New Onset, Aggravation and Recurrence of Crohn's Disease upon Treatment with Three Different Tumor Necrosis Factor Inhibitors.

Tumor necrosis factor (TNF) is a major cytokine in the pathogenesis of inflammatory bowel disease (IBD), and TNF inhibition is a cornerstone of contemporary IBD therapy. However, paradoxical induction of IBD has recently been reported upon treatment of rheumatologic disorders with TNF inhibitors. In previous cases, induction of IBD was associated with one single drug and IBD was successfully managed by switching TNF inhibitors. We report the case of a patient with juvenile rheumatoid arthritis under long-term treatment with etanercept. After switching TNF inhibition to adalimumab, symptoms of Crohn's disease (CD) occurred and the diagnosis of CD was established by endoscopy. Further treatment with adalimumab and subsequently infliximab aggravated the abdominal symptoms, necessitating ileocecal resection, after which symptoms resolved for several months. Etanercept treatment due to recurrent rheumatologic symptoms was followed by recurrent CD symptoms and findings, which resolved upon discontinuation of etanercept. This case suggests that induction, aggravation and recurrence of IBD can be rare class effects of TNF inhibition.