Impact statement
Severe acute asthma (SAA) is a severe asthma exacerbation usually requiring admission to a pediatric intensive care unit (PICU) and causes serious morbidity and mortality; moreover, over the past few decades the number of PICU admissions for SAA has shown a significant increase. The Coronavirus Disease 19 (COVID-19) pandemic has influenced the medical health care system as a whole including asthma and its exacerbation pattern. In this study, the relationship between number of PICU admissions for SAA and the COVID-19 pandemic lockdown regulations. Additionally, changes to possible environmental factors triggering severe exacerbations, including air pollution and pollen index, are explored. This study took place in a tertiary hospital in Amsterdam, The Netherlands, and included all children over two years of age admitted for SAA to the PICU between 2018 and 2021. It was found that when COVID-19 restrictions were strict, and lockdown was in place, the number of SAA admissions at the PICU drastically decreased. After most restrictions had lifted, especially from August to November of 2021, a large peak in admissions was observed. It is hypothesized that outbreak of viral infections other than COVID-19 might have been the cause for this association, as spread of viruses was decreased during regulations. Finally, no association between air pollution and pollen index and SAA admissions was observed. In the future, it must be known that large societal changes may have an impact on SAA patterns and physicians must be aware of the impact of these changes on the number of children coming to the ED with respiratory symptoms.