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dysgeusia (taste disorder)
Impairment of taste.
Etiology:
1) impairment of access to receptors in the taste buds
- xerostomia
- Sjogren's syndrome
- heavy metal intoxication
- bacterial colonization of the taste pore
- hyponatremia
2) injury to taste receptor cells (sensory loss)
a) inflammatory or degenerative disease in the oral cavity
- thermal or chemical burn
b) pharmaceutical agents
- anti-thyroid agents (methimazole, propylthiouracil)
- antineoplastic agents (cyclophosphamide, methotrexate ..)
- ACE inhibitors, ARBs, Ca+2 channel blockers (nifedipine)
- antibiotics (metronidazole, clarithromycin ..)
- drugs causing xerostomia (anticholinergic agents)
c) radiation therapy to the oral cavity & pharynx
d) viral infections
e) endocrine disorders
- diabetes mellitus
- Cushing's syndrome
- adrenal insufficiency
- hypothyroidism
f) neoplasms
g) aging
3) damage to gustatory afferent nerves
- neoplasms
- head trauma
- surgery
- exposure to toxins
4) CNS causes (general)
- Alzheimer's disease & other neurodegenerative diseases
- CNS neoplasms
- psychiatric disease
- stroke
5) other oral causes
- dental infection
- periodontal disease
- poor oral hygiene
- burning mouth syndrome
- candidiasis
- laceration
- salivary gland insufficiency (xerostomia)
6) nutritional deficiency
1) zinc deficiency
2) vitamin B12 deficiency
7) other pharmaceuticals altering taste
- acyclovir, allopurinol, amiloride, amitriptyline, amphotericin B, ampicillin, baclofen, buspirone, captopril, chlorpheniramine, desipramine, dexamethasone, diclofenac, dicyclomine, diltiazem, doxepin, enalapril, ethacrynic acid, ethambutol, fenoprofen, gemfibrozil, hydrochlorothiazide, imipramine, labetalol, levamisole, lomefloxacin, mexiletine, nabumetone, nelfinavir, nifedipine, ofloxacin, pentamidine, pentoxifylline, phenytoin, procainamide, prochlorperazine, promethazine, propafenone, propranolol, ritonavir, saquinavir, sulfamethoxazole, sulindac, terfenadine, tetracyclines, trifluoperazine, zidovudine
Pathology:
-> taste buds remain degenerate when their gustatory afferents are severed, but remain when their somatosensory afferents are severed
Clinical manifestations:
1) may be complete impairment of taste (sweet, salt, sour, bitter)
2) may be partial loss of taste; ability to recognize some, but not other gustatory sensations
3) may be specific loss in ability to taste certain foods
4) may be a distortion in the perception of taste
5) may be gustatory hallucinations
Laboratory:
1) testing with sucrose, citric acid, caffeine & NaCl
2) electrogustometry
3) biopsy of foliate or fungiform papillae
Differential diagnosis:
-> olfactory disorder
Management:
1) treat xerostomia
2) treat infection
3) withdraw offending pharmaceutical agents
4) zinc & vitamins recommended by some, but evidence of benefit is lacking
Related
taste
taste bud; caliculus gustatorius; Schwalbe corpuscle; gustatory bud
Specific
cacogeusia
metallic taste
General
sign/symptom
References
- Stedman's Medical Dictionary 26th ed, Williams &
Wilkins, Baltimore, 1995
- Harrison's Principles of Internal Medicine, 14th ed.
Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 173-74
- Prescriber's Letter 13(2): 2006
Detail-Document#: 220111
(subscription needed) http://www.prescribersletter.com
- Geriatric Review Syllabus, 7th edition
Parada JT et al (eds)
American Geriatrics Society, 2010
- Geriatric Review Syllabus, 8th edition (GRS8)
Durso SC and Sullivan GN (eds)
American Geriatrics Society, 2013