Covid-19 outbreak: does the use of a surgical mask impact the sense of smell?

Abstract

Background The current context of Covid-19 pandemic has broadened mask use. Objectives Evaluate the impact of wearing a surgical mask on sense of smell by comparing the results of sniffin’ sticks test (SST) with and without a surgical mask and evaluate the feasibility of practicing SST with a mask. Material and methods A crossover prospective comparative study between two groups of volunteers. The results of SST with a mask were compared to the results without a mask: group 1 first performed SST with a surgical mask and then one week later performed SST without a mask, while group 2 started without a mask. Results Twenty volunteers were included. In group 1 and 2, all the subjects, except one, had a significantly better total score (TDI) without a mask. The average TDI difference score with and without a mask, was inferior to 5. 8/20 (40%) subjects had a TDI difference superior to 5 with and without mask, while 4/20 (20%) were normosmic without a mask, while being recategorized as hyposmic with a mask. Conclusions and significance Wearing a surgical mask may reduce the sense of smell, in a cohort of normosmic patients. Further larger studies must be conducted in hyposmic subjects.