key: cord-0769281-q0tcrfgq
authors: Elangovan, Satheesh
title: Acute Loss of Smell or Taste Without Nasal Blockage Should Raise Suspicion for COVID-19 Infection
date: 2021-01-25
journal: J Evid Based Dent Pract
DOI: 10.1016/j.jebdp.2020.101525
sha: db318a3ffaecabc7c2a512c7f6f0a36bdddbd282
doc_id: 769281
cord_uid: q0tcrfgq

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Taste and smell as chemosensory dysfunctions in COVID-19 infection. Passarelli PC, Lopez MA, Mastandrea Bonaviri GN, Garcia-Godoy F, D'Addona A.Am J Dent 2020;33(3):135-137. SOURCE OF FUNDING: Information not available. TYPE OF STUDY/DESIGN: Systematic review.

Five cross-sectional studies that came from different parts of the world were included in this systematic review. Of the 10,818 patients with COVID-19 included in this systematic review, 74.8% (range: 5.1% to 85.6%) of the patients presented with olfactory disturbances (anosmia), whereas 81.6% (range: 5.6% to 88%) presented with taste disturbances (ageusia). One study reported that 18.6% of the patients with COVID-19 presented with both anosmia and ageusia.

Anosmia and ageusia are common symptoms that manifest early in COVID-19 infection.

Loss of smell and/or taste are common clinical manifestations that have long been associated with a spectrum of medical conditions, including neurodegenerative 

See page --for complete details regarding SORT and LEVEL OF EVIDENCE grading system.

Information not available.

Systematic review.

diseases such as Alzheimer's, in which olfaction is affected. 1 The evidence associating these clinical symptoms to COVID-19 has led to their inclusion on the list of COVID-19 symptoms by the Unites States Centers for Disease Control in April 2020 and brought these symptoms to the spotlight. The olfactory disturbances (anosmia) typically observed in upper respiratory infections are associated with inflammation and irritation of nasal mucosa or nasal blockage (rhinitis). By contrast, the olfactory disturbances observed in COVID-19 are not associated with nasal blockage. Hence, acute loss of smell or taste in the presence of a patent nasal airway should warrant investigation to rule out COVID-19. 2 Emerging yet inconclusive evidence also points to association of the increased presence of olfactory/taste disturbances with (1) younger patients and/ or (2) patients with lesser severity of COVID-19. [3] [4] [5] Certain methodological aspects of the systematic review in question are unclear. There is lack of information on whether more than one investigator was involved in the study selection and data extraction processes. It is also important to note that this review included studies only until April of 2020, and that 93% of the total patients included in this review came from a single study. 6 In spite of these limitations, the results of this systematic review are consistent with other publications, all confirming the existence of olfactory and taste disturbances in patients with COVID-19, in various populations. 7-9 A recent wellconducted living systematic review that included 10,228 patients with COVID-19 from 19 countries reported the prevalence of taste impairment in these patients to be 45% (95% CI: 34%-55%). 10 The differences in the prevalence of these clinical manifestations between studies could be due to the lack of a standardized method of testing for loss of taste or smell, under-reporting of symptoms, or variations in sample size, disease severity, and study conduction settings.

Adding a specific screening question on the acute loss of smell or taste without nasal blockage will aid in the identification of otherwise asymptomatic patients with COVID-19. In addition to smell and taste disturbances, case reports indicate that patients with COVID-19 could present with a range of oral manifestations, including white and erythematous plaques, blisters, ulcers, petechiae, and desquamative gingivitis. 10 Dentists should be cognizant of the nasopharyngeal and oral manifestations of COVID-19, to help guide patients to seek appropriate medical care and help prevent transmission of disease in the dental setting. It is equally important for clinicians to stay updated on the evolving scientific evidence related to COVID-19 to serve their patients better.

Loss of olfactory function-early indicator for Covid-19, other viral infections and neurodegenerative disorders

Smell and taste dysfunction in patients with COVID-19

Acute-onset smell and taste disorders in the context of COVID-19: a pilot multicentre polymerase chain reaction based casecontrol study

Immunology of COVID-19: current state of the science

Objective olfactory evaluation of self-reported loss of smell in a case series of 86 COVID-19 patients

Coincidence of COVID-19 epidemic and olfactory dysfunction outbreak in Iran

Prevalence of taste and smell dysfunction in coronavirus disease 2019

Hypogeusia as the initial presenting symptom of COVID-19

Early recovery following new onset anosmia during the COVID-19 pandemican observational cohort study

Oral manifestations in patients with COVID-19: a living systematic review