Abstract: 【Abstract】 Objective To evaluate the efficacy and safety of omalizumab in the treatment of chronic urticaria in children. Methods A retrospective study was conducted. Patients with chronic urticaria were collected from the Department of Dermatology, Hunan Children′s Hospital from January to December 2021, and divided into a control group and a combination group according to different medication regimens. The patients in the combination group received subcutaneous injections of omalizumab （150 mg, once every 4 weeks） combined with conventional-dosage antihistamines, while the patients in the control group were only treated with double-dosage or multiple types of antihistamines. The course of treatment was 3 to 6 months. The clinical efficacy and adverse reactions were observed at 3, 6, and 12 months after the start of treatment, and the recurrence was observed at 3 and 6 months after the end of treatment. Results A total of 46 children with chronic urticaria were collected. There were 13 males and 10 females in the combination group; they were aged from 6 to 17 years, including 16 aged from 6 to 12 years and 7 aged from 13 to 17 years; according to the total serum IgE levels before treatment, the patients in the combination group were divided into an increased IgE subgroup （11 cases） and a normal IgE subgroup （12 cases）. In the control group, there were 13 males and 10 females; they were aged from 6.33 to 16 years, including 15 aged from 6 to 12 years and 8 aged from 13 to 17 years. At 3, 6, and 12 months after the start of treatment, all the total response rates in the combination group were 86.96% （20/23）, which were all significantly higher than those in the control group （52.17% ［12/23］, 56.52% ［13/23］, 56.52% ［13/23］, P = 0.010, 0.022, 0.022, respectively）. In the combination group, the response rates at 3, 6, and 12 months after the start of treatment were all 14/16 in the children aged 6 to 12 years and 6/7 in those aged 13 to 17 years, and there were no significant differences between the two age groups （all χ2 = 0.01, all P = 0.907）; in the control group, the response rates were 5/15, 6/15 and 5/15 respectively in the children aged 6 to 12 years, which were significantly lower than those in the combination group （P = 0.002, 0.006, 0.006, respectively）. In the combination group, the response rates at 3, 6, and 12 months after the start of treatment were all 9/11 in the increased IgE subgroup and 11/12 in the normal IgE subgroup, and there were no significant differences between the two subgroups （all P = 0.484）. During the treatment, no serious adverse reactions were observed in the combination group and control group, and mild somnolence only occurred in 2 children in the control group. At 3 months after the end of treatment, there was no recurrence in 16 patients in the combination group and 2 experiencing recurrence in 6 in the control group, and the recurrence rate was lower in the combination group than in the control group （P = 0.030） at 6 months after the end of treatment, there was no recurrence in 16 patients in the combination group and 3 experiencing recurrence in 6 patients in the control group, and the recurrence rate was lower in the combination group than in the control group （P = 0.022）. Conclusion Omalizumab combined with conventional-dosage antihistamines could improve the clinical efficacy and reduce the recurrence rate in the treatment of chronic urticaria in children, with few adverse reactions.

Key words: Urticaria, Child, Therapy, Biological agents, Recurrence, Omalizumab, Chronic urticaria