Disorders of Taste and Olfaction by COVID- 19- Patients- A functional and morphological Study

ABSTRACT

Purpose We investigated the prevalence of smell and/or taste loss and the clinical characteristics and recovery in a cohort of consecutive patients treated by two COVID-19 reference hospitals and evaluated the late persistence of hyposmia. Material and Methods 53 consecutive RT-PCR diagnosed patients (23 males, 30 females, 42,54 ± 10, 95 years) who had been hospitalized between January- June 2021 in the COVID-19 care wards were contacted, excluding patients with cognitive disorders and severe deconditioning. These patients (Group A) have been examined twice, once direct after leaving the hospital, and once again 4-6 weeks later. The patients- nasal and oral mucosa (Fungiform Papillae on tongue-s tip-fPap) were examined with a contact endoscope. Their olfaction was also examined with Sniffin' Sticks. As control-group we have examined 53 healthy subjects (Group B). Results Significant alterations in form and vascularization of fPap have been detect, specially by the first examination. Patients EGM-Thresholds of both measurements are higher than those of healthy subjects, although those of the second one are clearly lower. The same results have been found using Schniffin- Sticks. Discussion Our findings suggest that COVID-19 can produce a mild to profound neuropathy of multiple cranial nerves, which are responsible for the regeneration of fPap and the transmission of the chemical stimuli.