Taste Dysfunction

Taste Dysfunction U.S. Prevalence: 19% in age >40 years (27% in age >80 years)
1. Rawai (2016) Chem Senses 41(1): 69-76 [PubMed]

See Smell Sensation
See Taste Sensation
Innervation via parasympathetic fibers
1. Anterior two thirds of Tongue: Lingual nerve
2. Posterior one third of Tongue: Glossopharyngeal Nerve
Loss of Taste Sensation is usually due to Anosmia
1. Tongue differentiates only bitter, salt, sour, sweet and savory (umami)

Most altered Taste Sensation is secondary to Olfactory Dysfunction (95% of cases)

See Olfactory Dysfunction
Miscellaneous Causes
1. Aging (difficulty detecting salty or bitter taste)
2. Anxiety Disorder
3. Cancer
4. Renal Failure
5. Hepatic failure
6. HIV Infection
Endocrine Disorders
1. Cushing's Syndrome
2. Hypothyroidism
3. Diabetes Mellitus (poorly controlled)
Vitamin Deficiency
1. Vitamin B12 Deficiency
2. Vitamin B3 Deficiency
3. Zinc Deficiency
4. Copper Deficiency
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)
Local infection
1. Oral Candidiasis
2. Oral abscess
3. Upper Respiratory Infection
Medications
1. See Drug-Induced Gustatory Dysfunction
2. Chlorhexidine (Peridex)
Neurologic conditions
1. Bell's Palsy
2. Familial Dysautonomia
3. Multiple Sclerosis
Toxin Exposure
1. See Olfactory Dysfunction for toxin-related causes
2. Pepper gas
3. Weed killer (trifluralin)