Non-uremic Calciphylaxis With Possible Initial Misdiagnosis as Erythema Multiforme/Toxic Epidermal Necrolysis Successfully Treated as Inpatient.

Non-uremic calciphylaxis (NUC) is a rare, high-mortality disease, and it can be easily misdiagnosed as other ulcerative dermatologic conditions. A female in her late 30s with a medical history of alcoholic liver cirrhosis and obesity who previously underwent gastric bypass surgery presented with an 11-month history of worsening bilateral lower extremity wounds following the initiation of spironolactone. A wound biopsy at the time of initial presentation favored erythema multiforme/toxic epidermal necrolysis (EM/TEN). She initially responded to systemic steroids, but her wounds later worsened, prompting her to seek representation a few months later. The initial suspicion was for a superimposed bacterial infection; however, her wounds did not improve following antibiotics. A repeat skin biopsy revealed calciphylaxis, for which she had multiple risk factors, including severe vitamin D deficiency causing secondary hyperparathyroidism. A multidisciplinary approach was successful in achieving a satisfactory response with pain control, wound care, skin grafting, and mitigation of risk factors in addition to the use of sodium thiosulfate. Upon our review, the initial biopsy did not demonstrate features of EM/TEN but did demonstrate features suspicious for calciphylaxis. The exposure to systemic corticosteroids due to the presumed diagnosis of EM/TEN may have worsened her condition since this is a known risk factor for calciphylaxis. Our case highlights the importance of clinicopathologic correlation as well as the place for calciphylaxis in the clinical and histopathologic differential diagnosis of ulcerated, necrotic lesions on the lower extremities in the absence of renal disease.