Classification
- Small-vessel: often have palpable purpura
- Medium-vessel: typically cause a lacy rash
- Large-vessel
- Variable-vessel
- Associated with a systemic disease
Clinical Manifestations
History
- Fever, fatigue, weight loss, arthralgias
- Scleritis
- Nasal crusting, epistaxis, or upper airway disease: GPA
- Acute foot or wrist drop
- Limb claudication, especially unusual patient or location: Takayasu or giant cell arteritis
- Hemoptysis: ANCA-associated vasculitis
- Glomerulonephritis: ANCA-associated vasculitis or anti-GBM disease
- Drug exposure in past 6-12 months
- Cocaine/Levamasole
- Hydralazine
- Propylthiouracil (PTU) more than methimazole (MMI)
- Minocycline
- Allopurinol, penicillamine, procainamide, thiamazole, clozapine, phenytoin, rifampicin, cefotaxime, isoniazid, indomethacin
- Hepatitis B or C
- Lupus or other rheumatologic diseases
Physical exam
- Mononeuritis multiplex: sensory or motor neuropathy, which can be subtle, and symmetric or asymmetric
- Palpable purpura: small-vessel
- Diminished peripheral pulses: large-vessel vasculitis
Investigations
- ANA: lupus and other rheumatologic diseases
- Complements: lupus and mixed cryoglobulinemia
- ANCA: for ANCA-associated vasculitis
- CXR if respiratory symptoms
- EMG if concern for mononeuritis multiplex
- Lumbar puncture if concern for primary CNS vasculitis