Oral Thrush: Symptoms, Causes & Treatment

Note: This article is for general information purposes and does not replace individual dental advice.

Oral thrush, also known as oral candidiasis, is an infection of the mouth and throat. It frequently affects the inside of the cheeks and lips. In some cases, however, the tongue or the palate may also be affected.

As a rule, oral thrush presents as a white coating on reddened mucous membrane. However, there are also other forms in which it can appear. Oral thrush occurs comparatively often in newborns and babies. Adults, by contrast, are affected relatively rarely. Most adult cases involve elderly or ill patients who take particular medications.

Causes and risk factors of oral thrush

To be able to prevent oral thrush, it helps to know its causes and risk factors. Oral thrush is usually caused by an infection with Candida albicans. This fungus is widespread and belongs to the family of yeasts. It can be detected in the mouth of as many as 50 per cent of all healthy people. It is also frequently found in the gut or on various mucous membranes.

However, an opportunistic infection only develops from this colonisation in people with a weakened immune system. The fungus finds a gap in the body's defences and multiplies rapidly. This is why oral thrush develops above all in newborns and babies, whose immune system is not yet fully developed.

Older children and adults suffer from oral thrush only in rare cases. It can occur here in particular when the immune defences are suppressed by medication. In addition, people with missing teeth or dentures are especially at risk. Once the risk factors are known, oral thrush can be prevented.

What to do about oral thrush?

To prevent an infection, it is advisable to pay careful attention to oral and dental hygiene, especially in babies and small children. Proper cleaning of dummies, teats and teething toys is essential. Anyone who wears a denture should always make sure that it fits correctly.

In addition, good oral hygiene should be maintained, particularly after meals, so that oral thrush can be avoided. Those with a weakened immune system may need to take an antifungal medication as a preventive measure. In any case, this should be discussed with a doctor beforehand.

In particular, women who have vaginal thrush can pass it on to their babies, who then develop oral thrush. For this reason, affected women should have it treated during pregnancy. Patients who are severely ill and fed artificially usually have reduced saliva flow. This encourages bacteria and fungi to multiply. Geriatric and nursing staff therefore often carry out thrush and parotitis prophylaxis, in which the mucous membranes of the persons concerned are moistened regularly in order to prevent oral thrush.

Symptoms of oral thrush

Severely reddened mucous membranes with white speckles
A furry sensation in the mouth
Dryness in the mouth
Increased thirst
Disturbances of taste, possibly a metallic taste
Bad breath
A burning sensation on the oral mucosa
In babies: fungal patches on the lips or in the corners of the mouth

Risk of infection with oral thrush

Newborns have usually already been infected with oral thrush during birth. The trigger is an unnoticed vaginal thrush infection in the mother. The fungus makes itself felt within the first days of life. Up to five per cent of all infants are affected. Later on, older babies can become infected through dummies or the saliva of other babies.

These are the forms of oral thrush

Pseudomembranous candidiasis: This is the most common form of oral thrush. It presents as a white coating that can be wiped off, sitting on reddened and inflamed mucous membrane.
Acute erythematous candidiasis: Characterised by a burning, severely reddened mucous membrane and tongue. No coatings are present in this form.
Hyperplastic candidiasis: In this case, a firm white coating sits on the mucous membrane and tongue, accompanied by red margins.

Diagnosis and treatment of oral thrush

A diagnosis is made, for example, by a dentist in Düsseldorf, a paediatrician or a dermatologist. The doctor first asks the parents about existing symptoms and also wants to know how long these signs have been noticeable. The doctor also asks about pre-existing conditions and whether any medications are being taken.

To treat oral thrush, those affected are given a special antimycotic. This is an antifungal medication suitable for the mouth and throat area. It can be taken in the form of lozenges, oral gel or a solution. The duration of treatment prescribed by the doctor should be adhered to in full, even if no fungus is visible any more. Careful oral hygiene is also important. In addition, bottle teats and dummies should be replaced or at least sterilised.

Preventing oral thrush

Good oral hygiene is the most important measure for preventing oral thrush. Regular tooth brushing, cleaning the tongue and regular professional teeth cleaning can reduce the risk of a fungal infection in the mouth. Strengthening the immune system through a balanced diet also contributes to prevention.

Frequently asked questions about oral thrush

Is oral thrush contagious?

The yeast Candida albicans can be passed on through direct contact (e.g. kissing) or via contaminated objects (dummies, cutlery). With an intact immune system, however, transmission does not necessarily lead to an infection.

What does oral thrush look like on the tongue?

Oral thrush on the tongue typically appears as a whitish coating that can be wiped off. The mucous membrane underneath is often reddened. In the erythematous form, the white coating is absent — instead, the tongue appears severely reddened and feels like it is burning.

How long does it take for oral thrush to clear up?

With the right antifungal treatment (gel, lozenges or solution), oral thrush usually subsides within 1 to 2 weeks. It is important to continue the treatment as prescribed, even if the symptoms are already easing.

When should you see a dentist about oral thrush?

If the symptoms do not improve after a week of self-treatment, if they worsen, or if you have difficulty swallowing, you should see a dentist or doctor promptly. With recurring oral thrush, a medical assessment is advisable in order to rule out underlying conditions.