Objective: To explore the impact of non-pharmacological interventions on inhaled allergen sensitization in children during the COVID-19 pandemic. Methods: The positive rate of inhaled allergens, allergens sIgE grade, and multiple sensitization rates before and during the pandemic were analyzed retrospectively in this study. Logistic regression analysis was used to compare the positive rate of allergens before and after the pandemic, using OR and OR 95%CI to investigate the impact of the pandemic on allergen sensitization. Results：Positive rates of d1(49.5% vs 38.5%), d2 (50.2% vs 32.2%), e2(10.1% vs 6.1%), e1(6.2% vs 1.7%), mx2(10.1% vs 2.7%), sycamore (7.2% vs 2.1%), w1(4.0% vs 1.7%),elm(3.1% vs 0.6%), w6(3.0% vs 1.7%), and u80(1.3% vs 0.5%) increased significantly during the COVID-19 pandemic. After adjusting gender, age, season and other potential influencing factors, the COVID-19 pandemic was found to be a risk factor for the positive rate of d1( OR=1.174,95%CI=1.015~1.358), d2( OR=1.301,95%CI=1.093~1.549), e2( OR=1.499,95%CI=1.280~1.756), mx2( OR=3.959,95%CI=3.358~4.446), w1( OR=1.828, 95%CI=1.353~2.470, w6( OR=1.538, 95%CI=1.123~2.106)), u80( OR=2.521, 95%CI=1.413~4.497) ( P<0.05). What’s more, d1 and d2 allergen sIgE grades increased during the COVID-19 pandemic(d1 ：X=9.576,P<0.05；d2 ：X=39.063,P<0.05). The proportion of multiple allergies was significantly higher than that before the pandemic, with a statistical significance( X=1621.815, P<0.05). Conclusion: During the COVID-19 pandemic, non-pharmacological interventions increased the positive rate of both indoor and outdoor allergens in children. The sIgE grade of dust mite allergen and multiple sensitization rate were significantly higher than those before COVID-19.

Background: Subcutaneous immunotherapy is an effective and safe treatment for allergic asthma. However, there have been very few studies about comparison of single mite vs double mite subcutaneous immunotherapy. In this study, we aimed to evaluate the difference in clinical efficacy and safety of subcutaneous immunotherapy with dust mite allergen vaccines in children with allergic asthma. Methods: This study is a retrospective and single-center study performed from Jan 2019 to Jun 2022. A total of 124 children who were grouped into single mite preparation group and double mite preparation group. The efficacy scores, changes in pulmonary function and the occurrence of adverse effects were compared between the 2 groups before and after treatment. Results: The efficacy scores were significantly decreased in all children with SCIT after 6 months treatment, and the quality of life significantly improved compared with those before treatment (P< 0.01). After 2 years of treatment, double mite preparation were statistically significant improved in PEF, FEV1, and FVC(P<0.05); single mite preparation were better for CS, VAS improvement(P<0.05); single mite preparation has higher rate of local and systemic adverse reactions(P < 0.05). Conclusion: Both preparations can achieve significant efficacy and safety in children with allergic asthma. The short-term improvement of asthma symptoms was more significant with the double mite preparation, but the single mite preparation was more effective as the treatment course was extended. Single mite preparation was more effective in improving the symptoms of rhinitis. Double mite preparation had a better safety and was better for lung function improvement.