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European Review For Medical and... Jan 2021The novel coronavirus disease-19 (COVID-19) pandemic had intense social and economic effects. Patients infected with COVID-19 may present with a series of conditions. A... (Review)
Review
OBJECTIVE
The novel coronavirus disease-19 (COVID-19) pandemic had intense social and economic effects. Patients infected with COVID-19 may present with a series of conditions. A considerable number of patients express taste and smell disturbances as a prodromal, coexistent, or as the only manifestation of COVID-19 infection. The objective of the present review is to review the hypothetical mechanisms of action and etiopathogenesis of dysgeusia in COVID-19 patients.
MATERIALS AND METHODS
Multiple scientific databases were explored, including PubMed, Medline, Scopus, Cochrane-library, LILACS, Livivo and OpenGrey. All types of articles that discussed the pathogenesis of dysgeusia were included, while articles that described dysgeusia without detail about its mode of action were excluded.
RESULTS
A total of 47 articles, with different designs, were included in this review. These articles suggested direct viral neural invasion to olfactory and gustatory nerves, viral cytotoxicity to taste buds, angiotensin II imbalance, augmented pro-inflammatory cytokines, and disturbances in salivary glands and sialic acid. COVID-19 induced-dysgeusia was also associated with systemic diseases, medications, zinc, chemicals, and disinfectants.
CONCLUSIONS
The most likely cause of transient dysgeusia in COVID-19 is peripheral neurotropism and direct toxicity to taste buds or olfactory epithelium. Other factors may also play a contributory role in dysgeusia, such as a defect in the quality and quantity of saliva, pro-inflammatory cytokines, angiotensin II accumulation, systemic diseases, hypozincemia, and excessive use of chemicals.
Topics: Ageusia; COVID-19; Dysgeusia; Humans; Olfaction Disorders; Prospective Studies; Renin-Angiotensin System; Retrospective Studies; Smell; Taste
PubMed: 33577069
DOI: 10.26355/eurrev_202101_24683 -
Current Nutrition Reports Sep 2020The sense of taste has evolved to enable the identification of appropriate substances to consume, to acquire nutrients, and to avoid consuming potential toxins. Five... (Review)
Review
PURPOSE OF REVIEW
The sense of taste has evolved to enable the identification of appropriate substances to consume, to acquire nutrients, and to avoid consuming potential toxins. Five basic taste classes have been recognized, although there may be others, including metallic taste, which have not been well defined. The purpose of this review was to survey available data from diverse sources to determine how much was known about the molecular basis for metallic taste.
RECENT FINDINGS
Metallic taste has been studied in the context of dysgeusia, primarily using non-heme iron as an inducer of metallic taste sensation. However, recent efforts by industry to develop plant-based meat substitutes have suggested that iron in the form of heme may be the main molecule underlying the taste of meat. Little work has been done on heme as a taste molecule. Data support a primary role for heme in metallic taste that may have evolved as part of a means to consume and preserve elemental iron for physiological needs.
Topics: Heme; Humans; Iron; Taste; Taste Perception
PubMed: 32572703
DOI: 10.1007/s13668-020-00320-6 -
Journal of Medical Virology Apr 2021Various new clinical signs and symptoms, such as dysfunction of smell (anosmia) and taste (dysgeusia) have emerged ever since the coronavirus disease 2019 (COVID-19)...
Various new clinical signs and symptoms, such as dysfunction of smell (anosmia) and taste (dysgeusia) have emerged ever since the coronavirus disease 2019 (COVID-19) pandemic begun. The objective of this study was to identify the clinical presentation and factors associated with 'new loss/change of smell (anosmia) or taste (dysgeusia)' at admission in patients positive by real time polymerase chain reaction for SARS-CoV-2 infection. All adult COVID-19 patients with new onset anosmia or dysgeusia at admission were included in study group. Equal number of age and gender matched COVID-19 patients without anosmia or dysgeusia at admission were included in the control group. A total of 261 COVID-19 patients were admitted during the study period of which 55 (21%) had anosmia and or dysgeusia. The mean (SD) age was 36 (13) years and majority were males (58%, n = 32). Comorbidity was present in 38% of cases (n = 21). Anosmia and dysgeusia were noted in more than 1/5th of the cases. Anosmia (96%, n = 53) was more common than dysgeusia (75%, n = 41). Presence of both ansomia and dysgeusia was noted in 71% of patients (n = 39). On comparing the cases with the controls, on univariate analysis, fever (higher in cases), rhinitis (lower in cases), thrombocytopenia, elevated creatinine and bilirubin (all higher in cases) were significantly associated with anosmia or dysgeusia. On multivariate analysis, only rhinitis (odds ratio [OR]: 0.28; 95% confidence interval [CI]: 0.09-0.83; p = .02) thrombocytopenia (OR: 0.99; 95% CI: 0.99-0.99; p = .01) and elevated creatinine (OR: 7.6; 95% CI: 1.5-37.6; p = .01) remained significant. In this retrospective study of COVID-19 patients, we found anosmia and dysgeusia in more than 1/5th of the cases. Absence of rhinitis, low platelet counts and elevated creatinine were associated with anosmia or dysgeusia in these patients.
