Clinical aspects of juvenile rheumatoid arthritis.

This paper reviews studies in epidemiology, differential diagnosis, clinical manifestations, and treatment of juvenile rheumatoid arthritis (JRA) that have appeared during the past year. One epidemiologic study suggested a decreased incidence recently; however, changes over time in the ethnic and racial characteristics of the patients studied may also have played a role. Findings from an Australian study suggested that some studies may underestimate the true incidence of JRA if visits of physicians are the only basis for the studies. Finally, a Canadian study of incidence showed no seasonal correlations--except for the Prairie region--raising the possibility that the disease varies by region because of environmental factors or variations in ethnic background. Differential diagnostic issues were covered in several reports. One study suggested that elevations in lactate dehydrogenase levels identified children with malignancies who presented with musculoskeletal symptoms. Another study of children with Lyme disease failed to find any patients with asymmetric joint involvement, in contrast to JRA patients. Two studies from Europe reached opposite conclusions regarding whether the incidence of celiac disease was increased in JRA patients. Clinical studies included a French study showing increased production of interleukin-6 and interleukin-1-Ra during fever spikes in children with systemic JRA. An Italian study explored the potential role of interleukin-6 in the anemia of JRA patients. An American study confirmed decreases in markers of bone formation in JRA patients. Two treatment studies addressed the use of intravenous gamma globulin in JRA. Another report described two JRA patients who developed nodules while receiving methotrexate. Finally, a report added confirmation to the successful use of cyclosporine for macrophage activation syndrome in JRA.