Background: Smell and taste dysfunctions (STDs) are symptoms associated with COVID-19 syndrome, even if their incidence is still uncertain and variable.
Aims: In this study, the effects of SARS-CoV-2 infection on chemosensory function have been investigated using both a self-reporting questionnaire on smell and flavor perception, and a simplified flavor test.
Methods: A total of 111 subjects (19 hospitalized [HOS] and 37 home-isolated [HI] COVID-19 patients, and 55 healthy controls [CTRL]) were enrolled in the study. They received a self-evaluation questionnaire and a self-administered flavor test kit. The flavor test used consists in the self-administration of four solutions with a pure olfactory stimulus (coffee), a mixed olfactory-trigeminal stimulus (peppermint), and a complex chemical mixture (banana).
Results: After SARS-CoV-2 infection, HOS and HI patients reported similar prevalence of STDs, with a significant reduction of both smell and flavor self-estimated perception. The aromas of the flavor test were recognized by HI and HOS COVID-19 patients similarly to CTRL; however, the intensity of the perceived aromas was significantly lower in patients compared to controls.
Conclusion: Data reported here suggests that a chemosensory impairment is present after SARS-CoV-2 infection, and the modified "flavor test" could be a novel self-administering objective screening test to assess STDs in COVID-19 patients.
Clinical trial registration no: NCT04840966; April 12, 2021, retrospectively registered.
Keywords: COVID-19; Flavor; Flavor test; Hyposmia; Retro-nasal olfaction; Smell.
© 2021. The Author(s).