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The Impact of Aging and Medical Status on Dysgeusia

Published:February 17, 2016DOI:https://doi.org/10.1016/j.amjmed.2016.02.003

      Abstract

      Disorders of taste and smell can cause an aversion to food in a sick patient and therefore affect his/her ability to maintain optimal nutrition. This can lead to a reduced level of strength, muscle mass, function, and quality of life. Additionally, reduced ability to differentiate between various intensities or concentrations of a tastant can result in increased intake of salt and sugar and exacerbation of chronic diseases such as heart failure and diabetes. These implications can be heightened in the elderly, who are particularly frail and are challenged by polypharmacy and multiple comorbid conditions. In this article, we will review the prevalence, etiology, and management of taste disorders. Additionally, we will review the association between taste and smell disorders and how disorders of smell can affect perception of taste.

      Keywords

      Clinical Significance
      • Dysgeusia is fairly prevalent in older adults, especially those admitted to hospitals or residing in long-term care facilities.
      • Dysgeusia can impact a patient's enjoyment of food, overall nutritional status, and management of chronic diseases.
      • Review of medications and attention to oral health should be prioritized in patients presenting with dysgeusia.

      Clinical Scenario

      Ms. Edwards is an 89-year-old female nursing home resident admitted to an inpatient medicine service for failure to thrive, severe malnutrition, loss of appetite, and a 25-pound weight loss in the past 6 months. Past medical history is significant for osteoporosis, congestive heart failure, chronic renal insufficiency, and hypothyroidism. She has been hospitalized twice during the past 6 months for exacerbation of heart failure, with resultant adjustment of her heart failure medication regimen. She notes a persistent loss of appetite and lack of taste in her food for the past 6 months, preventing her from enjoying her food. She denies any difficulty swallowing, nausea, vomiting, or abdominal pain on eating. She also denies being depressed. Basic blood work indicated acute renal insufficiency due to dehydration, which was corrected with intravenous fluids. Other blood work including electrolytes, liver function, and thyroid function labs were unremarkable. She underwent an upper gastrointestinal endoscopy and a colonoscopy, which failed to show any ulcers or evidence of malignancy.

      Terminology and Definitions

      Taste disorders (dysgeusias) can be classified into qualitative and quantitative disorders. The qualitative disorders include parageusia (inadequate or wrong taste perception elicited by a stimulus) and phantogeusia (presence of a persistent, unpleasant taste in the absence of any stimulus). The quantitative disorders include ageusia (a complete loss of the ability to taste), hypogeusia (a partial loss of the ability to taste), and hypergeusia (enhanced gustatory sensitivity).
      • Fark T.
      • Hummel C.
      • Hahner A.
      • Nin T.
      • Hummel T.
      Characteristics of taste disorders.
      Burning mouth syndrome (BMS), also referred to as glossodynia or stomatodynia, is a sensation of spontaneous, continuous burning pain felt in the tongue or oral mucosa, commonly seen in postmenopausal women.
      Impairment in sense of smell is called dysosmia and complete loss of sense of smell is called anosmia.

