[Systemic manifestations and diseases related to positive serology for Yersinia pseudotuberculosis. Apropos of 9 observations].

A series of 9 cases of systemic affections associated with positive serology for yersinia pseudotuberculosis is reported. The clinical presentation of four cases was classical reactive arthritis with or without erythema nodosa; in two cases the patients had sacroileitis or Reiter's syndrome. The other three patients had unusual presentations: one Löfgren's syndrome, one cutaneous leukocytoclasis vasculitis with polyarthritis and glomerulonephritis, and one rhizomelic pseudopolyarthritis. Four patients (45 p. 100) had a positive HLA B27 antigen. In the absence of absolute bacteriological proof of cause and effect the authors discuss the relationship between these syndromes and Yersinia pseudotuberculosis infection. Although a Yersinia infection has not been formally established as the cause, there is some indirect evidence pointing to the reality of systemic Yersinia pseudotuberculosis infection.