Categories: 未分類

味覚異常

Zinc Gluconate.
Approximately one half of drug-related taste distortions are caused by a zinc deficiency. Many medications are known to chelate， or bind， zinc， preventing the element from functioning properly. Due to the causal relationship of insufficient zinc levels to taste disorders， research has been conducted to test the efficacy of zinc supplementation as a possible treatment for dysgeusia. In a randomized clinical trial， fifty patients with idiopathic dysgeusia were given either zinc or a lactose placebo. The patients prescribed the zinc reported experiencing improved taste function and less severe symptoms compared to the control group， suggesting that zinc may be a beneficial treatment. The efficacy of zinc， however， has been ambiguous in the past. In a second study， 94% of patients who were provided with zinc supplementation did not experience any improvement in their condition. This ambiguity is most likely due to small sample sizes and the wide range of causes of dysgeusia. A recommended daily oral dose of 25–100 mg， as zinc gluconate， appears to be an effective treatment for taste dysfunction provided that there are low levels of zinc in the blood serum. There is not a sufficient amount of evidence to determine whether or not zinc supplementation is able to treat dysgeusia when low zinc concentrations are not detected in the blood.
A Cochrane Review in 2017 assessed the effects of different interventions for the management of taste disturbances. There was very low-quality evidence to support the role of zinc supplementation in the improvement of taste acuity and taste discrimination in patients with zinc deficiency or idiopathic taste disorders. Further research is required to improve the quality of evidence for zinc supplementation as an effective intervention for the management of dysgeusia.
Zinc infusion in chemotherapyEdit
It has been reported that approximately 68% of cancer patients undergoing chemotherapy experience disturbances in sensory perception such as dysgeusia. In a pilot study involving twelve lung cancer patients， chemotherapy drugs were infused with zinc in order to test its potential as a treatment. The results indicated that， after two weeks， no taste disturbances were reported by the patients who received the zinc-supplemented treatment while most of the patients in the control group who did not receive the zinc reported taste alterations. A multi-institutional study involving a larger sample size of 169 patients， however， indicated that zinc-infused chemotherapy did not have an effect on the development of taste disorders in cancer patients. An excess amount of zinc in the body can have negative effects on the immune system， and physicians must use caution when administering zinc to immunocompromised cancer patients. Because taste disorders can have detrimental effects on a patient's quality of life， more research needs to be conducted concerning possible treatments such as zinc supplementation.
Altering drug therapyEdit

Eprosartan. The effects of drug-related dysgeusia can often be reversed by stopping the patient's regimen of the taste altering medication. In one case， a forty-eight-year-old woman who had hypertension was being treated with valsartan. Due to this drug's inability to treat her condition， she began taking a regimen of eprosartan， an angiotensin II receptor antagonist. Within three weeks， she began experiencing a metallic taste and a burning sensation in her mouth that ceased when she stopped taking the medication. When she began taking eprosartan on a second occasion， her dysgeusia returned. In a second case， a fifty-nine-year-old man was prescribed amlodipine in order to treat his hypertension. After eight years of taking the drug， he developed a loss of taste sensation and numbness in his tongue. When he ran out of his medication， he decided not to obtain a refill and stopped taking amlodipine. Following this self-removal， he reported experiencing a return of his taste sensation. Once he refilled his prescription and began taking amlodipine a second time， his taste disturbance reoccurred. These two cases suggest that there is an association between these drugs and taste disorders. This link is supported by the ""de-challenge"" and ""re-challenge"" that took place in both instances. It appears that drug-induced dysgeusia can be alleviated by reducing the drug's dose or by substituting a second drug from the same class.
Alpha lipoic acidEdit

