The clinical introduction of tumour necrosis factor (TNF) inhibitors has deeply changed the treatment of inflammatory bowel diseases (IBD). It has demonstrated impressive efficacy as compared to alternative treatments, allowing for the chance to achieve near-remission and long-term improvement in function and quality of life and to alter the natural history of Crohn's disease (CD) and ulcerative colitis (UC). As a consequence of longer follow-up periods the number of side effects which may be attributed to treatment with biologics is growing significantly. Cutaneous reactions are among the most common adverse reactions. These complications include injection site reactions, cutaneous infections, immune-mediated complications such as psoriasis and lupus-like syndrome and rarely skin cancers. We review the recent literature and draw attention to dermatological side effects of anti-TNF therapy of inflammatory bowel disease.

Background. Few data are available on the safety and efficacy of infliximab biosimilar CT-P13 in patients with ulcerative colitis and Crohn's disease.Methods.

Introduction: Anti TNF-α agents have become a significant advance in the management of ulcerative colitis, proving to induce, with rapid onset, clinical and endoscopic remission. However, there is still a considerable unmet medical need in ulcerative colitis. Areas covered: The aim of this review was to summarize the patterns of use and the effectiveness of anti TNF-α in ulcerative colitis, highlighting their current position in treatment algorithms. Moreover, we set out a five-year view hypothesizing different treatment strategies. Expert commentary: The rapid onset of action and the effectiveness in inducing mucosal healing are the most important pros of anti TNF-α, supporting present and future use. Conversely, the relevant risk of loss of response and the safety profile have raised several concerns. In the future, the advent of different molecular targeting therapies can improve the management of UC patients, evolving to individually tailored strategies.

Background Psoriasis is an emerging paradoxical side effect in patients with inflammatory bowel disease (IBD) when treated with anti‐TNF alpha. Patients with severe skin lesions unresponsive to topical therapy need to withdraw from treatment. Aim To estimate the incidence of paradoxical psoriasis in a large cohort of IBD patients treated with anti‐TNF alpha and to analyse its clinical correlates. Methods A retrospective cohort study on all IBD patients who started anti‐TNF alpha at our IBD Centre from January 2008 to December 2013 was performed. Proportional hazards regression models were used to estimate the association between each predictor and time to the development of psoriasis. Time‐dependent predictors were updated at each available time point. Results Four hundred and two patients were included. Participants contributed a total of 839 person‐years of follow‐up, during which 42 incident cases of psoriasis were recorded, with an incidence rate of five per 100 person‐years. Cox‐regression survival analysis revealed smoking as independent predictor of psoriasis (HR: 2.37, 95% CI: 1.36–4.48; P = 0.008). Conversely, concomitant immunosuppressive therapy was inversely related to psoriasis (HR: 0.33, 95% CI: 0.12–0.92; P = 0.03). Conclusions Paradoxical psoriasis is a relevant side effect of anti‐TNF alpha therapy, with an incidence rate of five per 100 person‐years. Smoking is confirmed as the main risk factor for developing lesions. The combination therapy with anti‐TNF alpha plus immunosuppressants is associated with a reduced risk of paradoxical psoriasis.