of the T wave and represents the total time for ventricular depolarization and repolarization. The QT interval must be corrected based on the patient’s heart rate, known as the QTc. As the QTc interval lengthens, there is increased risk of R-on-T phenomena, which may result in Torsades de Pointes (TdP). Typical features of TdP include an antecedent prolonged QTc, cyclic polymorphic ventricular tachycardia on the surface ECG, and either a short-lived spontaneously terminating course or degeneration into ventricular fibrillation (VF) and sudden cardiac death.¹ These dysrhythmias become more likely as the QTc interval exceeds 500 msec.²

The combination of new-onset global T-wave inversions with prolongation of the QT interval has been reported in only a few limited conditions. Some known causes of these QT T changes include cardiac ischemia, status epilepticus, pheochromocytoma, and acute cocaine intoxication.³ One uncommon and rarely reported cause of extreme QT prolongation and T-wave inversion is acute pulmonary edema. The ECG findings are not present on initial patient presentation; rather the dynamic changes occur after resolution of the pulmonary symptoms. Despite significant ECG changes, all prior reported cases describe ECG normalization without significant morbidity.^4,5 We report a case of extreme QT prolongation following acute pulmonary edema that resulted in cardiac arrest secondary to VF.

Case Presentation

A 72-year-old male with medical history of combined systolic and diastolic heart failure, ischemic cardiomyopathy, coronary artery disease, cerebral vascular accident, hypertension, hyperlipidemia, type 2 diabetes mellitus, and tobacco dependence presented to the emergency department (ED) by emergency medical services after awaking with acute onset of dyspnea and diaphoresis. On arrival at the ED, the patient was noted to be in respiratory distress (ie, unable to speak single words) and was extremely diaphoretic. His initial vital signs included blood pressure, 186/113 mm Hg, heart rate, 104 beats per minute, respiratory rate, 40 breaths per minute, and temperature, 36.4 °C. The patient was quickly placed on bilevel positive airway pressure and given sublingual nitroglycerin followed by transdermal nitroglycerin with a single dose of 40 mg IV furosemide, which improved his respiratory status. A chest X-ray was consistent with pulmonary edema, and his brain natriuretic peptide was 1654 pg/mL. An ECG demonstrated new T-wave inversions, and his troponin increased from 0.04 to 0.24 ng/mL during his ED stay (Figure 1). He was started on a heparin infusion and admitted to the hospital for hypertensive emergency with presumed acute decompensated heart failure and non-ST-elevated myocardial infarction.

Throughout the patient’s first night, the troponin level started to down-trend after peaking at 0.24 ng/mL, and his oxygen requirements decreased allowing transition to nasal cannula. However, his repeat ECGs demonstrated significant T-wave abnormalities, new premature ventricular contractions, bradycardia, and a prolonging QTc interval to 703 msec (Figure 2). At this time, the patient’s electrolytes were normal, specifically a potassium level of 4.4 mEq/L, calcium 8.8 mg/dL, magnesium 2.0 mg/dL, and phosphorus 2.6 mg/dL. Given the worsening ECG changes, a computed tomography scan of his head was ordered to rule out intracranial pathology. While in the scanner, the patient went into pulseless VF, prompting defibrillation with 200 J. In addition, he was given 75 mg IV lidocaine, 2 g IV magnesium, and 1 ampule of both calcium chloride and sodium bicarbonate. With treatment, he had return of spontaneous circulation and was taken promptly to cardiac catheterization. The catheterization showed no significant obstructive coronary artery disease, and no interventions were performed. The patient was transferred to the cardiac intensive care unit for continued care.

During his course in the intensive care unit, the patient’s potassium and magnesium levels were maintained at high-normal levels. The patient was started on a dobutamine infusion to increase his heart rate and attempt to decrease his QTc. The patient also underwent cardiac magnetic resonance imaging (MRI) to evaluate for possible myocarditis, which showed no evidence of acute inflammation. Echocardiogram demonstrated an ejection fraction of 40% and global hypokinesis but no specific regional abnormalities and no change from prior echocardiogram performed 1 year earlier. Over the course of 3 days, his ECG normalized and his QTc shortened to 477 msec. Genetic testing was performed and did not reveal any mutations associated with long QT syndrome. Ultimately, an automated internal cardiac defibrillator (AICD) was placed, and the patient was discharged home.

Over the 2 years since his initial event, the patient has not experienced recurrent VF and his AICD has not fired. The patient continues to have ED presentations for heart-failure symptoms, though he has been stable from an electrophysiologic standpoint and his QTc remains less than 500 msec.

Discussion

Prolongation of the QT interval as a result of deep, global T-wave inversions after resolution of acute pulmonary edema has been minimally reported.^4,5 This phenomenon has been described in the cardiology literature but has not been discussed in the emergency medicine literature and bears consideration in this case.^4,5 As noted, an extensive evaluation did not reveal another cause of QTc prolongation. The patient had normal electrolytes and temperature, his neurologic examination and computed tomography were not remarkable. The patient had no obstructive coronary artery disease on catheterization, no evidence of acute myocarditis on cardiac MRI, no prescribed medications associated with QT prolongation, and no evidence of genetic mutations associated with QT prolongation on testing. The minimal troponin elevation was felt to represent a type II myocardial infarction related to ischemia due to supply-demand mismatch rather than acute plaque rupture.