Alpha Lipoic Acid
Alpha lipoic acid (ALA) is an antioxidant that is made naturally by human cells. It can also be administered in capsules or can be found in foods such as red meat， organ meats， and yeast. Like other antioxidants， it functions by ridding the body of harmful free radicals that can cause damage to tissues and organs. It has an important role in the Krebs cycle as a coenzyme leading to the production of antioxidants， intracellular glutathione， and nerve-growth factors. Animal research has also uncovered the ability of ALA to improve nerve conduction velocity. Because flavors are perceived by differences in electric potential through specific nerves innervating the tongue， idiopathic dysgeusia may be a form of a neuropathy. ALA has proven to be an effective treatment for burning mouth syndrome spurring studies in its potential to treat dysgeusia. In a study of forty-four patients diagnosed with the disorder， one half was treated with the drug for two months while the other half， the control group， was given a placebo for two months followed by a two-month treatment of ALA. The results reported show that 91% of the group initially treated with ALA reported an improvement in their condition compared to only 36% of the control group. After the control group was treated with ALA， 72% reported an improvement. This study suggests that ALA may be a potential treatment for patients and supports that full double blind randomized studies should be performed. Managing dysgeusiaEdit In addition to the aforementioned treatments， there are also many management approaches that can alleviate the symptoms of dysgeusia. These include using non-metallic silverware， avoiding metallic or bitter tasting foods， increasing the consumption of foods high in protein， flavoring foods with spices and seasonings， serving foods cold in order to reduce any unpleasant taste or odor， frequently brushing one's teeth and utilizing mouthwash， or using sialogogues such as chewing sugar-free gum or sour-tasting drops that stimulate the productivity of saliva. When taste is impeded， the food experience can be improved through means other than taste， such as texture， aroma， temperature， and color. Psychological impactsEdit People with dysgeusia are also forced to manage the impact that the disorder has on their quality of life. An altered taste has effects on food choice and intake and can lead to weight loss， malnutrition， impaired immunity， and a decline in health. Patients diagnosed with dysgeusia must use caution when adding sugar and salt to food and must be sure not to overcompensate for their lack of taste with excess amounts. Since the elderly are often on multiple medications， they are at risk for taste disturbances increasing the chances of developing depression， loss of appetite， and extreme weight loss. This is cause for an evaluation and management of their dysgeusia. In patients undergoing chemotherapy， taste distortions can often be severe and make compliance with cancer treatment difficult. Other problems that may arise include anorexia and behavioral changes that can be misinterpreted as psychiatric delusions regarding food. Symptoms including paranoia， amnesia， cerebellar malfunction， and lethargy can also manifest when undergoing histidine treatment.

今後の研究
Every year， more than 200，000 individuals see their physicians concerning chemosensory problems， and many more taste disturbances are never reported. Due to the large number of persons affected by taste disorders， basic and clinical research are receiving support at different institutions and chemosensory research centers across the country. These taste and smell clinics are focusing their research on better understanding the mechanisms involved in gustatory function and taste disorders such as dysgeusia. For example， the National Institute on Deafness and Other Communication Disorders is looking into the mechanisms underlying the key receptors on taste cells and applying this knowledge to the future of medications and artificial food products. Meanwhile， the Taste and Smell Clinic at the University of Connecticut Health Center is integrating behavioral， neurophysiological， and genetic studies involving stimulus concentrations and intensities in order to better understand taste function.

