Lesson of the month 2: Non-uraemic calciphylaxis - an unexpected differential diagnosis for a necrotic ulcer.

Calciphylaxis is an uncommon cause of skin necrosis seen almost exclusively in patients with end-stage renal disease. We present an unexpected diagnosis of calciphylaxis in a patient with normal renal and parathyroid function. The patient presented with a month-long history of painful bilateral necrotic leg ulcers, resistant to conventional treatment.