Review article: dermatological complications of immunosuppressive and anti‐TNF therapy in inflammatory bowel disease

Summary Background With the expanding list of medications available to treat patients with inflammatory bowel disease (IBD), it is important to recognise adverse events, including those involving the skin. Dermatological adverse events may be confused with extra‐intestinal manifestations of IBD. Aim To review drug‐related dermatological manifestations associated with immunosuppressive and anti‐tumour necrosis factor (anti‐TNF) therapy. Methods The literature was searched on PubMed for dermatological adverse events in IBD. Results Present thiopurine exposure was associated with a 5.9‐fold [95% confidence interval (CI), 2.1–16.4] increased risk of developing non‐melanoma skin cancer (NMSC). The peak incidence is highest in Caucasians over the age of 65 years with crude incidence rates of 4.0 and 5.7/1000 patient‐years for present and previous use. In anti‐TNF‐exposed subjects, drug‐induced lupus was reported in 1% of the cases and a psoriatic rash in up to 3% of the cases. Anti‐TNF monotherapy increases the risk of NMSC ~2‐fold to a rate of 0.5 cases per 1000 person‐years. Cutaneous lymphomas have been rarely reported in subjects on thiopurine or anti‐TNF drug monotherapy. Combination therapy seems to have an additive effect on the risk of developing NMSC and lymphoma. Conclusions Physicians need to be aware of the wide spectrum of dermatological complications of immunosuppressive and anti‐TNF therapy in IBD, especially psoriasis and non‐melanoma skin cancer. Vigilance and regular screening for non‐melanoma skin cancer is recommended. Case discussions between gastroenterologists and dermatologists should be undertaken to best manage dermatological adverse events.