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.

Chinese Abstract

背景：由于当前的 Covid-19 大流行, 使用口罩的规模扩大了。

目的：通过比较使用与不使用外科口罩的嗅探棒测试 (SST) 的结果, 评估佩戴口罩对嗅觉的影响, 并评估使用口罩进行嗅探棒测试的可行性。

材料和方法：两组志愿者之间的交叉前瞻性比较研究。将戴口罩的 SST结果 与不戴口罩的进行比较：第 1 组先戴口罩进行 SST, 一周后进行不戴口罩的 SST, 而第2组一开始进行 SST就不戴口罩。

结果：共纳入20名志愿者。在第 1 组和第 2 组中, 除 1 名外, 所有受试者没戴口罩的总分 (TDI) 均显著较高。戴与没有戴口罩的平均 TDI 差异分数低于 5。 20名受试者中8名 (40%) 的 TDI 差异高于 5, 无论是否使用口罩。而20名受试者中有4名 (20%) 不戴口罩时的测试结果为正常嗅觉, 而戴口罩时则被归类为低嗅觉者。

结论和意义：在一组正常嗅觉人群中, 戴外科口罩可能会降低嗅觉。必须在低嗅觉受试者中进行更大规模的研究。

Keywords:

• Anosmia
• Covid-19
• SARS-CoV-2
• sense of smell
• face mask
• Sniffin’ sticks test
• feasibility of SST

Acknowledgements

The authors would like to thank all the volunteers from the ENT and stomatology team and Pamela Haylock for English-language editing. This study was not sponsored by any external financial support.

Disclosure statement

No potential conflict of interest was reported by the author(s).