Clinical Characteristics and Risk Factors of Paradoxical Reactions in Psoriasis Patients Treated With Biologic Agents: A Single‐Center Real‐World Cohort Study in China

Background Biologic therapies have transformed psoriasis management, but paradoxical reactions (PRs) emerging during treatment remain a clinical challenge, affecting adherence and outcomes. Objective To identify risk factors and characterize PRs in psoriasis patients on biologics. Methods We retrospectively reviewed records of 549 psoriasis patients treated with biologic agents (including TNF‐α inhibitors, IL‐17 inhibitors, IL‐23 inhibitors, and IL‐12/23 inhibitors) between January 2016 and December 2024. Clinical characteristics were analyzed to determine the predictors of PRs. Results Among 549 patients, 76 (13.8%) developed PRs. Eczematous eruptions (56.6%) and atopic dermatitis–like lesions (19.7%) were the most common phenotypes. Because IL‐17 inhibitors accounted for the majority of biologic exposure in this cohort (450/549, 82.0%), most PR events were observed during IL‐17 inhibitor therapy. In multivariable Cox regression analysis of the full cohort, allergic rhinitis (adjusted HR: 3.07 and 95% CI: 1.84–5.11) and palmoplantar involvement (adjusted HR: 2.48 and 95% CI: 1.52–4.05) were identified as independent predictors of PRs. Most events were effectively managed with topical therapy (91.3%) or short‐term systemic treatment (75.0%), and 89.5% of affected patients ultimately achieved satisfactory disease control. Limitations Retrospective design and unbalanced biologic exposure may limit interpretation. Conclusion Our study identifies allergic rhinitis and palmoplantar involvement as predictors of PRs in psoriasis patients treated with biologics, aiding clinicians in optimizing treatment.