1. Definition of vasculitis (H-18thPg- 2786)
Vasculitis is a clinicopathologic process characterized by inflammation of and damage to blood vessels. The vessel lumen is usually compromised, and this is associated with ischemia of the tissues supplied by the involved vessel.
Clinical manifestations include
a. Constitutional signs and symptoms such as fever, myalgias, arthralgias, and malaise.
b. Local manifestations of downstream tissue ischemia.
c. Systemic necrotizing vasculitides, several types affects the aorta and medium sized vessels, but most affect small vessels, such as arterioles, venules, and capillaries (designated small vessel vasculitis).
Mechanisms of vasculitis are the direct invasion of vascular walls by infectious pathogens and immune-mediated mechanisms.
Table: Chapel Hill Consensus Classification and Characteristics of Selected Vasculitis
1. Causes of Large Vessel Vasculitis
a. Giant cell (temporal) arteritis
b. Takayasu arteritis (AIIMS Nov 09)
2. Causes of Medium Vessel Vasculitis
a. Polyarteritisnodosa (classic polyarteritisnodosa)
b. Kawasaki disease (AIIMS Nov 09)
3. Causes of Small Vessel Vasculitis
a. Wegener granulomatosis (AIIMS Nov 09)
b. Churg-Strauss syndrome
c. Microscopic polyangiitis (microscopic polyarteritis)
Table 326-2 Potential Mechanisms of Vessel Damage in Vasculitis Syndromes (H-18thPg- 2786, table 326.2)
Pathogenic immune complex formation and/or deposition
ii. Vasculitis associated with collagen vascular diseases
iii. Serum sickness and cutaneous vasculitis syndromes
iv. Hepatitis C–associated cryoglobulinemiavasculitis
v. Polyarteritisnodosa–like vasculitis associated with hepatitis B
Production of antineutrophilic cytoplasmic antibodies
i. Granulomatosis with polyangiitis (Wegener's)
ii. Churg-Strauss syndrome
iii. Microscopic polyangiitis
Pathogenic T lymphocyte responses and granuloma formation
i. Giant cell arteritis
ii. Takayasu's arteritis
iii. Granulomatosis with polyangiitis (Wegener's)
iv. Churg-Strauss syndrome