Smell and Taste in Severe CoViD-19: Self-Reported vs. Testing

Cells, 2022

Among the first clinical symptoms of the SARS-CoV-2 infection is olfactory–gustatory deficit; this continues for weeks and, in some cases, can be persistent. We prospectively evaluated 162 patients affected by COVID-19 using a visual analogue scale (VAS) for nasal and olfactory–gustatory symptoms. Patients were checked after 7, 14, 21, 28, 90, and 180 days. A total of 118 patients (72.8%) reported an olfactory VAS < 7 at baseline (group B), and 44 (27.2%) reported anosmia (VAS ≥ 7) (group A) and underwent the Brief Smell Identification Test (B-SIT) and Burghart Taste Strips (BTS) to quantify the deficit objectively and repeated the tests to confirm the sense recovery. Group A patients showed B-SIT anosmia and hyposmia in 44.2% and 55.8% of cases, respectively. A total of 88.6% of group A patients reported ageusia with VAS ≥ 7, and BTS confirmed 81.8% of ageusia and 18.2% of hypogeusia. VAS smell recovery was recorded starting from 14 days, with normalization at 28 days. The 28-da...

Chemical Senses, 2020

Recent anecdotal and scientific reports have provided evidence of a link between COVID-19 and chemosensory impairments, such as anosmia. However, these reports have downplayed or failed to distinguish potential effects on taste, ignored chemesthesis, and generally lacked quantitative measurements. Here, we report the development, implementation, and initial results of a multilingual, international questionnaire to assess self-reported quantity and quality of perception in 3 distinct chemosensory modalities (smell, taste, and chemesthesis) before and during COVID-19. In the first 11 days after questionnaire launch, 4039 participants (2913 women, 1118 men, and 8 others, aged 19–79) reported a COVID-19 diagnosis either via laboratory tests or clinical assessment. Importantly, smell, taste, and chemesthetic function were each significantly reduced compared to their status before the disease. Difference scores (maximum possible change ±100) revealed a mean reduction of smell (−79.7 ± 28.7, mean ± standard deviation), taste (−69.0 ± 32.6), and chemesthetic (−37.3 ± 36.2) function during COVID-19. Qualitative changes in olfactory ability (parosmia and phantosmia) were relatively rare and correlated with smell loss. Importantly, perceived nasal obstruction did not account for smell loss. Furthermore, chemosensory impairments were similar between participants in the laboratory test and clinical assessment groups. These results show that COVID-19-associated chemosensory impairment is not limited to smell but also affects taste and chemesthesis. The multimodal impact of COVID-19 and the lack of perceived nasal obstruction suggest that severe acute respiratory syndrome coronavirus strain 2 (SARS-CoV-2) infection may disrupt sensory-neural mechanisms.

JAMA Otolaryngology–Head & Neck Surgery

, a pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly from Wuhan, Hubei Province, China, to all over the world. 1 As of April 20, 2020, SARS-CoV-2 has been responsible for 2 414 595 infections and 165 174 deaths worldwide, with Italy accounting for 178 972 cases and 23 660 deaths. 2 The clinical spectrum of COVID-19 ranges from an asymptomatic or mild flu-like illness to a severe pneumonia and systemic disease requiring critical care. Main symptoms are fever, dry or productive cough, and dyspnea. 3 Human strains of coronavirus have been demonstrated to invade the central nervous system through the olfactory neu-roepithelium and propagate from within the olfactory bulb. 4 Furthermore, nasal epithelial cells display the highest expression of the SARS-CoV-2 receptor, angiotensin converting enzyme 2, in the respiratory tree. 5 Smell impairment was first observed among other neurologic manifestations of COVID-19 in hospitalized patients, 6 and subsequently has been reported to be a common symptom reported in patients with mild disease. 7,8 Recently, we reported the prevalence of altered smell or taste to be 64% among a case series of 202 mildly symptomatic home-isolated patients with confirmed SARS-CoV-2 infection. 8 The aim of this study was to evaluate the evolu-IMPORTANCE An altered sense of smell and taste has been reported to be associated with coronavirus disease 2019 (COVID-19). To understand the evolution of these symptoms during the course of the disease is important to identify patients with persistent loss of smell or taste and estimate the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on the burden of olfactory and gustative dysfunctions. OBJECTIVE To evaluate the evolution of the loss of sense of smell and taste in a case series of mildly symptomatic patients with SARS-CoV-2 infection. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional survey-based study included 202 mildly symptomatic adults (Ն18 years) consecutively assessed at Treviso Regional Hospital, Italy, between March 19 and March 22, 2020, who tested positive for SARS-CoV-2 RNA by polymerase chain reaction on nasopharyngeal and throat swabs. MAIN OUTCOMES AND MEASURES Prevalence of altered sense of smell and taste at follow-up and their variation from baseline. RESULTS Of 202 patients completing the survey at baseline, 187 (92.6%) also completed the follow-up survey (103 [55.1%] women; median age, 56 years). The evaluation of the evolution of altered sense of smell or taste in the 113 patients reporting sudden onset of these symptoms at baseline showed that 55 patients (48.7%; 95% CI, 39.2-58.3) reported complete resolution of smell or taste impairment, 46 (40.7%; 95% CI, 31.6-50.4) reported an improvement in the severity, and only 12 (10.6%; 95% CI, 5.6-17.8) reported the symptom was unchanged or worse. Persistent loss of smell or taste was not associated with persistent SARS-CoV-2 infection. CONCLUSIONS AND RELEVANCE At 4 weeks from the onset, 89% of the SARS-CoV-2-positive mildly symptomatic patients who had had a sudden onset of altered sense of smell or taste experienced a complete resolution or improvement of these symptoms. Persistent loss of smell or taste was not associated with persistent SARS-CoV-2 infection.

