Medical Terminology for Loss of Taste
The medical term for loss of taste is ageusia, while a partial reduction in taste sensation is called hypogeusia. 1, 2, 3, 4
Types of Taste Disorders
Taste disorders can be classified according to the type and site of lesion:
- Ageusia: Complete inability to detect any gustatory sensation
- Hypogeusia: Decreased sensitivity to tastants
- Dysgeusia/Parageusia: Distortion or perversion in taste perception
- Hypergeusia: Over-acuteness of taste sensation
- Phantogeusia: Perception of taste that occurs without a tastant present
Causes of Taste Loss
Taste impairments can result from multiple factors:
- Viral infections: Including upper respiratory infections and notably COVID-19 1, 2
- Medication side effects: Many drugs can cause taste disturbances 5
- Aging: Natural decline in taste sensitivity with age 6
- Hyposalivation: Reduced saliva production affects taste function 6
- Nasal/sinus conditions: Rhinitis can impair taste through the mucus barrier effect 7
- Trauma: Injury to taste buds or nerves
- Smoking and alcohol consumption: Both can damage taste receptors 2
- Poor oral health: Affects taste bud function
COVID-19 and Taste Loss
COVID-19 has highlighted taste disorders as a common neurological symptom:
- Taste loss (ageusia) and smell loss (anosmia) are frequently reported together 1
- In COVID-19 patients, taste dysfunction was reported in 64.4% of patients in one study 1
- Dysgeusia often starts approximately 3.3 days after disease onset 1
- Recovery of taste function typically occurs within 7-14 days for most patients 1
Clinical Implications
Loss of taste can significantly impact:
- Quality of life: Reduced enjoyment of food
- Nutritional status: Can lead to decreased appetite and unintended weight loss 7
- Food safety: Inability to detect spoiled food
- Psychological well-being: Depression and social isolation
Diagnostic Approach
Evaluation of taste disorders should include:
- Detailed history of onset, progression, and associated symptoms
- Medication review (current and former)
- Psychophysical taste evaluation using sprays or taste strips
- Testing of intensity perception by measuring thresholds
- Localized taste testing using chemicals or electrogustometry 3
Management Strategies
Treatment depends on the underlying cause:
- Addressing underlying conditions: Treating rhinitis, viral infections, etc.
- Medication adjustment: Discontinuing or changing medications that cause taste disturbances
- Salivary stimulation: Using umami taste stimulation to enhance salivary flow in cases of hypogeusia related to hyposalivation 6
- Time: Many cases resolve spontaneously, particularly those caused by viral infections 1, 7
Prognosis
- Most cases of taste impairment due to rhinitis or viral infections resolve when the underlying condition improves 7
- Recovery time varies depending on the cause
- For medication-induced taste disorders, it may take weeks or even months for complete recovery after discontinuation of the offending drug 5
In summary, ageusia (complete loss of taste) and hypogeusia (reduced taste sensitivity) are significant sensory impairments that can substantially affect quality of life and nutritional status. Proper identification of the underlying cause is essential for effective management.