Dysgeusia (pronounced “dis-GOOZ-ee-a”) is an abnormal taste or change in taste that won’t go away. It can be described as bad, metallic, salty, foul or rancid.
Your taste buds are found on your tongue and on the roof of your mouth. They contain cells that collect taste information and send it to the brain.
Some people with dysgeusia also have an altered sense of smell. About 75% of flavor and taste sensations come from nerve cells involved with smell. Both taste and smell cells work together to produce the sense of taste.
Our taste cells can identify four main qualities: sour, bitter, salty and sweet. More subtle aspects of flavor come from your sense of smell. Try this experiment. Take a sip of coffee or eat an orange slice while you hold your nose. It will be difficult to taste the flavor of the food or drink.
Dysgeusia is relatively uncommon. It can have numerous causes. Fortunately, many of the causes are temporary. For example, several infections can cause mild dysgeusia. They include the common cold, flu, strep throat and nasal or sinus infections. Causes of dysgeusia are rarely life-threatening, but the disorder does affect your quality of life.
Other causes include:
- Smoking (especially pipe smoking)
- Gingivitis (inflammation of the gums)
- Periodontal disease (advanced gum disease)
- A dental abscess
- Oral yeast infection
- Certain medicines, including lithium, antibiotics, ACE inhibitors and many cancer drugs
- Dry mouth (xerostomia), which can be caused by Sjögren’s syndrome and many medicines
- Vitamin or mineral deficiency
- A brain tumor or trauma to the head
- Damage to the taste nerves
- Metabolic or endocrine problems, such as diabetes or thyroid disease
- Surgery of the larynx (voice box)
- Head and neck radiation
- Migraine headache
- Chlorhexidine oral rinse for periodontal (gum) disease
- Bell’s palsy
- Dysgeusia may also occur along with burning mouth syndrome or glossitis, and other oral conditions.
Changes in the sense of taste (and sometimes smell) are the only symptoms.
Your physician will ask about your medical history and will examine you. He or she also will ask detailed questions about your dysgeusia. Common questions include how long you’ve had the problem and what kind of specific taste changes you’ve noticed.
The physician also will ask about possible causes (such as smoking, cold or flu). Make sure you tell him or her about all of the medicines you take, as well as any vitamins and herbal supplements.
Tests can be used to evaluate your senses of taste and smell. Certain chemicals made to produce the four major tastes — sour, sweet, bitter, salty — can be applied to areas of your tongue. Or you may be asked to take a taste test. In this test, you will sip certain liquids and try to identify their tastes.
The chemicals or liquids used to test taste have no odor.
A “scratch and sniff” test can be used to check out your sense of smell. The test uses special cards. Each one contains an odor that is released when scratched. You will be asked to identify the odor on each card.
Other tests that may be performed include imaging (MRI, CT scans), blood tests or saliva flow rate.
How long dysgeusia lasts depends on the cause. Sometimes the problem disappears once the cause is removed. This can occur if the cause is gum disease, plaque, a medicine you are taking for a short time or a short-term condition such as a cold.
If the cause is a yeast infection, the dysgeusia should disappear after the yeast infection is properly treated. In some cases — for example, if nerves have been damaged — the dysgeusia may be permanent.
Some causes of dysgeusia can be prevented, but most cannot. Quitting smoking will improve your sense of taste and smell. Practicing good oral hygiene, getting regular dental care, and having sinus problems treated also can help.
Many times, dysgeusia is treated by treating the cause. If the cause cannot be treated, your dysgeusia is tough to treat. An example would be irreversible nerve damage.
Nerve microsurgery may help some people with dysgeusia caused by a nerve injury within the first 90 days. Treatment of dry mouth or oral infection can help people with dysgeusia.
Diagnosis of Smell and Taste Disorders
The first step in diagnosing any deficit of taste and smell is obtaining a thorough history and physical examination. Give attention to any antecedent URI, nasal or sinus pathology, history of trauma, other medical problems, and medications taken.
Order sinus CT scans if the history and examination are not consistent with a common pattern (eg gradually progressing olfactory loss in a 38-year-old male).
Generally, olfactory loss in the absence of CNS symptoms or an abnormal neurologic examination is highly unlikely to be associated with an intracranial mass such as a meningioma.
However, an MRI of the brain is often recommended when the history is not straightforward or a secondary neurologic symptom or sign is obtained (eg, 50-year-old woman with a taste phantom that does not resolve after 6 months).
Although a standard laboratory panel is not recommended, tests to evaluate for allergy, diabetes mellitus, thyroid functions, renal and liver function, endocrine function, and nutritional deficiencies may be obtained based on history and the physical examination. Olfactory epithelium biopsy is used primarily as a research technique.
When To Call a Professional
Call your physician or dentist if any taste changes last for at least two weeks. Many times, dysgeusia will last only a few days if it is caused by a cold or other short-term problem. It is best to visit your primary-care physician first to rule out medical problems.
You may be referred to your general dentist or a specialist if an oral condition is involved. In some cases, you may need to visit a center that specializes in taste and smell disorders.
The outlook is excellent if the cause of the dysgeusia can be found. If the cause is gum disease, plaque or a short-term infection or medicine, the dysgeusia should disappear once the cause is removed.
Sometimes dysgeusia is related to an untreated disease, such as diabetes. In this case, it is likely to improve after medical treatment.
If no cause can be found, this is called “idiopathic dysgeusia.” It’s hard to say what the outlook for this condition will be. In some cases, idiopathic dysgeusia may go away on its own.
In others, it will not. It is important to be evaluated so that the known causes of dysgeusia can be ruled out. Research has been done to treat patients who have idiopathic dysgeusia with certain medicines.
One study found that idiopathic dysgeusia may be a nervous system condition similar to burning tongue syndrome.