Behçet's disease.

Behçet's disease (BD) is a chronic, relapsing multisystem vasculitis with predominant involvement of the oral and genital mucosa. It has a worldwide distribution, but the prevalence is highest in Central Asia and the Far East (along the ancient 'Silk Route'). Genetic, environmental, immunological and haemostatic factors play a role in the aetiopathogenesis. The International Study Group for BD proposed criteria for the diagnosis of this condition, the essential feature being recurrent oral ulceration. Genital ulcers and skin manifestations are common, while ocular changes are the most important cause of morbidity. Almost any organ in the body can be involved, and systemic involvement may portend a poorer prognosis. There is no pathognomonic test for BD and the diagnosis is made on clinical findings. Treatment of BD would require multidisciplinary cooperation, and early referral to an ophthalmologist is advisable to prevent ocular morbidity. Topical and systemic agents (colchicine, dapsone and thalidomide) are useful in controlling exacerbation of the oral and genital ulcers. Severe disease may require immunosuppressive agents and, more recently, biological agents have been used successfully. It tends to follow an unpredictable course, and the eventual prognosis depends on the systemic involvement.