Behçet's syndrome--classification criteria.

Behçet's syndrome, classified as a vasculitis, is a multisystem disease of uncertain pathogenesis without any specific diagnostic feature or laboratory investigation. Diagnosis, therefore, depends on the grouping together of sufficient clinical manifestations for the clinician to be convinced of the diagnosis. Over many years various sets of diagnostic criteria have been proposed. In 1989 international criteria were proposed, which are better known as classification criteria, which depend on the presence of recurrent oral ulceration plus two of recurrent genital ulceration, typical eye lesions, typical skin lesions or a positive pathergy (skin hyperreactivity) test. It is emphasized that these are criteria for the classification of groups of patients participating in research programmes to ensure comparability of the groups, and not for the diagnosis of the individual patient in the clinical situation.