Hx: 30 y F cocaine user, chronic sinusitis, left deviated septum, rhinitis, purulent rhinorrhea, macular rash on hands;Lab: ESR 5 mm/h; CPR 30 mg/L; WCC 11.1; p-ANCA+; c-ANCA-; anti-MPO-; anti-PR3-Nasal biopsy: ulceration, acute/chronic inflammation, fibrotic stroma, vessels permeated by inflammatory cells, no fibrinoid necrosisDx: CIMDLs and systemic levamisole vasculitisTx: abstinence, drug rehabilitation, surgical debridement. Here, MPO is linked to sinusitis.