Paradoxical Psoriasis Secondary to Anti-TNF Agents in Patients With Inflammatory Bowel Disease: A Nationwide Population-Based Cohort Study

Abstract

Introduction: Anti-tumor necrosis factor (anti-TNF) agents have proven to be highly effective in the management of inflammatory bowel disease (IBD). However, there are growing reports on dermatologic adverse effects including paradoxical psoriasis secondary to anti-TNF agents. Methods: A cross sectional nationwide population study was performed by using the Korea National Health Insurance Claim Data. A total of 42,165 patients with IBD consisting of ulcerative colitis (UC) (n=29,434) and Crohn's disease (CD) (n=12,731) were identified between 2009 and 2013. After excluding those who had coexisting any psoriasiform diseases during the one-year washout period of 2009, 1,631 patients who were treated with any anti-TNFs more than 6 months (the anti-TNF therapy group), and 8,057 matched controls who had never taken anti-TNFs (the non anti-TNF group) were established to compare incidences of psoriasis, psoriatic arthritis, and palmoplantar pustulosis (PPP) between 2010 and 2013. Results: Incidence of psoriasis was significantly higher in the anti-TNF therapy group (1.90%, 31/1,631) compared to the non anti-TNF group (0.79%, 64/8,057) (adjusted odds ratio [aOR] 2.531, 95% confidence interval [CI] 1.611- 3.896; p <.001). Psoriatic arthritis (aOR 1.450, 95% CI 0.689-2.831) and PPP (aOR 4.885, 95% CI 1.579-14.314) also showed higher incidence rates in the anti-TNF therapy group, respectively. In subgroup analyses, aORs for psoriasis by IBD subtype were 1.832 (95% CI 0.587-5.098) in UC and 2.656 (95% CI 1.603-4.294) in CD. aORs for psoriasis according to age groups were 3.584 (95% CI 1.190 to 9.925) under 20 years old, 2.621 (95% CI 1.502 to 4.448) between 21 to 39, and 1.574 (95% CI 0.420 to 4.735) aged 40 and over, which implies younger IBD patients have a higher risk of paradoxical psoriasis secondary to anti-TNF agents. Conclusion: The risk of psoriasis is increased by anti-TNF agents in patients with IBD, and especially in younger patients.