REPLY to “Self‐reported olfactory loss in COVID‐19: is it really a favorable prognostic factor?”

Carol H. Yan, Farhoud Faraji, Adam S. DeConde

First published: 12 May 2020

Note

We have previously reported a strong association between self-reported anosmia and ‘mild’ (outpatient) disease as compared to ‘moderate’ / ’severe’ (inpatient) disease, that is independent of other markers of disease severity (chest x-ray findings, vitals at time of COVID-19 testing). 

At the time of our study’s writing, only one study had reported COVID-19-related quantitative olfactory testing, specifically only in an inpatient cohort. 2 While objective olfactory dysfunction was ubiquitous in this cohort (97%), self-reported olfactory loss was significantly lower (35%). Therefore, we noted a suspicion that this difference was related to severity of chemosensory dysfunction. As our study suggested, milder cases of COVID-19 may be heralded by profound anosmia and higher self reporting, compared to the undetected or lesser degrees of hyposmia associated with moderate to severe COVID-19 cases. 

In their letter, Hopkins and colleagues felt that the recent psychophysical olfaction data that they collected were incongruent with our self-reported findings. However, in reviewing their findings, we note that patients with mild disease have more severe quantitative olfactory dysfunction compared to those with moderate disease (mean olfactory score 54.5 vs. 64.5). Thus, one may logically infer that in their cohort while mild, moderate, and severe patients all experience some level of olfactory dysfunction, the severity of the objective olfactory loss may ultimately drive a patient’s self-reported chemosensory experience. In fact, the objective data presented by Vaira et al could potentially be construed as supportive of our theory that milder cases of COVID-19 are associated with higher rates of self-reported olfactory loss.

Reference

Wiley – DOI: https://doi.org/10.1002/alr.22606