P0921Paradoxical dermatological manifestations under anti-tnf therapy in patients with Inflammatory Bowel Disease

Abstract Background Inflammatory bowel disease (IBD) may be associated with extra-intestinal manifestations, including dermatological involvement. Anti-TNF agents have transformed disease management but can induce paradoxical skin reactions. This study aimed to assess their frequency and characteristics in an IBD cohort. Methods This was a single-centre retrospective study including 1,806 IBD patients (1,204 Crohn’s disease; 602 Ulcerative Colitis) followed in our department. Among them, 246 patients (13.6%) received anti-tnf therapy (infliximab, adalimumab, golimumab). Clinical data, anti-tnf type, and the nature of skin lesions were collected. Statistical analyses were performed using chi-square and Student’s t tests, with significance set at p 0.05. Results Fifteen patients (6.1%) developed paradoxical dermatological manifestations. Psoriasis was the most frequent presentation (9 cases; 3.7%), including classical, scalp, inverse forms, or lesions associated with alopecia or vasculitis. Acneiform eruptions were observed in 2 patients (0.8%), and lichenoid dermatitis in 2 patients (0.8%). One case of Sweet’s syndrome was reported (0.4%). Thirteen affected patients (86.7%) had Crohn’s disease. Skin lesions occurred in 8 patients (3.3%) under infliximab, 6 patients (2.4%) under adalimumab, and none under golimumab (p = 0.605). The mean age of affected patients (41 years) was comparable to unaffected patients (43 years, p = 0.744). Management was mainly symptomatic. Two patients required discontinuation of anti-tnf therapy with a switch to another biologic class, with favourable outcomes under topical treatments. Conclusion The frequency of paradoxical dermatological manifestations in our cohort (6.1%) is consistent with international reports (3–10%). Paradoxical psoriasis was the most common presentation. No significant associations with the type of anti-tnf agent, IBD phenotype, or age were identified, suggesting an idiosyncratic mechanism. Most lesions were mild and did not require treatment . Close collaboration between gastroenterologists and dermatologists is essential for early detection and optimal management. Reference: 1-Mocci G, Marzo M, Papa A, Armuzzi A, Guidi L. Dermatological adverse reactions during anti-TNF treatments: focus on inflammatory bowel disease. J Crohns Colitis. 2013;7(10):769-779. doi:10.1016/j.crohns.2013.01.009 Conflict of interest: Dr. Elbasri, Ikram: No conflict of interest Lagdali, Nawal: No conflict of interest Sabbah, Selma: No conflict of interest kadiri, maryeme: No conflict of interest Chabib, Fatima-Zahra: No conflict of interest Borahma, mohamed: No conflict of interest Ajana, Fatima Zohra: No conflict of interest