Reply to letter on Acute-onset smell and taste disorders in the context of COVID-19: a pilot multicentre polymerase chain reaction based case-control study.

Dear Editor,

We thank our colleagues for their constructive discussion on our recently published study [1]. Regarding prevalence, indeed, growing literature yields a variable frequency of loss of smell (LOS) in COVID‐19 patients that may hypothetically be due to differences in the location and amount of viral load, to the different immune response between younger mild‐symptomatic outpatients (higher prevalence) and more severely affected inpatients (lower prevalence) [1, 2] and to the variable methods of measurement.

Likewise, there may be a mismatch between self‐reported and objective LOS, both over‐ and under‐estimation [3]. Standardized objective measurements are necessary for an accurate description of the syndrome, but we believe self‐reported LOS analysis is very relevant, and pragmatically more useful in a real‐life setting.

As for the low prevalence and/or lack of association of nasal obstruction with LOS, several previous reports [2, 4] agree with our findings, suggesting that it is likely that olfactory neuroepithelium damage is responsible for this sensory loss. Certainly, further investigation is warranted to confirm this [5].

Finally, we agree that we assumed a recall bias regarding our historical control sample of influenza. Unfortunately, during the maximum incidence of COVID‐19, there were not enough truly reliable SARS‐CoV‐2 polymerase chain reaction negative patients nor admissions for other respiratory infections in our centres.

DISCLOSURE OF CONFLICT OF INTEREST

The authors declare no financial or other conflicts of interest.