» Articles » PMID: 32556089

Anosmia in COVID-19: Mechanisms and Significance

Overview
Journal Chem Senses
Specialty Biochemistry
Date 2020 Jun 20
PMID 32556089
Citations 69
Authors
Affiliations
Soon will be listed here.
Abstract

The global pandemic of coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 remains a challenge for prevention due to asymptomatic or paucisymptomatic patients. Anecdotal and preliminary evidence from multiple institutions shows that these patients present with a sudden onset of anosmia without rhinitis. We aim to review the pathophysiology of anosmia related to viral upper respiratory infections and the prognostic implications. Current evidence suggests that SARS-CoV-2-related anosmia may be a new viral syndrome specific to COVID-19 and can be mediated by intranasal inoculation of SARS-CoV-2 into the olfactory neural circuitry. The clinical course of neuroinvasion of SARS-CoV-2 is yet unclear, however an extended follow up of these patients to assess for neurological sequelae including encephalitis, cerebrovascular accidents and long-term neurodegenerative risk may be indicated.

Citing Articles

Long COVID-19-related and non-COVID-19 postviral olfactory dysfunction a comparative MRI study focusing on the olfactory cleft and bulbs.

Li Y, Liu M, Zhang R, Wang Y, Liu J Front Neurol. 2025; 15:1535699.

PMID: 39882367 PMC: 11774702. DOI: 10.3389/fneur.2024.1535699.


Persistent Post-COVID-19 Olfactory Dysfunction and Its Association with Autonomic Nervous System Function: A Case-Control Study.

Ayoub L, Almarzouki A, Al-Raddadi R, Bendary M Diseases. 2025; 13(1).

PMID: 39851468 PMC: 11765322. DOI: 10.3390/diseases13010004.


Evaluating the Predictors of Persistent Long COVID Symptoms and Their Severity in COVID-19 Survivors 1 Year After Infection.

Aldhawyan A, A BuSaad M, Alamri B, Alsaihati M, Alanazi B, Alanazi R J Prim Care Community Health. 2024; 15():21501319241295686.

PMID: 39471195 PMC: 11528748. DOI: 10.1177/21501319241295686.


Humans without a sense of smell breathe differently.

Gorodisky L, Honigstein D, Weissbrod A, Weissgross R, Soroka T, Shushan S Nat Commun. 2024; 15(1):8809.

PMID: 39438441 PMC: 11496694. DOI: 10.1038/s41467-024-52650-6.


Determinants of persistence and recovery of chronic coronavirus disease 2019 chemosensory dysfunction.

Minichetti D, Boyd A, Lemire E, Hacker J, Haber A, Roditi R J Allergy Clin Immunol. 2024; 155(1):120-134.

PMID: 39270802 PMC: 11700771. DOI: 10.1016/j.jaci.2024.08.027.


References
1.
Crisafulli U, Xavier A, Dos Santos F, Cambiaghi T, Chang S, Porcionatto M . Topical Dexamethasone Administration Impairs Protein Synthesis and Neuronal Regeneration in the Olfactory Epithelium. Front Mol Neurosci. 2018; 11:50. PMC: 5845685. DOI: 10.3389/fnmol.2018.00050. View

2.
Beites C, Kawauchi S, Crocker C, Calof A . Identification and molecular regulation of neural stem cells in the olfactory epithelium. Exp Cell Res. 2005; 306(2):309-16. DOI: 10.1016/j.yexcr.2005.03.027. View

3.
Vaira L, Salzano G, Deiana G, De Riu G . Anosmia and Ageusia: Common Findings in COVID-19 Patients. Laryngoscope. 2020; 130(7):1787. PMC: 7228304. DOI: 10.1002/lary.28692. View

4.
Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y . Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet. 2020; 395(10223):497-506. PMC: 7159299. DOI: 10.1016/S0140-6736(20)30183-5. View

5.
Attems J, Walker L, Jellinger K . Olfaction and Aging: A Mini-Review. Gerontology. 2015; 61(6):485-90. DOI: 10.1159/000381619. View