Purpura and leukopenia in a cocaine user

A previously healthy 42-year-old woman presented to the emergency department (ED) for arthralgias and painful lesions on her ears, feet, and knee (Figures 1 and 2) that had developed over the last month. She had no significant past medical history and was not taking any prescribed medications. The rash was purpuric with violaceous borders and hemorrhagic bullae. While she had mild pain with movement, her joint examination was otherwise normal and without signs of infection. ED laboratory testing revealed leukopenia (2500/mm(3)) and cocaine metabolites in her urine.