Covid-19 affects taste independent of taste-smell confusions: Results from a combined chemosensory home test and online survey from a large global cohort

Ha Nguyen, Javier Albayay, Richard Höchenberger, Surabhi Bhutani, Sanne Boesveldt, Niko A. Busch, Ilja Croijmans, Keiland W. Cooper, Jasper H.B. De Groot, Michael C. Farruggia, Alexander W. Fjaeldstad, John E. Hayes, Thomas Hummel, Paule V. Joseph, Tatiana K. Laktionova, Thierry Thomas-Danguin, Maria G. Veldhuizen, Vera V. Voznessenskaya, Valentina Parma, M. Yanina PepinoKathrin Ohla

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

People often confuse smell loss with taste loss, so it is unclear how much gustatory function is reduced in patients self-reporting taste loss. Our pre-registered cross-sectional study design included an online survey in 12 languages with instructions for self-Administering chemosensory tests with 10 household items. Between June 2020 and March 2021, 10,953 individuals participated. Of these, 5,225 self-reported a respiratory illness and were grouped based on their reported COVID test results: COVID-positive (COVID+, N = 3,356), COVID-negative (COVID-, N = 602), and COVID unknown for those waiting for a test result (COVID?, N = 1,267). The participants who reported no respiratory illness were grouped by symptoms: sudden smell/taste changes (STC, N = 4,445), other symptoms excluding smell or taste changes (OthS, N = 832), and no symptoms (NoS, N = 416). Taste, smell, and oral irritation intensities and self-Assessed abilities were rated on visual analog scales. Compared to the NoS group, COVID+ was associated with a 21% reduction in taste (95% confidence interval (CI): 15-28%), 47% in smell (95% CI: 37-56%), and 17% in oral irritation (95% CI: 10-25%) intensity. There were medium to strong correlations between perceived intensities and self-reported abilities (r = 0.84 for smell, r = 0.68 for taste, and r = 0.37 for oral irritation). Our study demonstrates that COVID-19-positive individuals report taste dysfunction when self-Tested with stimuli that have little to none olfactory components. Assessing the smell and taste intensity of household items is a promising, cost-effective screening tool that complements self-reports and may help to disentangle taste loss from smell loss. However, it does not replace standardized validated psychophysical tests.

Original languageEnglish (US)
Article numberbjad020
JournalChemical senses
Volume48
DOIs
StatePublished - 2023

All Science Journal Classification (ASJC) codes

  • Physiology
  • Sensory Systems
  • Physiology (medical)
  • Behavioral Neuroscience

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