Oral Thrush Signs, Symptoms, and Best Treatment for Thrush

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Oral thrush, also called oral candidiasis, is the most common fungal infection of the mouth. It usually happens in people with weak or underdeveloped immune systems. It often presents with white lesions on the roof of the mouth, cheeks, and tongue. While the best treatment for thrush varies depending on the severity of symptoms and the person affected, antifungal medications are typically used to treat oral thrush. Read on to learn more about the signs, symptoms, and best treatment for oral thrush.

What Is Oral Thrush?

Oral thrush is a mouth infection usually caused by a fungus called Candida albicans. Candida albicans is part of the normal flora of the mouth, meaning that the fungus is normally present in the mouth and does not cause harm. However, sometimes it overgrows, leading to disease. A weakened immune system can lead to this overgrowth. So, people with conditions that weaken the immune system, such as cancer or HIV/AIDS, are more likely to be affected. Infants are also more likely to be affected by oral thrush than adults because their immune systems are not fully developed. If a breastfeeding infant has oral thrush, they can transmit the infection to their mother, passing it back and forth between mother and baby.

Other risk factors for oral thrush include:

  • Poorly controlled diabetes: People with uncontrolled diabetes may have high sugar levels in their saliva, which allows Candida albicans to grow
  • Vaginal yeast infections: Infants born to mothers with vaginal yeast infections, or fungal infections of the vagina, can get thrush when they pass through their mother’s birth canal. 
  • Use of antibiotics: Antibiotics can wipe out normal flora of the mouth, giving Candida albicans more space to grow in excess.
  • Use of corticosteroids: Corticosteroids generally suppress the immune system, preventing immune cells from suppressing Candida albicans proliferation
  • Smoking: Smoking can increase the risk of oral infection with Candida by drying out the mouth.
  • Denture use:  Denture use can increase the risk of oral infection with Candida by drying out the mouth.

Oral thrush may spread to the esophagus, leading to a condition called esophageal candidiasis. Esophageal candidiasis is considered an “AIDS-defining illness” because it is one of the most common infections seen in people living with HIV/AIDS.

Signs and Symptoms

The following signs and symptoms may occur in people with oral thrush:

  • White, raised lesions, typically on the tongue or cheeks, that look like cottage cheese
  • Redness, burning, or pain that may make eating and swallowing difficult
  • Cracks at the corners of the mouth (angular cheilitis)
  • A cotton-like feeling in the mouth
  • Loss of taste (ageusia)
  • Irritation and pain under dentures (denture stomatitis)

In addition to these symptoms, if you have esophageal candidiasis, you may experience pain when swallowing (odynophagia) and difficulty swallowing (dysphagia).

Infants affected by oral thrush may be fussier than normal and have difficulty feeding. Women whose breasts get infected with Candida from breastfeeding may experience unusual redness, flakiness, or pain on the areola (the darker, circular area of the nipple). They may also experience deeper, stabbing pains of the breasts3.

Diagnosis

Doctors usually diagnose oral thrush by asking patients about their symptoms and examining the mouth for white lesions that can easily be scraped away with a tongue depressor. Sometimes, they’ll take a sample of the fungus from a patient’s mouth to be examined under a microscope in a laboratory. However, people with severe cases of oral thrush or those with esophageal candidiasis may undergo further testing to determine the underlying causes of their condition and the extent of their infection. These tests include: 

  • A complete blood count (CBC), which shows how well the immune system responds to the infection.
  • A biopsy, where a fungus sample is grown on a special medium to identify the microorganism causing the infection.
  • An endoscopic exam, where the esophagus, stomach, and upper part of the small intestine (duodenum) are visualized with a camera-like device called an endoscope.
  • A physical exam to see if other body parts are infected with Candida.

Treatment Options

The most effective treatment for thrush varies slightly depending on the severity of the symptoms and the patient. 

Healthy Adults and Children

Mild cases of oral thrush in healthy adults and children are treated for one to two weeks with antifungal lozenges, tablets, liquids, or topical medication. Clotrimazole, miconazole, and nystatin are examples of antifungal medications that can be used for this condition. Oral or intravenous fluconazole is used for moderate to severe cases of oral thrush.

Infants and Nursing Mothers

Infants with oral thrush should be treated with miconazole gel or fluconazole. Breastfeeding females who have an infection of the breasts with Candida may be prescribed antifungal cream to apply to affected areas.

People with Weakened Immune Systems

Oral fluconazole is the best treatment for thrush in people with weak immune systems. Those with HIV/AIDS are also treated with antiretroviral therapy to prevent recurrent thrush infections. Esophageal candidiasis is treated with oral fluconazole for two to three weeks.

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Overall, oral fluconazole tends to be the best thrush treatment. While topical medication can be used for mild cases of thrush, recurring infections are more likely to happen with topical antifungals than with oral fluconazole. In rare cases, fluconazole is not effective against cases of thrush, and a medication called amphotericin B is used instead. 

Next Steps

There are a few simple steps you can take to prevent oral thrush.

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  • Maintain good oral hygiene: Brush and floss your teeth regularly. Replace your toothbrush often until the thrush is gone, and never share your toothbrush with others.
  • Keep your dentures clean: Ask your dentist about how to keep your dentures clean and how to avoid reinfecting yourself with oral thrush.
  • Rinse your mouth with saltwater: Dissolve about ½ teaspoon of salt in one cup of warm water. Swirl this water in your mouth and spit it out. Do not swallow this water.
  • Use nursing pads: If you get a fungal infection from breastfeeding, use nursing pads to prevent the fungus from spreading to your clothing. Plastic can encourage the growth of Candida, so avoid pads that have a plastic barrier. Wear a clean bra daily. Ask your doctor how to keep breast nipples, bottle nipples, pacifiers, and breast pumps clean and free of the fungus.

If you think you might have thrush, ask your doctor about your symptoms and what treatments are recommended.

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