Seasonality of asthma exacerbation in children caused by respiratory virus infection and allergen sensitization

Abstract

Purpose: Acute asthma exacerbations in children have seasonal variations and occur frequently in fall. Respiratory viral infections and environmental allergens are associated with asthma exacerbation. This study aimed to identify seasonal trends of asthma exac-erbation and the effects of respiratory viral infection and allergen sensitization on the seasonality of asthma exacerbation in children. Methods: Children under the age of 18 years who visited to the Emergency Department or hospitalized for acute asthma exacerba-tions from 2011 to 2019 were included. We reviewed medical records, including demographics, date of asthma exacerbation, results of respiratory virus and allergen sensitization, and they were analyzed to identify the seasonal trends of asthma exacerbation. Results: A total of 320 asthma exacerbations were included, with the highest frequency in fall. Human rhinovirus was positive in 64.7% and 60.0% in fall and spring exacerbations, respectively. House dust mite sensitization was highest in fall at 78.5%, while food sensitization was highest in spring at 76.9%. In patients who were sensitized to house dust mites or food allergens, respiratory viral infections further increased asthma exacerbation in fall and spring, respectively. Conclusion: Respiratory virus may be associated with asthma exacerbation in fall and spring. House dust mite and food sensitiza-tions may be associated with fall and spring asthma exacerbations by worsening the severity of asthma symptoms caused by respi-ratory viral infections. In childhood asthmatic patients with allergen sensitization, avoidance of sensitized allergens, prevention of viral infection, and more active treatment of viral infection may help prevent acute asthma exacerbations. (Allergy Asthma Respir Dis 2021;9:238-244)