Littmann published a case series of 9 cases of delayed onset T-wave inversion and extreme QTc prolongation in the 24 to 48 hours following treatment and symptomatic improvement in acute pulmonary edema.⁴ In each of his patients, an ischemic cardiac insult was ruled out as the etiology of the pulmonary edema by laboratory assessment, echocardiography, and left heart catheterization.All of the patients in this case series recovered without incident and with normalization of the QTc interval.⁴ Similarly, in our patient, significant QT T changes occurred approximately 22 hours after presentation and with resolution of symptoms of pulmonary edema. Pascale and colleagues also published a series of 3 patients developing similar ECG patterns following a hypertensive crisis with resolution of ECG findings and without any morbidity.⁵ In contrast, our patient experienced significant morbidity secondary to the extreme QTc prolongation.

Conclusions

We believe this is the first reported case of excessive prolongation of the QTc with VF arrest secondary to resolution of acute pulmonary edema. The pattern observed in our patient follows the patterns outlined in the previous case series—patients present with acute pulmonary edema and hypertensive crisis but develop significant ECG abnormalities about 24 hours after the resolution of the high catecholamine state. Our patient did have a history of prior cardiac insult, given the QTc changes developed acutely, with frequent premature ventricular contractions, and the cardiac arrest occurred at maximal QTc prolongation, yet after resolution of the high catecholamine state, the treatment team felt there was likely an uncaptured and short-lived episode of TdP that degenerated into VF. This theory is further supported by the lack of recurrent VF episodes, confirmed by AICD interrogation, after normalization of the QTc in our patient.

Aortitis is the all-encompassing term ascribed to the inflammatory process in the aortic wall that can be either infective or noninfective in origin, commonly autoimmune or inflammatory large-vessel vasculitis.¹ Infectious aortitis, also known as bacterial, microbial, or cryptogenic aortitis, as well as mycotic or infected aneurysm, is a rare entity in the current antibiotic era but potentially a life-threatening disorder.² The potential complications of infectious aortitis include emphysematous aortitis (EA), pseudoaneurysm, aortic rupture, septic emboli, and fistula formation (eg, aorto-enteric fistula).^2,3

EA is a rare but serious inflammatory condition of the aorta with a nonspecific clinical presentation associated with high morbidity and mortality.^2-6 The condition is characterized by a localized collection of gas and purulent exudate at the aortic wall.^1,3 A few cases of EA have previously been reported; however, no known cases have been reported in the literature due to Klebsiella pneumoniae (K pneumoniae).

The pathophysiology of EA is the presence of underlying damage to the arterial wall caused by a hematogenously inoculated gas-producing organism.^2,3 Most reported cases of EA are due to endovascular graft complications. Under normal circumstances, the aortic intima is highly resistant to infectious pathogens; however, certain risk factors, such as diabetes mellitus (DM), atherosclerotic disease, preexisting aneurysm, cystic medial necrosis, vascular malformation, presence of medical devices, surgery, or impaired immunity can alter the integrity of the aortic intimal layer and predispose the aortic intima to infection.^1,4-7 Bacteria are the most common causative organisms that can infect the aorta, especially Staphylococcus, Enterococcus, Streptococcus, Salmonella, and spirochete Treponema pallidum (syphilis).^1,2,4,8 The site of the primary infection remains unclear in some patients.^2,3,5,6 Infection of the aorta can arise by several mechanisms: direct extension of a local infection to an existing intimal injury or atherosclerotic plaque (the most common mechanism), septic embolism from endocarditis, direct bacterial inoculation from traumatic contamination, contiguous infection extending to the aorta wall, or a distant source of bacteremia.^2,3

Clinical manifestations of EA depend on the site and the extent of infection. The diagnosis should be considered in patients with atherosclerosis, fever, abdominal pain, and leukocytosis.^2,4-8 The differential diagnosis for EA includes (1) noninfective causes of aortitis, including rheumatoid arthritis and systemic lupus erythematosus; (2) tuberculous aortitis; (3) syphilitic aortitis; and (4) idiopathic isolated aortitis. Establishing an early diagnosis of infectious aortitis is extremely important because this condition is associated with a high rate of morbidity and mortality secondary to aortic rupture.^2-7

Imaging is critical for a reliable and quick diagnosis of acute aortic pathology. Noninvasive cross-sectional imaging modalities, such as contrast-enhanced computed tomography (CT), magnetic resonance imaging, nuclear medicine, or positron emission tomography, are used for both the initial diagnosis and follow-up of aortitis.¹ CT is the primary imaging method in most medical centers because it is widely available with short acquisition time in critically ill patients.³ CT allows rapid detection of abnormalities in wall thickness, diameter, and density, and enhancement of periaortic structures, enabling reliable exclusion of other aortic pathologies that may resemble acute aortitis. Also, CT aids in planning the optimal therapeutic approach.^1,3,5-8

This case illustrates EA associated with infection by K pneumoniae in a patient with poorly controlled type 2 DM (T2DM). In this single case, our patient presented to the Bay Pines Veterans Affairs Healthcare System (BPVAHS) in Florida with recent superficial soft tissue injury, severe hyperglycemia, worsening abdominal pain, and leukocytosis without fever or chills. The correct diagnosis of EA was confirmed by characteristic CT findings.

Case Presentation

A 72-year-old male with a history of T2DM, hypertension, atherosclerotic vascular disease, obstructive lung disease, and smoking 1.5 packs per day for 40 years presented with diabetic ketoacidosis, a urinary tract infection, and abdominal pain of 1-week duration that started to worsen the morning he arrived at the BPVAHS emergency department. He reported no nausea, vomiting, diarrhea, constipation, chest pain, shortness of breath, fever, chills, fatigue, or dysuria. He had a nonhealing laceration on his left medial foot that occurred 18 days before admission and was treated at an outside hospital.

