The clinical patterns of arthritis in children with familial Mediterranean fever.

We studied the clinical patterns of arthritis in 133 children with familial Mediterranean fever (FMF) over 5.5 years. Six clinical patterns were noted. The commonest was recurrent monoarticular arthritis as seen in 95 children (71%), mainly affecting the knee and ankle joints. This type followed two different courses: acute (< 1 month) and chronic (> 1 month). In 18 (14%) children, both knee or ankle joints were simultaneously and symmetrically involved: here too the course was either acute or chronic. Five (4%) children developed symmetric polyarthritis similar to juvenile rheumatoid arthritis (JRA). Six (4%) children developed asymmetric oligoarticular arthritis similar to acute rheumatic fever (ARF). The small joints of the hands (SJH) were involved in seven (5%) children, and the small joints of the feet in one. One child developed sacroiliitis similar to ankylosing spondylitis (AS). Between attacks, the joints were normal. Overall, outcome was good: residual damage of the hip joint occurred in one patient and of the shoulder in another. Although the clinical presentation and course of FMF arthritis are diverse, delineating these clinical patterns may help with earlier recognition and treatment. The low incidence of residual articular damage in this study may be related to the use of colchicine prophylaxis.