AbstractObjectiveTo investigate the prevalence of cumulative organ damage in patients with juvenile‐onset systemic lupus erythematosus (SLE) and its association with demographic and clinical variables, medication use, and quality of life.MethodsThe occurrence of organ system damage, as measured by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI), was determined for 387 patients consecutively enrolled in pediatric rheumatology centers from Europe, the US, Mexico, and Japan. Risk factors for damage included demographic variables; clinical manifestations at diagnosis; previous corticosteroid, immunosuppressive, and antimalarial therapies; disease activity; and quality of life.ResultsOverall, 195 (50.5%) patients had damage within a mean of 5.7 years after disease onset. Renal (21.8%) and neuropsychiatric (15.8%) system involvement were observed most frequently, followed by musculoskeletal (11.7%), ocular (10.9%) and skin (9.6%) system involvement, with a mean SDI score of 1.1. In multivariate models, the occurrence of neuropsychiatric manifestations at diagnosis, a longer disease duration, and a greater number of intravenous cyclophosphamide pulses showed the strongest association with the presence of damage.ConclusionWe found evidence of cumulative organ damage, as measured by the SDI, in half of the patients with juvenile‐onset SLE. Damage was significantly more likely in patients who had experienced neuropsychiatric manifestations at diagnosis, had a longer disease duration, and had received more intravenous pulses of cyclophosphamide.