Dermatologic Aspects of Systemic Vasculitis.

Systemic and localized vasculitis affects the skin and subcutis, due to large vascular beds and hemodynamic factors, such as stasis in lower extremities, and environmental influences, as occur in cold exposure. Initial cutaneous manifestations of vasculitides include diverse and dynamic patterns of discoloration, swelling, hemorrhage, and necrosis. One-half of affected patients present with localized, self-limited disease to the skin without any known trigger or associated systemic disease, known as idiopathic cutaneous leukocytoclastic vasculitis. Skin biopsy and dermatopathology contribute relevant information; however, they require correlation with clinical history, physical examination, and laboratory findings to reach an accurate diagnosis.