[Aseptic arthritis with positive serology for Yersinia pseudotuberculosis. Apropos of 6 new cases].

Six personal observations of aseptic acute arthritis with positive serology for yersinia pseudotuberculosis (YPT) have been related, the specific serodiagnosis was clearly positive (greater than 1/500) for all the patients and the rate variations of repeated examinations were constantly observed. These cases have been compared with 14 sporadic observations of the existing studies where such reactive arthritis were referred to a recent YPT infection, this confrontation leads us to specify the characteristics of this inflammatory rheumatism : starting by a prearthritic phase with variable combination of fever, diarrhea, abdominal pains, erythema nodosum, usually polyarticular affection (90%) mostly of the knees (89%), ankle-joints, wrists and elbows, marked inflammatory clinical and biological signs but without X. Rays abnormalities. The course which seems hastened by anti-inflammatory medication ends up several weeks or months later without recurrences or secondary diseases by a recovery. The presence of HLA B27 antigen in 50% out of the 10 tested cases enables us to discover the intervention of a predisposing genetic factor. A semiologic and nosologic comparison is established with polyarthritis of YEC infection. The discussion concerning the 18 observations where only serology based diagnosis exists, turns mainly on the reality of sporadic YPT rheumatism. If it is not yet possible to assert with certitude the authenticity of such YPT reactive arthritis there is several arguments in support of that, particularly the existence of post-septicemia aseptic polyarthritis and the existence of similar joint-affection during the far-east scarlatiniform fever which is a special form of YPT infection.