Inflammatory bowel disease in patients with psoriasis treated with interleukin-17 inhibitors

Interleukin 17 (IL-17) inhibitors provide an excellent treatment option for patients with psoriasis and psoriatic arthritis, resulting in high levels of efficacy for skin clearance and joint improvement. Safety has also been established in clinical trials for this group of biologic agents; however, rare case reports of exacerbation or induction of inflammatory bowel disease (IBD) have been reported in the literature. No causal relationship has been established. When IL-17 inhibitors were investigated for the management of IBD, no benefit was found and worsening of disease was noted for some patients. IBD is more common in patients with psoriasis and, therefore, it remains unknown if these drugs cause de novo IBD or if the reported cases of IBD in patients on IL-17 therapy is due to the background risk in this predisposed population who may have already had an underlying or subclinical disease.

A literature search was conducted for the terms 'IL-17 inhibitor,' 'ixekizumab,' 'secukinumab,' 'brodalumab' and 'inflammatory bowel disease,' 'ulcerative colitis,' and 'Crohn's disease' in PubMed and Google Scholar. Cases of new-onset or exacerbation of IBD were identified in the literature along with postmarketing pharmacovigilance data. These cases will be reviewed in this paper.

IL-17 inhibitors have proven efficacy for the treatment of psoriasis and psoriatic arthritis with a strong safety profile. However, rare cases of IBD onset and exacerbation in patients on IL-17 inhibitors have been reported in the literature, highlighting the need to select patients and therapeutic choices appropriately when treating this population.