こちらもご覧ください Anosmia Parosmia

参考文献
^ Steven K. Feske and Martin A. Samuels， Office Practice of Neurology 2nd ed. (Philadelphia: Elsevier Science， 2003) 114. ^ Hoffman HJ， Ishii EK， MacTurk RH (November 1998). ""Age-related changes in the prevalence of smell/taste problems among the United States adult population. Results of the 1994 disability supplement to the National Health Interview Survey (NHIS)"". Annals of the New York Academy of Sciences (Submitted manuscript). 855 (1): 716–22. Bibcode:1998NYASA.855..716H. doi:10.1111/j.1749-6632.1998.tb10650.x. PMID 9929676. S2CID 12659798.
^ Raber-Durlacher JE， Barasch A， Peterson DE， Lalla RV， Schubert MM， Fibbe WE (July 2004). ""Oral complications and management considerations in patients treated with high-dose chemotherapy"". Supportive Cancer Therapy. 1 (4): 219–29. doi:10.3816/SCT.2004.n.014. PMID 18628146.
^ Wiseman M (June 2006). ""The treatment of oral problems in the palliative patient"". Journal. 72 (5): 453–8. PMID 16772071.
^ Matsuo R （2000). ""Role of saliva in the maintenance of taste sensitivity"". Critical Reviews in Oral Biology and Medicine. 11 (2): 216–29. doi:10.1177/10454411000110020501. PMID 12002816.
^ Spielman AI (March 1990). ""Interaction of saliva and taste"". Journal of Dental Research. 69 (3): 838–43. doi:10.1177/00220345900690030101. PMID 2182682. S2CID 24639739.
^ ""Side Effects & Helpful Tips | Erivedge®(vismodegib)"". www.erivedge.com. Retrieved 2020-01-06.
^ Yasuda M， Tomita H (8 July 2009). ""Electron microscopic observations of glossal circumvallate papillae in dysgeusic patients"". Acta Oto-Laryngologica. Supplementum. 122 (546): 122–8. doi:10.1080/00016480260046508. PMID 12132609. S2CID 27053598.
^ Heckmann SM， Hujoel P， Habiger S， Friess W， Wichmann M， Heckmann JG， Hummel T (January 2005). ""Zinc gluconate in the treatment of dysgeusia--a randomized clinical trial"" (PDF). Journal of Dental Research. 84 (1): 35–8. doi:10.1177/154405910508400105. PMID 15615872. S2CID 5855839. ^ Joseph M. Bicknell， MD and Robert V. Wiggins， MD， “Taste Disorder From Zinc Deficiency After Tonsillectomy，” The Western Journal of Medicine Oct.1988: 458.
^ Sanofi-Aventis Australia Pty Limited. ""Product Information IMOVANE (zopiclone) Tablets"" (PDF). ADVERSE EFFECTS. p. 6. Archived from the original (PDF) on 9 November 2014. Retrieved 9 November 2014.
^ Simons FE (November 2004). ""Advances in H1-antihistamines"". The New England Journal of Medicine. 351 (21): 2203–17. doi:10.1056/NEJMra033121. PMID 15548781. ^ Steven K. Feske and Martin A. Samuels， Office Practice of Neurology 2nd ed. (Philadelphia: Elsevier Science， 2003) 119.
^ Janin， Alex (16 August 2022). ""What， Exactly， is 'Paxlovid Mouth，' and How do You Get Rid of It?"". Wall Street Journal.
^ Ciancio SG (October 2004). ""Medications' impact on oral health"". Journal of the American Dental Association. 135 (10): 1440–8， quiz 1468–9. doi:10.14219/jada.archive.2004.0055. PMID 15551986.

Dysgeusia

味覚異常は、味覚異常としても知られています。味覚障害はまた、味覚の完全な欠如であるアゲウスおよび味覚感度の低下である味覚低下を伴うことが多い. 味覚や嗅覚の変化は、さまざまな疾患状態における二次的なプロセスである場合もあれば、一次症状である場合も味覚の歪みが唯一の症状であり、味覚は他の感覚系と結びついているため、診断は通常複雑です。味覚障害の一般的な原因には、化学療法、アルブテロールによる喘息治療、および亜鉛欠乏。肝疾患、甲状腺機能低下症、まれに特定の種類の発作も味覚障害につながる可能性がさまざまな薬物が味覚を変化させ、味覚異常を引き起こす原因となる可能性も味覚障害の原因はさまざまであるため、味覚障害の症状を緩和または終結させるのに有効な治療法が数多くこれらには、人工唾液、ピロカルピン、亜鉛補給、薬物療法の変更、アルファリポ酸が含まれます.
味覚異常
他の名前
パラゲウシア
発音
/ d ɪ s ˈ ɡ uː ʒ ə /または/ d ɪ s ˈ ɡ juː z i ə /
専門
神経学

