Ankylosing spondylitis associated with Trichomonas vaginalis infection.

A patient is described who developed signs and symptoms of ankylosing spondylitis after prostatitis due to Trichomonas vaginalis. Chronic prostatitis of unknown cause had previously been reported as being common in patients with ankylosing spondylitis. The observations in this case raise the possibility that T. vaginalis might play a role in the prostatitis and pathogenesis of ankylosing spondylitis in some patients.