DEFINITION AND PATHOGENESIS
A clinicopathologic process characterized by inflammation of and damage to blood vessels, compromise of vessel lumen, and resulting ischemia. Clinical manifestations depend on size and location of affected vessel. Most vasculitic syndromes appear to be mediated by immune mechanisms. May be primary or sole manifestation of a disease or secondary to another disease process. Unique vasculitic syndromes can differ greatly with regards to clinical features, disease severity, histology, and treatment.
PRIMARY VASCULITIS SYNDROMES
Granulomatosis with Polyangiitis (Wegener's)
Granulomatous vasculitis of upper and lower respiratory tracts together with glomerulonephritis; upper airway lesions affecting the nose and sinuses can cause purulent or bloody nasal discharge, mucosal ulceration, septal perforation, and cartilaginous destruction (saddlenose deformity). Lung involvement may be asymptomatic or cause cough, hemoptysis, dyspnea; eye involvement may occur; glomerulonephritis can be rapidly progressive and asymptomatic and can lead to renal failure.
Granulomatous vasculitis of multiple organ systems, particularly the lung; characterized by asthma, peripheral eosinophilia, eosinophilic tissue infiltration; glomerulonephritis can occur.
Polyarteritis Nodosa (PAN)
Medium-sized muscular arteries involved; frequently associated with arteriographic aneurysms; commonly affects renal arteries, liver, GI tract, peripheral nerves, skin, heart; can be associated with hepatitis B.
Small-vessel vasculitis that can affect the glomerulus and lungs; medium-sized vessels also may be affected.
Inflammation of medium- and large-sized arteries; primarily involves temporal artery but systemic and large vessel involvement may occur; symptoms include headache, jaw/tongue claudication, scalp tenderness, fever, musculoskeletal symptoms (polymyalgia rheumatica); sudden blindness from involvement of optic vessels is a dreaded complication.
Vasculitis of the large arteries with strong predilection for aortic arch and its branches; most common in young women; presents with inflammatory or ischemic symptoms in arms and neck, systemic inflammatory symptoms, aortic regurgitation.
Characterized by involvement of skin, GI tract, kidneys; more common in children; may recur after initial remission.
Majority of cases are associated with hepatitis C where an aberrant immune response leads to formation of cryoglobulin; characterized by cutaneous vasculitis, arthritis, peripheral neuropathy, and glomerulonephritis.
Idiopathic Cutaneous Vasculitis
Cutaneous vasculitis is defined broadly as inflammation of the blood vessels of the dermis; due to underlying disease in >70% of cases (see "Secondary Vasculitis Syndromes," below) with 30% occurring idiopathically.
Miscellaneous Vasculitic Syndromes
Kawasaki disease (mucocutaneous lymph node syndrome)
Isolated vasculitis of the central nervous system
Polyangiitis overlap syndrome
SECONDARY VASCULITIS SYNDROMES