Oral thrush in babies and young children is a fungal infection in the mouth that’s usually harmless and is easy to treat.

Although babies and young children are particularly at risk, oral thrush can also affect adults.

Signs of oral thrush in babies

The main sign of oral thrush is a white coating on your baby’s tongue, although there may also be white patches elsewhere in the mouth.

When to seek medical advice

Oral thrush in babies isn’t usually serious, but you should get advice from a pharmacist if you think your child may have the condition.

You can also ask your health visitor for advice or call NHS 111.

If there’s any doubt about the diagnosis, contact your GP. They may take a swab from your baby’s mouth and send it to a lab to be tested.

If your baby is aged under 4 months, you should take them to see a GP.

Causes of oral thrush in babies

Oral thrush is caused by a yeast fungus called Candida albicans.

Healthy people have this fungus in their mouths and it doesn’t normally cause problems. But it can overgrow and infect the membranes in the mouth.

Babies are at an increased risk of oral thrush because their immune systems haven’t fully developed yet and are less able to resist infection.

This is particularly the case with babies born prematurely (before 37 weeks of pregnancy).

Oral thrush can also affect babies if they have recently been treated with antibiotics.

Antibiotics reduce the levels of healthy bacteria in your baby’s mouth, which can allow fungus levels to increase.

If you’re breastfeeding and have been taking antibiotics for an infection, the levels of healthy bacteria in your body can be affected.

This can also make you prone to a thrush infection that may then be passed to your baby during breastfeeding.

Treating oral thrush in babies

If the pharmacist or your health visitor feels your baby needs treatment, they’ll probably suggest you buy a mouth gel.

Babies aged under 4 months with signs of oral thrush should see a GP for treatment advice.

Treatment with a mouth gel usually lasts at least 7 days. Always follow the instructions on the medicine packet.

If you don’t see any improvement after 1 week of treatment with the mouth gel, speak to your GP or health visitor. They may suggest an alternative medicine.

Advice for breastfeeding mothers

If your baby has oral thrush and you’re breastfeeding, it’s possible for your baby to pass a thrush infection to you.

This can affect your nipples or breasts and cause nipple thrush.

Symptoms of nipple thrush can include:

  • pain while you’re feeding your baby, which may continue after the feed is finished
  • cracked, flaky or sensitive nipples and areolas (the darker area around your nipple)
  • changes in the colour of your nipples or areolas

If you have nipple thrush or there’s a risk of your baby passing thrush on to you, you’ll normally be advised to continue breastfeeding while using an antifungal cream such as miconazole to treat the infection.

You should apply the cream to your nipples after every feed and remove any that’s left before the next feed.

In severe cases of nipple thrush, antifungal tablets may be recommended.

Preventing oral thrush in babies

It’s not clear whether it’s possible to prevent oral thrush in babies.

Some doctors suggest the following advice may help:

  • sterilise dummies regularly, as well as any toys that your baby puts in their mouth
  • sterilise bottles and other feeding equipment after each use, especially the teats

Washing your hands thoroughly after changing your baby’s nappy can also be helpful in stopping thrush spreading because the infection can be passed through their digestive system.