ABSTRACT
Background: Patients with rhinitis to pollen can exhibit asthma. To control the spread of SARS-CoV-2, the use of face masks has become widespread worldwide. There is no clinical evidence that medical masks are efficient in birch pollen-induced asthma. Objective(s): To study the efficacy of medical face masks in reducing asthma in patients allergic to birch in ALYATEC Environmental Exposure Chamber (EEC). Method(s): 24 GINA 1 birch-related asthma patients, were exposed to 60 ng/m3 of airborne Bet v 1 in ALYATEC EEC. All patients had positive skin prick tests and specific IgE to birch at screening. Baseline exposures lasted 1 hour to assess asthma responses (20% drop in Forced Expiratory Volume in 1 second (FEV1). Patients with asthma were randomized into 2 groups: with and without a KOLMI face mask (OP-Air), for a 6-hour exposure to birch allergen. Result(s): At baseline, asthma occurred within 30 minutes. In group without mask, the median time for drop in FEV1 was 37 minutes, and 67 min in the group with mask (p=0.219). There was a threshold difference of time for onset of asthma between the 2 groups. At 1 hour-exposure, patients with masks still present in the EEC was twice as much as the group without masks. Asthma questionnaire was not statistically significant in both groups, but was highly correlated with the drop in FEV1 at 30 min exposure. The Kaplan Meyer graph showed that survival probability in EEC was higher for the group with masks than without masks. Borg's scale for dyspnea suggest a difference between the 2 groups starting at 2 hour-exposure. Conclusion(s): This pilot study showed a tendency of face masks to increase the time to develop asthma. Some patients reported mask effectiveness during pollen season.