Tuberculosis is a Mimicker of JIA: A Rare Case Report

Cystic tuberculosis of the bone is a rare form of tuberculosis (TB). The condition presents like Juvenile idiopathic arthritis (JIA) of children. In children, the lesions symmetrically involve the peripheral skeleton, which are less sclerotic than adults. A case report is presented here where the patient presented with i) the extensive involvement of bones with cystic lesion, ii) Hand & feet involvement with multiple bony exostosis iii) Synovial swelling of multiple joints and 4) fever for 6 months. Swelling of the joints was disproportionately greater than pain. For the last 6 month patient developed low grade fever with evening rise of temperature & dry cough. There was associated anorexia & significant weight loss. Patient was moderately anaemic & there was cervical lymphadenopathy on both sides. The chest examination revealed features suggestive of consolidation in the right lung. Regarding MSK findings there was swelling of both knee & right wrist with G-II tenderness, sublaxation of both anterior and posterior cruciate ligament with mild effusion. Bony exostosis at the base of left index finger & at the base of right middle finger was found. Investigation shows low Hb, very high ESR, positive tuberculin test. X-ray Chest suggestive of consolidation, FNA of right cervical lymph node consistent with tuberculosis. X-ray Pelvis has shown expansile mixed sclerotic radiolucent areas with interval septation involving upper part of both femoral shafts. MRI findings of right knee joint were suggestive of tuberculous osteomyelitis. At this stage the patient was put on Anti-TB chemotherapy. After 2 month and 4 month of follow up with Anti-TB drug both MSK & lung condition was improved significantly. Ultimately the patient was diagnosed as cystic tuberculosis of bone & continued Anti-TB drugs.