      Prevalence

      The National Health and Nutrition Examination Survey (NHANES) 2011-2012 reported that more than 5% of the over 142 million US respondents experienced taste disorders, and more than 10% experienced smell disorder in the past 12 months. Sex was not associated with the prevalence of either disorder, but increasing age was associated with increasing prevalence of both taste and smell disorders.
      • Bhattacharyya N.
      • Kepnes L.J.
      Contemporary assessment of the prevalence of smell and taste problems in adults.
      Additionally, taste disorders are more prevalent in hospitalized and institutionalized older adults compared with those living in the community.
      • Solemdal K.
      • Sandvik L.
      • Willumsen T.
      • Mowe M.
      Taste ability in hospitalised older people compared with healthy, age-matched controls.
      • Toffanello E.D.
      • Inelmen E.M.
      • Imoscopi A.
      • et al.
      Taste loss in hospitalized multimorbid elderly subjects.
      Glazar et al
      • Glazar I.
      • Urek M.M.
      • Brumini G.
      • Pezelj-Ribaric S.
      Oral sensorial complaints, salivary flow rate and mucosal lesions in the institutionalized elderly.
      reported taste disturbance in 13.9% of institutionalized individuals, compared with 3.2% of community-dwelling individuals.
      • Glazar I.
      • Urek M.M.
      • Brumini G.
      • Pezelj-Ribaric S.
      Oral sensorial complaints, salivary flow rate and mucosal lesions in the institutionalized elderly.
      Aging can affect gustatory function, as observed by increasing of electrogustometry thresholds and reduction in density of fungiform papillae.
      • Pavlidis P.
      • Gouveris H.
      • Anogeianaki A.
      • Koutsonikolas D.
      • Anogianakis G.
      • Kekes G.
      Age-related changes in electrogustometry thresholds, tongue tip vascularization, density, and form of the fungiform papillae in humans.
      Numerous medication conditions and surgeries (summarized in Table 1 and elaborated below in the article) are also associated with dysgeusia.
      Table 1Chronic Medical Conditions Contributing to Dysgeusia
      Sinusitis/upper respiratory infections
      Chronic hepatitis C
      Chronic kidney disease
      Diabetes mellitus
      Heart diseases
      Thyroid disorders, esp. hypothyroidism
      Cognitive disorders/dementias
      Parkinson disease
      Malignancies
      Dental/oral: periodontal disease, dental caries, oropharyngeal candidiasis
      Mental health disorders and epilepsy

      Anatomy

      Gustatory receptor cells are present in the taste buds on the dorsal and lateral surfaces of the tongue, the soft palate, uvula, larynx, pharynx, epiglottis, and esophagus. These receptor cells are innervated by afferent neurons and are able to regenerate with a half-life of about 15 days. Transduction of the 5 taste stimuli—acid, salt, bitter, sweet, and umami (a pleasant savory taste imparted by glutamate)—occurs by different chemical transmission systems. Taste sensations are transported via 3 cranial nerves: cranial nerve VII innervates the anterior third of the tongue and the palate; cranial nerve IX innervates the back of the tongue; and cranial nerve X innervates the oropharynx and the pharyngeal portion of the epiglottis. Additional taste receptors are found in the small intestine. The trigeminal nerve (cranial nerve V) is also involved in the transfer of sensations such as the temperature, texture, and spiciness of food. The brain stem, thalamus, and the anterior insula play a key role in the processing of the taste information by the central nervous system.
      • Deems D.A.
      • Doty R.L.
      • Settle R.G.
      • et al.
      Smell and taste disorders, a study of 750 patients from the University of Pennsylvania Smell and Taste Center.
      Due to involvement of multiple nerve tracts, it's rather difficult to completely lose the sense of taste.
      Olfaction, on the other hand, relies only on the olfactory nerve, and its axons pass through the cribriform plate of the ethmoid bone prior to dissemination on the surface of the olfactory bulb. This makes it highly vulnerable to injury during head trauma. In this situation, a complete loss of sense of smell is more common.

      Etiology

      Impairment in Sense of Olfaction and its Effect on Taste

      Because the taste sensations are conducted by 3 major nerves, a complete loss of taste (ageusia) is very rare and occurs in only 3% of all patients with dysgeusia.
      • Fark T.
      • Hummel C.
      • Hahner A.
      • Nin T.
      • Hummel T.
      Characteristics of taste disorders.
      Among those patients presenting for evaluation of loss of taste and smell, 70% report loss of smell alone or in addition to loss of taste. Less than 10% report an isolated loss of taste, while only 4% have a solitary measurable loss in gustation.
      • Fark T.
      • Hummel C.
      • Hahner A.
      • Nin T.
      • Hummel T.
      Characteristics of taste disorders.
      • Deems D.A.
      • Doty R.L.
      • Settle R.G.
      • et al.
      Smell and taste disorders, a study of 750 patients from the University of Pennsylvania Smell and Taste Center.
      Therefore, olfactory symptoms should be explored and olfactory function be evaluated in patients presenting with a complaint of loss of taste.

