Evaluation of rheumatic causes underlying childhood-onset arthritis.

Background/aim: Childhood-onset arthritis may result from various rheumatic diseases. This study aimed to systematically evaluate their distribution and characteristics in a large pediatric cohort. Materials and methods: We retrospectively analyzed all pediatric patients who presented with arthritis to the pediatric rheumatology clinic between January 2000 and January 2023. Results: A total of 1713 pediatric patients who presented with arthritis were included in this study (median age at diagnosis: 6.8 years; F/M = 1.2). Most of the patients (n = 859, 50.1%) had juvenile idiopathic arthritis (JIA) (especially oligoarticular JIA). Patients with familial Mediterranean fever, comprising 277 individuals (16.2%) presented with arthritis. The majority of them (n = 203, 73.3%) had short-lasting recurrent oligoarthritis (mostly monoarthritis) attacks. While arthritis was observed in 236 (13.8%) patients with vasculitis, immunoglobulin A vasculitis was the most common cause among them (n = 166, 70.3%). Most of the vasculitis patients had oligoarthritis (n = 221, 93.6%). Reactive arthritis was present in 147 patients (8.6%, mostly monoarthritis). Acute rheumatic fever was another cause of arthritis (4.7%, mostly polyarticular and migratory). Among autoimmune diseases (mostly systemic lupus erythematosus), arthritis was detected in 82 patients (4.8%, oligoarthritis or polyarthritis). Conclusion: In our study, we focused on the rheumatic etiologies underlying childhood arthritis. Given the heterogeneity of etiologies, clinical evaluation should be comprehensive, considering systemic features beyond joint involvement.