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. 2021 Mar;164(3):512-518.
doi: 10.1177/0194599820954825. Epub 2020 Sep 1.

Chemosensory Dysfunction in COVID-19: Prevalences, Recovery Rates, and Clinical Associations on a Large Brazilian Sample

Deusdedit Brandão Neto  1 , Marco Aurélio Fornazieri  1   2   3   4 , Caroline Dib  1 , Renata Cantisani Di Francesco  1 , Richard L Doty  4 , Richard Louis Voegels  1 , Fabio de Rezende Pinna  1
Affiliations

Chemosensory Dysfunction in COVID-19: Prevalences, Recovery Rates, and Clinical Associations on a Large Brazilian Sample

Deusdedit Brandão Neto et al. Otolaryngol Head Neck Surg. 2021 Mar.

Abstract

Objective: Our study aimed to measure the percentage of reported olfactory or taste losses and their severity, recovery time, and association with other features in a large cohort of patients with COVID-19.

Study design: Prospective survey.

Setting: Quaternary medical center and online survey.

Methods: The perceived chemosensory capacities of 655 patients with confirmed COVID-19 were assessed with 11-point category rating scales (0, no function; 10, normal function). Patients were contacted in hospital, by phone calls, or by internet regarding their ability to smell or taste, and 143 were interviewed by phone 1 to 4 months later to assess the recovery of their chemosensory abilities.

Results: The prevalence of self-reported olfactory, general taste, and taste quality-specific disturbances (sweet, sour, bitter, and salty) in the patients with COVID-19 were 82.4% (95% CI, 79.5%-85.3%), 76.2% (95% CI, 72.9%-79.4%), and 52.2% (95% CI, 48.3%-56.1%), respectively. The majority reported anosmia (42.9%). The presence of chemosensory symptoms was not associated with COVID-19 severity. At a median time >2 months after the onset of symptoms, rates of total and partial olfaction recovery were 53.8% and 44.7%, while complete or partial return to previous taste function was 68.3% and 27.6%. Less than 5% of the patients reported no chemosensory function improvement at all.

Conclusion: The prevalence of self-reported chemosensory dysfunction is high among patients with COVID-19. Almost all patients seem to recover a significant part of their smell and taste abilities in the first 4 months after the onset of symptoms.

Keywords: COVID-19; chemosensory disorder; smell loss; taste loss.

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Conflict of interest statement

Disclosures: Competing interests: Richard L. Doty is a consultant to Eisai Co, Ltd, Merck, the Michael J. Fox Foundation for Parkinson’s Research, Septodont, and Johnson & Johnson. He receives royalties from Cambridge University Press, Johns Hopkins University Press, and John Wiley & Sons, Inc. He is president of, and a major shareholder in, Sensonics International, a manufacturer and distributor of smell and taste tests.

Sponsorships: None.

Funding source: None .

Figures

Figure 1.
Figure 1.
Flow diagram of patient recruitment. TBI, traumatic brain injury.
Figure 2.
Figure 2.
Fitted multiple linear regression shows the inverse relationship between chemosensory complaint severity as measured by visual analog scale (0, function equal to that before COVID-19 infection; 10, no function) and days after the onset of symptoms.
See this image and copyright information in PMC

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