      Genetic

      In a study involving patients with phantogeusia, there was increased expression rate of some of the T2R taste receptor genes compared with controls, hinting that increased expression of taste receptor genes may be involved in the pathogenesis of phantogeusia.
      • Hirai R.
      • Takao K.
      • Onoda K.
      • Kokubun S.
      • Ikeda M.
      Patients with phantogeusia show increased expression of T2R taste receptor genes in their tongues.

      Postoperative

      Middle ear surgeries with resultant transection of the chorda tympani nerve can result in gustatory impairment.
      • Just T.
      • Pau H.W.
      • Witt M.
      • Hummel T.
      Contact endoscopic comparison of morphology of human fungiform papillae of healthy subjects and patients with transected chorda tympani nerve.
      Additionally, tonsillectomies, dental procedures such as extractions and treatment of abscessed teeth, and wearing dental prostheses can contribute to phantogeusia and glossodynia.
      • Fark T.
      • Hummel C.
      • Hahner A.
      • Nin T.
      • Hummel T.
      Characteristics of taste disorders.
      There have been case reports of ageusia after the use of laryngeal mask airways for surgery, and compression of the lingual nerve has been hypothesized as the cause. Local anesthetic injected near the inferior alveolar nerve during dental procedures has been reported to cause ipsilateral loss of taste and atrophy of fungiform papillae. However, these symptoms have been noted to resolve in a few months.
      • Hotta M.
      • Endo S.
      • Tomita H.
      Taste disturbance in two patients after dental anesthesia by inferior alveolar nerve block.

      Medications

      Numerous medicines are excreted in saliva by carrier-mediated transport or passive diffusion.
      • Lee N.
      • Duan H.
      • Hebert M.F.
      • Liang C.J.
      • Rice K.M.
      • Wang J.
      Taste of a pill: organic cation transporter-3 (OCT3) mediates metformin accumulation and secretion in salivary glands.
      They can affect sense of taste by various mechanisms including drug–receptor interaction, disturbance of action potential propagation in cell membranes of afferent and efferent neurons, and alteration of the neurotransmitter function. Additionally, limiting the access of taste chemicals to sensing receptors due to mucosal dryness, closing of taste pores, or altering the constituents of mucous or saliva can also impact the sense of taste.
      • Tuccori M.
      • Lapi F.
      • Testi A.
      • et al.
      Drug-induced taste and smell alterations: a case/non-case evaluation of an Italian database of spontaneous adverse drug reaction reporting.
      A review of the Italian national database of spontaneous adverse drug reactions (ADR) (Agenzia Italiana del Farmaco) from 1988-2008 showed that taste alteration alone was reported in 75% of cases of ADRs, and both taste and smell impairment were noted in 13% of ADRs. Macrolides, antimycotics, fluoroquinolones, protein kinase inhibitors, angiotensin-converting enzyme inhibitors, HMG-CoA reductase inhibitors (statins), and proton pump inhibitors were the leading culprits.
      • Tuccori M.
      • Lapi F.
      • Testi A.
      • et al.
      Drug-induced taste and smell alterations: a case/non-case evaluation of an Italian database of spontaneous adverse drug reaction reporting.
      Resolution of symptoms varied, with improvement reported within days to a few months after discontinuation of the offending medicine.
      Antiretroviral medications have been associated with dysgeusia in human immunodeficiency virus patients.
      • Raja J.V.
      • Rai P.
      • Khan M.
      • Banu A.
      • Bhuthaiah S.
      Evaluation of gustatory function in HIV-infected subjects with and without HAART.
      Chemotherapeutic drugs used for treatment of cancers, especially 5-fluorouracil and its oral analogs, have also been associated with dysgeusias, with greater prevalence in the elderly.
      • Miles D.
      • Baselga J.
      • Amadori D.
      • et al.
      Treatment of older patients with HER2-positive metastatic breast cancer with pertuzumab, trastuzumab, and docetaxel: subgroup analyses from a randomized, double-blind, placebo-controlled phase III trial (CLEOPATRA).
      Numerous other commonly prescribed drugs, described in Table 2, can contribute to dysgeusia.
      Table 2Medications Contributing to Dysgeusia
      Medication Groups Frequently Associated with DysgeusiaCommon Medicines in the Groups Associated with Dysgeusia
      Antimicrobial medicinesMacrolides, fluoroquinolones, ampicillin, metronidazole, tetracycline, trimethoprim-sulfamethoxazole, amphotericin B, terbinafine and other antimycotic drugs
      Angiotensin-converting enzyme (ACE) inhibitorsCaptopril, ramipril
      Antiarrhythmic medicationsAmiodarone, procainamide
      HMG-CoA reductase inhibitors (statins)Atorvastatin, simvastatin
      Proton pump inhibitors (PPI)
      Anti-retroviral medicationsAtazanavir, darunavir, and ritonavir
      Anti-epileptic medicationsCarbamazepine, phenytoin, topiramate
      DiureticsAcetazolamide
      Dopamine precursorLevodopa
      Protein kinase inhibitorsSunitinib, erlotinib, imatinib
      Anticholinergic medicinesAntispasmodics, antimuscarinics, tricyclic anti-depressants
      Psychiatric medicinesLithium, aripiprazole
      Gout medicinesColchicine, allopurinol
      Muscle relaxantsBaclofen
      Endocrine medicationsAntithyroid medications, corticosteroids, levothyroxine
      Chemotherapeutic agents5-fluorouracil, cisplatin

