Smell and Taste Loss Associated with COVID-19 Infection.

OBJECTIVE: The aim of this study was to quantify the impact of COVID-19 on olfactory and gustatory function in US adults. METHODS: From the 2021 Adult National Health Interview Survey, demographic and survey-specific module data concerning COVID-19 diagnoses, testing and disease severity, and data quantifying disturbances and eventual recovery of smell and taste were extracted. Sample weights were applied to obtain nationally representative statistics. The overall rate of COVID-19 infection was determined, and those diagnosed with COVID-19 were analyzed with respect to disease severity, smell and taste disturbance, and respective recoveries. RESULTS: In 2021, 35.8 million or 14% of the adult population (95% CI 13.5-14.7%; mean age, 43.9 years; 53.8% female) had been diagnosed with COVID-19. Among those, 60.5% (58.6-62.5%) and 58.2% (56.2-60.1%) reported accompanying losses  in smell or taste, respectively; there was a significant association between overall COVID-19 symptom severity and smell (p < 0.001) and taste disturbance (p < 0.001). Following infection, 72.2% (69.9-74.3%), 24.1% (22.2-26.2%), and 3.7% (3.0-4.6%) of the patients experienced complete, partial, and no smell recovery, respectively. Recovery rates for gustatory function paralleled olfaction, with 76.8% (74.6-78.9%), 20.6% (18.7-22.7%), and 2.6 (1.9-3.4%) reporting complete, partial, and no recovery of taste, respectively. When sensory disturbance was present, severity of overall symptomatology was negatively associated with smell and taste recovery (p < 0.001 for each). CONCLUSION: The majority of adults infected with COVID-19 in 2021 experienced olfactory or gustatory dysfunction with a non-negligible population reporting incomplete or no near-term sensory recovery. Our results are useful for providers counseling patients and suggest that interventions lessening overall COVID-19 symptom burden may prevent prolonged sensory dysfunction. LEVEL OF EVIDENCE: IV. Laryngoscope, 2023.

Incidence of Olfactory Dysfunction in Patients with COVID-19 in a Tertiary Hospital in Saudi Arabia.

Background: Coronavirus disease (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2, a novel virus that emerged in China in December 2019. In many cases of COVID-19, olfactory dysfunction (OD) is the only symptom. Objectives: This study aimed to examine the incidence of OD in patients with COVID-19 and identify an association between OD and COVID-19-related morbidity and admission. Design: This was a cross-sectional study. Methods: Real-time reverse transcription polymerase chain reaction-confirmed cases of COVID-19 from the Security Forces Hospital electronic registry from June 2020 to September 2020 were included in our study. Data on medical background, severity of the disease, and other related factors were collected through phone calls and electronic healthcare systems and analyzed to investigate OD in the participants. Results: Of the participants, 68% had OD, with a mean recovery time of 18 days and a mean follow-up time of 129 days (76-211 days). OD was negatively correlated with admission and morbidity. Conclusion: OD is a common presentation of COVID-19 and is more prevalent in mild cases of infection.

Oro-Facial manifestations of COVID-19 infection in a sample of Iraqi people

Public health officials are gravely concerned about the harm that viral illnesses continue to pose to humanity, various viral outbreaks, including the Middle East Respiratory Syndrome Corona-Virus (MERS-CoV), H1N1 influenza, the severe acute respiratory syndrome coronavirus (SARS-CoV-2) and SARS CoV-2 or COVID-19 that struck the globe in December 2019. A wide range of COVID-19 oral symptoms, such as ulceration, blisters, enanthems, hemorrhagic sores and cheilitis. Aim(s): to investigate the prevalence of oral symptoms amongst COVID-19 patients due to the disease's aggressive nature and diverse symptomatology and to assess the impact of oral health conditions on COVID-19 disease severity in a sample of Iraqi people. Material(s) and Method(s): a cross-sectional study was conducted on (200) patients in total, (81) male and (119) female, who were identified as SARS-COV2 patients. Result(s): COVID confirmed patients were involved in the present study with mean age (36.69+/-17.22) years & age range of (16-78) years. at least one of the oral manifestations was present in 72.5% of the patients, while about 27.5% did not experience any oro-facial symptoms. The oral symptom with the highest prevalence was dry mouth 50% followed by gustatory dysfunction 37% then burning mouth sensation 22.5% after that the oral pain 17%;myofacial pain 15.5 %;stomatitis\mucositis 14.5%;the prevalence of aphthous lesions, fissural cheilitis and tongue depapillation were at the same percentage which was 9.5%;then candidiasis 7.5%;the least prevalent oral symptoms was gingival bleeding at percentage of 2.5%. Conclusion(s): COVID-19 has a noticeable effect on oral cavity, there was a correlations between some general and orofacial manifestations of COVID-19.Copyright © 2023, Codon Publications. All rights reserved.

