Nurses who recorded allergic rhinitis symptoms in a two-week period during the COVID-19 pandemic reported significantly decreased symptoms while wearing an N95 or surgical face mask when compared to wearing no mask.
The survey was taken during the spring in Israel, when allergic reactions are known to be problematic. Among 1,824 nurses, there was a significant reduction in self-reported symptoms whether the wearer typically had minor or severe allergies, said lead author Eyal Sela, M.D., of Galilee Medical Center, Nahariya, Israel.
The findings are consistent with the intended function of face masks, which are designed to reduce the amount of particles breathed in, Sela and colleagues said. Standard surgical masks filter particles larger than 3 μm, whereas N95 respirators can filter particles as small as 0.04 μm. This enables both types to block a variety of the airborne allergens that play the role in seasonal allergies, including pollen, fungal spores and house dust mite feces, the authors reported.
In addition, face masks may alter the humidity and temperature of breathed air. This could lessen the impact of any allergens that leak into the mask, provoking a milder allergic response, the authors said.
Despite their better small-particle obstruction, N95 respirators were no better at reducing allergic rhinitis symptoms over standard surgical masks, the researchers noted. This finding may be due to unfiltered airflow through imperfectly sealed edges or allergen exposure when not wearing personal protective equipment, they surmised. In addition, dense N95 mask fibers may increase breathing effort, increasing the flow of unfiltered air through face seal leakage and particle penetration, they concluded.
Allergic rhinitis has a prevalence ranging from 10% to 20% in the general population.
The study was published in The Journal of Allergy and Clinical Immunology.