Topics: Adult; Anosmia; COVID-19; Case-Control Studies; Dysgeusia; Female; Humans; India; Male; Middle Aged; Multivariate Analysis; Odds Ratio; Pandemics; Platelet Count; Real-Time Polymerase Chain Reaction; Retrospective Studies; Rhinitis; SARS-CoV-2; Thrombocytopenia
PubMed: 33417259
DOI: 10.1002/jmv.26784 -
Sichuan Da Xue Xue Bao. Yi Xue Ban =... Mar 2023The taste buds in the human tongue contain specialized cells that generate taste signals when they are stimulated. These signals are then transmitted to the central... (Review)
Review
The taste buds in the human tongue contain specialized cells that generate taste signals when they are stimulated. These signals are then transmitted to the central nervous system, allowing the human body to distinguish nutritious substances from toxic or harmful ones. This process is critical to the survival of humans and other mammals. A number of studies have shown that dysgeusia, or taste disorder, is a common complication of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which can severely affect patients' nutritional intake and quality of life. Based on the physiological process of taste perception, the direct causes of dysgeusia include dysfunction of taste receptors and damage to the taste nervous system, while indirect causes include genetic factors, aging-related changes, bacterial and viral infections, and cancer treatments such as radiotherapy and chemotherapy. The pathogenic factors of dysgeusia are complicated, further research is needed to fully understand the underlying mechanisms, and some of the reported findings and conclusions still need further validation. All these form a great challenge for clinical diagnosis of the cause and targeted treatment of dysgeusia. Herein, we reviewed published research on the physiological process of taste perception, the potential mechanisms of taste disorders related to SARS-CoV-2 infection, and strategies for prevention and treatment, providing theoretical support for establishing and improving the comprehensive management of COVID-19 complicated by taste disorders.
Topics: Humans; COVID-19; Dysgeusia; Taste Perception; SARS-CoV-2; Taste; Quality of Life; Smell; Olfaction Disorders; Taste Disorders
PubMed: 36949695
DOI: 10.12182/20230260306 -
Journal of Dental Anesthesia and Pain... Oct 2020Fibromyalgia is a syndrome characterized by chronic pain in the skeletal system accompanied by stiffness, sleep disturbance, fatigue, and psychiatric problems, such as... (Review)
Review
Fibromyalgia is a syndrome characterized by chronic pain in the skeletal system accompanied by stiffness, sleep disturbance, fatigue, and psychiatric problems, such as anxiety and depression. Fibromyalgia commonly affects orofacial health, presenting with a variety of oral manifestations, including temporomandibular disorder, xerostomia, glossodynia, and dysgeusia. Therefore, oral healthcare providers need to be aware of this clinical entity to effectively manage oral symptoms and provide proper oral self-care modification and education on the nature of fibromyalgia. This review focuses on the epidemiology, pathophysiology, clinical manifestation, diagnosis, orofacial concerns, and treatment of fibromyalgia.
PubMed: 33195804
DOI: 10.17245/jdapm.2020.20.5.263 -
Neurology. Clinical Practice Apr 2021To evaluate the prevalence of hyposmia and dysgeusia in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and their temporal...
OBJECTIVE
To evaluate the prevalence of hyposmia and dysgeusia in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and their temporal relationship with the onset of other symptoms.
METHODS
We performed a retrospective analysis of patients admitted during the month of March 2020 to the nonintensive COVID unit of Udine University Hospital on the basis of a positive swab test and/or of clinical-radiologic signs of SARS-CoV-2 infection. Patients were interviewed with a standardized questionnaire. Clinical and laboratory data were collected. Data were analyzed with descriptive statistics, and results expressed as point estimates and 95% confidence intervals (CIs).
RESULTS
Of 141 patients admitted, 93 were interviewed. Hyposmia and dysgeusia were present in 58 cases (62.4%). In 22.4% of them, olfactory and gustatory impairment clearly preceded systemic symptoms. The presence of active smoking was very limited in both groups: 8.6% in hyposmic vs 2.9% in normosmic patients (odds ratio 3.2; 95% CI 0.3-28.6). Moreover, total leukocytes and neutrophils count were respectively 23% (effect estimate 1.23; 95% CI 1.06-1.42) and 29% (effect estimate 1.29; 95% CI 1.07-1.54) lower in the hyposmic cohort. No difference was found for other inflammatory biomarkers.
CONCLUSIONS
Hyposmia and dysgeusia are common in SARS-CoV-2 infection and can precede systemic symptoms. They should be actively searched and prompt close monitoring and isolation until infection is confirmed or disproven. The lower number of total leukocytes and neutrophils in hyposmic patients might indicate an early-phase virus-induced cytopenia.
