Gustatory dysfunction in long COVID

ABSTRACT

Background This study aims to investigate the prevalence and long-term development of gustatory dysfunction (GD) after COVID-19. Methods In the population-based cross-sectional COVIDOM-study, 667 patients above the age of 18 years (mean 48.2) who tested positive for SARSCoV- 2 via PCR-testing on average 9.09 months ago were examined between November 2020 and June 2021. Extensive medical history taking was conducted via questionnaires. Participants were asked to rate their ability to taste before, during and after COVID-19 on a Visual Analogue Scale (VAS) ranging from 0 to 10. Whole mouth gustatory testing with Taste Strips for the qualities sweet, sour, salty, and bitter was performed. Results 60.9 % (406 of 667) participants reported gustatory impairment during their infection. Out of those, 56.9 % perceived this symptom as severe and 13.3 % noticed it as the earliest symptom. At the time of our examination, 36.2 % had a persistent subjective GD, defined as a lower score on the VAS than before COVID-19 (mean difference -0.9 points). This difference was significant (p < 0.001). In the testing, 7.3 % (47 of 667) participants had a GD, defined as the correct identification of less than three out of four Taste Strips. No signifi- cant correlation was found between subjectively persistent and tested GD (p = 0.250). Conclusions SARS-CoV-2 seems to frequently affect the gustatory function in the long term as well, what might have an influence on patients' everyday-life. However, Patients' own perception does not always correspond with psychophysiological testing which might be caused by the common difficulty to differentiate between the chemosensory senses of taste and smell.