COVID-19-Related Quantitative and Qualitative Olfactory and Gustatory Dysfunction: Long-Term Prevalence and Recovery Rate.

INTRODUCTION: No studies have reported data on 2-year prevalence and recovery rates of self-reported COVID-19-related quantitative and qualitative olfactory and gustatory dysfunction. The aim of the present study was to estimate the 2-year prevalence and recovery rate of self-reported COVID-19-related olfactory and gustatory dysfunction in a cohort of patients with antecedent mild-to-moderate disease. METHODS: This is a prospective observational study, measuring the prevalence of altered sense of smell or taste at follow-up and their variation from baseline, on adult patients consecutively assessed at Trieste University Hospital, who tested positive for SARS-CoV-2 RNA by polymerase chain reaction during March 2020. RESULTS: Overall, 174 (68.8%), 53 (20.9%), and 36 (14.2%) of 253 responders reported an altered sense of smell or taste (SNOT-22 >0) at baseline, 12 months, and 24 months, respectively. Among the 174 patients who have complained a COVID-19-associated olfactory or gustatory dysfunction at baseline, 138 (79.3%) reported complete resolution of smell or taste impairment with 17 subjects (9.8%) recovering after more than 1 year after the initial infection, 33 (19.0%) reported a decrease in the severity, and only 3 (1.7%) reported that the symptom was unchanged at the 24-month interview. Twenty subjects (7.9%) complained of at least one qualitative long-term symptom. CONCLUSION: Two years after the infection, most patients experience a favourable evolution of COVID-19-related olfactory or gustatory dysfunction. A late recovery was observed in 10% of subjects.

Long-term Consequences of COVID-19: Chemosensory Disorders.

PURPOSE OF REVIEW: A number of sequelae after acute coronavirus disease 2019 (COVID-19) significantly affect the quality of life of patients. The chemosensory disorders including olfactory dysfunction (OD) and gustatory dysfunction (GD) are two of the commonest symptoms complained by patients with COVID-19. Although chemosensory function has been reported improved in over 60% of COVID-19 patients in a short time after acute infection, it may last as a major symptom for patients with long COVID-19. This narrative review discussed current literatures on OD and GD in long COVID-19 including the prevalence, risk factors, possible mechanisms, and potential therapies. RECENT FINDINGS: Although the prevalence of OD and GD has declined continuously after acute COVID-19, a considerable number of patients had persistent chemosensory disorders 3 months to 2 years after symptom onset. Female gender, initial severity of dysfunction, nasal congestion, emotional distress and depression, and SARS-CoV-2 variants have been identified as risk factors for persistent OD and GD in long COVID-19. The pathogenesis of OD and GD in long COVID-19 remains unknown, but may be analogous to the persistent OD and GD post common respiratory viral infection. Corticosteroids and olfactory training might be a potential choice regarding the treatment of lasting OD and GD after SARS-CoV-2 infection; however, more studies are needed to prove it. OD and GD are common long-term consequences of COVID-19 and influenced by gender, initial severity of dysfunction, emotional distress and depression, and SARS-CoV-2 variants. More studies are needed to illustrate their pathogenesis and to establish therapeutic strategies.

Alterations in smell or taste in individuals infected with SARS-CoV-2 during periods of Omicron variant dominance.

OBJECTIVES: To characterize the prevalence, severity, correlation with initial symptoms, and role of vaccination in patients with COVID-19 with smell or taste alterations (STAs). METHODS: We conducted an observational study of patients infected with SARS-CoV-2 Omicron admitted to three hospitals between May 17 and June 16, 2022. The olfactory and gustatory functions were evaluated using the taste and smell survey and the numerical visual analog scale at two time points. RESULTS: The T1 and T2 time point assessments were completed by 688 and 385 participants, respectively. The prevalence of STAs at two time points was 41.3% vs 42.6%. Furthermore, no difference existed in the severity distribution of taste and smell survey, smell, or taste visual analog scale scores between the groups. Patients with initial symptoms of headache (P = 0.03) and muscle pain (P = 0.04) were more likely to develop STAs, whereas higher education; three-dose vaccination; no symptoms yet; or initial symptoms of cough, throat discomfort, and fever demonstrated protective effects, and the results were statistically significant. CONCLUSION: The prevalence of STAs did not decrease significantly during the Omicron dominance, but the severity was reduced, and vaccination demonstrated a protective effect. In addition, the findings suggest that the presence of STAs is likely to be an important indicator of viral invasion of the nervous system.

