Human Nasal Epithelium Damage as the Probable Mechanism Involved in the Development of Post-COVID-19 Parosmia

PURPOSE: Since the beginning of the COVID-19 pandemic, understanding the physiopathological mechanisms of its manifestations has been crucial to understand the disease and its implications. As the disease evolved, post-infection complications have arisen such as olfactory dysfunctions including parosmia in which odourants are perceived in a distorted or an unpleasant way. METHODS: In this article, we attempt to clarify these mechanisms and the role of human nasal epithelium in the development of post-COVID-19 parosmia. RESULTS: The mechanisms by which SARS-CoV-2 generates olfactory dysfunction have not been elucidated, and multiple theories have been proposed pointing to the sustentacular cells of the olfactory epithelium as the main probable target of the virus. CONCLUSION: Establishing the main physiopathological mechanism of post-COVID-19 parosmia will set a path for further investigations and determine treatment and preventive options for patients who have been reported to be extensively affected in multiple aspects of their lives such as eating habits and mental health.