コンテンツ
1 徴候と症状
2 原因
2.1 化学療法 2.2 味蕾 2.3 亜鉛欠乏症 2.4 薬物 2.5 妊娠 2.6 その他の原因 2.7 通常機能
3 診断
3.1 味覚検査 3.2 診断ツール
4 トリートメント
4.1 人工唾液とピロカルピン 4.2 亜鉛欠乏症
4.2.1 亜鉛補給
4.2.2 化学療法における亜鉛注入
4.3 薬物療法の変更 4.4 アルファリポ酸 4.5 味覚障害の管理 4.6 心理的影響
5 今後の研究
6 こちらもご覧ください
7 参考文献
8 外部リンク

徴候と症状
味の意味での変化、通常は金属の味、時には匂いが唯一の症状です。

原因

化学療法
味覚障害の主な原因は、がんの化学療法です。化学療法はしばしば口腔への損傷を誘発し、口腔粘膜炎、口腔感染症、および唾液腺機能不全を引き起こします。口腔粘膜炎は、口の炎症と、組織のただれや潰瘍からなります。健康な人の口腔内には通常、さまざまな種類の微生物が生息しています。しかし、化学療法により、これらの典型的には非病原性の病原体が重篤な感染症を引き起こす可能性があり、その結果、唾液が減少する可能性がさらに、放射線療法を受ける患者は、唾液組織も失います。唾液は味覚メカニズムの重要な構成要素です。唾液は、口の中の味覚受容体と相互作用し、それを保護します。唾液は、それぞれ重炭酸イオンとグルタミン酸を介して酸味と甘味を仲介します。塩味は、塩化ナトリウムのレベルが唾液中の濃度を超えると誘発されます。化学療法患者の 50% が味覚障害または別の形の味覚障害を持っていることが報告されています。味覚障害を引き起こす化学療法の例としては、シクロホスファミド、シスプラチン、ビスモデギブおよびエトポシドが化学療法による味覚障害の正確なメカニズムは不明です。

味蕾
味蕾の歪みは、味覚障害を引き起こす可能性が日本の日本大学の安田雅英と富田仁が行った研究では、この味覚障害の患者は通常よりも微絨毛が少ないことが観察されています. さらに、味蕾細胞の核と細胞質が減少しています。彼らの調査結果に基づくと、味覚障害は微絨毛の喪失とIII 型細胞内小胞の減少に起因し、これらはすべて味覚経路を妨害する可能性が頭頸部への放射線は、唾液分泌量の変化の影響とは別に、味蕾の直接的な破壊ももたらします。

亜鉛欠乏症
味覚障害のもう 1 つの主な原因は、亜鉛欠乏症です。味覚障害における亜鉛の正確な役割は不明ですが、亜鉛は味蕾の修復と生成に部分的に関与していると言われています. 亜鉛は何らかの形で炭酸脱水酵素 VIと直接的または間接的に相互作用し、味蕾の生成に関連するガスチンの濃度に影響を与えます。亜鉛で治療された患者が唾液中のカルシウム濃度の上昇を経験することも報告されています. 適切に機能するために、味蕾はカルシウム受容体に依存しています。亜鉛は、最も豊富な酵素であるアルカリホスファターゼの重要な補因子です味蕾膜; また、正常な味蕾の発達と維持に重要な耳下腺唾液タンパク質の構成要素でも」

