Asthma does not increase the severity of coronavirus, study finds

People with asthma do not appear to be at higher risk of death or serious illness from coronavirus, according to researchers.

Doctors at Rutgers University said they found limited evidence to explain why those with the lung condition were no worse off.

The team called for further research into the effect of steroid inhalers and the role of age, other illnesses (comorbidities) and changes in behaviour.

“Older age and conditions such as heart disease, high blood pressure, chronic obstructive pulmonary disease, diabetes and obesity are reported risk factors for the development and progression of Covid-19,” said Reynold Panettieri Jr, a pulmonary critical care physician and director of the Rutgers Institute for Translational Medicine and Science.

“However, people with asthma – even those with diminished lung function who are being treated to manage asthmatic inflammation – seem to be no worse affected by Sars-CoV-2 than a non-asthmatic person.”

One explanation may be that asthmatics became hyper-vigilant about personal hygiene and social distancing as a result of reports about Covid-19, said Dr Panettieri.

Those who have self-isolated or shielded themselves may also have been less exposed to seasonal triggers for their existing condition.

Use of medication such as inhaled steroids may also decrease susceptibility to the virus and its infectivity. However corticosteroids may also worsen the effects of the disease.

Asthma sufferers also tend to be younger than those with other high-risk conditions, whereas the severity of Covid-19 increases with age.

“If Sars-CoV-2 is a disease that causes dysfunction in the cells that line blood vessels throughout the body, then diabetes, heart disease, obesity and other diseases associated with this condition may make people more susceptible to the virus than those who are asthmatic,” said Dr Panettieri.

“However, older people with asthma who also have high blood pressure, diabetes or heart disease may have similar instances of Covid-19 as non-asthmatics with those conditions.”