The cocaine trail: levamisole-induced leukocytoclastic vasculitis in a cocaine user.

Two million Americans use cocaine on a regular basis. Sixty-nine percent of cocaine in the United States is adulterated with levamisole, a veterinary antihelminthic drug. In 2008, the first cases of levamisole-induced agranulocytosis and vasculopathy associated with adulterated cocaine were reported in the southwestern United States.