薬物
また、ゾピクロン、アゼラスチンやエメダスチンなどのH 1 -抗ヒスタミン薬など、味覚障害を引き起こす可能性のあるさまざまな薬が COVID-19 の治療に使用される薬であるパクスロビッドを含む、約 250 の薬が味覚に影響を与えます。ウォール・ストリート・ジャーナルによると、いわゆる「パクスロビッドの口」を「一口の汚れた小銭と腐った豆乳」のように表現する人もいます。
味覚受容体に関連するナトリウムチャネルはアミロリドによって阻害される可能性があり、新しい味蕾と唾液の生成は抗増殖薬によって妨げられる可能性があります. 唾液には微量の薬物が含まれている可能性があり、口の中に金属の風味が生じます。例には、炭酸リチウムおよびテトラサイクリンが含まれる。ペニシラミンやカプトプリルなどのスルフヒドリル基を含む薬は、亜鉛と反応して欠乏症を引き起こす可能性があります. メトロニダゾールとクロルヘキシジン細胞膜に関連する金属イオンと相互作用することがわかっています。レニン – アンギオテンシン – アルドステロン系を遮断することによって作用する薬物、たとえばアンギオテンシン II 受容体に拮抗することによって作用する薬物(エプロサルタンのように) は、味覚障害に関連しています。アムロジピンのようなカルシウムチャネル遮断薬も、カルシウムに敏感な味蕾を遮断することにより、感覚異常を引き起こすと主張する症例報告はほとんどありません。

妊娠
妊娠中のエストロゲンなどのホルモンレベルの変化は、味覚に影響を与える可能性がある調査によると、妊娠中の女性の 93% が妊娠中に何らかの味覚の変化を報告したことがわかりました。

その他の原因
ドライマウス症候群としても知られる口腔乾燥症は、味覚を得るために正常な唾液の流れと濃度が必要であるため、味覚障害を引き起こす可能性が舌咽神経の損傷は、味覚障害を引き起こす可能性がさらに、すべて味覚経路を構成する橋、視床、および中脳に加えられた損傷は、潜在的な要因である可能性がある事例研究では、膀胱閉塞を経験していた患者の 22% が味覚障害も経験していました。障害物が取り除かれると、これらの患者の 100% で味覚障害が解消されました。膀胱の軽減と味覚障害との関係が何を伴うのかは不明ですが、脳の橋と大脳皮質の泌尿器系と味覚に関与する領域が近接していることが観察されています.
味覚障害は、しばしば未知の理由で発生します。この味覚障害には、胃の逆流、鉛中毒、糖尿病など、さまざまなさまざまな要因が関与している可能性が松の実の一部は、完全には証明されていない理由で明らかに味覚障害を引き起こす可能性があります. 特定の農薬は、口の中の味蕾や神経に有害な影響を与える可能性があります. これらの農薬には、有機塩素化合物とカルバメート農薬が含まれます。末梢神経への損傷は、顔面神経の鼓索枝への損傷とともに、味覚障害も引き起こします。喉頭鏡検査および扁桃摘出術の外科的リスクには、味覚障害が含まれます。口内炎症候群の患者は、閉経期の女性である可能性が最も高く

通常機能
味覚は、口の中の特殊な味覚細胞による化学物質の検出に基づいています。口、のど、喉頭、食道にはすべて味蕾があり、10日ごとに入れ替わります。各味蕾には受容細胞が含まれています。求心性神経は、味蕾の基部にある受容細胞と接触します。単一の味蕾は複数の求心性神経によって支配され、単一の遠心性線維は複数の味蕾を支配します。茸状乳頭は舌の前部に存在し、有郭乳頭と葉状乳頭は舌の後部に見られる。唾液腺味蕾を唾液で湿らせておく役割が
1 つの味蕾は 4 種類の細胞で構成されており、各味蕾には 30 ～ 80 個の細胞がタイプ I 細胞は薄い形をしており、通常は他の細胞の周囲にまた、大量のクロマチンも含まれています。II型細胞は、I型細胞よりもクロマチンがはるかに少ない顕著な核と核小体を持っています。タイプ III 細胞には、複数のミトコンドリアと大きな小胞がI型、II型、およびIII型の細胞にもシナプスが含まれています。IV型細胞は、通常、味蕾の後端に根ざしています。味蕾のすべての細胞は、末端で微絨毛を形成します。

