Skin Ulcers of Unknown Etiology.

A 41-year-old woman presented to the emergency department with leg ulcers and ecchymoses on her ears that began to develop one month prior. The leg ulcers began as painful, fluid-filled blisters and evolved into ulcers with a black crust. The lesions had appeared and resolved several times over the previous three years, but she did not seek medical attention. She took prednisone intermittently for psoriasis and had a long history of cocaine abuse. Physical examination showed multiple ulcerated lesions on the anterior aspect of both lower extremities (Figure 1) and multiple tender purpuric lesions on both ears (Figure 2). The examination showed psoriatic plaques on her legs, elbows, and fingers. Her vital signs were normal. A complete blood count, comprehensive metabolic panel, and coagulation laboratory test results were normal. Urine toxicology testing was positive for cocaine. She had an elevated C-reactive protein level (96.3 mg per L [917.16 nmol per L]) and erythrocyte sedimentation rate (48 mm per hour).