Taste and Olfaction in COVID-19-Patients
Abstract
Objectives: To test the prevalence and evolution of acute
olfactory and gustatory functional impairment and of their morphologic
correlates in COVID-19 patients who require hospitalization due to
COVID-19-related respiratory conditions.
Design: Electrogustometric (EGM) - thresholds at the tongue
area supplied by the chorda tympani, at the soft palate and at the
vallate papillae area were recorded bilaterally. Olfaction was examined
by Sniffin’ sticks. The patients’ nasal and oral mucosa (fungiform
papillae, fpap) were examined by contact endoscopy.
Setting: Tertiary referral medical centre.
Patients: 53 consecutive hospitalized patients (23 males, 30
females, age 42,54 ± 10, 95 yrs) with RT-PCR-confirmed COVID-19
diagnosis were included. Patients have been examined twice: just after
hospital discharge and 4-6 weeks later.
Main outcome measures: EGM-thresholds and taste strips,
Schniffin-Sticks, Contact-Endoscopyesults: EGM-thresholds in
patients were significantly higher at both instances than those of
healthy subjects. EGM-thresholds at the second measurement were
significantly lower than those at the first measurement. Accordingly,
patient-reported gustatory outcomes were improved at the second
measurement. The same pattern has been found using Sniffin’ sticks.
Significant alterations in form and vascularization of fPap have been
detected in patients, especially at the first instance.
Conclusions: COVID-19 affects both gustatory and olfactory
functions. It also affects in parallel the structure and vascularization
of both nasal and oral mucosa, although the nasal mucosa to a much less,
non-significant, extent. Our findings suggest that COVID-19 may cause a
mild to profound neuropathy of multiple cranial nerves.
Key-words: COVID-19, taste, olfaction, electrogustometry,
contact endoscopy