Frequency of asthma exacerbation in children during the coronavirus disease pandemic with strict mitigative countermeasures

Background Strict countermeasures for coronavirus disease (COVID‐19) were undertaken in China without knowing their influence on asthma. Objective To investigate the associations between the frequencies of asthma exacerbations and respiratory infections and air pollutants before and during the COVID‐19 pandemic, which were direct consequences of countermeasures undertaken for the pandemic. Methods Asthma exacerbations and respiratory infections among hospitalized children in the permanent population of Guangzhou City, China, from February to June 2016–2019 (before the pandemic) to February to June 2020 (during the pandemic) were collected in this cross‐sectional study in Guangzhou. Results The number of asthma exacerbation cases per month documented in the Guangzhou Women and Children's Hospital before (median: 13.5; range: 0–48) and during (median: 20; range: 0–34) the mitigative response to the COVID‐19 pandemic was similar. The frequency of severe asthma exacerbation cases per month decreased, whereas that of mild asthma exacerbation cases per year increased (p = .004). The number of patients hospitalized with infectious respiratory diseases decreased from 146 (range: 90–172) per month before the pandemic to 42 (range: 33–57) per month during the pandemic (p = .004). Most pathogens and air pollutants decreased during the COVID‐19 pandemic. The frequency of severe asthma exacerbations positively correlated to that of respiratory infections in children, but did not correlate to air pollutants. Conclusion Strict countermeasures undertaken for the pandemic were associated with a decreased the frequency of infectious respiratory diseases and severe asthma exacerbations among urban children.