Self-Reported Olfactory and Gustatory Dysfunctions in Hospitalized Patients Infected with SARS-CoV-2 Delta Variant.

OBJECTIVE: This study aimed to examine the olfactory and gustatory dysfunctions (OGDs) among hospitalized patients with a novel strain of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), lineage B.1.617.2, also known as the delta variant, in Xi'an, China through verbal interviews. METHODS: Clinical information of 370 hospitalized patients infected with the delta variant in the Aerospace City Branch of Xi'an People's Hospital in Xi'an, China from December 27, 2021 to January 10, 2022 were collected. The prevalence and characteristics of OGDs were collected using a simple questionnaire submitted to all infected patients, including questions about the presence and absence of OGDs. RESULTS: Among the 370 patients infected with the delta variant, 28 (7.6%) reported OGDs. A significant proportion of patients with self-reported OGDs were younger than those without (28.9 ± 10.5 vs. 35.3 ± 13.9, P = 0.005) and had significantly higher rates of sore throat and rhinitis (28.6% vs. 12.3%, P = 0.033; 42.9% vs. 9.9%, P = 0.000). Women were significantly more affected by OGDs than men (67.9% vs. 32.1%, P = 0.012). Vaccinated and unvaccinated delta variant-infected patients showed statistically significant differences in terms of disease severity (P = 0.002). CONCLUSIONS: The prevalence of OGDs in the delta variant infection was lower than that in wild-type SARS-CoV-2 infection. Meanwhile, young age, female sex, and upper respiratory tract symptoms could be closely related to the occurrence of OGDs in the delta variant infection. In addition, a satisfactory level of efficacy was obtained with coronavirus disease 2019 vaccines against moderate and severe delta variant infections.

Incidence of Olfactory and Gustatory Dysfunctions in the Early Stages of COVID-19: An Objective Evaluation.

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.

The Prevalence and Implications of Olfactory/Gustatory Dysfunctions among Adult COVID-19 Patients: A Retrospective Cohort Multiethnic Populations Study.

(1) Background: Olfactory and gustatory dysfunctions (OGDs) was found in COVID-19 patients. Only a few studies looked into the prevalence of OGDs in the United Arab Emirates (UAE). The purpose of this study was to estimate the prevalence OGDs among multiethnic COVID-19 patients in the UAE, and its association to patients' characteristics and disease outcomes; (2) Methods: There were 1785 COVID-19 patients included in our cohort; (3) Results: Males made up most of the study participants (86.3%). A total of 11.7% of the participants reported OGDs. Female gender and ethnicity had significantly higher symptom prevalence (p < 0.001). COVID-19 severity had a strong inverse association with OGDs (p = 0.007). Other illness outcomes, such as ICU admission, pneumonia development, and mortality, showed no correlation. Males, Asians, and patients with comorbidities all had statistically significantly lower prevalence odds. On the other hand, Emirati, Arab, and Iranian patients had a higher prevalence. COVID-19 patients with OGDs had a considerably shorter time until viral clearance than those without the symptom; (4) Conclusions: in nonsevere COVID-19, olfactory/gustatory dysfunction is common. As a result, it could be applied as a predictive sign for early disease diagnosis and prognosis.

Long-standing gustatory and olfactory dysfunction in COVID-19 patients: a prospective study.

