About this Book

Vasculitis refers to a broad spectrum of diseases characterized by inflammation and the destruction of blood vessels and can develop in any organ of the body. The skin is one of the most commonly affected organs, and small-vessel vasculitis of the skin is the most frequent type of vasculitis. Cutaneous Vasculitis (CV) may be a component of systemic vasculitis, including the skin, skin-limited or skin-dominant expression, or variant of systemic vasculitis. Finally, it may be a single-organ vasculitis of the skin. Identifying the etiologic factors causing CV can be a diagnostic challenge, and a wide range of diseases can be considered in its differential diagnosis. Therefore it is important to highlight the morphological components and clinicopathologic correlation of elementary lesions, which may increase the speed and accuracy of diagnosis. Here, morphological features of purpuric lesions, including size, erythema, palpability, symmetry or retiform pattern (branched/star-shaped purpuric lesions), may provide clues to possible etiologies. Although palpable purpura is the most critical lesion, many different elementary lesions can be obtained in the vasculitis spectrum. The depth of the vessels affected determines the type of cutaneous lesions. Small superficial vessel involvement often results in urticarial papules, plaques and palpable purpura. Deeper involvement (dermohypodermic junction/hypodermis) causes ulcers, nodules, or livedo. The cells in the inflammatory infiltrate, and the type of inflammation is also critical in diagnosing CV.