Functional and Morphological Disorders of Taste and Olfaction in COVID-19-Patients (preprint)

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. Key-words COVID-19, taste, olfaction, electrogustometry, contact endoscopy 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.