Asthma itself is not a risk factor for hospitalization or more severe COVID-19, and people whose asthma is triggered by allergies may actually be at lower risk, according to new research presented at the American Academy of Allergy, Asthma and Immunology virtual annual meeting.
Researchers at Stanford University studied 5,596 patients who tested positive for COVID-19 from March to September 2020.
Of these, 11% were hospitalized, including 100 patients with asthma. After accounting for patients’ other medical conditions that have been linked with more severe COVID-19 illness, including high blood pressure, heart disease, diabetes and obesity, “asthma was no longer a risk factor for hospitalization,” said Dr. Lauren Eggert.
Among patients who were hospitalized, asthma was not significantly associated with disease severity, she said. Researchers also found that patients with allergic asthma were nearly half as likely as patients with other types of asthma to need hospitalization.
A possible explanation, Eggert said, is that in allergic asthma, the immune system “downregulates,” or reduces the production, of the ACE2 proteins on cell surfaces that are a major port of entry for the coronavirus.