Methotrexate in Resistant Juvenile Rheumatoid Arthritis: Results of the U.S.A.–U.S.S.R. Double-Blind, Placebo-Controlled Trial

JUVENILE rheumatoid arthritis is the most common rheumatic condition of childhood, with an annual incidence of about 1.4 cases per 10,000 children under the age of 16 years in the United States, and a prevalence of roughly 1 per 1000. 1 , 2 Three types of onset of juvenile rheumatoid arthritis are recognized, each of which has a characteristic clinical, epidemiologic, and genetic pattern. 3 The systemic-onset form produces a rheumatoid rash and intermittent fever (temperature, >39.4°C, with daily return to normal); anemia, pericarditis, and hepatosplenomegaly are common. The arthritis usually involves multiple joints. Polyarticular onset is characterized by arthritis in five or more . . .