Long-lasting olfactory dysfunction in COVID-19 patients

Prem B, Liu DT, Besser G, Sharma G, Dultinger LE, Hofer S, Matiasczyk MM, Renner B, Mueller CA (2021)

Publication Type: Journal article

Publication year: 2021


DOI: 10.1007/s00405-021-07153-1


Objectives: Olfactory dysfunction (OD) is a common symptom of Coronavirus Disease 2019 (COVID-19). Although many patients have been reported to regain olfactory function within the first month, long-term observation reports vary. Therefore, we aimed to assess the course of chemosensory function in patients diagnosed with COVID-19 within 3–15 months after the infection. Methods: One hundred and two patients (71 females and 31 males; mean age 38.8 years) diagnosed with laboratory-confirmed COVID-19 and subjective OD participated in this single-center study 111–457 days after onset of OD. Patients first performed chemosensory tests at home, followed by psychophysical testing (Sniffin’ Sticks (TDI), 27-item Candy Smell Test (CST), Taste Strips Test (TST)) in the clinic. Questionnaires regarding importance of olfaction (IOQ) and olfactory-specific quality of life (QOD) were applied at both timepoints. Results: After a mean 216 days (SD 73; range 111–457) between OD onset and follow-up testing, the mean Sniffin’ Sticks (TDI) score was 27.1 points (SD 5.8; range 4.25–38.5): 4.0% were anosmic, 72.5% hyposmic, and 23.5% normosmic. At follow-up testing, 73.5% of patients reported improvement, 5.9% deterioration, and 20.6% no change in OD. Moreover, full recovery of self-perceived smell, flavor, and taste was not observed. According to questionnaires, the individual importance of smell did not change, but participants showed improvement in OD-related quality of life (p < 0.001) and had increased parosmia scores (p = 0.014) at follow-up. Conclusion: Our results show that long-lasting OD after SARS-CoV-2 infection is a common symptom. The majority of patients had OD in the range of hyposmia, which was confirmed by comprehensive smell tests.

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Prem, B., Liu, D.T., Besser, G., Sharma, G., Dultinger, L.E., Hofer, S.,... Mueller, C.A. (2021). Long-lasting olfactory dysfunction in COVID-19 patients. European Archives of Oto-Rhino-Laryngology. https://doi.org/10.1007/s00405-021-07153-1


Prem, Bernhard, et al. "Long-lasting olfactory dysfunction in COVID-19 patients." European Archives of Oto-Rhino-Laryngology (2021).

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