Oral Thrush: Causes, Treatment, and Prevention

Oral thrush is a fungal infection that occurs in the mouth and throat. It is usually caused by a fungus called Candida albicans. The mouth fungus can affect the inside of the cheeks and lips, sometimes the tongue and the palate.

Oral Thrush: Causes, Treatment, & Prevention
Oral Thrush: Causes, Treatment, & Prevention

Oral thrush, also known as oral candidiasis, is a yeast infection that occurs in the mouth and throat. It can develop on the inside of chicks, tongue, and palate. It is usually caused by a fungus called Candida albicans. This fungus is found normally in the mouth and under certain conditions, it can overgrow leading to an infection in the mouth and inflammation of the oral mucosa. Oral thrush is usually characterized by a white to a yellow coating on a red, inflamed oral mucosa, however, there are also other forms. It occurs frequently in newborns and babies but also in adults with weakened immune system or who take certain drugs such as antibiotics. Oral thrush is not a serious condition and rarely causes complications in healthy people. However, it can cause severe symptoms and spread to other parts of the body in people with weakened immune system.

Causes of Oral Thrush

Oral thrush is usually caused by a fungus known as “Candida albicans”. In many healthy people, this fungus is found normally in the oral cavity, intestine, or skin and is usually not causing any problems. However, in people with weakened immune system, the Candida albicans fungus use a gap in the body-defense system and begins to multiply quickly. This is why oral thrush occurs in newborns and babies who don’t yet have a strong immune system. Also, adults can develop oral thrush if the immune system suppressed by medications or weakened by a disease such as cancer, HIV/AIDS, or diabetes.

Risk Factors for Oral Thrush

Almost all people come into contact with the Candida albicans fungus, but the infection only breaks under certain circumstances. The risk factors include:

  • Weakened immune system: the infection occurs in newborns and babies because they don’t have a strong immune system. In adults, the immune system is weakened by some medical conditions such as:
    • HIV/AIDS.
    • Cancer (eg: leukemia).
    • Diabetes mellitus (poorly controlled).
    • Malnutrition especially hematinic deficiencies (iron, vitamin B12, folic acid).

Also, some drugs can suppress the immune system such as drugs used in organ transplantation and HIV/AIDS treatment.

  • Medications: the long-term use of some medication is one of the possible triggers of oral thrush such as:
    • Antibiotics.
    • Steroids (contained in asthma sprays)
    • Cytotoxic drugs (used to treat cancer)
  • Vaginal fungus: newborns with oral thrush have usually infected at birth due to a possibly unnoticed vaginal fungus in the mother.
  • Dry mouth condition: some medications and smoking can reduce the production of saliva that may lead to the development of oral thrush. Also, radiation and chemotherapy can cause dry mouth condition.
  • Ill-fitting dentures: the candida albicans fungus may enter the oral mucosa through injuries caused by braces and ill-fitting dentures.

Symptoms of Oral Thrush

The typical symptoms of oral thrush are red, inflamed oral mucosa covered with a white coating. It is usually found on the inside of cheeks, tongue, or palate. The white coating can be easily wiped off and a red, shiny, dry surface appears underneath that begins to bleed easily. This form is known as pseudomembranous candidiasis, the most common form of oral thrush. In the advanced stage, symptoms may include:

  • Burning sensation in the mouth.
  • Dry mouth.
  • Unpleasant or metallic taste in the mouth.
  • Redness and cracking at the corner of the mouth.
  • Pain during eating or drinking (especially in babies).
  • Difficulty swallowing due to the spread of infection to the esophagus (candida esophagitis).

As long as the infection is still in the initial stage, these symptoms may not occur. However, oral thrush in babies is very unpleasant and may cause difficulty feeding, fussiness, or irritability. If the infection spread to the esophagus, further symptoms may occur:

  • Heartburn.
  • Difficulty swallowing.
  • chest pain behind the breastbone (sternum).
  • Vomiting.
  • Hiccup.

Infants and mothers

The infection can be transmitted from infants to their mothers during breastfeeding. Then, the infection can be transmitted back from mother’s breast to the infant’s mouth. Mothers with infected breast may have:
Burning, itchy, cracked, red, or sensitive nipples surrounded by flaking or shiny skin.
Deep breast pain during or after breastfeeding.