PURPOSE: Our study aimed to describe recovery of gustatory dysfunction (GD) and olfactory dysfunction (OD) in COVID-19 patients, and to analyze variables associated with early or late recovery. METHODS: Telephone surveys were administered during an 18-month follow-up after COVID-19 diagnosis. One hundred and thirty-two included patients rated olfactory and gustatory function at each follow-up. RESULTS: One hundred and twenty-nine patients reported GD, of whom 91 (70.5%) reported severe GD, and 99 patients reported OD, of whom 84 (84.9%) reported severe OD. Seventy-two/129 (55.8%) and 52/99 (52.5%) patients reported an improvement in GD and in OD during the first 7 days from the onset, respectively. At 3-month follow-up, 110/120 patients (85.3%) recovered from GD, while 80/99 patients (80.8%) recovered from OD. At 18-month follow-up, a total of 120/129 patients (93.0%) recovered from GD and 86/99 patients (86.9%) recovered from OD; while 10 patients (7.0%) still reported GD and 13 patients (13.1%) still reported OD. Severe GD/OD at presentation were associated with late complete recovery of taste/smell (p = 0.019 and p = 0.034, respectively). Improvement over the first 7 days from onset was significantly associated with faster recovery (p < 0.001). CONCLUSIONS: More than 80% of patients reported complete recovery of olfactory/gustatory function in the first 3 months after symptom onset. At 18-month follow-up, patients reporting complete recovery of gustatory and olfactory function were 93% and 87%, respectively. Severity of chemosensory dysfunction at the onset was negatively correlated to recovery, and improvement of taste and/or smell function within the first 7 days from symptom onset was significantly associated with early resolution.

SARS-CoV-2 Infection and Taste Alteration: An Overview.

Since the worldwide spread of SARS-CoV-2 infection, the management of COVID-19 has been a challenge for healthcare professionals. Although the respiratory system has primarily been affected with symptoms ranging from mild pneumonia to acute respiratory distress syndrome, other organs or systems have also been targets of the virus. The mouth represents an important route of entry for SARS-CoV-2. Cells in the oral epithelium, taste buds, and minor and major salivary glands express cellular entry factors for the virus, such as ACE2, TMPRSS2 and Furin. This leads to symptoms such as deterioration of taste, salivary dysfunction, mucosal ulcers, before systemic manifestation of the disease. In this review we report and discuss the prevalence and socio-demographics of taste disturbances in COVID-19 patients, analysing the current international data. Importantly, we also take stock of the various hypothesized pathogenetic mechanisms and their impact on the reported symptoms. The literature indicated that COVID-19 patients frequently present with gustatory dysfunction, whose prevalence varies by country, age and sex. Furthermore, this dysfunction also has a variable duration in relation to the severity of the disease. The pathogenetic action is intricately linked to viral action which can be expressed in several ways. However, in many cases these are only hypotheses that need further confirmation.

Systematic review and meta-analysis of olfactory and gustatory dysfunction in COVID-19.

BACKGROUND: Chemosensory disorders associated with COVID-19 have been widely discussed during the pandemic. We performed a meta-analysis to assess the risk factors for olfactory and gustatory dysfunction in patients with COVID-19. METHODS: Three databases (PubMed, Embase, and Cochrane Library) were searched for studies published between December 1, 2019, and August 31, 2021. We selected random-effects model or fixed-effects model to pool data based on heterogeneity. The results were reported as odds ratios (ORs) or standardized mean differences (SMDs) and the corresponding 95% confidence intervals (CIs). Heterogeneity was reported as I2. RESULTS: Twenty-six studies with a total of 13,813 patients were included. The pooled data indicated that sex (OR 1.47; 95% CI 0.93-2.31), age (SMD -5.80; 95% CI -13.35 to 1.75), smoking (OR 2.04; 95% CI 0.72-5.79), and comorbidity (OR 1.21; 95% CI 0.58-2.53) of patients with COVID-19 had no effect on gustatory dysfunction. Olfactory dysfunction was more likely to occur in older patients with COVID-19 (SMD, -5.22; 95% CI, -8.28 to -2.16). Patients with COVID-19 with nasal congestion (OR 3.41; 95% CI 2.30-5.06) and rhinorrhea (OR 2.35; 95% CI 1.60-3.45) were more prone to olfactory dysfunction. CONCLUSION: These findings emphasize that older patients with COVID-19 are more likely to experience olfactory dysfunction. Symptoms of nasal congestion and rhinorrhea may affect the recognition of olfactory dysfunction.

The COVOSMIA-19 trial: Preliminary application of the Singapore smell and taste test to objectively measure smell and taste function with COVID-19.

