Thrush, Adult

Thrush is a yeast infection that develops in the mouth and throat and on the tongue. The medical term for this is oropharyngeal candidiasis, or OPC. Thrush is most common in older adults, but it can occur at any age. Thrush occurs when a yeast called candida grows out of control. Candida normally is present in small amounts in the mouth and on other mucous membranes. However, under certain circumstances, candida can grow rapidly, causing thrush. Thrush can be a recurring problem for people who have chronic illnesses or who take medications that limit the body's ability to fight infection (weakened immune system). Since these people have difficulty fighting infections, the fungus that causes thrush can spread throughout the body. This can cause life-threatening blood or organ infections.

CAUSES

Candida, the yeast that causes thrush, is normally present in small amounts in the mouth and on other mucous membranes. It usually causes no harm. However, when conditions are present that allow the yeast to grow uncontrolled, it invades surrounding tissues and becomes an infection. Thrush is most commonly caused by the yeast Candida albicans. Less often, other forms of candida can lead to thrush.

There are many types of bacteria in your mouth that normally control the growth of candida. Sometimes a new type of bacteria gets into your mouth and disrupts the balance of the germs already there. This can allow candida to overgrow. Other factors that increase your risk of developing thrush include:

  • An impaired ability to fight infection (weakened immune system). A normal immune system is usually strong enough to prevent candida from overgrowing.

  • Older adults are more likely to develop thrush because they may have weaker immune systems.

  • People with human immunodeficiency virus (HIV) infection have a high likelihood of developing thrush. About 90% of people with HIV develop thrush at some point during the course of their disease.

  • People with diabetes are more likely to get thrush because high blood sugar levels promote overgrowth of the candida fungus.

  • A dry mouth (xerostomia). Dry mouth can result from overuse of mouthwashes or from certain conditions such as Sjögren's syndrome.

  • Pregnancy. Hormone changes during pregnancy can lead to thrush by altering the balance of bacteria in the mouth.

  • Poor dental care, especially in people who have false teeth.

  • The use of antibiotic medications. This may lead to thrush by changing the balance of bacteria in the mouth.

SYMPTOMS

Thrush can be a mild infection that causes no symptoms. If symptoms develop, they may include the following:

  • A burning feeling in the mouth and throat. This can occur at the start of a thrush infection.

  • White patches that adhere to the mouth and tongue. The tissue around the patches may be red, raw, and painful. If rubbed (during tooth brushing, for example), the patches and the tissue of the mouth may bleed easily.

  • A bad taste in the mouth or difficulty tasting foods.

  • Cottony feeling in the mouth.

  • Sometimes pain during eating and swallowing.

DIAGNOSIS

Your caregiver can usually diagnose thrush by exam. In addition to looking in your mouth, your caregiver will ask you questions about your health.

TREATMENT

Medications that help prevent the growth of fungi (antifungals) are the standard treatment for thrush. These medications are either applied directly to the affected area (topical) or swallowed (oral).

Mild thrush

In adults, mild cases of thrush may clear up with simple treatment that can be done at home. This treatment usually involves using an antifungal mouth rinse or lozenges. Treatment usually lasts about 14 days.

Moderate to severe thrush

  • More severe thrush infections that have spread to the esophagus are treated with an oral antifungal medication. A topical antifungal medication may also be used.

  • For some severe infections, a treatment period longer than 14 days may be needed.

  • Oral antifungal medications are almost never used during pregnancy because the fetus may be harmed. However, if a pregnant woman has a rare, severe thrush infection that has spread to her blood, oral antifungal medications may be used. In this case, the risk of harm to the mother and fetus from the severe thrush infection may be greater than the risk posed by the use of antifungal medications.

Persistent or recurrent thrush

Persistent (does not go away) or recurrent (keeps coming back) cases of thrush may:

  • Need to be treated twice as long as the symptoms last.

  • Require treatment with both oral and topical antifungal medications.

