Oral Thrush and White Tongue: Causes and Treatment

Oral thrush is a fungal infection with Candida that causes white patches on the tongue, the roof of the mouth or the cheeks. The patches wipe off and leave red, sore skin. It is common in babies, denture wearers, after antibiotics and with steroid inhalers. A doctor decides on an antifungal treatment. This guide is by Dr. Pedro Yelamo Vera, a GP licensed in Spain (Colegiado No. 484814280).

What is oral thrush?

It is a mouth infection caused by a fungus called Candida. It normally lives in the mouth without causing trouble. When your defences or the balance in the mouth change, it overgrows. MedlinePlus describes it as a yeast infection of the tongue and the lining of the mouth. In Spain it is called candidiasis oral, and in babies muguet.

What are the symptoms of oral thrush?

The NHS lists:

• White patches on the tongue, roof of the mouth, gums or inside the cheeks that can be wiped off.
• Red, sore areas under the patches.
• Cracks at the corners of the mouth (angular cheilitis).
• A bad taste or loss of taste.
• Burning or pain when you eat or drink.
• In babies, refusing feeds. A breastfeeding mother may feel nipple pain.

What causes oral thrush?

• Being a baby or an older adult.
• Wearing dentures, above all if they are not cleaned well or you sleep in them.
• Taking antibiotics.
• Using steroid inhalers for asthma or COPD without rinsing your mouth after.
• Having a dry mouth from medicines or illness.
• Smoking.
• Diabetes that is not well controlled.
• A weak immune system: chemotherapy, HIV or other treatments that lower immunity.

How is oral thrush treated?

A doctor confirms it by looking in your mouth and, if needed, prescribes an antifungal. The most used are nystatin liquid, such as Mycostatin, and miconazole oral gel. Miconazole can interact with blood thinners such as warfarin, so tell the doctor everything you take. The dose and how long to use it are set by the prescription. For babies, a children's doctor decides.

It also helps to:

• Rinse your mouth after using a steroid inhaler.
• Clean dentures well and take them out at night.
• Brush your teeth gently morning and night.
• Sterilise dummies and bottle teats for babies.
• Keep blood sugar in range if you have diabetes.

Why is my tongue white if it is not thrush?

The most common cause of a white tongue is a coated tongue. It is a whitish layer of food bits, germs and dead cells trapped between the tiny bumps on the tongue. It is linked to not drinking enough, mouth breathing, smoking, fever and poor mouth care. Brushing the tongue and drinking more water help. Other causes:

• Geographic tongue: smooth red patches with a white edge that move around. It is harmless.
• Oral lichen planus: lacy white lines inside the cheeks.
• Leukoplakia: a white patch that does not scrape off, more common in smokers. It must be checked, as it can sometimes turn into cancer.

What is a fissured tongue?

It is a tongue with grooves or cracks on the surface. It is a normal variant, often present from birth or appearing with age, and it often comes with geographic tongue. It is not catching and not dangerous. Brush the tongue gently, because food can collect in the grooves and cause soreness or bad breath.

Is oral thrush contagious?

It does not usually pass from one healthy adult to another. It can pass between a baby's mouth and the mother's breast during breastfeeding, so sometimes both are treated.

When to see a doctor

• White patches or mouth pain are not better within a week.
• It is hard or painful to swallow, as the infection may spread to the food pipe.
• Thrush keeps coming back for no clear reason, which may mean diabetes or a weak immune system.
• Your baby will not feed or has patches in the mouth.
• A white patch or ulcer will not go and lasts more than three weeks.
• You have an odd taste that will not go: read about a bitter taste in the mouth.

When to call 112

• Swelling of the tongue, lips or throat, or trouble breathing.
• Not being able to swallow even your saliva.
• A high fever and feeling very unwell in someone with a weak immune system.
• A baby with no wet nappies, or who is very floppy or drowsy.

Frequently asked questions about oral thrush

Getting a medical assessment

If you are in Spain and have white patches in your mouth, you can book a video consultation with Dr. Pedro Yelamo Vera, a physician registered in Spain. You can also read about urgent, non-emergency video care, yeast and fungal infections and asthma and inhalers. A prescription is never guaranteed: it is issued only where clinically appropriate after a genuine evaluation, as a private electronic prescription under Spanish law. This service is for urgent, non-emergency care. In an emergency, call 112.

This guide is general information. It does not replace the package leaflet or the advice of your doctor or pharmacist.