Noninflammatory disorders mimic juvenile idiopathic arthritis.

Juvenile idiopathic arthritis (JIA) is the most common chronic childhood arthritis; unfortunately, no diagnostic tool is available. Genetic disorders with musculoskeletal involvement that mimic chronic polyarthritis should be considered in the differential diagnostics of JIA. Normal inflammatory markers and characteristic radiological features are able to distinguish these disorders from JIA. Timely diagnosis of these disorders is crucial to offer the family proper genetic counseling and avoid inappropriate therapy. This review highlights selected noninflammatory disorders that often present with articular manifestations and that are often mislabeled as JIA. The focus is on the clinical, biochemical, and imaging features of these disorders.