# Analysis of exacerbating factors of pediatric asthma before and after the COVID-19 pandemic

## TL;DR

This study found that asthma-related emergency visits in children dropped sharply during the pandemic, likely due to reduced virus spread and social distancing.

## Contribution

The study provides new insights into how pandemic measures impacted asthma exacerbations in children and adolescents.

## Key findings

- Emergency department visits for asthma dropped by 73.8% during the pandemic compared to pre-pandemic years.
- Asthma exacerbations shifted from spring and autumn peaks to only autumn during the pandemic.
- Rhinovirus infections were not linked to asthma exacerbations during the pandemic.

## Abstract

The incidence of the existing respiratory virus and air pollutants had disappeared or decreased due to social distancing during the coronavirus disease 2019 (COVID-19) pandemic. Therefore, there was no increase in asthma exacerbations in 2020. This study aimed to analyze the emergency department (ED) visits of children and adolescent patients with asthma before and after the COVID-19 outbreak and examine the effects of respiratory virus infection and air pollutants.

This study included pediatric and adolescent patients with asthma aged 2–18 years who visited 419 EDs nationwide during February to December in 2018, 2019, and 2020. The patients who were diagnosed with asthma, ie, J45 or J46 (International Classification of Diseases, 10th revision) in the ED medical history, diagnosis history at discharge, and diagnosis at discharge after hospitalization through the ED were included using the National Emergency Department Information System. Data were analyzed by dividing the period as follows: pre-COVID-19 (from February to December 2018 and 2019) and COVID-19 pandemic (from February to December 2020).

The monthly average of 673 visiting patients (95% confidence interval [CI], 474–872) during the pre-COVID-19 period decreased to 176 (95% CI, 113–239) during the COVID-19 pandemic, which is a 73.8% decrease (p < 0.001).

In the pre-COVID-19 period, peaks were observed in spring and autumn. Meanwhile, during the COVID-19 pandemic, a peak was observed only during autumn. During the COVID-19 pandemic, no relationship was found between the rhinovirus infection and asthma exacerbations (p < 0.001).

Respiratory virus infections are strongly associated with asthma exacerbations in children and adolescents. In this study, air pollution is not a major factor for ER visits due to asthma exacerbations. Even though the prevalence of respiratory viruses is decreasing, ED visits due to worsening asthma are trending in the fall. This phenomenon may indicate that asthma has worsened due to other causes such as pollen or fluctuations in temperature and air pressure.