[Clinical characteristics of COVID-19 Omicron variant infection in children with allergic diseases].

Objective: To analyze the clinical characteristics of infection of COVID-19 Omicron variants in children with allergic diseases. Methods: This was a cross-sectional retrospective study. A total of 657 pediatric patients with allergic diseases aged between 0-17 years confirmed with COVID-19 infection were enrolled from the Children's Hospital affiliated to Capital Institute of Pediatrics from January to March 2023. The median age was 6.6(4.7,9.9) years, with 443 males (67.4%) and 214 females (32.6%). Demographic data, vaccination status, clinical manifestations, therapeutic drugs, and other data were collected. The patients were then divided into different groups according to the age, type of allergic diseases and vaccination status, and their clinical characteristics were compared. Results: A total of 657 children with allergic diseases were included in this study, among them 568 with asthma. Fever is the most common symptoms after COVID-19 infection (627/657, 95.4%), and 509 children (77.5%) with high fever. Cough was observed in 446 (67.9%) and fatigue in 167 (25.4%) cases.10 cases (1.5%) were diagnosed as pneumonia. The proportion of pharyngalgia(22%,84/382, χ2 =19.847, P <0.01), fatigue (31.7%, 121/382, χ2 =23.831, P <0.01), headache(34.6%, 132/382, χ2 =57.598, P <0.01), muscle joint pain(16.0%, 61/382, χ2 =22.289, P <0.01) and vomiting(11.0%, 42/382, χ2 =12.756, P <0.01) were highest in the>6 years group. Children younger than 3 years had the lowest proportion of runny nose(8.8%, 5/57, χ2 =8.411, P <0.01), cough(45.6%, 26/57, χ2 =6.287, P <0.05) and expectoration(7.0%, 4/57, χ2 =5.950, P <0.05). 62.8%(137/218) of the patients in 3-6 year group had the highest rate of cough( χ2 =6.287, P <0.05), with a higher proportion of wheezing (10.1%, 22/218). Cough and/or wheezing symptoms were most quickly relieved in the 6 year old group, who had a highest proportion of 68.8%(260/382) in duration of respiratory symptoms within 1 week compared with 52.2% (114/218)of 3-6 years group and 41.2% (22/57)of<3 year group, respectively( χ2 =23.166, P <0.01). The asthma group had a significant higher proportion of cough(59.7% vs 41.6%, χ2 =10.310, P <0.01), wheezing (8.5% vs 0.0%, χ2 =8.114, P <0.01) and expectoration (19.2% vs 7.9%, χ2 =10.310, P <0.01) than that of non-asthma group. Besides, patients with cough and/or wheezing in the asthma group had more impact on exercise and sleep (16.1% vs 0, χ2 =5.436, P <0.05) and a longer duration over 4 weeks (25.1% vs 3.7%, χ2 =6.244, P <0.05). Conclusions: The most common symptoms in children with allergy infected with COVID-19 Omicron variant were fever and cough. Children under 3 years of age had relatively fewer respiratory symptoms while those with asthma or aged 3-6 years were more likely to have cough and wheezing and longer duration of symptoms. The data suggested that the prevention and management of COVID-19 should be strengthened in children with allergy.