The patient’s surgical history included a left common femoral endarterectomy and a left femoral popliteal above-knee reverse saphenous vein bypass 4 years ago for severe critical limb ischemia due to occlusion of his left superficial femoral artery with distal embolization to the first and fifth toes. About 6 months later, he developed disabling claudication in his left lower extremity due to distal popliteal artery occlusion and had another bypass surgery to the below-knee popliteal artery with a reverse saphenous vein graft harvested from the right thigh.

Discussion

This case contributes to the evidence that poorly controlled T2DM can be a predisposing factor for multiple vascular complications, including the infection of the aortic wall with progression to EA. Klebsiella species are considered opportunistic, Gram-negative pathogens that may disseminate to other tissues, causing life-threatening infections, including pneumonia, UTIs, bacteremia, and sepsis.⁹K pneumoniae infections are particularly challenging in neonates, the elderly, and immunocompromised individuals.⁹ CT is sensitive and specific in the detection of this pathologic entity.^1,3 In patients with a suspected infectious etiology, the presence of foci of gas on CT in solid organ tissues is usually associated with an anaerobic infection. Gas can also be produced by Gram-negative facultative anaerobes that can ferment glucose in necrotic tissues.⁹

Although any microorganism can infect the aorta, K pneumoniae cultured from the blood specimen, urine culture, and intraoperative specimens in our patient was responsible for the formed gas in the aortic wall. Occurrence of spontaneous gas by this microorganism is usually associated with conditions leading to either increased vulnerability to infections and/or enhanced bacterial virulence.⁹ Although a relationship between EA and T2DM has not been proved, it is well known that patients with T2DM have a defect in their host-defense mechanisms, making them more susceptible to infections such as EA. Furthermore, because patients with T2DM are prone to the development of Gram-negative sepsis, organisms such as K pneumoniae would tend to emerge. Patients with poorly controlled T2DM and the presence of an infectious source can be predisposed to infectious aortitis, eventually leading to a gas-forming infection of the aorta.^5,7

Conclusions

This case report can help bring awareness of this rare and potentially life-threatening condition in patients with T2DM. Clinicians should be aware of the risk of AE, particularly in patients with several additional risk factors: recent skin/soft tissue trauma, prior vascular graft surgery, and an underlying pancreatic mass. CT is the imaging method of choice that helps to rapidly choose a necessary emergent treatment approach.

Aortitis is the all-encompassing term ascribed to the inflammatory process in the aortic wall that can be either infective or noninfective in origin, commonly autoimmune or inflammatory large-vessel vasculitis.¹ Infectious aortitis, also known as bacterial, microbial, or cryptogenic aortitis, as well as mycotic or infected aneurysm, is a rare entity in the current antibiotic era but potentially a life-threatening disorder.² The potential complications of infectious aortitis include emphysematous aortitis (EA), pseudoaneurysm, aortic rupture, septic emboli, and fistula formation (eg, aorto-enteric fistula).^2,3

EA is a rare but serious inflammatory condition of the aorta with a nonspecific clinical presentation associated with high morbidity and mortality.^2-6 The condition is characterized by a localized collection of gas and purulent exudate at the aortic wall.^1,3 A few cases of EA have previously been reported; however, no known cases have been reported in the literature due to Klebsiella pneumoniae (K pneumoniae).

The pathophysiology of EA is the presence of underlying damage to the arterial wall caused by a hematogenously inoculated gas-producing organism.^2,3 Most reported cases of EA are due to endovascular graft complications. Under normal circumstances, the aortic intima is highly resistant to infectious pathogens; however, certain risk factors, such as diabetes mellitus (DM), atherosclerotic disease, preexisting aneurysm, cystic medial necrosis, vascular malformation, presence of medical devices, surgery, or impaired immunity can alter the integrity of the aortic intimal layer and predispose the aortic intima to infection.^1,4-7 Bacteria are the most common causative organisms that can infect the aorta, especially Staphylococcus, Enterococcus, Streptococcus, Salmonella, and spirochete Treponema pallidum (syphilis).^1,2,4,8 The site of the primary infection remains unclear in some patients.^2,3,5,6 Infection of the aorta can arise by several mechanisms: direct extension of a local infection to an existing intimal injury or atherosclerotic plaque (the most common mechanism), septic embolism from endocarditis, direct bacterial inoculation from traumatic contamination, contiguous infection extending to the aorta wall, or a distant source of bacteremia.^2,3

Clinical manifestations of EA depend on the site and the extent of infection. The diagnosis should be considered in patients with atherosclerosis, fever, abdominal pain, and leukocytosis.^2,4-8 The differential diagnosis for EA includes (1) noninfective causes of aortitis, including rheumatoid arthritis and systemic lupus erythematosus; (2) tuberculous aortitis; (3) syphilitic aortitis; and (4) idiopathic isolated aortitis. Establishing an early diagnosis of infectious aortitis is extremely important because this condition is associated with a high rate of morbidity and mortality secondary to aortic rupture.^2-7

Imaging is critical for a reliable and quick diagnosis of acute aortic pathology. Noninvasive cross-sectional imaging modalities, such as contrast-enhanced computed tomography (CT), magnetic resonance imaging, nuclear medicine, or positron emission tomography, are used for both the initial diagnosis and follow-up of aortitis.¹ CT is the primary imaging method in most medical centers because it is widely available with short acquisition time in critically ill patients.³ CT allows rapid detection of abnormalities in wall thickness, diameter, and density, and enhancement of periaortic structures, enabling reliable exclusion of other aortic pathologies that may resemble acute aortitis. Also, CT aids in planning the optimal therapeutic approach.^1,3,5-8

This case illustrates EA associated with infection by K pneumoniae in a patient with poorly controlled type 2 DM (T2DM). In this single case, our patient presented to the Bay Pines Veterans Affairs Healthcare System (BPVAHS) in Florida with recent superficial soft tissue injury, severe hyperglycemia, worsening abdominal pain, and leukocytosis without fever or chills. The correct diagnosis of EA was confirmed by characteristic CT findings.

