Vasculitis: an approach for physicians.

In the absence of a satisfactory classification, a sequential approach to the problems of vasculitis is recommended to the clinician. Clinical recognition will result from a presentation of: i. a well-defined syndrome; ii. a visually identifiable vasculitis (cutaneous or retina); iii--vasculitis-associated disease (connective tissue disease, infectious and neoplastic diseases); iv. multisystem syndrome. Aetiology will be sought from infectious, drug, autoimmune or tumour origin in the main. Helpful pathological features include vessel size, cellular infiltrate, granulomata, necrosis and immune deposits. Immunopathogenesis must clearly distinguish initiators (e.g. immune complexes) from amplifiers and regulators (e.g. fibrin, complement, protease inhibitors, phagocytes). Sites of pathology may be determined by such localising mechanisms as cryoglobulins, immune complex receptors and rheological factors. A rational approach to management dependent on awareness of immunopathology includes inflammatory mediator inhibitors, immunosuppression or plasmapheresis.