BEHÇET’S SYNDROME (BS) BS is a multisystem vasculitic inflammation that has one basic major feature- recurrent oral aphthous ulcers (AUs)- and two of any of the following features: recurrent genital AU, eye lesions (anterior or posterior uveitis), skin lesions (erythema nodosum or acneiform papulo-pustules), and a positive pathergy test. Other manifestations include synovitis, neurologic disorders, and thrombophlebitis.

Epidemiology İÖ 5.yy, Hipokrat 1936, Behçet ( eye disease+orogenital ulcers) Age of onset: Third and fourth decades, peak incidence 20-35 y %2-5 familial (Middle east %10-15) Prevalence: Highest in Japan (1: 10000), Turkey (80:100000), Southeast Asia, the Middle East, southern Europe. Rare in northern Europe, United States. Sex: Males > females

Pathogenesis Etiology unknown (neutrophilic vascular reactions or leukocytoclastic vasculitis, vascular thrombosis, autoimmune responses) - Infectious (HSV, Hep C, parvovirus B19, sreptococcus..) Immunologic ( circulating immune complexes, ↑circulating TNF-alpha, Il-1β, Il-8→ activation of neutrophils↔↑intreaction with endothelial cells) Genetic + enviromental factors HLA-B5 and HLA-B51 association (eastern Mediterranean and East Asia) The lesions are the result of leukocytoclastic (acute) and lymphocytic (late) vasculitis.

History Painful ulcers erupt in a cyclic fashion in the oral cavity and/or mucous membranes.

Physical Examination (1) Skin and Mucous Membranes Aphthous Ulcers: Punched-out (3-10mm) with rolled borders and necrotic base; red rim; occur in crops (2 to 10) on oral mucous membrane (%100), vulva, penis, and scrotum; very painful Erythema Nodosum-like Lesions: Painful inflammatory nodules on the arms and legs Other: Inflammatory pustules, superficial thrombophlebitis, inflammatory plaques resembling those in Sweet’s syndrome, pyoderma-gangrenosum-like lesions, palpable purpuric lesions of necrotizing vasculitis.

Physical Examination (2) Systemic Findings Eyes: Leading cause of morbidity. Posterior uveitis, anterior uveitis, retinal vasculitis, hypopyon, secondary cataracts, glaucoma, neovascular lesions Musculoskletal: Nonerosive, asymmetric oligoarthritis Neurologic: 25 %, onset delayed. Meningoencephalitis, BİH, cranial nerve pulsies, brainstem lesions, pyramidal/extrapyramidal lesions, psychosis. Vascular: Aneurysms, arterial occlusions, venous thrombosis, varices; hemoptysis. Coronary vasculitis: myocarditis, coronary arteritis, endocaditis, valvular disease. GI Tract: AUs throughout.

Laboratory Examinations Dermatopathology Pathergy Test HLA Typing (Japanese, Koreans, Turks)

Differential Diagnosis - Viral infection (HSV, VZV), hand-foot-and mouth disease, herpangina, chancre, mucous patch, eritema multiforme, pemfigus, lichen planus, squamous cell carcinoma,avitaminosis (pellegra, scurvy)

COURSE AND PROGNOSIS Highly variable course, with recurrences and remissions Remissions may last for weeks, months or yaers One of the leading causes of blindness With CNS involvement, there is a higher mortality rate

MANAGEMENT Aphtous ulcers: Potent topical glucocorticoids. Intralesional triamcinolone, 3 to 10 mg/ml, injected into ulcer base. Thalidomide, 50-100 mg PO. Colchicine, 0.6 mg PO 3 times a day. Dapsone, 50-100mg PO/day. Systemic involvement: Prednisone with or without azathioprine, cyclophosphamide, azathioprine alone, chlorambucil, cyclosporine.