Case Presentation

A 72-year-old male with a history of T2DM, hypertension, atherosclerotic vascular disease, obstructive lung disease, and smoking 1.5 packs per day for 40 years presented with diabetic ketoacidosis, a urinary tract infection, and abdominal pain of 1-week duration that started to worsen the morning he arrived at the BPVAHS emergency department. He reported no nausea, vomiting, diarrhea, constipation, chest pain, shortness of breath, fever, chills, fatigue, or dysuria. He had a nonhealing laceration on his left medial foot that occurred 18 days before admission and was treated at an outside hospital.

The patient’s surgical history included a left common femoral endarterectomy and a left femoral popliteal above-knee reverse saphenous vein bypass 4 years ago for severe critical limb ischemia due to occlusion of his left superficial femoral artery with distal embolization to the first and fifth toes. About 6 months later, he developed disabling claudication in his left lower extremity due to distal popliteal artery occlusion and had another bypass surgery to the below-knee popliteal artery with a reverse saphenous vein graft harvested from the right thigh.

Discussion

This case contributes to the evidence that poorly controlled T2DM can be a predisposing factor for multiple vascular complications, including the infection of the aortic wall with progression to EA. Klebsiella species are considered opportunistic, Gram-negative pathogens that may disseminate to other tissues, causing life-threatening infections, including pneumonia, UTIs, bacteremia, and sepsis.⁹K pneumoniae infections are particularly challenging in neonates, the elderly, and immunocompromised individuals.⁹ CT is sensitive and specific in the detection of this pathologic entity.^1,3 In patients with a suspected infectious etiology, the presence of foci of gas on CT in solid organ tissues is usually associated with an anaerobic infection. Gas can also be produced by Gram-negative facultative anaerobes that can ferment glucose in necrotic tissues.⁹

Although any microorganism can infect the aorta, K pneumoniae cultured from the blood specimen, urine culture, and intraoperative specimens in our patient was responsible for the formed gas in the aortic wall. Occurrence of spontaneous gas by this microorganism is usually associated with conditions leading to either increased vulnerability to infections and/or enhanced bacterial virulence.⁹ Although a relationship between EA and T2DM has not been proved, it is well known that patients with T2DM have a defect in their host-defense mechanisms, making them more susceptible to infections such as EA. Furthermore, because patients with T2DM are prone to the development of Gram-negative sepsis, organisms such as K pneumoniae would tend to emerge. Patients with poorly controlled T2DM and the presence of an infectious source can be predisposed to infectious aortitis, eventually leading to a gas-forming infection of the aorta.^5,7

Conclusions

This case report can help bring awareness of this rare and potentially life-threatening condition in patients with T2DM. Clinicians should be aware of the risk of AE, particularly in patients with several additional risk factors: recent skin/soft tissue trauma, prior vascular graft surgery, and an underlying pancreatic mass. CT is the imaging method of choice that helps to rapidly choose a necessary emergent treatment approach.

Aortitis is the all-encompassing term ascribed to the inflammatory process in the aortic wall that can be either infective or noninfective in origin, commonly autoimmune or inflammatory large-vessel vasculitis.¹ Infectious aortitis, also known as bacterial, microbial, or cryptogenic aortitis, as well as mycotic or infected aneurysm, is a rare entity in the current antibiotic era but potentially a life-threatening disorder.² The potential complications of infectious aortitis include emphysematous aortitis (EA), pseudoaneurysm, aortic rupture, septic emboli, and fistula formation (eg, aorto-enteric fistula).^2,3

EA is a rare but serious inflammatory condition of the aorta with a nonspecific clinical presentation associated with high morbidity and mortality.^2-6 The condition is characterized by a localized collection of gas and purulent exudate at the aortic wall.^1,3 A few cases of EA have previously been reported; however, no known cases have been reported in the literature due to Klebsiella pneumoniae (K pneumoniae).

The pathophysiology of EA is the presence of underlying damage to the arterial wall caused by a hematogenously inoculated gas-producing organism.^2,3 Most reported cases of EA are due to endovascular graft complications. Under normal circumstances, the aortic intima is highly resistant to infectious pathogens; however, certain risk factors, such as diabetes mellitus (DM), atherosclerotic disease, preexisting aneurysm, cystic medial necrosis, vascular malformation, presence of medical devices, surgery, or impaired immunity can alter the integrity of the aortic intimal layer and predispose the aortic intima to infection.^1,4-7 Bacteria are the most common causative organisms that can infect the aorta, especially Staphylococcus, Enterococcus, Streptococcus, Salmonella, and spirochete Treponema pallidum (syphilis).^1,2,4,8 The site of the primary infection remains unclear in some patients.^2,3,5,6 Infection of the aorta can arise by several mechanisms: direct extension of a local infection to an existing intimal injury or atherosclerotic plaque (the most common mechanism), septic embolism from endocarditis, direct bacterial inoculation from traumatic contamination, contiguous infection extending to the aorta wall, or a distant source of bacteremia.^2,3

