Clinical Features of Olfactory Dysfunction in COVID-19 Patients.

Abstract

BACKGROUND:

The aim of this study was to evaluate the subjective and objective olfactory function in coronavirus disease 2019 (COVID-19) patients and the effect of olfactory training.

METHODS:

A prospective cohort study was performed in 53 patients who recovered from COVID-19 and visited our tertiary hospital. Subjective olfactory function was evaluated using the 11-point Likert scale (0-10) and the Korean version of the Questionnaire of Olfactory Disorders (QOD). Objective olfactory function was evaluated using Cross-Cultural Smell Identification Test (CC-SIT). Confirmed patients were followed up after 2 months of olfactory training.

RESULTS:

The median, interquartile range (Q1-Q3) score of subjective olfactory function significantly deteriorated in patients with olfactory dysfunction (OD) than in those without OD, even after 3 months of onset (11-point Likert scale, 8, 6-9 vs. 10, 10-10; short version of QOD-negative statements, 19, 16-21 vs. 21, 21-21; QOD-visual analogue scale, 7, 1-13 vs. 0, 0-0; all P < 0.001). However, the objective olfactory function was not significantly different between the two groups (median, interquartile range; 11, 9-11 vs. 11, 9-11, P = 0.887). The percentage of patients with objective hyposmia (CC-SIT ≤ 10) was also not significantly different (47.4% vs. 40%, P = 0.762). OD in COVID-19 was normalized after 2 months of olfactory training in 70% of patients even after 3 months of olfactory impairment.

CONCLUSION:

Although subjective olfactory function is significantly decreased in the OD group, the objective olfactory function was not significantly different. Moreover, olfactory training is effective in COVID-19 patients with OD.

• Authors: Min Young Seo, Won Suk Choi, Seung Hoon Lee
• Journal: Journal of Korean medical science (J Korean Med Sci) Vol. 36 Issue 22 Pg. e161 (Jun 07 2021) ISSN: 1598-6357 [Electronic] Korea (South)
• PMID: 34100564 (Publication Type: Journal Article)
• Copyright: © 2021 The Korean Academy of Medical Sciences.

Topics

• Adult
• COVID-19 (complications, diagnosis, virology)
• Female
• Follow-Up Studies
• Humans
• Male
• Middle Aged
• Olfaction Disorders (etiology, pathology)
• Prospective Studies
• SARS-CoV-2 (isolation & purification)
• Severity of Illness Index
• Surveys and Questionnaires
• Tertiary Care Centers