What are the factors associated with the duration of remission of intra-articular corticosteroid injection in juvenile idiopathic arthritis?

Introduction Intra-articular corticosteroid injection (IACI) is generally used in the management of juvenile idiopathic arthritis (JIA) to obtain rapid relief of active synovitis and functional recovery and to prevent the need for regular systemic therapy. The aim of this study was to investigate the outcome of IACI treatment and the factors associated with remission of synovitis. Methods The clinical records of JIA patients who received IACI between January 2014 and December 2020 in two pediatric rheumatology centers were reviewed. The procedure was evaluated in terms of efficacy, factors that may affect the duration of remission, procedural and drug-related complications. Results During the study period, 134 patients received 227 injections and 37 joints were injected more than once. One hundred and six (79%) patients had persistent oligoarticular disease. At the time of injection, all patients were receiving non-steroidal anti-inflammatory drugs, 74 patients were on methotrexate, and 14 patients were on biologics. The median duration of remission without exacerbation of synovitis treated with IACI was 15 (range 1–64) months. The inactivity rate was 81% at the 6th month after the injection. It has been shown that being less than 7 years old at disease onset and low initial CRP levels were correlated with a long remission period ( p 0.05). Only two patients (1.5%, 95% CI − 0.6 to 3.5) developed cutaneous hypopigmentation and subcutaneous atrophy as side effects of injection. Conclusion Intra-articular corticosteroid injection was more effective especially in patients with low initial CRP levels and younger than 7 years of age. The duration of remission was longer in these patients. Key Points • Intra-articular corticosteroid injection is an effective method for controlling joint inflammation and achieving long-term remission without significant side effects. • Intra-articular corticosteroid injection can be preferred in all forms of juvenile idiopathic arthritis as primary therapy or to relieve the patient while waiting for the effect of systemic agents or to avoid increasing the dose of systemic drugs. • It can be recommended as a treatment option at any stage of the disease, especially in young pa