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.