Background Chronic spontaneous urticaria (CSU) is a mast cell–driven skin disorder characterized by wheals, angioedema, or both lasting more than 6 weeks. While standard‐dose omalizumab (300 mg every four weeks) is effective in many cases, a subset of patients requires higher doses. Predictive biomarkers for such treatment escalation remain unclear. Objective To identify clinical and laboratory parameters associated with the need for high‐dose omalizumab therapy (450–600 mg/4 weeks) in patients with CSU. Methods This retrospective observational study included 199 CSU patients treated with omalizumab following the failure of fourfold second‐generation H1 antihistamines. Patients were grouped by dose regimen: standard dose ( n = 168) and high dose ( n = 31). Demographic, clinical, and laboratory data were analyzed and compared between groups using appropriate statistical tests. Results In unadjusted analyses, patients in the high‐dose omalizumab group were significantly older (mean age 45.94 vs. 41.29 years, p = 0.050), had higher BMI (28.30 vs. 25.88, p = 0.016), showed a higher prevalence of prior cyclosporine use (9.7% vs. 1.2%, p = 0.028), exhibited elevated D‐dimer levels (32.3% vs. 15.6%, p = 0.027), and presented with angioedema (45.2% vs. 21.6%, p = 0.005) compared with the standard‐dose group. However, in multivariate logistic regression analysis, only elevated D‐dimer levels remained an independent predictor of high‐dose omalizumab use. Conclusion Older age, higher BMI, angioedema, and prior cyclosporine use were more frequent among patients receiving high‐dose omalizumab in unadjusted analyses; however, only elevated D‐dimer levels remained independently associated with dose escalation. This readily available biomarker may help identify CSU patients who are more likely to require high‐dose omalizumab, although prospective multicenter studies are needed to confirm these findings.
Dizman et al. (2026) studied this question.