Life

Background: Although smell and taste disorders are highly prevalent symptoms of COVID-19 infection, the predictive factors leading to long-lasting chemosensory dysfunction are still poorly understood. Methods: 102 out of 421 (24.2%) mildly symptomatic COVID-19 patients completed a second questionnaire about the evolution of their symptoms one year after the infection using visual analog scales (VAS). A subgroup of 69 patients also underwent psychophysical evaluation of olfactory function through UPSIT. Results: The prevalence of chemosensory dysfunction decreased from 82.4% to 45.1% after 12 months, with 46.1% of patients reporting a complete recovery. Patients older than 40 years (OR = 0.20; 95% CI: [0.07, 0.56]) and with a duration of loss of smell longer than four weeks saw a lower odds ratio for recovery (OR = 0.27; 95% CI: [0.10, 0.76]). In addition, 28 patients (35.9%) reported suffering from parosmia, which was associated with moderate to severe taste dysfunction at the basel...

Turkish Journal of Internal Medicine, 2021

Background Establishing a relationship between COVID-19 severity and olfactory dysfunction may be beneficial in-patient follow-up. Thus, in this study, we aimed to evaluate the association between self-reported olfactory dysfunction and the clinical stages of COVID-19. Material and Methods The patients included in this study were divided into three groups according to the severity of the novel coronavirus disease as mild, severe, and critical (life-threatening) patients. Patients were then contacted by phone and asked questions with the help of structured documentation form that evaluated their general status, sense of smell, taste and compared the data within the three groups. Results Among the 126 subjects evaluated in the present study (mild, n=51; severe, n=53, critical, n=22), 61 of the participants were males, and 65 were females. The findings showed that olfactory loss was the most prominent feature of the COVID-19's mild clinical course and the majority of the patients with loss of smell were female and young patients. Conclusions The findings obtained from clinically mild cases suggest that more olfactory dysfunction, indicating that the effects of viral load alone, is not decisive for olfactory dysfunction.

European Archives of Oto-Rhino-Laryngology, 2021

Purpose The objective of this study is to evaluate smell and taste dysfunction (STD) in coronavirus disease 2019 (COVID-19) positive and negative patients, and to assess the factors associated with STD in COVID-19 positive patients. Methods Patients who had been tested with the real-time reverse transcriptase-polymerase chain reaction (RT-PCR) for COVID-19 were identified, and according to the RT-PCR test results, patients were separated into Positive and Negative Groups. A telephone-based assessment was applied to both groups using the American Academy of Otolaryngology-Head and Neck Surgery Anosmia Reporting Tool. Patients in Positive Group were also asked to rate STD, nasal breathing, and anxiety in three different time periods (pre-/during-/post-COVID) using the visual analog scale (VAS). Results A total of 53 COVID-19 positive and 51 negative patients completed the surveys. STD was eightfold more frequent (OR 8.19; CI 95% 3.22-20.84) in the Positive Group. Of the 53 COVID-19 positive patients, 32 reported STD and 21 did not. 'Ground-glass appearance' on chest-computed tomography was more frequent and median lymphocyte count was significantly lower in COVID-19 positive patients with STD. During-COVID STD and nasal breathing VAS scores were significantly lower than the pre-and post-COVID scores. During-COVID STD scores were significantly correlated with anxiety scores (Spearman's rho-0.404, p = 0.022) but not correlated with nasal breathing scores. Conclusion STD may be related to increased inflammatory response as well as damage of olfactory neuronal pathway or non-neuronal olfactory mucosa. Understanding the exact cause of chemosensory impairment in COVID-19 can be helpful in explaining the pathophysiology of the disease.

