Outcome in juvenile arthritis.

Juvenile chronic arthritis has a number of subtypes with only seropositive juvenile rheumatoid arthritis and systemic juvenile chronic arthritis having equivalents in adult life. In 75% of patients the inflammatory disease has subsided by adulthood, leaving some with degenerative and mechanical problems. Systemic, polyarticular and pauciarticular subgroups, based on mode of presentation, have been related to prognosis. Seropositive polyarticular disease behaves as an aggressive form of adult rheumatoid arthritis. Standard methods of assessment are inappropriate in children. Active joint score is most useful. Radiographs are difficult to interpret because of growth and lack of early erosive disease. Growth and social outcome is important. Death occurs in 7% of cases and is due to infection and cardiac involvement during active systemic disease, and due to secondary amyloidosis later. Slow-acting drugs and surgical procedures may alter outcome. The aetiology of these diseases remains unknown and there is a need for diagnostic tests, particularly to identify those children who will do badly.