1. Dr.Yugandar 2. Is an inflammation & necrosis of blood vessels resulting in a wide variety of clinical manifestations Cutaneous & systemic Small vessel vasculitis is characterized by palpable purpura on dependent parts ie ankle & lower legs Large vessel vasculitis is characterized by necrotizing livedo reticularis or multiple sites of peripheral gangrene. 3. Inflammatory destruction of the wall of blood vessel by leukocytes obstruction of the lumen ischemia & infarction of the tissues supplied. Triggered by various factors: infection, medications, underlying diseases such as connective tissue diseases, IBD, myelodysplastic & malignancies. 4. CLASSIFICATION ZECK differentiated necrotizing angitis: 1) Periarteritis nodosa 2) Hypersensitivity arteritis 3) Rheumatic arteritis 4) Allergic granulomatous angitis 5) Temporal arteritis 5. American college of rheumatology criteria for hypersensitivity vasculitis: 3 of 5 criteria has 83 % specificity & 71 % sensitivity. 1) Age at disease onset > 16 yrs 2) Medication at disease onset 3) Palpable purpura 4) Maculopapular rash 5) Biopsy including arteriole & venule with histological changes showing granulocytes in a perivascular or extra vascular location 6. 1994, CHAPEL HILL CONSENSUS CONFERENCE, 1) LARGE VESSEL VASCULITIS: a) Giant cell arteritis b) Takayasus arteritis 2) MEDIUM VESSEL WALL VASCULITIS: a) classic polyarteritis nodosa b) kawasaki disease c) nodular vasculitis 3) SMALL VESSEL VASCULITIS: a) Wegener's granulomatosis b) churg-strauss syndrome c) microscopic polyangitis 7. d) Henoch-schonlein purpura e) Essential cryoglobulinaemia f) Cutaneous leukocytoclastic vasculitis g) Drug induced vasculitis h) Other syndromes: i) Acute hemorrhagic edema of infancy ii) Urticarial vasculitis iii) Serum sickness iv) Erythema elevatum diutinum v) Granuloma faciale vi) Eosinophilic vasculitis 8. 1976, upgraded version of GILLIUMS, proposed working classification of vasculitis: a) SMALL VESSEL VASCULITIS 1) Cutaneous small vessel vasculitis 2) H-S purpura 3) Essential mixed cryoglobulinaemia 4) Urticarial vasculitis 5) Erythema elevatum diutinum 6) waldenstorms hypergammaglobulinaemic purpura 9. 7) Eosinophilic vasculitis 8) Rheumatoid nodules 9) Reactive leprosy 10) Septic vasculitis b) LARGE VESSEL VASCULITIS: 1) Polyarteritis nodosa Micoscopic polyarteritis Cutaneous form Systemic form 10. 2) Granulomatous vasculitis: Wegeners granulomatosis Churg-strauss syndrome Lymphomatoid granulomatosis 3) Giant cell arteritis Temporal arteritis Takayasus arteritis 4) Large vessel vasculitis with collagen vascular diseases 5) Nodular vasculitis 11. PATHOGENESIS The proposed mechanisms for production of vascular inflammation include: 1) Hypersensitivity reactions mediated by immune complexes 2) Auto antibodies 3) Cellular immune responses 12. ROLE OF PATHOGENIC IMMUNE COMPLEXES ANTIGENS {MICROBES, DRUGS, TUMOUR, AUTOANTIGENS} ANTIBODIES {FORMATION OF IMMUNE COMPLEXES DEPOSITION OF COMPLEXES IN & AROUND THE BLOOD VESSELS ACTIVATION OF COMPLEMENT CASCADE & GENERATION OF C3 A& C5 A { ANAPHYLATOXINS}