Forms of Oral Thrush

There are different forms of oral thrush, including:

  • Pseudomembranous candidiasis: this is the most common form of oral candidiasis. It is characterized by a red, inflamed oral mucosa covered with a white coating. The coating can be easily wiped off and a red, shiny surface appears beneath it that begins to bleed easily. Pseudomembranous is an acute form of oral candidiasis.
  • Erythematous candidiasis: it is also known as atrophic candidiasis. It is characterized by a burning sensation in the mouth and a red, raw-looking lesion that appears on the dorsum of the tongue and palate. Erythematous candidiasis is subdivided into acute and chronic form. The acute form develops mainly in people who take long-term antibiotics or corticosteroids. The chronic form usually develops in association with denture wearing.
  • Hyperplastic candidiasis: it is also known as candidal leukoplakia. It is uncommon and usually chronic. It appears as a firm white lesion with red edges which can’t be easily wiped off. This form of oral candidiasis is common in people with weakened immune system and can persist for months or years.

Diagnosis of Oral Thrush

The diagnosis of oral thrush can be performed by a dentist, dermatologist, pediatrician, or general practitioner. The diagnosis is based on the characteristic, mostly visible symptoms (white lesion on the inside of cheeks, tongue, or palate).

The doctor will wipe off the white lesion to reveal a red shiny surface underneath to distinguish the pseudomembranous candidiasis from other white lesions that can’t be wiped off. Also, the doctor may ask some questions about:

  • How long have they excited?
  • Existing or previous medical conditions.
  • Do you take any medication?
  • Do you have asthma?

To confirm the diagnosis, the doctor may perform more tests and investigations such as:

  • Smears: the doctor will scrape the lesion gently with a tongue blade and apply the debris directly to a glass slide to be examined microscopically.
  • Fungal culture: to determine the exact nature of the candida fungus.
  • Biopsy: if hyperplastic candidiasis is suspected.
  • Blood test: to identify the underlying medical condition.

Complications of Oral Thrush

Oral thrush rarely causes complications in healthy people. In people with weakened immune system (such as HIV/AIDS), the infection may spread to the esophagus. Also, it may spread into deeper tissue layers and enter the bloodstream. This can lead to the spread of infection to other parts of the body such as brain, heart, liver.

Treatment of Oral Thrush

For the treatment of the oral thrush, the doctor usually prescribes antifungal medications suitable for the mouth and throat area that contain active ingredients such as nystatin, miconazole, fluconazole, or amphotericin B. these antifungal medications are available in the form of lozenges, tablets, or mouthwashes that you swish in your mouth then swallow.

Home remedies for oral thrush

These recommendations may help in the treatment of oral thrush:

  • Brush your teeth at least twice daily with a soft-bristled toothbrush.
  • Replace the toothbrush daily until the infection clears up.
  • Don’t share your toothbrush with anyone.
  • Control your blood sugar, if you have diabetes mellitus.
  • Clean and disinfect your dentures (ask your dentist).

If you are breastfeeding and your infant is infected with oral thrush, you should:

  • Visit your doctor. he/she may prescribe an antifungal cream for you and antifungal medication for the baby.
  • Clean pacifiers, bottle nipples, and your breast nipples.
    Use nursing pads to prevent the spread of fungal infection to your clothes.

Prevention of Oral Thrush

There are various measures that you can use to prevent oral thrush:

  • Brush your teeth regularly at least twice a day. Also, floss your teeth daily.
    If you wear dentures, make sure that it fits properly. Also, clean them after each meal.
  • Wash your mouth after using a corticosteroid inhaler.
  • Control your blood sugar if you have a diabetes mellitus.
  • For babies, maintaining a good oral hygiene is very important to prevent the development of oral candidiasis. Also, pacifiers and toys that placed in the mouth should be cleaned on a regular basis.
  • The vaginal fungus can be transferred from the mother to the baby at birth and appears as oral thrush in the newborn. So, an appropriate treatment of the infected mother is recommended before birth.
  • Breastfeeding mothers with infected breast should visit the doctor to prevent the spread of infection to the baby. The doctor may prescribe an antifungal cream for the mother and antifungal medication for the baby. Remember that the infection can occur in both directions.
  • Avoid smoking. Tobacco smoking decreases the production of saliva leading to the development of oral candidiasis.
  • Visit your doctor if you have a weakened immune system or are taking a medication that may increase the risk of developing oral candidiasis. The doctor may prescribe a course of antifungal medication.