Having asthma or allergy does not increase risk for severe COVID-19

Having asthma or allergy does not make COVID-19 severe, a new study presented at ACAAI 2020 has shown.

In November 2020, the US Centers for Disease Control and Prevention issued a warning that individuals with moderate-to-severe asthma may be at an elevated risk for severe COVID-19. The basis for the warning was a pooled study on patients infected with different respiratory viruses, not COVID-19, explained study author Dr Dylan Timberlake, an allergist-immunologist from Nationwide Children’s Hospital in Columbus, Ohio, US. [Arch Virol 2018;163:845-853]

This information was overshadowed by a new study of over 500 adult individuals in August which demonstrated that atopic status exerts a protective effect vs COVID-19. Among hospitalized patients with severe COVID‐19, atopic patients had less severe disease. [Allergy 2020;doi: 10.1111/all.14551]

No reason to lower guard

As there were not enough data one way or another at that time, “we had to tell our patients to take extra precautions,” Timberlake revealed. His team conducted a retrospective chart review of data from 275 patients admitted to the Nationwide Children’s Hospital or the Ohio State University Wexner Medical Center in the US from March 1 to May 5, 2020 after they tested positive for SARS-CoV-2. [ACAAI 2020, abstract P350]

Of these, 91 patients reported atopic disease (either asthma, atopic dermatitis, allergic rhinitis, or food allergy). Sixty patients had a documented diagnosis of asthma.

“Food allergy and allergic rhinitis are overreported, so we confirmed that patients had an allergy or skin tests,” Timberlake shared. Results showed that chronic obstructive pulmonary disease (COPD) was more common in the 67 patients with atopic disease than in 208 patients without the condition (38.8 percent vs 17.3 percent; p<0.001). “This led us to believe that COPD is a confounding condition,” he added.

Mortality trend was lower in patients with atopic disease than in those without, after adjustment for COPD presence (odds ratio [OR], 0.55; p=0.16). However, secondary outcomes were similar between patients with or without atopic disease. ICU admission was 43 percent in those with atopic disease vs 44.7 percent in those without. Similarly, supplemental oxygen use was 79.1 percent in those with atopic disease vs 73 percent in those without. The same was true for intubation rates (35.8 percent vs 36.5 percent, respectively).

Neutral results call for more research

“From our findings, it doesn’t look like having asthma or allergies puts individuals at any increased risk,” reported Timberlake. “There was no evidence of severe disease. And there was no evidence of protection either.”

He said his team intends to continue their study, taking to mind that if they can control for obesity, they may be able to prove that atopic disease exerts some level of protection.

Timberlake’s findings were supported by another study showing that despite a substantial prevalence of asthma in COVID-19 patients, asthma was not associated with an elevated risk of hospitalization as was the use of inhaled corticosteroids. [J Allergy Clin Immunol 2020;146:307-314.e4]