Clinical manifestations of EA depend on the site and the extent of infection. The diagnosis should be considered in patients with atherosclerosis, fever, abdominal pain, and leukocytosis.^2,4-8 The differential diagnosis for EA includes (1) noninfective causes of aortitis, including rheumatoid arthritis and systemic lupus erythematosus; (2) tuberculous aortitis; (3) syphilitic aortitis; and (4) idiopathic isolated aortitis. Establishing an early diagnosis of infectious aortitis is extremely important because this condition is associated with a high rate of morbidity and mortality secondary to aortic rupture.^2-7

Imaging is critical for a reliable and quick diagnosis of acute aortic pathology. Noninvasive cross-sectional imaging modalities, such as contrast-enhanced computed tomography (CT), magnetic resonance imaging, nuclear medicine, or positron emission tomography, are used for both the initial diagnosis and follow-up of aortitis.¹ CT is the primary imaging method in most medical centers because it is widely available with short acquisition time in critically ill patients.³ CT allows rapid detection of abnormalities in wall thickness, diameter, and density, and enhancement of periaortic structures, enabling reliable exclusion of other aortic pathologies that may resemble acute aortitis. Also, CT aids in planning the optimal therapeutic approach.^1,3,5-8

This case illustrates EA associated with infection by K pneumoniae in a patient with poorly controlled type 2 DM (T2DM). In this single case, our patient presented to the Bay Pines Veterans Affairs Healthcare System (BPVAHS) in Florida with recent superficial soft tissue injury, severe hyperglycemia, worsening abdominal pain, and leukocytosis without fever or chills. The correct diagnosis of EA was confirmed by characteristic CT findings.

Case Presentation

A 72-year-old male with a history of T2DM, hypertension, atherosclerotic vascular disease, obstructive lung disease, and smoking 1.5 packs per day for 40 years presented with diabetic ketoacidosis, a urinary tract infection, and abdominal pain of 1-week duration that started to worsen the morning he arrived at the BPVAHS emergency department. He reported no nausea, vomiting, diarrhea, constipation, chest pain, shortness of breath, fever, chills, fatigue, or dysuria. He had a nonhealing laceration on his left medial foot that occurred 18 days before admission and was treated at an outside hospital.

The patient’s surgical history included a left common femoral endarterectomy and a left femoral popliteal above-knee reverse saphenous vein bypass 4 years ago for severe critical limb ischemia due to occlusion of his left superficial femoral artery with distal embolization to the first and fifth toes. About 6 months later, he developed disabling claudication in his left lower extremity due to distal popliteal artery occlusion and had another bypass surgery to the below-knee popliteal artery with a reverse saphenous vein graft harvested from the right thigh.

Discussion

This case contributes to the evidence that poorly controlled T2DM can be a predisposing factor for multiple vascular complications, including the infection of the aortic wall with progression to EA. Klebsiella species are considered opportunistic, Gram-negative pathogens that may disseminate to other tissues, causing life-threatening infections, including pneumonia, UTIs, bacteremia, and sepsis.⁹K pneumoniae infections are particularly challenging in neonates, the elderly, and immunocompromised individuals.⁹ CT is sensitive and specific in the detection of this pathologic entity.^1,3 In patients with a suspected infectious etiology, the presence of foci of gas on CT in solid organ tissues is usually associated with an anaerobic infection. Gas can also be produced by Gram-negative facultative anaerobes that can ferment glucose in necrotic tissues.⁹

Although any microorganism can infect the aorta, K pneumoniae cultured from the blood specimen, urine culture, and intraoperative specimens in our patient was responsible for the formed gas in the aortic wall. Occurrence of spontaneous gas by this microorganism is usually associated with conditions leading to either increased vulnerability to infections and/or enhanced bacterial virulence.⁹ Although a relationship between EA and T2DM has not been proved, it is well known that patients with T2DM have a defect in their host-defense mechanisms, making them more susceptible to infections such as EA. Furthermore, because patients with T2DM are prone to the development of Gram-negative sepsis, organisms such as K pneumoniae would tend to emerge. Patients with poorly controlled T2DM and the presence of an infectious source can be predisposed to infectious aortitis, eventually leading to a gas-forming infection of the aorta.^5,7

Conclusions

This case report can help bring awareness of this rare and potentially life-threatening condition in patients with T2DM. Clinicians should be aware of the risk of AE, particularly in patients with several additional risk factors: recent skin/soft tissue trauma, prior vascular graft surgery, and an underlying pancreatic mass. CT is the imaging method of choice that helps to rapidly choose a necessary emergent treatment approach.

THE CASE

A 72-year-old man was admitted to our Dallas hospital with a 4-day history of fevers and new-onset urinary frequency. He did not report any joint pain, sick contacts, or recent travel or recall any skin findings (rashes, insect bites). Past medical history was significant for hypertension, hyperlipidemia, diabetes, benign prostatic hyperplasia, recurrent urinary tract infections, and lumbar radiculopathy.

Initial signs and symptoms were suggestive of sepsis: a temperature of 102.7 °F, tachycardia, and a suspected genitourinary infection. This was supported by initial labs concerning for end-organ damage: elevated creatinine of 1.58 mg/dL (reference range, 0.67-1.17 mg/dL), elevated international normalized ratio (INR) of 1.6 (reference range, 0.9-1.1), hemoglobin of 12.8 g/dL (reference range, 13.5 - 17.5 g/dL), and platelet count of 99 ×10⁹/L (reference range, 160-383 ×10⁹/L).

