An observational study based on UK adults has found that people with allergic conditions such as hay fever and rhinitis atopuc eczema might have lower chances of developing Covid-19. The study was exploring what contribution demographic, socioeconomic, lifestyle, diet, medical treatment and underlying conditions might make to the risk of developing COVID-19 and was published in BMJ. It prepared a detailed questionnaire and analyzed the responses to it from 14,348 people to reach the conclusions that atopic diseases triggered by allergens, including rhinitis and eczema, lowered the risks of covid infection by about 23 percent and asthma lowered the risk by about 38 percent. 

At the same time, the study also pointed out that age, sex and diets cannot be associated with Covid risk in people, contrary to previous research results. While acknowledging their limitations, the researchers pointed out that household overcrowding and obesity did play a part in increased risks.