Volume 163, Issue 1 p. 12-15
Review Articles

Olfactory Dysfunction: A Highly Prevalent Symptom of COVID-19 With Public Health Significance

Ahmad R. Sedaghat MD, PhD

Corresponding Author

Ahmad R. Sedaghat MD, PhD

Department of Otolaryngology–Head and Neck Surgery, University of Cincinnati Medical Center, Cincinnati, Ohio, USA

Ahmad R. Sedaghat, MD, PhD, Department of Otolaryngology–Head and Neck Surgery, University of Cincinnati College of Medicine, Medical Sciences Building Room 6410, 231 Albert Sabin Way, Cincinnati, OH 45267-0528, USA. Email: [email protected]Search for more papers by this author
Isabelle Gengler MD

Isabelle Gengler MD

Department of Otolaryngology–Head and Neck Surgery, University of Cincinnati Medical Center, Cincinnati, Ohio, USA

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Marlene M. Speth MD, MA

Marlene M. Speth MD, MA

Klinik für Hals-, Nasen-, Ohren- Krankheiten, Hals-und Gesichtschirurgie, Kantonsspital Aarau, Switzerland

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First published: 05 May 2020
Citations: 76

Abstract

Objective

Coronavirus disease 2019 (COVID-19) is a global pandemic affecting millions of individuals, killing hundreds of thousands. Although typically described with characteristic symptoms of fever, cough, and shortness of breath, greater understanding of COVID-19 has revealed myriad clinical manifestations. Olfactory dysfunction (OD)—hyposmia and anosmia—has recently been recognized as an important symptom of COVID-19 and increasingly gained traction as a public health tool for identifying COVID-19 patients, in particular otherwise asymptomatic carriers who, unawares, may be major drivers of disease spread. The objective of this study is to review the scientific evidence about anosmia in COVID-19.

Data Sources

PubMed, Google Scholar, and Web of Science.

Review Methods

Comprehensive literature search of primary studies pertinent to the objectives of this review using the chosen data sources.

Conclusions

Current evidence shows that OD is highly prevalent in COVID-19, with up to 80% of patients reporting subjective OD and objective olfactory testing potentially showing even higher prevalence. OD is frequently accompanied by taste dysfunction. Up to 25% of COVID-19 patients may experience sudden-onset OD as the first symptom. A large proportion of COVID-19 OD cases may resolve over the period of a few weeks.

Implications for Practice

Sudden anosmia should be considered a symptom of COVID-19. Assessing for sudden-onset anosmia may increase sensitivity of COVID-19 screening strategies, in particular for identifying patients at the earliest stages of disease. Since many cases of OD due to COVID-19 may resolve in the short term, conservative management, including observation, is reasonable, while advanced imaging is unnecessary.