Features distinguishing juvenile idiopathic arthritis among children with musculoskeletal complaints.

backgroundMusculoskeletal (MSK) complaints in children vary, ranging from benign, self-limited conditions to serious disorders. Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease, initially presenting with MSK complaints. Delayed diagnosis and appropriate treatment have an enormous impact on the long-term outcomes and the level of disability. This study aimed to identify the features distinguishing JIA among children presenting with MSK complaints and to describe the spectrum of diseases at a large, single, tertiary center.

methodsA retrospective chart review was performed of patients evaluated by pediatric rheumatology consultation at the Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand, from July 2011 to June 2015.

resultsOf 531 patients, 285 (53.6%) had at least one MSK complaint. The mean age of the patients was 9.1 ± 4.1 years. Joint pain was the most common MSK complaint (86.3%), followed by limping (33%) and refusal to walk (19.6%). Joint swelling and limited range of motion were found in 146 (51.2%) and 115 (40.4%) patients, respectively. Seventy-three (25.6%) patients were diagnosed as JIA. The other common diagnoses included Henoch-Schönlein purpura (16.1%), reactive arthritis (14.2%), and systemic lupus erythematosus (13.7%). Morning stiffness  ≥ 15 minutes [odds ratio (OR) 8.217 (3.404-19.833)]; joint swelling on MSK examination [OR 3.505 (1.754-7.004)]; a duration of MSK complaints of more than 6 weeks [OR 2.071 (1.120-3.829)]; and limping [OR 1.973 (1.048-3.712)] were significantly associated with the ultimate diagnosis of JIA.

conclusionsMorning stiffness ≥ 15 minutes is a strong predictor of JIA. Comprehensive history taking and an MSK examination will provide clues for making the ultimate diagnosis for children with MSK complaints.