Causation or coincidence? Phenotype of asthma exacerbations during the coronavirus disease 2019 pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has influenced almost every part of health care and touched on all diseases, including pediatric asthma. Asthma exacerbations are a common cause of pediatric emergency department (ED) visits and hospitalizations. Early in the COVID-19 pandemic, there was concern that children with asthma would be at higher risk for severe disease, given the previous association of pediatric asthma exacerbations and viral respiratory diseases. Instead, during the early COVID-19 pandemic, there was an overall decrease in pediatric asthma ED visits and hospitalizations, and indeed, like severe acute respiratory syndrome and Middle East respiratory syndrome, severe acute respiratory syndrome coronavirus 2 infection did not seem to exacerbate asthma. However, even though there were fewer total ED visits and hospitalizations for pediatric asthma during the pandemic, the rate of patients who presented to the ED who required hospitalization, including intensive care unit admission, appeared to be higher.

The study “Effect of the COVID-19 pandemic on morbidity among children hospitalized for an asthma exacerbation” from this issue of the Annals of Allergy, Asthma & Immunology performed a retrospective chart review to compare the characteristics of children hospitalized with an asthma exacerbation before the pandemic compared with those hospitalized with an asthma exacerbation during the pandemic. They hypothesized that although fewer children were hospitalized during the pandemic for asthma, those who were hospitalized presented with a higher severity of disease and higher needs of clinical management. The primary outcome was receipt of intravenous magnesium sulfate in the ED, an objective measure of increased severity of asthma exacerbations at presentation. Secondary outcomes included initial admission location, length of stay, and medications administered in the ED and throughout hospital admission. Demographic information was collected including age, sex, race, and ethnicity. Characteristics of the exacerbation included duration of symptoms before presenting to the ED, documented trigger, and associated allergies.

The authors of this article found an overall 80% reduction in asthma hospitalizations to their pediatric medical center. Those patients who presented during the pandemic were significantly older (p<0.001) and had a lower presence of eczema and food allergies. The authors found that intravenous magnesium sulfate was more frequently administered during the pandemic. This suggested that patients who presented with an asthma exacerbation during the pandemic had more severe disease than those who presented in the previous year. Similarly, there was a higher proportion of reported noncompliance with controller medication in patients with an exacerbation during the pandemic. The results of the current study are clear—patients who presented with an asthma exacerbation during the pandemic had more severe and less allergic-based disease, but the underlying causation of the findings is much more opaque. For example, rather than assuming that during the pandemic, there was less use of controller medications owing to a reduction in the use of aerosolized therapies, an alternative explanation could be that because of masking, there was a decrease in allergic trigger-induced asthma during the pandemic. This would translate into less eczema and fewer food allergies in patients who presented to the ED, and patients being an older age at presentation (given most childhood asthma is allergic). Furthermore, in this study, the authors did not determine pollen allergen levels between the 2 years. This raises an additional concern—if the pollen levels were not similar, then the reduction in allergic asthma may simply reflect normal variability in allergen levels from 1 year to the next. Therefore, although in this single-center study, patients presenting with an asthma exacerbation during the pandemic were older, had less atopy, and had more severe asthma than those who presented with an asthma exacerbation in the preceding year, the actual cause of these differences cannot easily be discerned.

In the 2009 H1N1 influenza pandemic, those individuals hospitalized with influenza who had asthma had less severe courses and required less intensive therapy. This has suggested to some that atopy might be protective of respiratory viral induced illness. The results from the current study might also argue for a similar protective effect, and several meta-analyses support this contention. However, our own research did not demonstrate a protective effect of atopy on COVID-19 severity. Nonetheless, the current study adds to our literature base on the impacts of the COVID-19 pandemic on healthcare utilization, regardless of the underlying reasons for the differences in patients presenting with an asthma exacerbation to the ED.