A case of juvenile idiopathic arthritis exhibiting repair of systemic bone erosion in response to continuation of MTX therapy after achievement of clinical remission.

We report a patient with rheumatoid factor-positive polyarthritis-type juvenile idiopathic arthritis (JIA) in whom clinical remission was achieved within 10 months after the start of methotrexate (MTX) therapy, and systemic repair of bone erosion was noted 8 months after clinical remission. These results indicate that even in cases of active JIA with the development of bone erosion, continuation of MTX therapy after the achievement of clinical remission can improve the prognosis, including repair of bone destruction.