Oral Thrush: Everything You Need to Know

Oral thrush is a fungal infection that develops on the mucous membranes of the mouth. The pathogen responsible is a microscopic fungus. In most cases, this is Candida albicans, a yeast also involved in vaginal and skin fungal infections. Typical symptoms of oral thrush include the appearance of white patches in the mouth, a red and inflamed tongue, and an unpleasant burning sensation.

The different types of oral thrush

There are several types of oral thrush, which can be identified by their symptoms:

Thrush: Very common in babies, thrush causes a white coating on the tongue, which is sometimes mistaken for milk residue. However, the white patches caused by a fungus on the tongue are more difficult to remove and, when you try to scrape them off, the mucous membrane beneath the patches is often red and irritated.

Angular cheilitis: This oral fungal infection affects the corners of the mouth. Angular cheilitis manifests as small, red, weeping cracks, accompanied by a burning sensation. The pain intensifies when the mouth is opened, which can make even simple actions such as speaking or smiling difficult.

Acute erythematous candidiasis: Red, shiny, painful patches appear on the mucous membranes of the mouth, along with dry mouth. This type of fungal infection is often associated with an imbalance in the oral flora following a course of antibiotics.

Chronic hyperplastic candidiasis: This mainly affects smokers and presents as thick white patches on the tongue and gums. These patches adhere firmly and are difficult to remove.

Chronic atrophic candidiasis: Also known as denture stomatitis, this fungal infection develops under dentures, particularly when they are poorly fitted or not cleaned thoroughly. This causes chronic inflammation of the gum tissue beneath the denture.

How long does a mouth thrush infection last?

An oral thrush infection may clear up on its own within a few weeks, or it may continue to spread and worsen. It is therefore essential to see a doctor so that they can assess the most appropriate course of treatment. Once antifungal treatment begins, symptoms usually disappear within 1 to 3 weeks.

Our bodies are home to thousands of micro-organisms, mainly bacteria but also fungi, which form a veritable ecosystem. Sometimes, one species proliferates abnormally and takes over the others, causing an imbalance that leads to an infection. Candida albicans is a yeast naturally present in our various microbial communities. When it proliferates uncontrollably, it can cause a fungal infection that may manifest on the skin, genitals, or even in the mouth. Several factors can promote its growth, such as:

A diet high in sugar: Candida albicans thrives on sugar. Consequently, a diet rich in sweets, sugary drinks (fruit juices, fizzy drinks, etc.) and refined grains (white bread, white pasta, etc.) encourages its proliferation.

A weakened immune system: Intense stress or severe fatigue can temporarily weaken the body’s defences, making it more vulnerable to pathogens. Oral thrush is also common in babies, as their immune systems are not yet fully developed.

Taking certain medicines: Certain treatments, such as antibiotics, corticosteroids and antipsychotics, can promote the growth of Candida albicans. This is because antibiotics alter the oral flora and inhibit the bacteria that normally regulate its presence. Corticosteroids can weaken the immune system. Antipsychotics, for their part, can cause dry mouth, which increases the risk of fungal overgrowth.

Poor dental hygiene: Inadequate tooth brushing promotes tartar buildup and creates an imbalance in the oral flora.

Poorly fitting dentures: When dentures are poorly positioned, they cause friction and moisture, creating an ideal environment for fungal growth.

Dry mouth: Saliva helps maintain oral health. When saliva is insufficient, Candida albicans finds an environment conducive to growth.

Certain medical conditions: Oral thrush is more common in people with type 2 diabetes, as high sugar levels in saliva promote the growth of fungi. People living with HIV are also more vulnerable, as their immune system is less effective at containing the growth of the infectious agent.

Oral thrush symptoms can vary depending on the location and type of infection. However, the following symptoms are commonly observed:

• Whitish patches: A white, creamy coating appears on the tongue, cheeks, roof of the mouth or gums.

