[Rheumatic fever: atypical joint manifestations].

The diagnosis of rheumatic fever (RF) continues to be a difficult one in Pediatrics, mainly because of the polymorphism of its clinical presentation and the lack of specific laboratory test. Among the Jones' major criteria, arthritis is the most frequent and the least specific. Ninety three children with RF who presented 117 flares of the disease were studied in the Department of Pediatrics, Escola Paulista de Medicina, between Dec. 1989 and Dec. 1991. The presence of arthritis was defined as an inclusion criterion. The diagnosis was based on history, physical and laboratory examinations (Modified Jones' Criteria). The mean age was 10 years and the sex ratio was 1 male: 1.4 female. In 45% of the flares, arthritis was the only major criterion. In 44% there were arthritis and carditis, in 7% arthritis and chorea and in 4% arthritis, carditis and chorea. In 64% of the flares the pattern of articular involvement was migratory and in 36% addictive. Polyarthritis and oligoarthritis were observed respectively in 64% and 36%. Monoarthritis was reported in 3%. The definitive diagnosis of RF with atypical articular involvement only was possible in the presence of carditis or chorea. The authors conclude that physicians should be aware of the atypical involvement observed in some cases of RF, specially when arthritis is the only major criterion.