Gustatory Dysfunction in Covid 19 Patients: A Cross Sectional Study Volume 5 - Issue 4

Abhishek M¹*, Bandiahanapalya Narasappa Yogesh¹, Borlingegowda Viswanatha², Harshavardhan Annigeri¹ and Sahana Raju³

• ¹Senior Resident, Department of Otorhinolaryngology, Bangalore Medical College and Research Institute, India
• ²Professor and Head, Department of Otorhinolaryngology, Bangalore Medical College and Research Institute, India
• ³Junior Resident, Department of Otorhinolaryngology, Bangalore Medical College and Research Institute, India

Received: December 18, 2020   Published: January 06, 2021

Corresponding author: Abhishek M, Senior Resident, Department of Otorhinolaryngology, Bangalore Medical College and Research Institute, India

DOI: 10.32474/SJO.2021.05.000221

Abstract PDF

Abstract

Background: Loss of smell and taste are considered potential discriminatory symptoms indicating triaging for coronavirus disease 2019 (COVID-19) and early case identification. However, the estimated prevalence essential to guide public health policy varies in published literature.

Methods: The prospective study evaluated 100 individuals with a COVID-19 infection, as confirmed by Reverse transcriptase PCR laboratory testing. Olfactory and gustatory testing were carried out by an examiner utilizing stringent safety standards and wearing full personal protective equipment.

Results: Among the 100 patients included in this study, 54% were male and 46% were female with a mean age of 38.82±12.21 years (18-72). Among the 100 patients included in this study, 13 patients had isolated taste dysfunction, 16 patients had isolated olfactory dysfunction, 51 patients had combined dysfunction, and 20 patients had neither taste nor olfactory dysfunction. Among the 51 patients who had combined olfactory and gustatory dysfunction, 31.3 % of them had predominant gustatory dysfunction, 47.1 % predominant olfactory dysfunction and 21.6% of the patients had both olfactory and gustatory dysfunction equally.

Conclusions: Olfactory and gustatory dysfunctions are strongly associated with SARS-CoV-2 infection. Olfactory with or without gustatory dysfunctions is potentially a reliable indicator of latent COVID-19.

Keywords:COVID-19; gustatory dysfunction; taste; SARS-CoV-2

Introduction

Coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus, first presented in December 2019 in Wuhan, China, and has quickly spread all around the world [1,2]. It was declared by the World Health Organization as a pandemic and global health emergency on March 11, 2020 [3]. Across the globe, the SARSCoV- 2 virus has infected millions of individuals and killed hundreds of thousands. In January 2020, angiotensin-converting enzyme 2 (ACE-2) was identified as the functional receptor for SARS-CoV-2, present in multiple human organs including the central nervous system. The common symptoms of COVID-19 are general malaise, fever, cough, and shortness of breath. Other symptoms include muscle and joint pain, sore throat, headache, nausea, or vomiting, diarrhoea, and some nasal symptoms, especially smell and taste dysfunction. Like other upper airway viral infections (URTI), such as common cold or flu, the loss of smell is a frequent symptom in COVID-19 patients. However, a sudden, severe, and isolated loss of smell and/or taste may also be present in COVID-19 patients who are otherwise asymptomatic [4]. The nasal and oral cavities are a common portal of entry, and it is known that the viral organism gets adapted and multiplies therein before being propagated to the lower respiratory tract. In the last few months, researchers have been focusing mainly on the analysis of olfactory disorders and have often overlooked taste dysfunctions, mainly for the following two reasons:

a) The olfactory pathway could be a way of access to the central nervous system for the coronavirus [5]. Thus, the olfactory dysfunctions could represent a sign of neuro invasion, while ageusia and hypogeusia would not have any possible interesting pathogenetic implication.

b) The gustatory disturbances have generally been classified as a result of the retro nasal olfactory loss [6]. The aim of this study is to evaluate the prevalence of gustatory disturbance i.e., ageusia/hypogeusia among the COVID 19 patients.

Methods

This prospective study was undertaken in Bangalore medical college and research center, a designated COVID hospital. The study evaluated a consecutive series of patients between September 2020 and October 2020. All the patients enrolled in the study were diagnosed with COVID-19. 100 hospitalized patients were included in this cross sectional study satisfying the inclusion and exclusion criteria.

Inclusion criteria

a) Age> 18 years.

b) Laboratory-confirmed COVID-19 infection (reverse transcription−polymerase chain reaction, RT-PCR).

c) Patients clinically stable.

) Patients giving consent to participate in the study.

Exclusion criteria

a) Patients without a laboratory-confirmed diagnosis of COVID-19 infection.

b) Patients in the intensive care unit.

c) Patients with olfactory or gustatory dysfunctions before the epidemic due to congenital anosmia, the side effects of drugs (chemotherapy), previous surgery or radiotherapy in the oral and nasal cavities, head injury, sinonasal diseases, allergic rhinitis.

d) Patients with systemic diseases (iron deficiency, autoimmune diseases).

e) Patients with neurodegenerative disorders (Parkinson’s disease, disease Alzheimer’s disease, dementia).

f) Patients with major depression.

Gustatory testing

Gustatory testing was carried out by the examiners utilizing stringent safety standards and wearing full personal protective equipment. Gustatory testing involved the identification of three solutions in the water representing different types of taste: sweet, salty, and sour.

a) Sweet-tasting solution was 50% sucrose.

b) Saltiness was tested using 0.9% saline solution.

c) Sour taste, 4.2% vinegar was given.

The testing hours were during the morning to prevent any confounding effects from circadian alterations. The subjects had not eaten or drunk anything within the hour preceding the test. Each participant rinsed his or her mouth with distilled water first. Swab sticks were dipped into the previously prepared solutions and applied to the anterior two-thirds of the lingual dorsum. The identification of the taste was recorded for each taste and for each subject. The participants used distilled water to flush out their mouths completely between the application of the next solution.

Olfactory testing

Olfaction was tested using common household items like soap, coffee, cinnamon, and lemon. The odorants were presented one at a time, in identical and opaque containers covered by gauze.

Results

Among the 100 patients included in this study, 54% were male and 46% were female with a mean age of 38.82±12.21 years (18-72) (Figure 1 & Table 1). Among the 100 patients included in this study, 13 patients had isolated taste dysfunction, 16 patients had isolated olfactory dysfunction, 51 patients had combined dysfunction, and 20 patients had neither taste nor olfactory dysfunction (Figure 2 & Table 2). Among the 51 patients who had combined olfactory and gustatory dysfunction, 31.3 % of them had predominant gustatory dysfunction, 47.1 % predominant olfactory dysfunction and 21.6% of the patients had both olfactory and gustatory dysfunction equally (Figure 3 & Table 3).

Table 1: Sex Distribution.