Curbing Covid brought unexpected benefit for asthma patients

• There was a significant decrease in the average number of asthma hospitalisations during the first part of 2020
• A possible explanation is that better hygiene as a result of Covid-19 reduced exposure to asthma triggers
• Enhanced precautions and preventative asthma medications could also have had an effect

Measures enacted to slow the spread of the new coronavirus also appeared to reduce hospitalisations for asthma, a new study finds.

Researchers compared weekly data on hospitalisations at 272 hospitals in Japan in the first five months of 2020 to the same period in 2017, 2018 and 2019.

Asthma hospitalisations in 2017–19 and 2020 showed similar trends until week eight, but in 2020 hospitalisations began to decline in week nine, the study found.

Hospitalisations for Covid-19 were first recorded during week seven of 2020. Further analysis found a significant decrease in the average number of asthma hospitalisations during weeks nine to 22 of this year compared to 2017–19.

Enhanced precautions

The findings were published on 13 October in The Journal of Allergy and Clinical Immunology: In Practice.

"Asthma hospitalisations usually indicate that an individual's asthma is not currently under control," corresponding author Dr Atsushi Miyawaki, of the University of Tokyo, said in a journal news release. "This would suggest that asthma control improved during the pandemic. It illustrates the importance of environmental factors when it comes to treating and managing patients with asthma."

One possible explanation is that increased hygiene to prevent Covid-19 would also reduce exposure to asthma triggers, according to the researchers. Enhanced precautions – such as frequent cleaning and reduced smoking – by people concerned that Covid-19 may trigger asthma may also have helped reduce triggers.

Other possible explanations include people being more likely to use preventative asthma medications, and community Covid-19 prevention measures helping reduce other respiratory infections, which can cause worse asthma.

^{Image credit: iStock}