An Insight on the Possible Association between Inflammatory Bowel Disease and Biologic Therapy with IL-17 Inhibitors in Psoriasis Patients

Psoriasis is a chronic, inflammatory, multisystemic disease which affects approximately 2–3% of the population globally, whose onset is triggered by genetic and environmental factors which activate both dendritic cells and keratinocytes, resulting in the production of proinflammatory cytokines such as tumor necrosis factor alpha, interleukin 17, interleukin 23, interleukin 22, and interleukin 1β. An in-depth understanding of the pathophysiology of psoriasis led to significant advances in the development of safe and efficient novel therapeutic options, with four classes of biologic therapy being approved for the management of moderate to severe psoriasis: tumor necrosis factor alpha inhibitors, interleukin 23 inhibitors, anti-interleukin 12/23 agents, anti-interleukin 17 agents, as well as small-molecule inhibitors, such as apremilast. Psoriasis is associated with comorbid conditions, namely psoriatic arthritis, cardiovascular disease, metabolic syndrome, psychiatric disorders, malignancy, as well as inflammatory bowel disease. For patients affected by both psoriasis and inflammatory bowel disease, there is a strong recommendation to avoid IL-17 inhibitors since they may play a part in the exacerbation of the gastrointestinal disease. Our aim was to perform a thorough literature review regarding the development of inflammatory bowel disease lesions in psoriasis patients treated with IL-17 inhibitors, along with a case presentation to emphasize the need for close follow-up of these patients.