Chlamydia-induced reactive arthritis.

: Chlamydia trachomatis infection is now recognized as the most prevalent veneral disease in the Western World. The majority of cases of Reiter's syndrome, one type of reactive arthritis, are secondary to sexually transmitted infections. Evidence of urogenital C. trachomatis infection is found in 36% to 61% of cases of Reiter's syndrome. We investigated the prevalence of infection by this organism in a group of patients with spondyloarthropathies. Positive cultures were obtained in 39.4% of patients with Reiter's syndrome, as well as in 22.2% of patients with psoriatic arthritis and in 20% of patients with ankylosing spondylitis. An important percentage of patients also had positive serum antibodies against C. trachomatis (62.1% of patients with Reiter's syndrome), suggesting presence of infection at some point during the course of the disease. Our findings and those from other authors support the use of long-term antibiotic therapy in patients with reactive arthritis, mainly in those in whom positive culture for C. trachomatis has been obtained as well as in their sex partners.