Sudden loss of smell and/or taste has been identified as an early symptom of SARS-CoV-2 2019 (COVID-19) infection, and presents an effective target for prompt self-isolation and reducing community spread. The current study sought to develop and test a novel, rapid, self-administered test to objectively measure smell and taste losses associated with COVID-19, and administered self-report questionnaires to characterise symptoms associated with COVID-19 in Singapore. Participants (N = 99) completed questionnaires to record recent changes in smell and taste ability. This was followed by the 'Singapore Smell and Taste Test' (SSTT), a personal, objective testing kit for daily self-assessment of smell and taste function at their place of residence. Seventy-two recruited participants were confirmed as COVID-19 positive at baseline, of which 58 completed the SSTT at home. Of these, 36.2% had objectively measured smell and/or taste loss. The SSTT measures of smell and taste function were positively associated with participants' self-reported smell and taste acuity, and rated smell intensity of 6 common household items. This study presents the first application of the SSTT as a rapid, cost-effective, objective tool to self-monitor smell and taste function in a residential setting, and ensures comparability across individuals through the use of standardised stimuli. The SSTT has potential for future application in populations with limited access to formal COVID-19 testing as a self-administered objective method to monitor sudden changes in smell and taste, and to prompt early self-isolation, in order to reduce community transmission of COVID-19.

Gustatory and Saliva Secretory Dysfunctions in COVID-19 Patients with Zinc Deficiency.

Given the ever-progressing studies on coronavirus disease 2019 (COVID-19), it is critical to update our knowledge about COVID-19 symptomatology and pathophysiology. In the present narrative review, oral symptoms were overviewed using the latest data and their pathogenesis was hypothetically speculated. PubMed, LitCovid, ProQuest, and Google Scholar were searched for relevant studies from 1 April 2021 with a cutoff date of 31 January 2022. The literature search indicated that gustatory dysfunction and saliva secretory dysfunction are prevalent in COVID-19 patients and both dysfunctions persist after recovery from the disease, suggesting the pathogenic mechanism common to these cooccurring symptoms. COVID-19 patients are characterized by hypozincemia, in which zinc is possibly redistributed from blood to the liver at the expense of zinc in other tissues. If COVID-19 induces intracellular zinc deficiency, the activity of zinc-metalloenzyme carbonic anhydrase localized in taste buds and salivary glands may be influenced to adversely affect gustatory and saliva secretory functions. Zinc-binding metallothioneins and zinc transporters, which cooperatively control cellular zinc homeostasis, are expressed in oral tissues participating in taste and saliva secretion. Their expression dysregulation associated with COVID-19-induced zinc deficiency may have some effect on oral functions. Zinc supplementation is expected to improve oral symptoms in COVID-19 patients.

Taste loss as a distinct symptom of COVID-19: a systematic review and meta-analysis.

Chemosensory scientists have been skeptical that reports of COVID-19 taste loss are genuine, in part because before COVID-19 taste loss was rare and often confused with smell loss. Therefore, to establish the predicted prevalence rate of taste loss in COVID-19 patients, we conducted a systematic review and meta-analysis of 376 papers published in 2020-2021, with 241 meeting all inclusion criteria. Drawing on previous studies and guided by early meta-analyses, we explored how methodological differences (direct vs. self-report measures) may affect these estimates. We hypothesized that direct measures of taste are at least as sensitive as those obtained by self-report and that the preponderance of evidence confirms taste loss is a symptom of COVID-19. The meta-analysis showed that, among 138,897 COVID-19-positive patients, 39.2% reported taste dysfunction (95% confidence interval: 35.34%-43.12%), and the prevalence estimates were slightly but not significantly higher from studies using direct (n = 18) versus self-report (n = 223) methodologies (Q = 0.57, df = 1, P = 0.45). Generally, males reported lower rates of taste loss than did females, and taste loss was highest among middle-aged adults. Thus, taste loss is likely a bona fide symptom of COVID-19, meriting further research into the most appropriate direct methods to measure it and its underlying mechanisms.

Exploring the Clinical Utility of Gustatory Dysfunction (GD) as a Triage Symptom Prior to Reverse Transcription Polymerase Chain Reaction (RT-PCR) in the Diagnosis of COVID-19: A Meta-Analysis and Systematic Review.

