[Diagnosis and treatment of juvenile idiopathic arthritis (JIA)].

JIA is a chronic disease characterized by joint inflammation of unknown cause which occurs before 16 years of age. It includes 7 forms of clinical subtypes, and it affects about 1 individuals in every 10,000 Japanese children. The treatment strategy and an assessment tool for disease activity (JADAS) to evaluate the treatment efficacy have been established. In addition, induction of biologic agents for JIA patient refractory to conventional therapy resulted in remarkable improvement in the disease course and their joint prognosis. These drastic changes enforce recognition on rheumatologists that the major cause of poor prognosis of JIA at present is not due to disease severity but due to the delay or inappropriate treatment