Behçet disease.

Behçet's disease is a multisystem inflammatory disorder of unknown origin, characterized by recurrent oral and genital ulcerations, ocular and cutaneous lesions, arthritis, central nervous system, and vascular disease. There is no pathognomonic laboratory test, but there are clinical criteria to assist in establishing the diagnosis. Behçet's is most common along the Silk Road. It is particularly common among persons who have the HLA-B51 major histocompatibility type. Cutaneous lesions include pustules, erythema nodosum-like lesions, Sweet's-like lesions, pyoderma gangrenosum-ike lesions, and pathergy. The major cutaneous findings may be classified as neutrophilic vascular reactions. There is considerable morbidity resulting from Behçet's disease, most notably a high risk of blindness from ocular involvement. Mortality may occur as a result of neurologic or vascular disease or gastrointestinal perforation.