Arthritis in children.

Arthritis in children may result from many conditions. The rheumatic diseases, including juvenile rheumatoid arthritis, the spondyloarthropathies, rheumatic fever, lupus erythematosus, dermatomyositis, and the various vasculitis syndromes all can cause arthritis; these diseases are distinguished by their characteristic clinical appearances. Several nonrheumatic disorders such as infections, malignancies, congenital or genetic conditions, orthopedic conditions, and psychological disorders may closely simulate the various rheumatic diseases. The evaluation of children with arthritis rests chiefly on historical and physical findings; radiographs, laboratory tests, and occasionally biopsies also may be helpful. It is particularly important to identify specifically treatable diseases, such as bacterial infections or childhood malignancies, early and to avoid labeling nonrheumatic conditions as rheumatic. Accurate diagnosis of the various rheumatic disease syndromes is important for optimal therapy.