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.

Objectives: The purpose of this study was the evaluation of any alterations in the microvascular network of the nasal mucosa in patients with pulmonary sarcoidosis and the investigation of potential correlations with olfactory acuity and serum levels of angiotensin-converting enzyme (sACE). Design: Patients’ nasal mucosa was examined with contact endoscopy (CE). A novel classification scheme for the microvascular pattern at the anterior septal mucosa (Little’s area) was introduced and implemented. Olfaction was tested using sniffin’sticks. Fifteen healthy subjects served as controls. Participants: 15 patients with pulmonary sarcoidosis and sinonasal symptoms. Main outcome measures: Microvascular pattern at the anterior septal mucosa (Little’s area). Olfaction tested using sniffin’sticks. Setting: Tertiary referral medical centre. Results: The nasal microvascular network was disrupted under CE in most (14/15) patients, while in one patient no microvascular net could be detected. Moreover, hyposmia was documented in four patients and complete anosmia in one patient. In healthy subjects, a very strong correlation between vascular pattern of the mucosa and olfactory test results was found (r=0.93). Conclusions: Contact endoscopy findings show promise and should be further tested, to evaluate their validity as a surrogate marker of mucosal nasal inflammation in sarcoidosis patients with sinonasal symptoms. Vascular patterns of nasal mucosa and olfaction seem to be strong correlated.