Rationale
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 pollen-induced asthma. We studied the efficacy of medical face masks in reducing asthma in patients allergic to birch in ALYATEC Environmental Exposure Chamber (EEC).
Methods
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), then randomized into 2 groups: with and without a KOLMI® face masks (OP-Air), for a 6-hour birch allergen exposure.
Results
At baseline, asthma occurred within 30 minutes. In the group without masks, 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 score 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.
Conclusions
This pilot study showed a tendency of face masks to increase the time to develop asthma. Some patients reported mask effectiveness during pollen season.
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