• Epidemiology
  1. Rare disease seen most often in men
  • Pathophysiology
  1. Similar to Classic Polyarteritis Nodosa
  2. Small Vessel, Granulomatous Vasculitis
    1. Multiple organ system involvement
    2. Interstitial Lung Disease
  • Phases
  1. Phase 1: Prodromal (esp. Upper Respiratory)
    1. Severe Asthma
    2. Allergic Rhinitis
    3. Eczema
  2. Phase 2: Eosinophilic (esp. Lower Respiratory)
    1. Eosinophilic lung infiltrate
  3. Phase 3: Vasculitis (occurs within 3 years of onset)
    1. Granulomatous ANCA-associated Small Vessel Vasculitis
  1. Eosinophilic tissue infiltration
  • Labs
  1. Antineutrophil Cytoplasmic Antibody (ANCA)
    1. Positive in 70% of cases (usually MPO-ANCA)
  2. Complete Blood Count (CBC)
    1. Eosinophilia >10%
  • Complications (often cause of death)
  1. Coronary arteritis
  2. Myocarditis
  • Differential Diagnosis
  1. Polyarteritis Nodosa (medium vessel Vasculitis)
  2. ANCA-Associated Small Vessel Vasculitis
    1. Granulomatosis with Polyangiitis (previously known as Wegener's Granulomatosis)
    2. Microscopic Polyangiitis
  • Management
  1. High-dose Corticosteroids
  2. Control vascular injury
    1. Hypertension
    2. Diabetes Mellitus
    3. Tobacco Abuse
    4. Hyperlipidemia
  • References
  1. Calabrese in Ruddy (2001) Kelly's Rheum, p. 1179-81
  2. Eustace (1999) J Am Soc Nephrol 10(9):2048-55 [PubMed]