      Nicotine

      Smoking can affect taste acuity, as smokers have increased electrogustometry thresholds and decreased vascularization and density of fungiform papillae compared with nonsmokers.
      • Pavlidis P.
      • Gouveris C.
      • Kekes G.
      • Maurer J.
      Changes in electrogustometry thresholds, tongue tip vascularization, density and form of the fungiform papillae in smokers.

      Dementia

      Patients with mild cognitive impairment and Alzheimer dementia have increased impairment in olfaction and taste compared with controls.
      • Steinbach S.
      • Hundt W.
      • Vaitl A.
      • et al.
      Taste in mild cognitive impairment and Alzheimer's disease.
      Alzheimer dementia and vascular dementia can affect the insula and therefore, taste cognition.
      • Suto T.
      • Meguro K.
      • Nakatsuka M.
      • et al.
      Disorders of “taste cognition” are associated with insular involvement in patients with Alzheimer's disease and vascular dementia: “Memory of food is impaired in dementia and responsible for poor diet”.
      Additionally, medications prescribed for management of dementias (eg, cholinesterase inhibitors) can also contribute to taste disturbance.
      Up to 70% of patients with Parkinson disease experience dysosmia,
      • Haehner A.
      • Boesveldt S.
      • Berendse H.W.
      • et al.
      Prevalence of smell loss in Parkinson's disease—a multicenter study.
      and 9% experience dysgeusia.
      • Kashihara K.
      • Hanaoka A.
      • Imamura T.
      Frequency and characteristics of taste impairment in patients with Parkinson's disease: results of a clinical interview.
      Lewy body-related degeneration has been observed in pathological examination of the olfactory bulbs in patients with Parkinson disease, which can explain the strong association between dysosmia and Parkinson disease.
      • Woda A.
      • Dao T.
      • Gremeau-Richard C.
      Steroid dysregulation and stomatodynia (burning mouth syndrome).
      As taste information also connects to the amygdala and hippocampus, patients with Parkinson disease can experience dysgeusia. Additionally, patients with Parkinson disease may have underlying depression, poor oral hygiene, gastrointestinal disease, and zinc deficiency, which may explain dysgeusia in absence of dysosmia.

