Smell and taste disorders in COVID-19: From pathogenesis to clinical features and outcomes. (23rd March 2021)

• Record Type: Journal Article
• Authors: Mastrangelo, Andrea; Bonato, Matteo; Cinque, Paola
• Is Part Of: Neuroscience letters. Volume 748(2021)
• Publication Date: 2021-03-23
• Subjects: COVID-19 -- Anosmia -- Ageusia; Neurology -- Periodicals; Neurology -- Periodicals; Research -- Periodicals; Neurologie -- Périodiques; Neuroanatomie -- Périodiques; Neuropharmacologie -- Périodiques; Neurophysiologie -- Périodiques; Neurology; Periodicals; Electronic journals; 617.48
• DOI: 10.1016/j.neulet.2021.135694
• Languages: English
• ISSNs: 0304-3940

Abstract

Highlights: Smell and taste disorders are frequent and appear early in COVID-19. Their detection could be helpful in diagnosing COVID-19. Anosmia likely results from infection of non-neuronal cells in olfactory mucosa. Direct infection of olfactory neurons seems to be less probable. Smell and taste disorders occasionally persist after resolution of other symptoms. Abstract: Patients with COVID-19 often complain of smell and taste disorders (STD). STD emerge early in the course of the disease, seem to be more common in SARS-CoV-2 infection than in other upper respiratory tract infections, and could in some cases persist for long after resolution of respiratory symptoms. Current evidence suggests that STD probably result from a loss of function of olfactory sensory neurons and taste buds, mainly caused by infection, inflammation, and subsequent dysfunction of supporting non-neuronal cells in the mucosa. However, the possible occurrence of other mechanisms leading to chemosensory dysfunction has also been hypothesized, and contrasting data have been reported regarding the direct infection of sensory neurons by SARS-CoV-2. In this mini-review, we summarize the currently available literature on pathogenesis, clinical manifestations, diagnosis, and outcomes of STD in COVID-19 and discuss possible future directions of research on this topic.