Hx: 53 y F cannabis/cocaine user, admitted with extensive, painful retiform symmetric purpura patches in limbs, buttocks/abdomen with necrosis evolutionLab: neutropenia, thrombocytopenia, CPR 13 mg/L; LA-; anticardiolipin antibody-; cryoglobulins-; c-ANCA+Skin biopsy: thrombotic vasculopathyDx: levamisole-induced vasculitisTx: corticosteroids, surgical debridement of necrotic tissue. The gene discussed is PRTN3; the disease is Decreased total neutrophil count.