診断
一般に、味覚障害の診断と評価は困難です。味覚機能は、嗅覚、体性感覚系、および痛みの知覚(辛い食べ物を味わうときなど) と結びついているため、個々のシステムを介した感覚を調べることは困難です。さらに、嗅覚障害と比較すると、味覚障害はまれです。
味覚障害の診断は、患者が唾液分泌、嚥下、咀嚼、口腔痛、以前の耳の感染症（おそらく聴覚またはバランスの問題によって示される）、口腔衛生、および胃の問題について質問されることから始まります. 初期病歴評価では、糖尿病、甲状腺機能低下症、またはがんなどの付随疾患の可能性も考慮されます。臨床検査が実施され、舌と口腔の検査が含まれます。さらに、鼓索の病変はこの部位に好発するため、外耳道を検査します。

味覚検査
味覚障害の程度をさらに分類し、臨床的に味覚を測定するために、味覚検査を行うことができます。味覚テストは、口全体の手順または局所テストとして実行されます。どちらの手法でも、自然刺激または電気刺激を使用できます。地域のテストでは、ピペット、浸したろ紙ディスク、または綿棒を使用して、20 ～ 50 μL の液体刺激を前舌と後舌に提示します。口全体の検査では、少量 (2 ～ 10 mL) の溶液が投与され、患者は口の中で溶液を振り回すように求められます。
スクロース（甘味）、クエン酸（酸味）、塩化ナトリウム（塩味）、キニーネの閾値試験またはカフェイン（苦味）最も頻繁に使用される手法の 1 つは、「3 滴テスト」です。このテストでは、3 滴の液体が被験者に与えられます。そのうちの 1 滴は味覚刺激用で、残りの 2 滴は純粋な水です。閾値は、患者が味を 3 回連続して正しく識別する濃度として定義されます。
Suprathreshold tests， which provide intensities of taste stimuli above threshold levels， are used to assess the patient’s ability to differentiate between different intensities of taste and to estimate the magnitude of suprathreshold loss of taste. From these tests， ratings of pleasantness can be obtained using either the direct scaling or magnitude matching method and may be of value in the diagnosis of dysgeusia. Direct scaling tests show the ability to discriminate among different intensities of stimuli and whether a stimulus of one quality (sweet) is stronger or weaker than a stimulus of another quality (sour).味覚刺激が異常なレベルで知覚されているかどうかを判断するために、ダイレクトスケーリングを使用することはできません。この場合、マグニチュードマッチングが使用され、患者は味覚刺激の強度と別の刺激の強度を評価するよう求められます。sensory system， such as the loudness of a tone， on a similar scale. For example， the Connecticut Chemosensory Clinical Research Center asks patients to rate the intensities of NaCl， sucrose， citric acid and quinine-HCl stimuli， and the loudness of 1000 Hz tones.
Other tests include identification or discrimination of common taste substances. Topical anesthesia of the tongue has been reported to be of use in the diagnosis of dysgeusia as well， since it has been shown to relieve the symptoms of dysgeusia temporarily. In addition to techniques based on the administration of chemicals to the tongue， electrogustometry is frequently used. It is based on the induction of gustatory sensations by means of an anodal electrical direct current. Patients usually report sour or metallic sensations similar to those associated with touching both poles of a live battery to the tongue. Although electrogustometry is widely used， there seems to be a poor correlation between electrically and chemically induced sensations. Diagnostic toolsEdit Certain diagnostic tools can also be used to help determine the extent of dysgeusia. Electrophysiological tests and simple reflex tests may be applied to identify abnormalities in the nerve-to-brainstem pathways. For example， the blink reflex may be used to evaluate the integrity of the trigeminal nerve–pontine brainstem–facial nerve pathway， which may play a role in gustatory function.
Structural imaging is routinely used to investigate lesions in the taste pathway. Magnetic resonance imaging allows direct visualization of the cranial nerves. Furthermore， it provides significant information about the type and cause of a lesion. Analysis of mucosal blood flow in the oral cavity in combination with the assessment of autonomous cardiovascular factors appears to be useful in the diagnosis of autonomic nervous system disorders in burning mouth syndrome and in patients with inborn disorders， both of which are associated with gustatory dysfunction. 真菌または細菌感染が疑われる場合にも、細胞培養が使用されることが
さらに、味覚受容体への味の輸送や味覚受容体の保護など、味覚受容体の環境を構成する唾液の分析を行う必要が典型的な臨床調査には、唾液分泌測定法と唾液分泌化学が含まれます。研究によると、唾液サンプルから得られた味覚受容体の電子顕微鏡写真は、味覚障害やその他の味覚障害を持つ患者の味蕾の病理学的変化を示しています。