Over the next several days, the patient’s condition worsened, and he experienced a decline in mental status, despite initiation of broad-spectrum antibiotics and fluid resuscitation. Although lumbar puncture was warranted, neither Neurology nor Interventional Radiology were willing to risk the procedure given the patient’s worsening hemoglobin (8.3 g/dL) and platelet count (51 ×10⁹/L).

Preliminary work-up included a urinalysis negative for leukocytes, nitrites, and ­bacteria—despite a urine culture that showed gram-positive cocci. His chest x-ray was unremarkable, and computed tomography of his brain showed generalized atrophy without acute changes. The work-up was expanded to fungal cultures and immunochemical assays. Empiric treatment with micafungin and acyclovir was started without improvement.

Further conversation with family revealed that the patient liked to spend time outdoors and he’d had a similar episode in which he’d been diagnosed with an unknown disease from an insect bite. Pertinent negative tests included: HIV, syphilis, rapid heterophile antibody, influenza, respiratory virus panel, blood culture, fungal culture, antineutrophil cytoplasmic antibodies, histoplasmosis, brucellosis, malaria, Epstein-Barr virus, cytomegalovirus, and parvovirus. Coxiella burnetii and West Nile virus immunoglobulin (Ig) G were positive, suggesting a prior exposure.

THE DIAGNOSIS

Given these new findings and reported outdoor activities, Infectious Diseases recommended we start our patient on doxycycline for possible rickettsia infection. On Day 8, doxycycline 200 mg IV once daily was started. (The IV form was initiated due to the patient’s altered mentation.) The patient started to show improvement, and on Day 14, an immunofluorescence antibody (IFA) assay revealed Rickettsia typhi IgM titers 1:512 (< 1:64) and IgG titers 1:256 (< 1:64), consistent with a diagnosis of murine (endemic) typhus.

DISCUSSION

Murine typhus is an acute febrile disease caused by R typhi, an obligate, intracellular gram-negative organism.¹ Worldwide, transmission to humans occurs mainly from infected rat fleas harbored by rodents. In the United States, it’s been suggested that opossums serve as an important reservoir in peri-domestic settings, with cat fleas as vectors.^2-4 The disease is endemic to southern California and south Texas.⁴

Continue to: Incidence of murine typhus

Incidence of murine typhus has declined in the United States since 1945 with the use of the insecticide dichlorodiphenyltrichloroethane (DDT). However, a recent rise in murine typhus cases—likely due to ecological changes—makes timely diagnosis and treatment essential.⁵ An epidemiologic study of 1762 confirmed cases in Texas from 2003 to 2013 found an increase in the number of cases and an expansion of the geographic areas impacted.³ Thus, in the work-up of acute fever of unknown origin, it is not unreasonable to include murine typhus in the differential.

Serologic testing with IFA is the preferred diagnostic method; however, a definitive diagnosis is not needed before treatment can be started.

Murine typhus can be difficult to diagnose due to nonspecific clinical manifestation.^3,4 A 2016 systematic review of 2074 patients reported common symptoms of fever, headache, malaise, chills, and myalgia.⁶ The most common laboratory abnormalities in adults were elevated aminotransferases, lactate dehydrogenase, hypoalbuminemia, and thrombocytopenia.⁶ A 4-fold increase in typhus group IgM or IgG-specific antibody titer by IFA is supportive of diagnosis.⁴ 

The differential diagnosis included urosepsis, prostatitis, syphilis, HIV, and meningitis. However, lack of response to broad-spectrum antibiotics and antifungals made a diagnosis of urologic infection unlikely. A negative sexually transmitted infection screen ruled out syphilis and HIV. An incidental, elevated INR and delirium prevented us from obtaining a lumbar puncture to test for meningitis.

Treatment may begin without a definitive diagnosis

Serologic testing with IFA is the preferred diagnostic method; however, a definitive diagnosis is not needed before treatment can be initiated. Doxycycline is the first-line therapy for all rickettsioses. Adults are advised to take doxycycline 200 mg orally once, followed by 100 mg twice daily until the patient improves, has been afebrile for 48 hours, and has received treatment for at least 7 days.⁷ Oral chloramphenicol is considered a second-line treatment; however it is not available in the United States and is associated with adverse hematologic effects.⁷

Our patient responded remarkably well to the doxycycline. After a 14-day course was completed, he was discharged to a skilled nursing facility for physical rehabilitation.

Continue to: THE TAKEAWAY

Rickettsia diseases, such as murine typhus, should be considered in the differential if a patient presents with a worsening clinical picture of unresolved delirium; fever despite use of broad-spectrum antibiotics, antifungals, and antivirals; and a history of potential outdoor exposure. Sources include opossums or cats when flea contact is likely. Rickettsia diseases belong in the differential when there is a history of travel to tropical areas, as well. All suspected cases should be reported to the local health department.

CORRESPONDENCE
Tenzin Tsewang MD, 5200 Harry Hines Boulevard, Dallas, TX 75235; [email protected]

THE CASE

A 72-year-old man was admitted to our Dallas hospital with a 4-day history of fevers and new-onset urinary frequency. He did not report any joint pain, sick contacts, or recent travel or recall any skin findings (rashes, insect bites). Past medical history was significant for hypertension, hyperlipidemia, diabetes, benign prostatic hyperplasia, recurrent urinary tract infections, and lumbar radiculopathy.

Initial signs and symptoms were suggestive of sepsis: a temperature of 102.7 °F, tachycardia, and a suspected genitourinary infection. This was supported by initial labs concerning for end-organ damage: elevated creatinine of 1.58 mg/dL (reference range, 0.67-1.17 mg/dL), elevated international normalized ratio (INR) of 1.6 (reference range, 0.9-1.1), hemoglobin of 12.8 g/dL (reference range, 13.5 - 17.5 g/dL), and platelet count of 99 ×10⁹/L (reference range, 160-383 ×10⁹/L).

