Mucolipidosis: A mimicker of juvenile idiopathic arthritis.

Juvenile idiopathic arthritis is the most common form of chronic arthritis in children and at times misdiagnosed in those presenting with arthropathy secondary to non-inflammatory causes. The overlap of symptoms often pose a diagnostic challenge for clinicians. This mostly results in a delayed diagnosis subjecting children to unnecessary use of long-term immunosuppressants and disease-modifying drugs. We present the case of a 9-year-old boy who was previously misdiagnosed as a case of juvenile idiopathic arthritis. Detailed evaluation later led to the diagnosis of mucolipidosis (type III) which was confirmed on genetic testing. Emphasis on detailed history and clinical examination including the subtle hints like lack of signs of inflammation, family history, no morning stiffness and normal inflammatory markers should be picked up to make a timely diagnosis. In today's era of genetic testing and diagnosis, it is prudent to offer these tests for such patients to make an accurate diagnosis and prognosticate them for the long-term outcome.