Microscopic polyarteritis presenting with skin necrosis in a patient with sickle-cell disease.

A 20-year-old Caribbean woman with sickle cell anaemia was admitted with a 4-day history of fever and a painful swollen right ankle. She rapidly developed skin necrosis. The differential diagnosis is discussed. This case illustrates the difficulty in identifying the cause of cutaneous necrosis in an acutely ill patient. In our patient, histopathology implicated a vasculitic process, which was subsequently identified as a manifestation of microscopic polyarteritis.