REACTIVE ARTHRITIS: UROGENTTAL SWAB CULTURE IS THE ONLY USEFUL DIAGNOSTIC METHOD FOR THE DETECTION OF THE ARTHRITOGENIC INFECTION IN EXTRA-ARTICULARLY ASYMPTOMATIC PATIENTS WITH UNDIFFERENTIATED OLIGOARTHRITIS

Reactive arthritis (ReA) is a scronegative oligoarthritis triggeredby a preceding extra-articular infection. While evidence ofa microbial infection is mandatory for establishing the diagnosisof ReA, the sensitivity of bacteriological and serological testshas not been determined in patients without symptoms of infection.In a retrospective study, we evaluated the usefulness of urogenitalswab cultures, serology and stool culture to identify infectionsin 234 patients with undifferentiated oligoarthritis. One hundredand forty-four patients complaining about joint pain who hadno sign or history of inflammatory arthritis served as controls.Urogenital swab cultures showed a microbial infection in 44%of the patients with oligoarthritis (15% Chlamydia, 14% Mycoplasma,28% Ureaplasma), whereas in the control group only 26% had apositive result (4% Chlamydia, 7% Mycoplasma, 21% Ureaplasma)(P < 0.001). A Chlamydia IgG-antibody titre