Abstract
BACKGROUND: Chronic spontaneous urticaria (CSU) affects 0.5-1% of the population, with 40% remaining refractory to guideline-recommended therapy. Thyroid autoantibodies (TPOAb/TgAb) coexist in 20-30% of cases, yet their prognostic value in euthyroid patients remains controversial. METHODS: We conducted a propensity score-matched retrospective cohort study of 350 euthyroid CSU patients between 2020 and 2023. The primary endpoint was Week 24 treatment response (complete/partial response defined by UAS7/UCT scores). Secondary outcomes included time-to-response, relapse rates, and treatment escalation requirements. Conditional logistic regression and Cox proportional hazards models assessed associations. RESULTS: Antibody-positive patients exhibited significantly lower Week 24 response rates (47.6% vs. 69.4%; p < 0.001). Median time-to-response was delayed by 4.0 weeks (14.0 vs. 10.0 weeks, HR 0.56, p < 0.001). Relapse rates were higher among responders (27.1% vs. 14.0%, p = 0.036), and treatment escalation was more frequent (omalizumab: 38.7% vs. 21.0%; cyclosporine: 12.9% vs. 4.8%, both p < 0.001). A dose-response gradient was observed, with dual-positive patients showing the poorest outcomes. Effects were amplified in severe disease (UAS7 ≥ 16) and omalizumab-treated subgroups. CONCLUSION: Thyroid autoantibody positivity independently predicts inferior long-term treatment response, delayed therapeutic onset, and increased relapse risk in euthyroid CSU patients. Routine TPOAb/TgAb screening at diagnosis could enable personalized treatment escalation, improving outcomes.