Those with underlying conditions have been mindful of staying safe during the COVID-19 pandemic. Asthma is a chronic airway condition, and therefore it has been considered a risk factor for severe symptoms of COVID-19. However, this may not be the case. Initial studies from China did not show more severe illness in patients with allergic asthma or respiratory allergy. This relates to the lower manifestation of the SARS-CoV-2 receptor ACE2 in those with allergic disease.


The Research:

In a study of 318 children from the Urban Environment and Childhood Asthma (URECA) cohort, an inverse relationship was found between allergic sensitization and the expression of ACE2 in the nasal epithelium. This was found to be independent of asthma status. Asthmatic children with moderate and high allergic sensitization were found to have greater reductions in expressions of ACE2. High levels of ACE2 were found with lower levels of type 2 biomarkers, including the number of positive specific IgE results and total IgE.

In another study, 24 adults with allergic rhinitis, once exposed to cat and environmental allergens, had the amount of ACE2 expression reduced. In a group of 23 adults with mild asthma the ACE2 expression was reduced in the lower airway epithelium after they did not receive asthma controller therapy and were exposed to dust mite, ragweed, or cat.


What Does This Mean:

The results of the mentioned research suggest that those with respiratory allergy and allergen challenges have a reduced ACE2 expression. ACE2 expression is lowest among those with asthma and high levels of allergic sensitization. Nonatopic asthma does not affect ACE2 expression.

The ACE2 receptor is important for SARS-CoV-2 (COVID-19) infection. This suggests a potential protection against severe COVID-19 infection for those with asthma. Those with asthma can still get the COVID-19 infection. These findings show that their asthma does not seem to increase the risk of hospitalization. This is all preliminary data of course, and more will be understood with more research.


For more information on COVID-19, please visit the CDC website. If you have any concerns about COVID-19 in relation to your specific condition, our providers at National Allergy & ENT can provide their expert opinion during an in-office or virtual visit. To schedule an appointment please call (843) 797-8162 or schedule online.

Source: Jackson DJ, Busse WW, Bacharier LB: Association of respiratory allergy, asthma, and expression of the SARS-CoV-2 receptor ACE2.
J Allergy Clin Immunol. 146:203-206.