Smell and taste alterations in COVID-19: a cross-sectional analysis of different cohorts

Int Forum Allergy Rhinol. 2020 Aug;10(8):955-962. doi: 10.1002/alr.22610. Epub 2020 Jun 25.

Abstract

Background: Olfactory (OD) and gustatory (GD) dysfunction have been proven to be a typical symptom of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. However, their prevalence in different patient populations still needs to be clarified.

Methods: A cross-sectional study was performed from March 27 to April 1, 2020, in Northern Italy. Physicians administered a survey-based questionnaire to SARS-CoV-2-positive patients with the aim of assessing symptoms, focusing on OD and GD. Two groups were studied: group A, patients hospitalized at Azianda Socio Sanitaria Territoriale (ASST) Spedali Civili University Hospital of Brescia; and group B, home-quarantined subjects.

Results: A total of 508 patients were enrolled: 295 in group A and 213 in group B. Mean age ± standard deviation (SD) was 55 ± 15 years; 56% were men. Overall, OD and GD were present in 56% (95% confidence interval [CI], 51% to 60%) and 63% (95% CI, 59% to 67%) of cases, respectively. In group A, the prevalence of OD and GD was 44% (95% CI, 38% to 50%) and 52% (95% CI, 46% to 58%), respectively. In group B, the prevalence of OD and GD was 72% (95% CI, 65% to 79%) and 79% (95% CI, 73% to 84%), respectively. In the entire cohort, total loss of olfaction and taste was reported in 64% and 60% of cases, respectively. OD and GD occurred as the first symptom in 10% and 11% of cases, respectively; in the remaining cases, they occurred after a mean of 4 ± 3 days following the first symptom. At the time of the questionnaire, complete resolution of OD and GD was reported in 52% and 55% of cases, respectively (mean duration, 9 ± 5 days in both).

Conclusion: OD and GD are more prevalent in home-quarantined subjects, and they are independently associated with younger age and female gender.

Keywords: COVID-19; SARS-CoV-2; gustatory dysfunction; olfactory dysfunction; smell; taste.

MeSH terms

  • Age Factors
  • Betacoronavirus
  • COVID-19
  • Coronavirus Infections* / epidemiology
  • Coronavirus Infections* / physiopathology
  • Cross-Sectional Studies
  • Dysgeusia* / diagnosis
  • Dysgeusia* / epidemiology
  • Dysgeusia* / etiology
  • Female
  • Humans
  • Italy / epidemiology
  • Male
  • Middle Aged
  • Olfaction Disorders* / diagnosis
  • Olfaction Disorders* / epidemiology
  • Olfaction Disorders* / etiology
  • Pandemics*
  • Pneumonia, Viral* / epidemiology
  • Pneumonia, Viral* / physiopathology
  • Prevalence
  • Recovery of Function
  • SARS-CoV-2
  • Sex Factors
  • Smell
  • Symptom Assessment / methods