This child had presented with polyarticular arthritis with fever. Though his Mantoux test is positive, it is unlikely that tuberculosis should lead to a polyarticular disease. The most likely diagnosis in this child would be Juvenile Idiopathic Arthritis (JIA) especially since he had similar complaints a year ago that subsided with oral medications given over a period of 4 months and also since he had mid-interphalangeal joint involvement. Distal interphalangeal joint involvement is usually seen in osteoarthritis and mid-interphalangeal joint involvement is seen typically with JIA.
Another possibility that one may consider is malignancy. However, the child does not have any organomegaly and has not lost weight. Also, his hemogram shows a normal WBC count and platelet count. Thus, it is unlikely to be a malignancy.
With a diagnosis of JIA, an acute febrile episode for 25 days, non-response to analgesics, increasing joint involvement, and symptoms of inability to walk for 6 months, one must consider the use of Disease-Modifying agents such as
Methotrexate in this child. However, the action of
Methotrexate would usually start after 2-3 months after the start of therapy. Hence apart from NSAIDs, physiotherapy and
Methotrexate with a short course of steroids may be needed to control the disease progression. In this child, IV
Methylprednisolone followed by oral
Prednisolone along with oral
Methotrexate helped to resolve the symptoms.