Cutaneous vasculitis and their differential diagnoses.

Vasculitis is defined as an inflammatory cell infiltration and destruction of blood vessels identified upon histologic examination. Cutaneous manifestations are frequent during the course of many systemic vasculitis. Lesions are often not specific, the most frequent being palpable purpura. They may be the first and only manifestation of the disease or be a part of a systemic condition. Histology is mandatory to confirm the diagnosis of vasculitis to avoid a delayed and inappropriate diagnosis that could lead to improper management. Cutaneous histology gave some data that may help to classify the vasculitis without determining precisely its type. A histological examination of all other skin lesions is necessary. The result of the biopsy has to be correlated to DIF data, medical history, physical examination, laboratory and radiological findings leading to the correct diagnosis and effective treatment.In this review, we discuss the diagnosis of cutaneous vasculitis (CV) and the pitfalls related to the cutaneous pathology. We also describe the essential features of the major categories of skin vasculitis.