A controlled study of sacroiliitis in Behçet's disease.

The aim of the study was to evaluate the prevalence of sacroiliitis in a group of patients with Behçet's disease (BD). Pelvic X-rays of 27 patients with BD responding to the International Study Group of BD and 30 controls (15 AS and 15 sciatica) were read blind and sacroiliac involvement was graded according to the New York criteria. In a second step, patients or controls with equivocal sacroiliitis had a sacroiliac CT scan. Two patients with BD (7.4%) and all patients with AS had evident bilateral sacroiliitis (at least grade 2). One patient with BD and two patients with sciatica had equivocal sacroiliitis (grade 1). CT confirmed sacroiliitis in the two patients with BD and eliminated inflammatory sacroiliitis in the three other patients with equivocal sacroiliitis showing mild degenerative lesions. A review of the literature showed that sacroiliitis and AS are rarely associated with BD. There remains insufficient evidence to suggest that sacroiliitis is an intrinsic feature of BD and that BD belongs to the group of SpA.