The Arthropathy of Down Syndrome: An Underdiagnosed and Under-recognized Condition

Objective To define the clinical manifestations, determine prevalence, and heighten awareness about the arthropathyof Down syndrome. Study design Using diagnostic codes for Down syndromeand juvenile idiopathic arthritis (JIA), we identified 9 cases in our hospital system. Each case met diagnostic criteria for JIA. Cases were compared with 21 additional literature cases. Prevalence was determined with diagnostic codes. Results Average delay from symptom onset to diagnosis was 2 years. Age at onset varied from 20 months to 12 years. Sex distribution was equal. At symptom onset, 57% had polyarticular disease, and 43% had oligoarticular disease, but 54% with oligoarticular disease progressed to polyarticular disease. Seventy-two percent had an elevated erythrocyte sedimentation rate. Most required second-line therapy, and almost half had development of joint subluxation. Prevalence of Down syndrome arthropathyis 8.7/1000, more than 6 times higher than JIA in the general population. Conclusion The arthropathyof Down syndromeis an underrecognized condition that results in chronic disability and functional impairment in a population already at significant risk. Children with Down syndromeare predisposed to autoimmune disorders, but arthritis is overlooked in surveillance guidelines. To maximize joint function and quality of life, providers caring for children with Down syndromeneed a high index of suspicion for the related arthropathy.