  • People with weakened immune systems can take an antifungal medication on a continuous basis to prevent thrush infections.

It is important to treat conditions that make you more likely to get thrush, such as diabetes, human immunodeficiency virus (HIV), or cancer.

HOME CARE INSTRUCTIONS

  • If you are breast-feeding, you should clean your nipples with an antifungal medication, such as nystatin (Mycostatin). Dry your nipples after breast-feeding. Applying lanolin-containing body lotion may help relieve nipple soreness.

  • If you wear dentures and get thrush, remove dentures before going to bed, brush them vigorously, and soak in a solution of chlorhexidine gluconate or a product such as Polident® or Efferdent®.

  • Eating plain, unflavored yogurt that contains live cultures (check the label) can also help cure thrush. Yogurt helps healthy bacteria grow in the mouth. These bacteria stop the growth of the yeast that causes thrush.

  • Adults can treat thrush at home with gentian violet (1%), a dye that kills bacteria and fungi. It is available without a prescription. If there is no known cause for the infection or if gentian violet does not cure the thrush, you need to see your caregiver.

Comfort measures

Measures can be taken to reduce the discomfort of thrush:

  • Drink cold liquids such as water or iced tea. Eat flavored ice treats or frozen juices.

  • Eat foods that are easy to swallow such as gelatin, ice cream, or custard.

  • If the patches are painful, try drinking from a straw.

  • Rinse your mouth several times a day with a warm saltwater rinse. You can make the saltwater mixture with 1 tsp (5 g) of salt in 8 fl oz (0.2 L) of warm water.

PROGNOSIS

  • Most cases of thrush are mild and clear up with the use of an antifungal mouth rinse or lozenges. Very mild cases of thrush may clear up without medical treatment. It usually takes about 14 days of treatment with an oral antifungal medication to cure more severe thrush infections. In some cases, thrush may last several weeks even with treatment.

  • If thrush goes untreated and does not go away by itself, it can spread to other parts of the body.

  • Thrush can spread to the throat, the vagina, or the skin. It rarely spreads to other organs of the body.

Thrush is more likely to recur (come back) in:

  • People who use inhaled corticosteroids to treat asthma.

  • People who take antibiotic medications for a long time.

  • People who have false teeth.

  • People who have a weakened immune system.

RISKS AND COMPLICATIONS

Complications related to thrush are rare in healthy people.

There are several factors that can increase your risk of developing thrush.

Age

Older adults, especially those who have serious health problems, are more likely to develop thrush because their immune systems are likely to be weaker.

Behavior

  • The yeast that causes thrush can be spread by oral sex.

  • Heavy smoking can lower the body's ability to fight off infections. This makes thrush more likely to develop.

Other conditions

  • False teeth (dentures), braces, or a retainer that irritates the mouth make it hard to keep the mouth clean. An unclean mouth is more likely to develop thrush than a clean mouth.

  • People with a weakened immune system, such as those who have diabetes or human immunodeficiency virus (HIV) or who are undergoing chemotherapy, have an increased risk for developing thrush.

Medications

Some medications can allow the fungus that causes thrush to grow uncontrolled. Common ones are:

  • Antibiotics, especially those that kill a wide range of organisms (broad-spectrum antibiotics), such as tetracycline commonly can cause thrush.

  • Birth control pills (oral contraceptives).

  • Medications that weaken the body's immune system, such as corticosteroids.

Environment

Exposure over time to certain environmental chemicals, such as benzene and pesticides, can weaken the body's immune system. This increases your risk for developing infections, including thrush.

SEEK IMMEDIATE MEDICAL CARE IF:

  • Your symptoms are getting worse or are not improving within 7 days of starting treatment.

  • You have symptoms of spreading infection, such as white patches on the skin outside of the mouth.

  • You are nursing and you have redness and pain in the nipples in spite of home treatment or if you have burning pain in the nipple area when you nurse. Your baby's mouth should also be examined to determine whether thrush is causing your symptoms.