Oral thrush, also known as oral candidiasis, is a fungal infection that can affect the mouth. Symptoms include a white or yellow buildup on the tongue, an unpleasant taste, and discomfort. Home and medical remedies can treat it.

A person who may have oral thrush.Share on Pinterest
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Oral thrush most commonly occurs due to the fungus Candida albicans. However, the following can also cause the infection:

  • Candida glabrata
  • Candida tropicalis
  • Candida krusei

For the majority of individuals, oral thrush does not cause any serious problems. However, if a person has a weakened immune system, their signs and symptoms may be much more severe.

This article will cover all aspects of oral thrush, including the causes, symptoms, and treatment.

Doctors will usually prescribe anti-fungal medications, such as nystatin or miconazole, in the form of drops, gel, or lozenges.

Alternatively, a doctor may prescribe a topical oral suspension. To take this treatment, a person washes it around their mouth for a few minutes and then swallows or spits out the solution (depending on the formulation).

According to a 2021 article, a healthcare professional will prescribe the following treatment options based on the severity of the condition:

  • Mild oral thrush: A doctor may prescribe 10 milligrams (mg) of clotrimazole troche five times a day. A clotrimazole troche is a lozenge that a person dissolves slowly in their mouth. Another option includes 5 milliliters of nystatin oral suspension four times a day.
  • Moderate to severe oral thrush: A doctor may prescribe 200mg of fluconazole once followed by 100mg once a day, for 7–14 days. A person will take this medication orally.
  • Oral thrush that is not responding to treatment: Options include:
    • 200mg of Itraconzole oral solution once a day for 28 days
    • 400mg posaconzaole suspension twice a day for 3 days, followed by 400 mg once a day for 28 days
    • 200mg voriconazole twice a day for 28 days

For people who also have advanced cancer, a doctor may prescribe 150 mg of fluconazole as a single dose.

Alongside medical treatment, the following can help reduce the risk of worsening the condition:

  • rinsing the mouth with salt water
  • using a soft toothbrush to avoid scraping the lesions
  • using a new toothbrush every day until the infection has gone
  • eating unsweetened yogurt to restore healthy bacteria levels
  • avoiding using mouthwashes or sprays

The National Health Service notes that the use of steroid inhalers, or corticosteroid inhalers, can increase the chance of developing oral thrush. A person can use a spacer or rinse their mouth after use to help prevent oral thrush from developing

Oral thrush in babies presents as a white coating on the tongue that resembles cottage cheese. A caregiver will not be able to rub the coating off easily. However, they will be able to scrape the coating off, leaving a red area.

Oral thrush in adults generally appears as thick, white, or cream-colored deposits on the mucous membrane of the mouth. The inside of the mouth may appear swollen and slightly red and may feature raised spots.

The white spots may join together to form larger ones, also known as plaques. These plaques may then take on a grayish or yellowish color.

Occasionally, the affected area simply becomes red and sore, with no detectable white spots.

If a person scrapes the cream or white-colored deposits, bleeding may occur.

Other symptoms include:

  • cracks at the corners of the mouth
  • an unpleasant taste
  • pain, such as a sore tongue or gum
  • difficulty eating or drinking

Individuals who wear dentures may have areas that are constantly red and swollen under their dentures. Poor oral hygiene or not taking the dentures out before going to sleep may increase the risk of oral thrush.

A 2015 reviewnotes that medical professionals sometimes divide oral thrush into three groups based on appearance, although the condition can sometimes sit between categories. The three groups are:

  • Pseudomembranous: A person may develop white to whitish-yellow plaques on the tongue that resemble cottage cheese.
  • Erythematous, or atrophic: The condition appears red raw rather than white.
  • Hyperplastic: Also known as “plaque-like candidiasis” or “nodular candidiasis” due to the presence of a hard-to-remove, solid, white plaque. This is the least common variant and is most often present in patients with HIV.

