Cutaneous vasculitis.

Cutaneous vasculitis comprises a wide spectrum of clinical syndromes and histopathologic findings that share the common theme of vascular inflammation and blood vessel damage. Clinical pattern and proper histopathologic studies are essential to the proper classification and evaluation of vasculitis. This article discusses the major types of cutaneous vasculitis typified by necrotizing or leukocytoclastic vasculitis and includes discussions of Henoch-Schönlein purpura, urticarial vasculitis, erythema elevatum diutinum, cutaneous polyarteritis nodosa, livedoid vasculitis, and cutaneous granulomatous vasculitis.