Researchers from the Queen Mary University of London looked at more than 16,000 adults in the UK between May 2020 and February 2021. They found that hay fever and eczema sufferers are nearly 25 per cent less likely to contract the virus, the report said.
What's more, people with asthma are almost 40 per cent less likely to be infected, even if they use steroid inhalers.
For the study, which was published on Thursday, the team recruited 16,081 adults between May 1, 2020 and February 5, 2021.
Of the participants, 15,227 filled out at least one follow-up questionnaire and 14,348 people completed the final questionnaire on or before February 5.
The adults were asked to provide information on their age, height, weight, diet, lifestyle and whether they were taking any medication or had been vaccinated against Covid.
Overall, 446 participants, nearly 3 per cent, tested positive for the virus over the course of the study period.
They found that among those with atopic diseases - such as eczema and dermatitis, which are triggered by allergens - as well as those with hay fever or rhinitis had 23 per cent lower risk of Covid, the Daily Mail reported.
Additionally, for asthma sufferers, there was 38 per cent lower risk of infection, even when using steroid inhalers.
Surprisingly, the researchers found that in contrast to past studies, patients who were older, male or had other underlying conditions were not at an increased risk of infection.
However, those of Asian descent or lived in overcrowded households had higher odds of contracting Covid-19, the report said.