There are a number of other lesions that can also appear with oral thrush. Sometimes, these lesions might be due to other types of bacteria that are also present in the area. These can include:

  • Denture stomatitis: Healthcare professionals may also refer to this as chronic atrophic candidiasis and affects approximately 50–65% of those who wear dentures. The areas where the dentures normally sit may be inflammed. The lesions are usually asymptomatic, although a person may experience a burning sensation.
  • Angular cheilitis: This is inflammation and splitting in the corners of the mouth.
  • Median rhomboid glossitis: This is a large, red, painless mark in the center of the tongue.
  • Linear gingival erythema: This is a band of inflammation running across the gums.
  • Canker sores: These are small, shallow ulcers in the mouth.
  • Leukoplakia: This is a white patch in the mouth that can appear on the tongue, gums, the inside of the cheeks, and the roof of the mouth. These patches are not painful and are irregular in shape. A person will not be able to remove the patches, unlike the patches that occur due to oral thrush.

Oral thrush is not contagious in adults.

However, thrush can pass between an infant and parent during breastfeeding or chestfeeding.

Some people may find oral thrush painful. The spots can become raised, and a person may experience discomfort and a burning sensation. In other instances, a person may develop no spots but experience a general soreness in the mouth.

If a person scrapes their spots, they may bleed and experience some mild pain.

Tiny quantities of Candida fungus exist in various parts of our body. It is present in the digestive system, skin, and mouth. Generally, these fungi cause no problems to healthy individuals.

However, people on certain medications, with reduced immune systems, or with certain medical conditions are susceptible to oral thrush when C. albicans grows out of control.

According to the Centers for Disease Control and Prevention (CDC), those under 1 month of age have a higher chance of developing oral thrush.

Adult oral thrush is more likely to become a problem for the following groups:

  • Dentures: People who wear dentures are at a higher risk of developing oral thrush. Especially if they do not keep them clean, they own dentures that do not fit properly, or if the person does not take them out before going to sleep.
  • Antibiotics: People who are on antibiotics have a higher risk of developing oral thrush. Antibiotics may destroy the bacteria that prevent the Candida from growing out of control.
  • Steroid medication: Long-term use of steroid medication can increase the risk of oral thrush.
  • Weakened immune system: People with weakened immune systems are more likely to develop oral thrush.
  • Diabetes: People with diabetes are more likely to have oral thrush, especially if they poorly control their disease.
  • Dry mouth: People with less than normal quantities of saliva, or xerostomia are more prone to oral thrush.
  • Smoking: Heavy smokers are more at risk of developing oral thrush. The reasons behind this are unclear.

Other risk factors include:

  • Use of steroid inhalers: One 2016 study found that those who took inhaled corticosteroid or long-acting beta-2-agonist fixed-dose combination inhalers had a higher chance of developing oral thrush, compared with those who took long-acting bronchodilators alone.
  • Malnutrition: A 2015 article states that a deficiency in iron the the most common nutrient linked to the growth of candida. Other nutritional deficiencies related to an increase of oral thrush risk include:
    • vitamin A
    • magnesium
    • selenium
    • zinc
    • folic acid
    • essential fatty acids
  • Prolonged hospital stays: This can increase the chance of oral thrush in newborns.
  • Cancer treatments: Chemoradiation therapy for head and neck cancer can lead to mucositis, which is when the mouth becomes sore and inflamed. A 2020 study notes that Candida infection is both a result of chemo-radiation mucositis and a risk factor.

The CDC states that the doctor can look into the person’s mouth and ask some questions about symptoms to diagnose oral thrush.

The doctor may scrape some tissue from the inside of the mouth for analysis.

If the doctor believes that medication or some other underlying cause is behind the thrush, then they will attempt to deal with it accordingly. Treatments in such cases depend on the underlying cause.

Oral thrush is a fungal infection that develops on the mucous membranes of the mouth.

Common symptoms of oral thrush include thick, white, or cream-colored spots on the mucous membrane. These spots may be raised and can cause some pain and discomfort,

For most people, oral thrush does not cause serious problems. However, people with weakened immune systems may experience more severe symptoms and a higher chance of the infection spreading into the bloodstream.

Doctors can treat oral thrush with anti-fungal drugs, such as nystatin or miconazole. They may also prescribe a topical oral suspension.

Some circumstances may increase a person’s risk of developing oral thrush. These include smoking, diabetes, the use of dentures, the use of antibiotics, and a weakened immune system.