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Taste Dysfunction

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Taste Dysfunction, Taste Impairment, Loss of Taste, Ageusia, Dysgeusia, Hypogeusia, Phantogeusia

  • See Also
  1. Metallic Taste
  2. Drug-Induced Gustatory Dysfunction
  3. Olfactory Dysfunction
  • Definitions
  1. Ageusia
    1. Loss of Taste Sensation
  2. Hypogeusia
    1. Diminished Taste Sensation
  3. Dysgeusia
    1. Altered Taste Sensation
  4. Phantogeusia
    1. Gustatatory Hallucination (without external taste stimulus)
  • Pathophysiology
  1. See Smell Sensation
  2. See Taste Sensation
  3. Innervation via parasympathetic fibers
    1. Anterior two thirds of Tongue: Lingual nerve
    2. Posterior one third of Tongue: Glossopharyngeal Nerve
  4. Loss of Taste Sensation is usually due to Anosmia
    1. Tongue differentiates only bitter, salt, sour, sweet
  • Precaution
  1. Most altered Taste Sensation is secondary to Olfactory Dysfunction (95% of cases)
  1. See Olfactory Dysfunction
  2. Miscellaneous Causes
    1. Aging (difficulty detecting salty or bitter taste)
    2. Anxiety Disorder
    3. Cancer
    4. Renal Failure
    5. Hepatic failure
    6. HIV Infection
  3. Endocrine Disorders
    1. Cushing's Syndrome
    2. Hypothyroidism
    3. Diabetes Mellitus (poorly controlled)
  4. Vitamin Deficiency
    1. Vitamin B12 Deficiency
    2. Vitamin B3 Deficiency
    3. Zinc Deficiency
    4. Copper Deficiency
  5. Local injury or inflammation
    1. Radiation Therapy (secondary Xerostomia and mucositis)
    2. Glossitis
    3. Tobacco Abuse
    4. Denture use (if associated with poor hygiene or cleansing of dentures)
    5. Periodontal Disease or Gingivitis
    6. Middle ear surgery (affecting Chorda Tympani)
    7. Dental surgery (wisdom Tooth Extraction is more commonly related)
  6. Local infection
    1. Oral Candidiasis
    2. Oral abscess
    3. Upper Respiratory Infection
  7. Medications
    1. See Drug-Induced Gustatory Dysfunction
    2. Chlorhexidine (Peridex)
  8. Neurologic conditions
    1. Bell's Palsy
    2. Familial Dysautonomia
    3. Multiple Sclerosis
  9. Toxin Exposure
    1. See Olfactory Dysfunction for toxin-related causes
    2. Pepper gas
    3. Weed killer (trifluralin)
  • References
  1. Baloh in Goldman (2000) Cecil Medicine, p. 2249-50
  2. Mirowski in Feldman (2002) Sleisenger GI, p. 339-40
  3. Malaty (2013) Am Fam Physician 88(1): 852-9 [PubMed]