WORKING CLASSIFICATION OF VASCULITIS

Vasculitis is defined as angiocentric segmental inflammation of the bl ood vessels and fibrinoid necrosis of the vessel wall. Classification of vasculitis is a controversial problem, because of the difficulty in incorporating globally different criteria such as histologic features , size of affected blood vessels, etiology, pathogenesis and other fac tors in a single classification schema. In this paper rye review the p rincipal classifications and make a novel attempt to classify vasculit is on the basis of the size of affected vessels. We hope that a new ge neration of basic and clinical investigators can achieve a better unde rstanding of the pathogenesis of various vasculitis-related syndromes and that this understanding will facilitate future classification sche mas.