Nosology of primary vasculitis.

PURPOSE OF REVIEW: Recent developments in the nosology of primary systemic vasculitis are placed in the context of an historical overview. The ongoing attempts to develop criteria for classification and diagnosis are discussed. RECENT FINDINGS: Giant cell arteritis has supplanted temporal arteritis as the preferred term for chronic granulomatous arteritis in older adults. A new classification system for childhood vasculitis has been proposed by a European collaborative group. A study of idiopathic polyarteritis nodosa demonstrates greater similarity to microscopic polyangiitis in relapse rate than previously reported. Controversy has arisen over the eponym Wegener's granulomatosis because of alleged involvement of Friedrich Wegener in the Nazi regime during World War II. Diagnostic criteria for Kawasaki disease are problematic because many patients with coronary artery involvement do not fulfill current criteria at the time of presentation. Classification of antineutrophil cytoplasm autoantibody-associated small vessel vasculitis based on antineutrophil cytoplasm autoantibody specificity has been complicated by the finding that different ethnic groups may have very different clinical features relative to antigen specificity; for example, most patients with Wegener's granulomatosis in China have myeloperoxidase-antineutrophil cytoplasm autoantibodies rather than proteinase 3-antineutrophil cytoplasm autoantibodies. SUMMARY: Within the past year, new classification systems for primary vasculitis have been proposed, new classification criteria have been developed, and the appropriateness of a longstanding eponym has been challenged.