[Yersinia arthritis (author's transl)].

Clinical picture and differential diagnosis of Yersinia arthritis are shown by means of three own observations. It is an acute oligoarthritis affecting especially knee- and ankle-joints. The involved joints are very painful, swollen and warm. There may be a history of enteritis or suspicion of acute appendicitis because of lower abdominal pain, but this is not obligatory. The laboratory parameters of inflammation (ESR, C-reactive protein, white blood count, serumproteinelectrophoresis) are changed significantly. Diagnosis is made by serum agglutination reaction (Widal-reaction) against ceesurface antigens (O-antigens) of Yersinia enterocolitica. Almost only people with the HL-A antigen B27 tend to get arthritis during Yersinia infection. The differential diagnosis has to consider reactive arthritis during Salmonella or Shigella infections, acute sarcoidosis, Reiter's disease and rheumatoid arthritis.