Are antihistamines still used during omalizumab treatment for chronic spontaneous urticaria?

Background: The guidelines for the treatment of chronic spontaneous urticaria (CSU) recommend adding omalizumab to the treatment of patients with uncontrolled disease despite four-fold doses of second-generation antihistamines (AH). On the contrary, some studies revealed that omalizumab was effective without concomitant AH and several authors suggest tapering off AH when CSU is controlled with omalizumab. Objectives: The aim of our study was to evaluate the use of AH during treatment with omalizumab in patients with CSU in real clinical practice. Materials & Methods: This was a multicentre cross-sectional and observational study conducted by the Catalan and Balearic Chronic Urticaria Network (XUrCB) based on a cohort of 298 CSU patients treated with omalizumab. Results: In total, 23.5% of our patients decided themselves to stop taking AH during omalizumab treatment. The ratio of patients with CSU without concomitant inducible urticaria and the percentage of patients with a good response to omalizumab (UAS7≤6 and/or UCT ≥ 12) were higher in those who stopped taking AH. Conclusion: More studies are required to identify the phenotypic characteristics of patients responding to omalizumab as monotherapy in order to avoid overtreating with AH. Our study suggests that patients with CSU without concomitant inducible urticaria and those who achieve a good response to omalizumab tend to be controlled by omalizumab without AH. In order to establish guidelines on how to stop AH, further evidenced-based studies are required.