Chronic Spontaneous Urticaria Combined Atopic Dermatitis/Other Atopic Comorbidities: Clinical Characteristics, Therapeutic Response to Omalizumab, and Drug Survival

Background: Atopic comorbidities are common in chronic spontaneous urticaria (CSU), yet their impact on clinical presentation and omalizumab response remains poorly defined. Objective: To compare clinical profiles and omalizumab treatment outcomes in CSU patients with atopic dermatitis (AD) and other atopic comorbidities (OACs). Methods: This single-center retrospective study included 381 CSU patients treated with ≥3 doses of omalizumab (300 mg/4 weeks) and followed ≥6 months (January 2023–March 2025). Based on the presence or history of atopic comorbidities, patients were stratified into 3 groups: CSU with AD (CSU-AD, n = 76), CSU with OACs (CSU-OACs, n = 93), and CSU with no atopic comorbidities (CSU-NA, n = 212). Clinical features, treatment response (efficacy, speed, and adverse events), and—among 12-month completers—dose reduction/discontinuation and drug survival rates were analyzed. Results: Of all enrolled patients, 44.4% had comorbid allergic diseases. CSU-OACs patients had earlier onset ( P = 0.033) and higher angioedema prevalence ( P = 0.042); CSU-AD showed higher baseline UAS7 ( P = 0.031). Overall omalizumab response rates did not differ significantly among the 3 groups ( P = 0.115), but a significantly higher portion of faster-response speed was observed in CSU-OAC ( P = 0.019). Adverse events were significantly higher in CSU-OACs ( P = 0.004), especially injection-site reactions ( P = 0.033) and systemic effects (eg, headache and fatigue; P = 0.025). Drug survival was significantly higher in the CSU-OAC vs. CSU-NA group ( P = 0.007). Conclusion: CSU-AD differs only in higher baseline activity, otherwise resembling CSU-NA in treatment response and drug survival. CSU-OACs exhibit not only distinct features such as earlier onset, higher angioedema risk, faster response, and higher drug survival but also more adverse events, indicating that CSU-OAC requires individualized management. Larger multicenter studies are needed to further define the impact of AD and OACs in CSU.