[Reactive arthritis shortly after Streptococcus b-hemolyticus type A and Salmonella type B infection].

We report the case of a girl aged 2 years and 8 months with monoarticular arthritis of the knee. Onset and outcome were slow. The child had suffered uncomplicated pharyngitis and a diarrheal process 1 and 2 weeks respectively prior to developing the disease. Additional data suggested the presence of reactive arthritis after Streptococcus infection. Salmonella was also detected in the feces. Unlike rheumatic fever, post-streptococcus reactive arthritis does not follow Jones' criteria and the clinical course is slow. Because gastrointestinal infection with both Streptococcus and Salmonella occurred simultaneously, the interaction between both agents, each of which alone can cause reactive arthritis, might have produced a synergic action in our patient.