トリートメント
Artificial saliva and pilocarpineEdit
Because medications have been linked to approximately 22% to 28% of all cases of dysgeusia， researching a treatment for this particular cause has been important. Xerostomia， or a decrease in saliva flow， can be a side effect of many drugs， which， in turn， can lead to the development of taste disturbances such as dysgeusia. Patients can lessen the effects of xerostomia with breath mints， sugarless gum， or lozenges， or physicians can increase saliva flow with artificial saliva or oral pilocarpine. Artificial saliva mimics the characteristics of natural saliva by lubricating and protecting the mouth but does not provide any digestive or enzymatic benefits. Pilocarpine is a cholinergic drug meaning it has the same effects as the neurotransmitter acetylcholine. Acetylcholine has the function of stimulating the salivary glands to actively produce saliva. The increase in saliva flow is effective in improving the movement of tastants to the taste buds.Zinc deficiencyEdit Zinc supplementationEdit

Zinc Gluconate.
Approximately one half of drug-related taste distortions are caused by a zinc deficiency. Many medications are known to chelate， or bind， zinc， preventing the element from functioning properly. Due to the causal relationship of insufficient zinc levels to taste disorders， research has been conducted to test the efficacy of zinc supplementation as a possible treatment for dysgeusia. In a randomized clinical trial， fifty patients with idiopathic dysgeusia were given either zinc or a lactose placebo. The patients prescribed the zinc reported experiencing improved taste function and less severe symptoms compared to the control group， suggesting that zinc may be a beneficial treatment. The efficacy of zinc， however， has been ambiguous in the past. In a second study， 94% of patients who were provided with zinc supplementation did not experience any improvement in their condition. This ambiguity is most likely due to small sample sizes and the wide range of causes of dysgeusia. A recommended daily oral dose of 25–100 mg， as zinc gluconate， appears to be an effective treatment for taste dysfunction provided that there are low levels of zinc in the blood serum. There is not a sufficient amount of evidence to determine whether or not zinc supplementation is able to treat dysgeusia when low zinc concentrations are not detected in the blood.
A Cochrane Review in 2017 assessed the effects of different interventions for the management of taste disturbances. There was very low-quality evidence to support the role of zinc supplementation in the improvement of taste acuity and taste discrimination in patients with zinc deficiency or idiopathic taste disorders. Further research is required to improve the quality of evidence for zinc supplementation as an effective intervention for the management of dysgeusia.
Zinc infusion in chemotherapyEdit
It has been reported that approximately 68% of cancer patients undergoing chemotherapy experience disturbances in sensory perception such as dysgeusia. In a pilot study involving twelve lung cancer patients， chemotherapy drugs were infused with zinc in order to test its potential as a treatment. The results indicated that， after two weeks， no taste disturbances were reported by the patients who received the zinc-supplemented treatment while most of the patients in the control group who did not receive the zinc reported taste alterations. A multi-institutional study involving a larger sample size of 169 patients， however， indicated that zinc-infused chemotherapy did not have an effect on the development of taste disorders in cancer patients. An excess amount of zinc in the body can have negative effects on the immune system， and physicians must use caution when administering zinc to immunocompromised cancer patients. Because taste disorders can have detrimental effects on a patient’s quality of life， more research needs to be conducted concerning possible treatments such as zinc supplementation.
Altering drug therapyEdit

