Oral thrush

Also called Oral candidiasis, Thrush in the mouth

A fungal infection of the mouth. Common, easily treated, and usually a sign of something else worth finding.

What it is

Oral thrush is an overgrowth of candida, a yeast that lives harmlessly in most mouths. It causes white patches, soreness and a changed sense of taste.

It matters here because in an adult it is rarely just bad luck. It usually means something has changed: inhaled steroids used without rinsing, antibiotics, dry mouth, dentures, poorly controlled diabetes, immunosuppression, or malnutrition.

So treating the thrush and stopping there misses the point. The useful question is why now.

In care settings it is very common and very often untreated, and it is one of the reasons people stop eating.

Signs you might notice

White or creamy patches on the tongue, inner cheeks or palate, which leave a red, sometimes bleeding, area when wiped.

Soreness, burning, and a cottony feeling in the mouth.

Loss of taste, or a persistent unpleasant taste.

Cracking and soreness at the corners of the mouth, called angular cheilitis.

Pain on swallowing, which may mean the infection extends into the oesophagus and needs prompt treatment.

In someone who cannot report it: refusing food, particularly anything hot, acidic or textured, and new distress at mealtimes.

How it can affect day-to-day life

The eating consequences are the practical problem. A sore mouth reduces intake within days, and in a frail person that becomes dehydration and weight loss quickly.

Inhaler technique is a very common and entirely preventable cause. Rinsing the mouth after a steroid inhaler, and using a spacer, prevents most of it, and many people have never been told.

Dentures that are not cleaned and left out overnight are a reservoir; treating the mouth without treating the denture means it comes straight back.

Supporting someone well

Look in the mouth. Again, this is the check that finds it.

Treat with antifungal gel or drops as prescribed, and complete the course.

Treat the dentures too: clean them daily, soak as advised, and leave them out overnight.

Rinse the mouth with water after every steroid inhaler, and use a spacer.

Ask why. Check glucose, review recent antibiotics, consider dry mouth and medication, and check nutrition.

Monitor food and fluid intake while the mouth is sore, and offer cool, soft, bland food.

Pain on swallowing needs prompt medical assessment rather than a longer course of gel.

Where to get help

A pharmacist can treat straightforward oral thrush; a GP for recurrent or severe cases, or if swallowing hurts.

Repeated thrush without an obvious cause warrants blood tests including glucose.

The Oral Health Foundation have practical mouth care guidance for carers.