      Endocrine Disorders

      Diabetes can affect gustatory function. Diabetics have been observed to have higher electrogustometric thresholds and lower density of the fungiform papillae compared with age-matched controls.
      • Pavlidis P.
      • Gouveris H.
      • Kekes G.
      • Maurer J.
      Electrogustometry thresholds, tongue tip vascularization, and density and morphology of the fungiform papillae in diabetes.
      This can affect their food choices and glycemic control.
      Both dysgeusia and dysosmia have been reported in patients with untreated hypothyroidism, with improvement in symptoms after treatment of the thyroid disease.
      • McConnell R.J.
      • Menendez C.E.
      • Smith F.R.
      • Henkin R.I.
      • Rivlin R.S.
      Defects of taste and smell in patients with hypothyroidism.
      BMS has also been reported in a few case series as a presenting feature of hypothyroidism.
      • Femiano F.
      • Lanza A.
      • Buonaiuto C.
      • et al.
      Burning mouth syndrome and burning mouth in hypothyroidism: proposal for a diagnostic and therapeutic protocol.
      Due to increased prevalence of BMS in postmenopausal women, steroid dysregulation has also been hypothesized as a possible contributor.
      • Woda A.
      • Dao T.
      • Gremeau-Richard C.
      Steroid dysregulation and stomatodynia (burning mouth syndrome).

      Chronic Diseases

      Upper respiratory disorders are frequently associated with both taste and smell disorders. Up to 38% of individuals with taste problems in NHANES 2011-2012 reported experiencing nasal congestion.
      • Bhattacharyya N.
      • Kepnes L.J.
      Contemporary assessment of the prevalence of smell and taste problems in adults.
      Additionally, survey participants with a history of heart failure, heart attack, liver problems, and impaired vision reported increased taste disturbance in the past 12 months compared with participants who did not have these medical conditions. This association was valid even after adjustment for risk factors including head or nasal injury or sinus infections.
      • Shiue I.
      Adult taste and smell disorders after heart, neurological, respiratory and liver problems: US NHANES, 2011-2012.
      Dysgeusia, including metallic taste and impairment in identification and intensity of different flavors, has also been observed in individuals with chronic kidney disease and chronic hepatitis C. Individuals with chronic hepatitis C experience problems in identification and intensity of different food flavors. Numerous hypotheses have been put forth, including alteration in function of affected brain cells in the taste area by the virus, and alteration in secretion of neurotransmitters involved in taste perception.
      • Musialik J.
      • Suchecka W.
      • Klimacka-Nawrot E.
      • Petelenz M.
      • Hartman M.
      • Blonska-Fajfrowska B.
      Taste and appetite disorders of chronic hepatitis C patients.
      Uremic state in chronic kidney disease can affect salivary flow leading to dry mouth and dysgeusia.
      • Manley K.J.
      Saliva composition and upper gastrointestinal symptoms in chronic kidney disease.
      Additionally, medications and zinc deficiency can affect taste perception in patients with chronic kidney disease.
      The association between heart diseases and taste disturbance is usually due to concomitant renal dysfunction and adverse effects of medications.

      Electrolyte and Nutritional Deficiency

      The principle nutrient deficiency commonly associated with taste loss is that of zinc. A reduction in number and size of taste buds in zinc-deficient animal models has been demonstrated. However, this has not been consistently verified in double-blind trials. Vitamin A deficiency has been associated with atrophy of taste buds in animal models, and vitamin B12 deficiency can lead to atrophic glossitis, resulting in loss of taste sensation. Additionally, electrolyte disturbances including hyponatremia have been reported to cause taste disturbance.
      • Hopcraft M.S.
      • Morgan M.V.
      • Satur J.G.
      • Wright F.A.
      Utilizing dental hygienists to undertake dental examination and referral in residential aged care facilities.

