History, Classification and Pathophysiology of Small Vessel Vasculitis

Systemic vasculitides are a heterogenous group of disorders characterized by destructive inflammation and fibrinoid necrosis of the blood vessel wall, blood vessel occlusion and ischemia of surrounding tissue. Typical clinical manifestations vary depending on the size of the affected blood vessels, and include fever, weight loss, malaise, arthralgias and arthritis. Vasculitides can be idiopathic, primary, secondary to another disease such as Systemic Lupus Erythematosus (SLE) and Rheumatoid Artritis (RA), or associated with infections, such as infective endocarditis, pharmaceutical drug use, such as propylthiouracil and hydralazine, or other chemical exposures [1]. Vasculitis can be isolated to one organ or vessel and be relatively insignificant clinically or can present as a systemic life-treatening illness involving several organs and vessels [2].