Over the next several days, the patient’s condition worsened, and he experienced a decline in mental status, despite initiation of broad-spectrum antibiotics and fluid resuscitation. Although lumbar puncture was warranted, neither Neurology nor Interventional Radiology were willing to risk the procedure given the patient’s worsening hemoglobin (8.3 g/dL) and platelet count (51 ×10⁹/L).

Preliminary work-up included a urinalysis negative for leukocytes, nitrites, and ­bacteria—despite a urine culture that showed gram-positive cocci. His chest x-ray was unremarkable, and computed tomography of his brain showed generalized atrophy without acute changes. The work-up was expanded to fungal cultures and immunochemical assays. Empiric treatment with micafungin and acyclovir was started without improvement.

Further conversation with family revealed that the patient liked to spend time outdoors and he’d had a similar episode in which he’d been diagnosed with an unknown disease from an insect bite. Pertinent negative tests included: HIV, syphilis, rapid heterophile antibody, influenza, respiratory virus panel, blood culture, fungal culture, antineutrophil cytoplasmic antibodies, histoplasmosis, brucellosis, malaria, Epstein-Barr virus, cytomegalovirus, and parvovirus. Coxiella burnetii and West Nile virus immunoglobulin (Ig) G were positive, suggesting a prior exposure.

THE DIAGNOSIS

Given these new findings and reported outdoor activities, Infectious Diseases recommended we start our patient on doxycycline for possible rickettsia infection. On Day 8, doxycycline 200 mg IV once daily was started. (The IV form was initiated due to the patient’s altered mentation.) The patient started to show improvement, and on Day 14, an immunofluorescence antibody (IFA) assay revealed Rickettsia typhi IgM titers 1:512 (< 1:64) and IgG titers 1:256 (< 1:64), consistent with a diagnosis of murine (endemic) typhus.

DISCUSSION

Murine typhus is an acute febrile disease caused by R typhi, an obligate, intracellular gram-negative organism.¹ Worldwide, transmission to humans occurs mainly from infected rat fleas harbored by rodents. In the United States, it’s been suggested that opossums serve as an important reservoir in peri-domestic settings, with cat fleas as vectors.^2-4 The disease is endemic to southern California and south Texas.⁴

Continue to: Incidence of murine typhus

Incidence of murine typhus has declined in the United States since 1945 with the use of the insecticide dichlorodiphenyltrichloroethane (DDT). However, a recent rise in murine typhus cases—likely due to ecological changes—makes timely diagnosis and treatment essential.⁵ An epidemiologic study of 1762 confirmed cases in Texas from 2003 to 2013 found an increase in the number of cases and an expansion of the geographic areas impacted.³ Thus, in the work-up of acute fever of unknown origin, it is not unreasonable to include murine typhus in the differential.

Serologic testing with IFA is the preferred diagnostic method; however, a definitive diagnosis is not needed before treatment can be started.

Murine typhus can be difficult to diagnose due to nonspecific clinical manifestation.^3,4 A 2016 systematic review of 2074 patients reported common symptoms of fever, headache, malaise, chills, and myalgia.⁶ The most common laboratory abnormalities in adults were elevated aminotransferases, lactate dehydrogenase, hypoalbuminemia, and thrombocytopenia.⁶ A 4-fold increase in typhus group IgM or IgG-specific antibody titer by IFA is supportive of diagnosis.⁴ 

The differential diagnosis included urosepsis, prostatitis, syphilis, HIV, and meningitis. However, lack of response to broad-spectrum antibiotics and antifungals made a diagnosis of urologic infection unlikely. A negative sexually transmitted infection screen ruled out syphilis and HIV. An incidental, elevated INR and delirium prevented us from obtaining a lumbar puncture to test for meningitis.

Treatment may begin without a definitive diagnosis

Serologic testing with IFA is the preferred diagnostic method; however, a definitive diagnosis is not needed before treatment can be initiated. Doxycycline is the first-line therapy for all rickettsioses. Adults are advised to take doxycycline 200 mg orally once, followed by 100 mg twice daily until the patient improves, has been afebrile for 48 hours, and has received treatment for at least 7 days.⁷ Oral chloramphenicol is considered a second-line treatment; however it is not available in the United States and is associated with adverse hematologic effects.⁷

Our patient responded remarkably well to the doxycycline. After a 14-day course was completed, he was discharged to a skilled nursing facility for physical rehabilitation.

Continue to: THE TAKEAWAY

Rickettsia diseases, such as murine typhus, should be considered in the differential if a patient presents with a worsening clinical picture of unresolved delirium; fever despite use of broad-spectrum antibiotics, antifungals, and antivirals; and a history of potential outdoor exposure. Sources include opossums or cats when flea contact is likely. Rickettsia diseases belong in the differential when there is a history of travel to tropical areas, as well. All suspected cases should be reported to the local health department.

CORRESPONDENCE
Tenzin Tsewang MD, 5200 Harry Hines Boulevard, Dallas, TX 75235; [email protected]

THE CASE

A 72-year-old man was admitted to our Dallas hospital with a 4-day history of fevers and new-onset urinary frequency. He did not report any joint pain, sick contacts, or recent travel or recall any skin findings (rashes, insect bites). Past medical history was significant for hypertension, hyperlipidemia, diabetes, benign prostatic hyperplasia, recurrent urinary tract infections, and lumbar radiculopathy.