      Oral/Dental Conditions

      The mouth is the gateway for food into the body. Therefore, changes in the oral cavity can have an impact on taste. Older adults frequently have poor oral hygiene with increased dental caries and periodontal disease. Poor oral health may be more pronounced in institutionalized older adults where access to dental care may be limited and daily oral hygiene inadequate.
      • Hopcraft M.S.
      • Morgan M.V.
      • Satur J.G.
      • Wright F.A.
      Utilizing dental hygienists to undertake dental examination and referral in residential aged care facilities.
      Additionally, xerostomia (dry mouth) is frequently experienced by patients taking numerous medications and patients with dehydration, diabetes, Sjögren disease, and thyroid conditions.
      Dental caries, periodontal disease, candidiasis, stomatitis, dental-alveolar infections, xerostomia, tumors, and mechanical trauma can lead to taste disorders in the elderly.
      • Glazar I.
      • Urek M.M.
      • Brumini G.
      • Pezelj-Ribaric S.
      Oral sensorial complaints, salivary flow rate and mucosal lesions in the institutionalized elderly.
      • Brauchle F.
      • Noack M.
      • Reich E.
      Impact of periodontal disease and periodontal therapy on oral health-related quality of life.
      Dentures, especially those that do not fit well, can cause traumatic ulcers, stomatitis, and fungal infections. Additionally, patients wearing dentures that cover the hard palate report increased taste problems.
      • Yoshinaka M.
      • Yoshinaka M.F.
      • Ikebe K.
      • Shimanuki Y.
      • Nokubi T.
      Factors associated with taste dissatisfaction in the elderly.

      Malignancies

      Chemosensory dysfunction is fairly prevalent in individuals with advanced malignancies. One study showed that 86% of individuals with advanced cancer (defined as locally recurrent or metastatic) reported some degree of chemosensory abnormality, especially persistent bad taste in the mouth and taste distortion.
      • Hutton J.L.
      • Baracos V.E.
      • Wismer W.V.
      Chemosensory dysfunction is a primary factor in the evolution of declining nutritional status and quality of life in patients with advanced cancer.
      Radioactive iodine therapy for thyroid cancers has been shown to affect salivary flow, especially from parotid glands, and high-dose radioactive iodine therapy has been associated with increased oral pain and problems with taste and chewing.
      • Almeida J.P.
      • Vartanian J.G.
      • Kowalski L.P.
      Clinical predictors of quality of life in patients with initial differentiated thyroid cancers.
      Head and neck cancer patients treated with radiotherapy or chemotherapeutic agents, or both, can develop altered taste acuity, radiation-induced xerostomia, and dysphagia, which can lead to anorexia. However, with the use of intensity-modulated radiotherapy in the treatment of head and neck cancer, >80% of cancer survivors reported normal or near-normal taste function at 3 and 5 years after intensity-modulated radiotherapy.
      • Chen A.M.
      • Daly M.E.
      • Farwell D.G.
      • et al.
      Quality of life among long-term survivors of head and neck cancer treated by intensity-modulated radiotherapy.

      Mental Health Disorders and Epilepsy

      Dysgeusia has been reported in depressed, nondelusional patients.
      • Miller S.M.
      • Naylor G.J.
      Unpleasant taste—a neglected symptom in depression.
      Impairment in suprathreshold measures of sucrose taste intensities has been shown in patients with major depression, compared with controls.
      • Amsterdam J.D.
      • Settle R.G.
      • Doty R.L.
      • Abelman E.
      • Winokur A.
      Taste and smell perception in depression.
      Gustatory (and olfactory) hallucinations can also be a feature of psychiatric disorders such as schizophrenia, schizoaffective disorder, and bipolar disorder, or a manifestation of parietal, temporal, or temporoparietal partial seizures.
      • Lewandowski K.E.
      • DePaola J.
      • Camsari G.B.
      • Cohen B.M.
      • Ongur D.
      Tactile, olfactory, and gustatory hallucinations in psychotic disorders: a descriptive study.
      • Hausser-Hauw C.
      • Bancaud J.
      Gustatory hallucinations in epileptic seizures. Electrophysiological, clinical and anatomical correlates.