PubMed: 33842076
DOI: 10.1212/CPJ.0000000000001029 -
Nutrients Sep 2021Oral cancer is the most common tumor of the head and neck region. Its management is based on surgical and systemic therapies. Taste disorders represent the most common... (Review)
Review
Oral cancer is the most common tumor of the head and neck region. Its management is based on surgical and systemic therapies. Taste disorders represent the most common side effect of these treatments; indeed, dysgeusia is noted by 70% of oral cancer patients. Despite survival remaining the primary endpoint of cancer patients, taste impairments can cause psychological distress. This comprehensive review describes the last decade's knowledge from the literature regarding taste alterations in patients with oral and oropharyngeal squamous cell carcinoma. A total of 26 articles in English, including prospective, cross-sectional, and case-control studies, and clinical trials were evaluated. Literature analysis shows that anti-cancer treatments can destroy taste cells, decrease and alter their receptors, and interrupt nerve transmission. Furthermore, the tumour itself can destroy the oral mucosal lining, which encloses the taste buds. Dysgeusia typically occurs in 3-4 weeks of treatments, and usually taste sensation is recovered within 3-12 months. However, some patients exhibit incomplete or no recovery, even several years later. Thus, dysgeusia can become a chronic issue and negatively influence patients' quality of life, worsening their dysphagia and their nutritional status. Physicians should be focused on preventing oncological treatment-related symptoms, offering the most suitable personalized support during therapy.
Topics: Dysgeusia; Humans; Mouth Neoplasms; Oropharyngeal Neoplasms
PubMed: 34684326
DOI: 10.3390/nu13103325 -
Laryngo- Rhino- Otologie Aug 2021
Topics: Dysgeusia; Humans; Quality of Life; Smoking
PubMed: 34320671
DOI: 10.1055/a-1499-5488 -
Journal of Dental Research Oct 2023COVID-19, mainly manifested as acute respiratory distress syndrome, has afflicted millions of people worldwide since 2019. Taste dysfunction is a common early-stage... (Review)
Review
COVID-19, mainly manifested as acute respiratory distress syndrome, has afflicted millions of people worldwide since 2019. Taste dysfunction is a common early-stage symptom of COVID-19 infection that burdens patients for weeks or even permanently in some cases. Owing to its subjectivity and complexity, the mechanism of taste disorder is poorly studied. Previous studies have reported that the COVID-19 entry receptors are highly expressed in taste buds, thereby intensifying the cytocidal effect. Taste receptor cells are vulnerable to inflammation, and the COVID-19-induced cytokine storm causes secondary damage to taste function. Interferon and various proinflammatory cytokines can trigger cell apoptosis and disrupt the renewal of taste bud stem cells. This immune response can be further enhanced by the accumulation of Angiotensin II (Ang II) caused by an unbalanced local renin-angiotensin system (RAS) system. In addition, severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is neurotropic and can invade the brain through the olfactory bulb, affecting the nervous system. Other factors, such as host zinc deficiency, genetic susceptibility, sialic acid, and some neurotransmitters, also contribute to the pathogenesis process. Although several medical interventions have displayed effectiveness, only a few strategies exist for the treatment of postinfectious dysgeusia. Stem cell-based taste regeneration offers promise for long-term taste disorders. Clinical studies have demonstrated that stem cells can treat long COVID-19 through immune regulation. In dysgeusia, the differentiation of taste bud stem cells can be stimulated through exogenous epithelial-derived and neural-derived factors to regenerate taste buds. Tongue organoids are also emerging as functional taste buds, offering new insights into the study of taste regeneration. This review presents the current evidence of the pathogenesis of COVID-19-related dysgeusia, summarizes currently available treatments, and suggests future directions of taste regeneration therapy.
Topics: Humans; COVID-19; SARS-CoV-2; Dysgeusia; Post-Acute COVID-19 Syndrome; Taste Disorders; Taste Buds; Taste
PubMed: 37729625
DOI: 10.1177/00220345231182926 -
Zhurnal Nevrologii I Psikhiatrii Imeni... 2022Taste disturbances are present in 20.3-88.0% of COVID-19 cases and are the first signs of infection in 11.0-18.1% of cases. They often manifested 3-7 days after the...
Taste disturbances are present in 20.3-88.0% of COVID-19 cases and are the first signs of infection in 11.0-18.1% of cases. They often manifested 3-7 days after the onset of general respiratory symptoms and last 2 to 16 days, followed by recovery. There are also prolonged disturbances of taste sensation (up to 61-76 days or more), which is associated with damage to various types of receptor cells of the mucous membrane of the tongue. More severe taste disturbances are recorded in the elderly. In women, changes in taste sensation are noted more often than in men, and with a longer recovery period. Severe and critical forms of taste disorders predominate in COVID-19; dysgeusia, as a rule, prevails over hypogeusia and ageusia. Taste disturbance is a common clinical symptom in COVID-19, which can and should be considered as a marker of early manifestation of coronavirus infection.
Topics: Male; Female; Humans; Aged; COVID-19; Taste Disorders; Ageusia; Dysgeusia; Olfaction Disorders
PubMed: 36537627
DOI: 10.17116/jnevro202212212123