BACKGROUND: The diagnosis of COVID-19 is made using reverse transcription polymerase chain reaction (RT-PCR) but its sensitivity varies from 20 to 100%. The presence of gustatory dysfunction (GD) in a patient with upper respiratory tract symptoms might increase the clinical suspicion of COVID-19. AIMS: To perform a systematic review and meta-analysis to determine the pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-) and diagnostic odds ratio (DOR) of using GD as a triage symptom prior to RT-PCR. METHODS: PubMed and Embase were searched up to 20 June 2021. Studies published in English were included if they compared the frequency of GD in COVID-19 adult patients (proven by RT-PCR) to COVID-19 negative controls in case control or cross-sectional studies. The Newcastle-Ottawa scale was used to assess the methodological quality of the included studies. RESULTS: 21,272 COVID-19 patients and 52,298 COVID-19 negative patients were included across 44 studies from 21 countries. All studies were of moderate to high risk of bias. Patients with GD were more likely to test positive for COVID-19: DOR 6.39 (4.86-8.40), LR+ 3.84 (3.04-4.84), LR- 0.67 (0.64-0.70), pooled sensitivity 0.37 (0.29-0.47) and pooled specificity 0.92 (0.89-0.94). While history/questionnaire-based assessments were predictive of RT-PCR positivity (DOR 6.62 (4.95-8.85)), gustatory testing was not (DOR 3.53 (0.98-12.7)). There was significant heterogeneity among the 44 studies (I2 = 92%, p < 0.01). CONCLUSIONS: GD is useful as a symptom to determine if a patient should undergo further testing, especially in resource-poor regions where COVID-19 testing is scarce. Patients with GD may be advised to quarantine while repeated testing is performed if the initial RT-PCR is negative. FUNDING: None.

How common are taste and smell abnormalities in COVID-19? A systematic review and meta-analysis.

OBJECTIVE: Olfactory and gustatory dysfunction (OGD) are important early clinical symptoms of COVID-19. We aim to calculate the pooled prevalence of these symptoms and discuss the likely implications on clinical practice such as their use as screening tools and potential prognosis indicators. METHODS: Using a combination of keywords and medical subject headings, we searched for observational studies in the following five databases: Medline/PubMed, Scopus, Cochrane Library, Web of Science, and Google Scholar. Two authors independently screened and selected the final articles according to the inclusion criteria. Two investigators independently assessed the risk of bias in individual studies using the Newcastle-Ottawa Scale. Heterogeneity and publication bias were also assessed. The reported outcome of the pooled analysis was the prevalence of OGD calculated using a random-effect model. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to report results. RESULTS: Seventeen studies with a total sample size of 4149 were included in this meta-analysis. Out of these, 2106 and 2676 patients reported some degree of olfactory and/or gustatory dysfunction with COVID-19, respectively. The reported outcomes were in terms of pooled prevalence, with gustatory dysfunction being 57.33% and olfactory dysfunction being 59.69%, a significantly high occurrence. CONCLUSION: There is a high occurrence of smell and taste impairment in COVID-19. Given the lack of objective testing for detecting OGD in most studies, the high prevalence found is likely to be an underestimation of the true prevalence. This implies that physicians must use them as reliable early indicators of COVID-19 and employ them before using expensive tests.

New Onset of Smell and Taste Loss Are Common Findings Also in Patients With Symptomatic COVID-19 After Complete Vaccination.

The aim of this study is to investigate the clinical profile of patients who developed coronavirus disease 2019 (COVID-19) after full vaccination. Demographic, epidemiological and clinical data were collected through medical records and online patient-reported outcome questionnaire from patients who developed symptomatic SARS-CoV-2 infection, confirmed by nasopharyngeal swab, at least 2 weeks after completion of vaccination. A total of 153 subjects were included. The most frequent symptoms were: asthenia (82.4%), chemosensory dysfunction (63.4%), headache (59.5%), runny nose (58.2%), muscle pain (54.9%), loss of appetite (54.3%), and nasal obstruction (51.6%). Particularly, 62.3% and 53.6% of subjects reported olfactory and gustatory dysfunction, respectively. Symptom severity was mild or moderate in almost all cases. Chemosensory dysfunctions have been observed to be a frequent symptom even in subjects who contracted the infection after full vaccination. For this reason, the sudden loss of smell and taste could continue to represent a useful and specific diagnostic marker to raise the suspicion of COVID-19 even in vaccinated subjects. In the future, it will be necessary to establish what the recovery rate is in these patients. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:419-421, 2022.

Treatment and Prognosis of COVID-19 Associated Olfactory and Gustatory Dysfunctions.

Olfactory and gustatory dysfunctions are important initial symptoms of coronavirus disease 2019 (COVID-19). However, the treatment modality for these conditions has yet to be clearly established. Therefore, most physicians have been administering empirical treatments for COVID-19-associated olfactory dysfunction, including topical or systemic steroid supplementation and olfactory training. In this literature review, we summarize the clinical course and effects of various treatments currently being conducted in patients with COVID-19-associated olfactory and gustatory dysfunctions.