Dermatologic complications from levamisole-contaminated cocaine: a case report and review of the literature.

Levamisole is a veterinary anthelmintic drug with immunomodulatory properties in humans. It has become increasingly common as a contaminant in cocaine and is now detected in the majority of cocaine seized in the United States. A variety of adverse reactions have been reported in association with levamisole, the most severe being agranulocytosis, vascular occlusive disease, and thrombotic vasculopathy, with or without vasculitis. The combination of rapidly progressive cutaneous ecchymosis and purpura leading to necrosis, often affecting the ears and cheeks; neutropenia or agranulocytosis; serologic autoantibodies; and thrombotic vasculopathy, with or without associated vasculitis, in a patient who has recently used cocaine is characteristic of exposure to contaminant levamisole. We report the case of a 54-year-old man who presented with the clinical findings of levamisole-contaminated cocaine use and review the literature regarding cutaneous reactions associated with levamisole. Our case highlights this important public health issue and represents a clinical course that is unusually severe.