Prospective study of articular manifestations in Behçet's disease: five-year report.

Aim: To evaluate different aspects of articular involvements (prevalence, types, relation to extra-articular manifestations, etc.) in Iranian patients with Behcet's disease (BD).

Methods: In a prospective study, all patients with BD attending an outpatient BD clinic were enrolled. The type of articular involvements (peripheral or axial), involved joints, duration of attacks and their relation to extra-articular manifestations, human leukocyte antigen (HLA)-B5 and HLA-B27 were evaluated. Data analysis was done by using descriptive statistical indices such as mean and confidence interval. The comparisons were done by chi-square test.

Results: In a 5-year period, 2312 patients were recruited. Musculoskeletal manifestations were recorded in 430 patients (190 without previous history of these involvements). The remaining 1882 patients showed no musculoskeletal involvements, of which 753 had past histories of musculoskeletal manifestations. The 5-year incidence rate was 18.6%, and the prevalence rate was 51.2%. History of previous musculoskeletal involvements has no effect in its new development (P = 0.2). Arthritis was the most common type of involvement (289/430, 67%). The most frequent pattern was monoarthritis (191/289, 66%), and the most frequent involved joints were knees (147/289, 50.9%). The arthritic attacks were unilateral in 82.4% of cases. Ankylosing spondylitis was seen in 44/430 (10.2%). There was no association between HLA-B5 or HLA-B27 and any type of musculoskeletal involvements (P > 0.5). Pseudofolliculitis was the only extra-articular manifestation related to arthritic attacks (P = 0.046).

Conclusion: Musculoskeletal involvement is a common manifestation of BD seen in more than half of patients. Acute knee monoarthritis was the most common pattern of articular involvement in BD.