[Onset of Crohn's disease induced by etanercept therapy: a case report].

A 27-year-old-man was diagnosed as having ankylosing spondylitis (AS) in 2003 and received a treatment by etanercept. Typical symptoms of active Crohn's disease (CD) developed 11 months after initiation of etanercept therapy. At colonoscopy, lesions compatible with CD were found endoscopically and histologically. Etanercept was interrupted and CD responded to standard treatment. A switch to infliximab was decided to treat a flare up ofAS. New onset CD may be considered an immune mediated injury induced by etanercept, but the causative role of the latter has not been demonstrated at this stage.