Juvenile chronic arthritis and juvenile spondyloarthropathy.

Clinically recognized subgroups of juvenile chronic arthritis and the juvenile spondyloarthropathies are gradually being shown to be immunogenetically distinct; greater subdivision may ultimately be required. Mechanisms by which the association of certain genes work await further elucidation. Meanwhile, therapy such as intravenous gamma globulin may be most effective in systemic disease. Sulfasalazine is recommended for patients with later-onset pauciarticular disease, particularly HLA-B27 patients. Methotrexate should probably be reserved for severe unresponsive disease, particularly polyarthritis, until side effect profiles are better evaluated.