Eprosartan. The effects of drug-related dysgeusia can often be reversed by stopping the patient’s regimen of the taste altering medication. In one case， a forty-eight-year-old woman who had hypertension was being treated with valsartan. Due to this drug’s inability to treat her condition， she began taking a regimen of eprosartan， an angiotensin II receptor antagonist. Within three weeks， she began experiencing a metallic taste and a burning sensation in her mouth that ceased when she stopped taking the medication. When she began taking eprosartan on a second occasion， her dysgeusia returned. In a second case， a fifty-nine-year-old man was prescribed amlodipine in order to treat his hypertension. After eight years of taking the drug， he developed a loss of taste sensation and numbness in his tongue. When he ran out of his medication， he decided not to obtain a refill and stopped taking amlodipine. Following this self-removal， he reported experiencing a return of his taste sensation. Once he refilled his prescription and began taking amlodipine a second time， his taste disturbance reoccurred. These two cases suggest that there is an association between these drugs and taste disorders. This link is supported by the “”de-challenge”” and “”re-challenge”” that took place in both instances. It appears that drug-induced dysgeusia can be alleviated by reducing the drug’s dose or by substituting a second drug from the same class.
Alpha lipoic acidEdit

Alpha Lipoic Acid
Alpha lipoic acid (ALA) is an antioxidant that is made naturally by human cells. It can also be administered in capsules or can be found in foods such as red meat， organ meats， and yeast. Like other antioxidants， it functions by ridding the body of harmful free radicals that can cause damage to tissues and organs. It has an important role in the Krebs cycle as a coenzyme leading to the production of antioxidants， intracellular glutathione， and nerve-growth factors. Animal research has also uncovered the ability of ALA to improve nerve conduction velocity. Because flavors are perceived by differences in electric potential through specific nerves innervating the tongue， idiopathic dysgeusia may be a form of a neuropathy. ALA has proven to be an effective treatment for burning mouth syndrome spurring studies in its potential to treat dysgeusia. In a study of forty-four patients diagnosed with the disorder， one half was treated with the drug for two months while the other half， the control group， was given a placebo for two months followed by a two-month treatment of ALA. The results reported show that 91% of the group initially treated with ALA reported an improvement in their condition compared to only 36% of the control group. After the control group was treated with ALA， 72% reported an improvement. This study suggests that ALA may be a potential treatment for patients and supports that full double blind randomized studies should be performed. Managing dysgeusiaEdit In addition to the aforementioned treatments， there are also many management approaches that can alleviate the symptoms of dysgeusia. These include using non-metallic silverware， avoiding metallic or bitter tasting foods， increasing the consumption of foods high in protein， flavoring foods with spices and seasonings， serving foods cold in order to reduce any unpleasant taste or odor， frequently brushing one’s teeth and utilizing mouthwash， or using sialogogues such as chewing sugar-free gum or sour-tasting drops that stimulate the productivity of saliva. When taste is impeded， the food experience can be improved through means other than taste， such as texture， aroma， temperature， and color. Psychological impactsEdit People with dysgeusia are also forced to manage the impact that the disorder has on their quality of life. An altered taste has effects on food choice and intake and can lead to weight loss， malnutrition， impaired immunity， and a decline in health. Patients diagnosed with dysgeusia must use caution when adding sugar and salt to food and must be sure not to overcompensate for their lack of taste with excess amounts. Since the elderly are often on multiple medications， they are at risk for taste disturbances increasing the chances of developing depression， loss of appetite， and extreme weight loss. This is cause for an evaluation and management of their dysgeusia. In patients undergoing chemotherapy， taste distortions can often be severe and make compliance with cancer treatment difficult. Other problems that may arise include anorexia and behavioral changes that can be misinterpreted as psychiatric delusions regarding food. Symptoms including paranoia， amnesia， cerebellar malfunction， and lethargy can also manifest when undergoing histidine treatment.

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