Olfactory Dysfunction is Associated with More Severe Clinical Course in COVID-19

Area of Science:

• Otolaryngology
• Infectious Diseases
• Epidemiology

Background:

• Olfactory dysfunction is a recognized symptom of COVID-19.
• The correlation between olfactory dysfunction and COVID-19 severity requires further quantitative investigation.

Purpose of the Study:

• To quantitatively assess olfactory dysfunction in COVID-19 patients.
• To evaluate the association between olfactory dysfunction and COVID-19 disease severity.

Main Methods:

• A cross-sectional study was conducted on 91 RT-PCR positive COVID-19 patients (68 inpatients, 23 asymptomatic).
• The Iran Smell Identification Test (IR-SIT) was used for quantitative olfactory assessment.
• Demographic and clinical data were collected to correlate olfactory function with disease severity.

Main Results:

• Only 24% of patients self-reported hyposmia, but quantitative testing revealed olfactory dysfunction in 45% (IR-SIT score 1-4).
• Olfactory dysfunction was detected in 80% of severe COVID-19 cases versus 50% of mild cases.
• Patients with olfactory dysfunction had a significantly increased risk (OR 4) of severe disease (p=0.028).

Conclusions:

• Quantitative olfactory testing detects significantly more cases of hyposmia than self-reporting in COVID-19 patients.
• Olfactory dysfunction is a strong predictor of increased COVID-19 disease severity.