Cocaine abuse is associated with various skin and rheumatological diseases that mimic primary autoimmune diseases, including retiform purpura with involvement of the ears, cocaine-induced midline destructive lesions (CIMDL), and eruptive pyoderma gangrenosum (PG). Previous reports have suggested the use of perinuclear antineutrophil cytoplasmic antibodies (pANCA) with specificity against human neutrophil elastase (HNE) to differentiate these cocaine-induced diseases from primary autoimmune diseases. We describe a case of a 54-year-old woman with a history of cocaine abuse, who had PG lesions on her legs with accompanying CIMDL and lung lesions similar to those seen in Wegener granulomatosis. Detection of HNE-positive pANCA, and improvement or clinical recurrence after cessation or consumption of cocaine, respectively, were key to differentiating this presentation from primary autoimmune disease.