Turkish Archives of Otorhinolaryngology

The severe acute respiratory syndrome-coronavirus-2 pandemic is one of the largest of the recent times and can cause many symptoms including smell and taste disorders. In the literature, smell disorders caused by coronavirus disease-2019 (COVID-19) have been reported within a wide range from 3.2% to 98.3%. A small number of these studies demonstrated smell and taste disorders through objective tests. Our aim in this study was to determine the prevalence of smell and taste disorders in hospitalized patients due to COVID-19 infection. The study was carried out with 100 patients who were positive for real-time polymerase chain reaction and treated at the Kayseri City Hospital, and 100 healthcare worker relatives. We used the Connecticut Chemosensory Clinical Research Center test to evaluate the sense of smell. Sense of taste was evaluated using four different standardized bottles of preparations, and the results were scored according to the patients' statements. Results: Patient (Group 1) and control (Group 2) groups were compared for age, gender, smell and taste disorders. There were 39 women and 61 men in the patient group, and 40 women and 60 men in the control group. Mean age was 50.2±1.37 (range 21-70) years in Group 1 and 47.6±1.25 (range 18-70) years in Group 2, and there was no significant difference between the two groups. While the rate of smell disorder was 80% in Group 1, we found this rate as 35% in Group 2. Taste disturbance was identified in 38 patients, of whom 16 had mild hypogeusia, 17 had moderate hypogeusia, four had severe hypogeusia, and one patient had ageusia. We found that taste disorder was 38% in Group 1 and 3% in Group 2. Smell and taste dysfunctions are very common symptoms in COVID-19 patients. The results obtained using objective test methods are higher than the rates obtained from patient statements.

Indian Journal of Otolaryngology and Head & Neck Surgery

The World Health Organization (WHO) has cautioned on specific respiratory symptoms for suspecting an individual of Corona Virus Disease 2019 (COVID-19). Meanwhile, many suspects are reporting dysfunctions of smell and taste. This study aimed to investigate the percentage of positive COVID-19 who had associated loss of sensation as detected by psychophysical testing. Eight hundred and thirty two suspects were enrolled. At the time of sampling for testing COVID-19 status, olfactory dysfunction (OD) and gustatory dysfunction (GD) tested using odorants like coffee and camphor and solutions of sweet and salty solvants, respectively. The strength of the association between test results of these sensory losses and COVID-19 positivity was assessed by calculating sensitivity, specificity, and predictive values. The responses in positive and negative individuals presented as age-adjusted odds ratio with 95% CI. Seventy six (9.1%) [95% CI: 7.4%-11.3%] of 832 suspects were tested positive for COVID-19. Paediatric cases of age between 2 and 10 years could not reply appropriately, hence OD in 134 and GD in 118 could not be tested. Anosmia or hyposmia was present in 62 (81.6%) and ageusia in 64 (84.2%) of the total 76 confirmed cases. The OD and GD dysfunctions were significantly higher among confirmed COVID-19 cases compared to negative subjects [ Adj OR (95% CI): Smell 3.22 (1.77-5.88); taste 3.05 (1.61-5.76), p \ 0.001]. In this study, testing of smell and taste dysfunctions had higher sensitivity in identifying recent-onset loss of sensations in COVID-19 cases. Hence, it may be used as a simple and cost-effective screening test.

International Archives of Otorhinolaryngology, 2022

Introduction Coronavirus disease 2019 (COVID-19) is a dangerous infectious disease caused by a newly discovered severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that has various clinical presentations. Numerable cases with non-specific olfactory and gustatory dysfunctions in COVID-19 have been reported from all over the globe. This is important as awareness will let people to self-isolate and help in limiting disease spread. Objective To objectively evaluate the frequency of olfactory and gustatory dysfunction, which may occur independently or with other symptoms, in laboratory confirmed COVID-19 patients at an early stage of the disease. Methods Objective evaluation of olfactory and gustatory function of 322 COVID-19 patients treated at our hospital, (SMGS, Government Medical College, Jammu), from August 2020 until November 2020. Results Our study population included 127 (39.4%) males and 195 (60.6%) females. Two hundred and twenty-six (70.2%) COVID-19 patients experienced olfactory and gustatory disorders. One hundred and sixty-five (51.2%) cases experienced both olfactory and gustatory disorders. Isolated olfactory dysfunction was reported in 34 (10.6%) patients, while 27 (8.4%) patients experienced only gustatory dysfunction. Conclusion The olfactory and gustatory dysfunctions, without any nasal obstruction or rhinorrhea, are significant symptoms in the clinical presentation of early COVID-19 patients. This presentation can be recognized at the earliest one, and it can reduce the high communicability of the COVID-19 disease.

Cureus, 2023

Coronavirus Disease-2019 (COVID-19) causes olfactory loss one of the initial diagnostic criteria. The brief smell identification test (BSIT) is an objective test frequently used in olfactory dysfunction. This study aimed to observe the changes in olfactory functions and clinical features in a short time in COVID-19. In this prospective study involving 64 patients, the BSIT was performed at two different times; at the time of first application and on the 14th day. Demographic features, laboratory findings, body mass index (BMI), blood oxygen saturation values (SpO2), complaints at first admission, fever, follow-up place, and treatment schemes were noted. There was a significant difference between the BSIT scores at the first admission and when the polymerase chain reaction (PCR) became negative on the 14th day (p<0.001). Low oxygen saturation values at first admission were associated with low BSIT scores. No relationship was found between olfactory functions and complaints at admission, fever, follow-up place, and treatment schemes. As a result, negative effects of COVID-19 on olfactory functions have been demonstrated even in the short follow-up period. In addition, low saturation values at first admission were associated with low BSIT scores.