DDx
- Polyarteritis nodosa: fever, hypertension, abdominal pain, often hepatitis B or C
- Microscopic polyangiitis: overlaps with PAN, glomerulonephritis, pulmonary hemorrhage
- Churg-Strauss syndrome: asthma, transient pulmonary infiltrates
- Wegener’s granulomatosis: respiratory disease and glomerulonephritis
- Temporal (giant cell) arteritis: headache, jaw claudication, blindness, associated with polymyalgia rheumatica
- Takayasu’s arteritis: young Asian women, aortic arch vasculitis
- Henoch-Schönlein purpura: children, palpable purpura, abdominal pain
- Hypersensitivity (leukocytoclastic) vasculitis: lower extremity palpable purpura; associated with drugs, neoplasms, connective tissue disease, viral or bacterial infection, cryoglobulinemia, serum sickness
- Thromboangiitis obliterans (Buerger’s disease): smokers, extremity ischemia
- Behçet’s syndrome: oral and genital ulcers, ocular lesions
- Kawasaki disease: children, fever, rash, conjunctivitis, cardiac disease