[Postinfectious (reactive) arthritis--an important differential diagnosis to juvenile chronic arthritis (JCA) (author's transl)].

Symptoms, laboratory findings and clinical course of 10 pediatric patients suffering from postinfectious arthritis are described. The postinfectious arthritis is caused by an infection with Salmonella, Versina, Brucella or Shigella. The illness results from a preceding enteritis accompanied by fever. It differs from the juvenile chronic arthritis by the more clarified etiology and pathogenesis and particularly by the markedly shorter course, the lack of functional deterioration and by normal X-ray findings of the joint structure. In the parainfectious cases a similar pathogenesis is suggested, but the time relation is not as clear; the arthritis is diagnosed ahead of the enteritis. The human leucocyte antigen HLA-B 27 can frequently (90%) be proven in patients suffering from postinfectious arthritis. This is related to a genetic disposition of this type of arthritis as it can be observed in juvenile spondylitis ankylosans and in Reiter-syndrome, which can be considered as a special type of postinfectious arthritis.