Cutaneous Manifestations in Biological-Treated Inflammatory Bowel Disease Patients: A Narrative Review

The biologic era has greatly improved the treatment of Crohn's disease and ulcerative colitis. Biologics can however induce a wide variety of skin eruptions, especially those targeting the TNF-α and Th17 pathway. These include infusion reactions, eczema, psoriasis, lupus, alopecia areata, vitiligo, lichenoid reactions, granulomatous disorders, vasculitis, skin cancer, and cutaneous infections. It is important to recognize these conditions as treatment-induced adverse reactions and adapt the treatment strategy accordingly. Some conditions can be treated topically while others require cessation or switch of the biological therapy. TNF-α antagonists have the highest rate adverse skin eruptions followed by ustekinumab and anti-integrin receptor blockers. In this review, we provide an overview of the most common skin eruptions which can be encountered in clinical practice when treating IBD (Inflammatory bowel disease) patients and propose a therapeutic approach for each condition.