Initial signs and symptoms were suggestive of sepsis: a temperature of 102.7 °F, tachycardia, and a suspected genitourinary infection. This was supported by initial labs concerning for end-organ damage: elevated creatinine of 1.58 mg/dL (reference range, 0.67-1.17 mg/dL), elevated international normalized ratio (INR) of 1.6 (reference range, 0.9-1.1), hemoglobin of 12.8 g/dL (reference range, 13.5 - 17.5 g/dL), and platelet count of 99 ×10⁹/L (reference range, 160-383 ×10⁹/L).

Over the next several days, the patient’s condition worsened, and he experienced a decline in mental status, despite initiation of broad-spectrum antibiotics and fluid resuscitation. Although lumbar puncture was warranted, neither Neurology nor Interventional Radiology were willing to risk the procedure given the patient’s worsening hemoglobin (8.3 g/dL) and platelet count (51 ×10⁹/L).

Preliminary work-up included a urinalysis negative for leukocytes, nitrites, and ­bacteria—despite a urine culture that showed gram-positive cocci. His chest x-ray was unremarkable, and computed tomography of his brain showed generalized atrophy without acute changes. The work-up was expanded to fungal cultures and immunochemical assays. Empiric treatment with micafungin and acyclovir was started without improvement.

Further conversation with family revealed that the patient liked to spend time outdoors and he’d had a similar episode in which he’d been diagnosed with an unknown disease from an insect bite. Pertinent negative tests included: HIV, syphilis, rapid heterophile antibody, influenza, respiratory virus panel, blood culture, fungal culture, antineutrophil cytoplasmic antibodies, histoplasmosis, brucellosis, malaria, Epstein-Barr virus, cytomegalovirus, and parvovirus. Coxiella burnetii and West Nile virus immunoglobulin (Ig) G were positive, suggesting a prior exposure.

THE DIAGNOSIS

Given these new findings and reported outdoor activities, Infectious Diseases recommended we start our patient on doxycycline for possible rickettsia infection. On Day 8, doxycycline 200 mg IV once daily was started. (The IV form was initiated due to the patient’s altered mentation.) The patient started to show improvement, and on Day 14, an immunofluorescence antibody (IFA) assay revealed Rickettsia typhi IgM titers 1:512 (< 1:64) and IgG titers 1:256 (< 1:64), consistent with a diagnosis of murine (endemic) typhus.

DISCUSSION

Murine typhus is an acute febrile disease caused by R typhi, an obligate, intracellular gram-negative organism.¹ Worldwide, transmission to humans occurs mainly from infected rat fleas harbored by rodents. In the United States, it’s been suggested that opossums serve as an important reservoir in peri-domestic settings, with cat fleas as vectors.^2-4 The disease is endemic to southern California and south Texas.⁴

Continue to: Incidence of murine typhus

Incidence of murine typhus has declined in the United States since 1945 with the use of the insecticide dichlorodiphenyltrichloroethane (DDT). However, a recent rise in murine typhus cases—likely due to ecological changes—makes timely diagnosis and treatment essential.⁵ An epidemiologic study of 1762 confirmed cases in Texas from 2003 to 2013 found an increase in the number of cases and an expansion of the geographic areas impacted.³ Thus, in the work-up of acute fever of unknown origin, it is not unreasonable to include murine typhus in the differential.

Serologic testing with IFA is the preferred diagnostic method; however, a definitive diagnosis is not needed before treatment can be started.

Murine typhus can be difficult to diagnose due to nonspecific clinical manifestation.^3,4 A 2016 systematic review of 2074 patients reported common symptoms of fever, headache, malaise, chills, and myalgia.⁶ The most common laboratory abnormalities in adults were elevated aminotransferases, lactate dehydrogenase, hypoalbuminemia, and thrombocytopenia.⁶ A 4-fold increase in typhus group IgM or IgG-specific antibody titer by IFA is supportive of diagnosis.⁴ 

The differential diagnosis included urosepsis, prostatitis, syphilis, HIV, and meningitis. However, lack of response to broad-spectrum antibiotics and antifungals made a diagnosis of urologic infection unlikely. A negative sexually transmitted infection screen ruled out syphilis and HIV. An incidental, elevated INR and delirium prevented us from obtaining a lumbar puncture to test for meningitis.

Treatment may begin without a definitive diagnosis

Serologic testing with IFA is the preferred diagnostic method; however, a definitive diagnosis is not needed before treatment can be initiated. Doxycycline is the first-line therapy for all rickettsioses. Adults are advised to take doxycycline 200 mg orally once, followed by 100 mg twice daily until the patient improves, has been afebrile for 48 hours, and has received treatment for at least 7 days.⁷ Oral chloramphenicol is considered a second-line treatment; however it is not available in the United States and is associated with adverse hematologic effects.⁷

Our patient responded remarkably well to the doxycycline. After a 14-day course was completed, he was discharged to a skilled nursing facility for physical rehabilitation.

Continue to: THE TAKEAWAY

Rickettsia diseases, such as murine typhus, should be considered in the differential if a patient presents with a worsening clinical picture of unresolved delirium; fever despite use of broad-spectrum antibiotics, antifungals, and antivirals; and a history of potential outdoor exposure. Sources include opossums or cats when flea contact is likely. Rickettsia diseases belong in the differential when there is a history of travel to tropical areas, as well. All suspected cases should be reported to the local health department.

CORRESPONDENCE
Tenzin Tsewang MD, 5200 Harry Hines Boulevard, Dallas, TX 75235; [email protected]