First Things First (assess & treat for the following)

• Vasculitic syndromes are characterized by inflammation & necrosis of blood vessel walls, resulting in narrowing or occlusion of the lumen or formation of aneurysms.
• Sequelae of anatomic changes include ischemia, infarction, turbulent flow and/or bleeding from aneurysmal rupture.
• Blood vessels anywhere throughout the body can be affected, but the extent & site of vessel involvement vary considerably in different cases & syndromes.
• Vascular involvement tends to be irregular & segmental rather than continuous.
• The vasculitides have in common vascular inflammation, yet there are different types & presentations. They could be isolated (skin, retina, CNS, etc.); they can be systemic (multiple organ involvement); they can be acute w/ all lesions at same stage or chronic w/ lesions at different stages of inflammation.
• Prognosis is variable: some have a benign self-limited course (ie, Henoch-Schönlein purpura [HSP]); others can be life- or organ-threatening w/ fatal prognosis if untreated (ie, Wegener’s).
  • Pathogenic mechanisms are varied & complex. Vessel damage can be mediated by:
    • Immune complex deposition
    • Antiendothelial cell antibodies
    • Antibodies against lysosomal enzymes
    • Pathogenic cellular immune response & granuloma formation
    • Infection agents, tumor cells, drugs
  • Classification: vasculitides are grouped according to size of predominant blood vessels involved.
    • Large vessel vasculitis
      • Takayasu’s arteritis (TA)
      • Giant cell (temporal) arteritis (GCA)
    • Medium vessel vasculitis
      • Polyarteritis nodosa (PAN)
      • Kawasaki’s disease
      • Isolated CNS vasculitis
    • Small vessel vasculitis; Also known as hypersensitivity/allergic vasculitis or leukocytoclastic vasculitis.
      • Anti-GBM disease
      • ANCA-associated syndromes: Wegener’s granulomatosis (WG), microscopic polyangiitis, Churg-Strauss syndrome (CSS), pauci-immune necrotizing crescentic glomerulonephritis (GN)
      • Cryoglobulinemic vasculitis (hepatitis C)
      • HSP
      • Primary cutaneous leukocytoclastic angiitis: drugs, infectious, malignancy, autoimmune
      • Hypocomplementemic urticarial vasculitis
      • Thromboangiitis obliterans (Buerger’s disease) not a true vasculitis