What is Ageusia?
Ageusia is a rare disorder where a person completely loses their sense of taste. It’s different from other taste-related conditions such as hypogeusia (a reduced ability to taste all flavors), hyperguesia (an enhanced sensitivity to taste), dysgeusia (a foul or unpleasant perception of a flavor), and phantogeusia (the sensation of tasting something when no food or drink is present). While ageusia isn’t life-threatening, it can cause discomfort, leading to a lack of appetite, weight loss, and even a need to stop certain medications in some already ill individuals. This can result in other health issues and can significantly impact the person’s psychological well-being.
What Causes Ageusia?
Ageusia, or loss of taste, can be caused by numerous factors. Some of these include damage to taste nerves, poor diet, or other health conditions like an underactive thyroid, diabetes, anemia, Sjogren syndrome, and Crohn’s disease. Other causes can involve nerve issues due to shingles, blockages of arteries in the neck, or growths in the brain. Surgery or injury can also lead to ageusia, as can certain nerve-related conditions or diseases like diphtheria, porphyria, lupus, or amyloidosis.
Cancer patients undergoing radiation therapy for the head or neck may experience ageusia because the treatment can harm the taste buds, nerves, and salivary glands, affecting the sense of taste.
Not having enough zinc, a key nutrient, can also lead to problems with taste. Ageusia can be caused by drug reactions, injuries or inflammation around the mouth, certain dental medications, infections in the mouth or gums, certain oral conditions, issues with dentures or dental restorations, and issues with the salivary gland.
Many types of drugs have also been linked to ageusia, including certain antibiotics, cancer treatments, neurological medications, heart drugs, antipsychotics, antidepressants, thyroid medications, antihistamines, bronchodilators, antifungals, and antivirals.
Lastly, just getting older or factors related to aging can make people more susceptible to problems with taste.
Risk Factors and Frequency for Ageusia
Complete ageusia, or total loss of taste, is extremely rare. It only happens in about 1 or 2 out of every 1000 people. As people get older, it’s normal for taste function to decrease, but it’s uncommon for people to lose their sense of taste completely.
Signs and Symptoms of Ageusia
Assessing patients with taste-related issues involves first understanding their main concerns, carefully checking the head, neck, and mouth areas, and reviewing medical, dental, medication, and social histories.
In order to pinpoint the cause of the problem:
- A thorough history is collected, which includes information about systemic illnesses, current medications, and recent dental procedures. Any changes in medications are also important.
- The mouth is physically examined to identify local factors that could be causing the issue.
There are a few different taste tests that can be done:
- Electrogustometry applies weak electrical currents to different taste buds in the mouth. Chemogustometry uses specific taste solutions to assess taste sensitivity.
- A spatial test evaluates different spots in the mouth by applying a taste solution with a cotton swab. Patients are also asked to swallow some of the solution to test taste buds in the throat.
- Taste test strips soaked in a flavor can be used for the patient to identify tastes. These have the advantage of lasting a long time.
If a taste issue is suspected, the next step might be to apply a numbing anesthetic to the tongue. If the issue goes away, it’s likely local. If it remains, there could be a systemic condition or a problem in the central nervous system.
Testing for Ageusia
In addition to taking a patient’s medical history and physically examining them, doctors can use two more methods to assess someone who might have a taste disorder. These are psychophysical evaluation and medical imaging.
Through psychophysical evaluation, doctors can get a deeper understanding of the patient’s symptom. This process can also measure the level of lost taste sensation. During this process, the doctor must also take note of the patient’s mental health. Depression, for instance, can either be a result of a taste problem or can make the problem appear worse than it actually is.
With medical imaging, doctors can get a better understanding of what’s happening inside a patient’s body. These images can help the doctor see if any parts of the nervous system, specifically the brain stem, thalamus, or pons, have been damaged. This damage could explain the taste disorder.
Treatment Options for Ageusia
If you lose your sense of taste, known as ageusia, the cause of this loss must be found in order to treat it effectively. Some taste disorders get better on their own, without any treatment. There’s no specific treatment plan for taste disorders like ageusia. However, if the loss of taste is caused by chemotherapy, it may come back once the medication is stopped. But, it isn’t always possible to stop taking these medications for people with serious conditions such as cancer, diabetes, or uncontrolled infections.
In such cases, supplements might be helpful. For example, zinc gluconate has been found helpful, especially for patients undergoing treatments like radiotherapy/chemotherapy, if taken in a dose of 140 mg per day. Another supplement, alpha-lipoic acid, could also be beneficial if taken in a dose of 600 mg per day for a few months.
For those experiencing a distorted sense of taste, known as dysgeusia, and a burning mouth, certain medications such as tricyclic antidepressants and clonazepam could possibly help. If the dysgeusia is severe, topical anesthetics like lidocaine gel might provide some relief. After an injury or surgery that affects the nerves supplying the taste buds, there’s no specific treatment. The condition could either get better on its own or stay the same. For patients who experience a dry mouth condition, known as xerostomia, artificial saliva can be used as a treatment option.
What else can Ageusia be?
When testing for ageusia, which is the complete loss of taste, it’s important to first determine if the person has lost all taste or just specific tastes. A thorough review of the person’s medical history is crucial for making this diagnosis. The doctor must take into account past illnesses related to the nose or nasal sinus, any recent viral infections, allergies, exposure to pollutants at work (like chemical vapors), and current medication use. There are numerous potential causes of ageusia:
- Medications and physical factors like radiation therapy
- Brain disorders like strokes
- Tumors
- Head injuries
- Skull base fractures
It’s also worth noting that a natural part of aging can cause a person’s sense of taste to fade. Therefore, age should also be considered when diagnosing ageusia.
What to expect with Ageusia
The effectiveness of treating ageusia, a condition where one loses their sense of taste, largely depends on what’s causing it. It’s common for many patients to feel depressed as they worry about how serious their condition might be.
Possible Complications When Diagnosed with Ageusia
Ageusia, or a loss of taste, can lead to significant health problems. If caused by certain medications, it can aggravate conditions common in older adults, including lack of appetite, extreme weight loss, and inability to control urination and bowel movements. It can also increase the risk of heart disease, diabetes, stroke, and other illnesses that require special diets.
When a person’s sense of taste is impacted, their eating habits can change drastically. This could lead to not getting the right nutrients. Some might eat less and lose weight, while others might eat more and gain weight. In severe cases, losing the sense of taste can even cause depression.
Preventing Ageusia
Ageusia, or loss of taste, can significantly affect a person’s mental health and overall well-being, especially in older individuals. There are times when finding a cure can be difficult. During these times, the best way to help the patient is to teach them how to manage their condition. Helpful tips include eating smaller, more frequent meals, using more spices and condiments, adding more fats and sauces to their food, and prioritizing mouth care. These strategies can make living with ageusia easier and improve their quality of life.