      Evaluation and Management of Taste Disorders

      It is important to screen for taste or smell disorders if your patient is experiencing appetite problems and weight loss. A proposed screening question has been adapted from the NHANES 2011-2012 survey:
      Have you experienced problems with taste or smell in the past 12 months?
      A detailed history should include questions about salivary flow, problems with taste and smell, chewing problems, pain in the oral cavity, problems with teeth and dentures, dental hygiene, and ear or upper respiratory infections.
      A loss of taste can be both regional and quality specific, with different thresholds for different substances in different regions of the tongue, palate, and pharynx. Primary care physicians can use easily available stimuli such as sugar (sweet), citric acid (acid), sodium chloride (salty), or caffeine or quinine (bitter) to do a quick and objective taste assessment in their office. A referral to an otolaryngologist may be warranted for detailed evaluation.
      Evaluation and management of upper respiratory infections, oral candidiasis, and basic blood work to rule out metabolic or endocrine disorders should be pursued.
      A thorough review of medications can help identify medications contributing to dysgeusia. Based on the comorbidities and indication of the culprit medication, an evaluation to stop the medicine or change to an alternative medication with less taste distortion side effects may be warranted. Taste-related side effects should be discussed as part of the potential risks of prescribed medications prior to initiation of therapy.
      Many older adults lack private dental insurance, and Medicare does not cover routine dental care. Medicaid dental coverage for adults varies by state, with only about one half of the states paying for preventive dental care or restorative services.

      Medicaid and CHIP Payment and Access Commission (MACPAC). Medicaid coverage of dental benefits for adults. Available at: https://macpac.gov/wp-content/uploads/2015/06/Medicaid-Coverage-of-Dental-Benefits-for-Adults.pdf. Accessed February 20, 2016.

      This greatly limits access to dental care for low-income older adults who rely on Medicaid. A dental referral for examination and treatment of oral disease should be a priority when there is a complaint of altered taste. This should also include evaluation and management of dry mouth. Additionally, primary care physicians should discuss the importance of good oral hygiene and the role of good oral health in the overall health of an individual.
      Currently there is insufficient evidence to recommend zinc supplementation to improve taste perception or acuity in zinc deficiency-related or idiopathic dysgeusia.
      • Nagraj S.K.
      • Naresh S.
      • Srinivas K.
      • et al.
      Interventions for the management of taste disturbances.

      Follow-Up on Ms. Edwards

      Ms. Edwards continued to eat poorly and complain of taste impairment during her hospital stay. The inpatient medical team reviewed her medications with the help of a clinical pharmacist and identified numerous medicines including lisinopril, atorvastatin, digoxin, levothyroxine, donepezil, and oxybutynin, which may cause taste problems. Based on clinical indication and weighing benefits and risks of treatments, the team decided to stop donepezil and oxybutynin. She was advised to see a dentist and her primary care physician upon discharge from the hospital. Her dentist diagnosed periodontal disease, which was treated. She saw a dietician who educated her and her family on optimal nutrition and a liberalized diet. Her primary care doctor and cardiologist agreed to discontinue digoxin. Six months later, her appetite had gradually improved and her weight stabilized.
      This case highlights the importance of a multidisciplinary approach to the management of taste disorders in older adults (Figure) and how medical status, including oral health and medications, can impact taste disorders. Recognizing the causes of dysgeusia and knowing how to treat this can have a great impact on general health and overall well-being of patients.
      Figure thumbnail gr1
      FigureSchematic diagram of management of taste disorders. HbA1c = glycated hemoglobin; LFT = liver function test; TSH = thyroid-stimulating hormone.

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