• A burning sensation: Inflammation of the mucous membranes causes pain similar to that of a burn, often accompanied by a feeling of dryness.

• Cheilitis: In the case of angular cheilitis, painful cracks appear at the corners of the lips, making it difficult to open the mouth.

• A red, painful tongue: The infection causes inflammation, which irritates the taste buds.

• Loss of or altered sense of taste: Some people experience a reduced sense of taste or an unpleasant metallic taste.

• Difficulty swallowing: In the most severe cases, the fungal infection can spread as far as the throat, which can cause pain when swallowing.

• Itching: Although less common, some cases of oral thrush can cause a tingling or itchy sensation.

If you think you may have oral thrush, we recommend that you make an appointment with your GP. A medical examination is necessary to confirm the diagnosis, particularly if this is the first time you have experienced these symptoms. A simple examination of the lesions is usually enough for the doctor to identify oral thrush. Depending on your circumstances and the stage of the infection, they can suggest a suitable course of treatment. In most cases, topical antifungal treatments are sufficient to clear up the infection. These come in the form of creams, lozenges, or drops applied directly into the mouth. In more advanced cases, doctors may prescribe oral antifungal medicines for a broader effect. Sometimes, further tests may be considered, particularly in cases of chronic infection. These help identify the pathogen responsible for recurrent fungal infections and enable more effective, tailored treatment.

To complement your treatment, you can use a natural mouthwash made with bicarbonate of soda. This helps reduce acidity in the mouth, creating an environment that is unfavourable to fungal growth. To use this natural remedy for oral thrush, mix 1 teaspoon of bicarbonate of soda into half a glass of water. Gargle with the mixture, holding it in your mouth for 1 minute, then spit it out.

To get rid of oral thrush for good, you need to maintain or restore the balance of your oral flora. To do this, you can add certain steps and good habits to your daily routine.

1. Cut down on your sugar intake: This is the first essential step if you’re prone to recurrent thrush. Limit sugary drinks, alcohol (particularly beer, which is high in sugar and yeast), pastries, biscuits, white bread and refined cereals as much as possible.

2. Boost your immune system: A strong immune system is your best defence against infections. Zinc, vitamins C and D, and omega-3s all help the body’s natural defences to function properly. You can find them in small oily fish, seafood, seeds and nuts, and fresh fruit and vegetables. If you’re feeling temporarily tired, you could also take supplements to give your body an extra boost.

3. Maintain impeccable oral hygiene: Brush your teeth at least twice a day with a soft-bristled toothbrush. Make sure you always brush from the gum line towards the tooth. This helps to avoid damaging your gums and prevents food debris from being pushed back underneath them. You can also complement your oral hygiene routine by using a tongue scraper to remove debris from your tongue. Finally, avoid using mouthwash too frequently, as this can disrupt the balance of your oral microbiome.

4. Clean your dentures every day: Even when you can’t be bothered, do it anyway. This daily habit significantly reduces the risk of denture stomatitis. And if you experience any discomfort with your dentures, don’t hesitate to speak to your dentist.

5. Give up smoking: By giving up smoking, you’ll help restore the balance of your oral flora and improve the health of your gums. To support and motivate you through this process, take a look at our article in which we share 6 effective tips for giving up smoking.

If your symptoms persist despite treatment, or if you develop a fever or pain when swallowing, consult your doctor again. This will help rule out any complications and allow the treatment to be adjusted if necessary.

Our oral health depends largely on the balance of our oral microbiome. Many factors can disrupt this delicate ecosystem, such as an unbalanced diet, excessively hot drinks, or overuse of mouthwashes. Maintaining this balance daily is therefore the best way to prevent oral fungal infections and to keep your mouth healthy.

Amandine is a writer specialising in natural health. With a passion for alternative medicine, she is training to become a naturopath. Through her articles, she aims to make her knowledge accessible to a wide audience, helping readers bring greater well-being and balance to their everyday lives.