CME Case Challenge: A 48-year-old woman was being evaluated for enlarging lower extremity ulcers, starting as small pustules 7 months earlier. She was afebrile but hypotensive despite broad-spectrum antibiotics. Physical examination revealed a circumferential ulcer on the left shin, with exposed bone and a tender and violaceous border (Fig 1, A), and similar ulcers on the right shin (Fig 1, B), groin, and axillae. Laboratory findings were notable for an elevated white blood cell count and creatinine; skin biopsy was performed (Fig 2). Testing for antineutrophil cytoplasmic antibodies (ANCA), antineutrophil antibodies, cryoglobulins, coagulation panel, serum immunofixation, and microbial cultures was negative. The patient partially responded to oral prednisone (1 mg/kg), but ultimately died of refractory shock. What’s the diagnosis?
A. Nonuremic calciphylaxis
B. Antiphospholipid syndrome
C. Pyoderma gangrenosum
D. Necrotizing fasciitis
E. ANCA-negative medium vessel vasculitis