Candidiasis, oral (babies)

Page last reviewed: 13/07/2011

Oral thrush is a fungal infection in the mouth, caused by the yeast fungus Candida albicans. It is common in healthy babies under two years old.

The main symptom is one or more white spots or patches in your baby's mouth (see Symptoms for more information), although some infants may not have any symptoms.

Babies rarely have oral thrush in their first week of life. It is most common in babies around four weeks old. Older babies can get it too, but this is less common.

Some babies can have repeated infections.

Oral thrush in babies is not usually linked with other illnesses or conditions. It may not bother your baby, but if their mouth is sore they may be reluctant to feed.

If your GP decides that your baby needs treatment, they will probably prescribe an antifungal medicine called miconazole, which kills the fungus in your baby's mouth (see Treatment for more information).

If you are breastfeeding, your baby can pass a thrush infection to you

Breastfeeding advice

Breastfeeding mothers may develop a thrush infection on their nipples and/or within their milk ducts. This can cause painful, cracked nipples and can make breastfeeding unbearable. If you think you have a thrush infection on your nipples, see your GP straight away.

Page last reviewed: 13/07/2011

Not all infants with oral thrush will have symptoms.

Whitish patches

In babies, symptoms of oral thrush can include one or more white spots or patches in and around the baby's mouth.

The patches in your baby's mouth may look yellow or cream-coloured, like curd or cottage cheese. They can also join together to make larger plaques.

You may see patches:

  • on your baby's gums
  • on the roof of their mouth (palate)
  • inside their cheeks

You can easily rub the patches off. The tissue underneath will be red and raw. It may also bleed a little.

The patches may not seem to bother your baby. But if they are sore, your baby may be reluctant to feed.

Other symptoms

Other signs and symptoms of oral thrush in babies are:

  • a whitish sheen to their saliva
  • fussiness at the breast (keeps detaching from the breast)
  • refusing the breast
  • clicking sounds during feeding
  • poor weight gain
  • nappy rash

Some babies may dribble more saliva than normal if they have an oral thrush infection.

Page last reviewed: 13/07/2011

Oral thrush is caused by a yeast fungus called Candida albicans. Healthy people have this fungus in their mouths and it does not normally cause problems.

However, if the level of fungus increases too much (called overgrowth), the lining (mucosa) of your baby's mouth can become infected.

Immature immune system

Oral thrush may occur in babies because their immune systems take time to mature, making them less able to resist infection.

Oral thrush is more common in premature babies (babies born before 37 weeks of pregnancy) because:

  • their immune systems are not as strong
  • they have not had as many of their mother's antibodies passed to them


Oral thrush infections can also happen after treatment with antibiotics. This is because antibiotics reduce the levels of healthy bacteria in your baby's mouth, which allows fungus levels to increase.

If you are breastfeeding and have been taking antibiotics for an infection, your own levels of healthy bacteria can be affected, making you or your baby more prone to a thrush infection.

In babies, oral thrush is not usually due to poor hygiene.

Page last reviewed: 13/07/2011

Your GP will look in your baby's mouth and will be able to diagnose oral thrush based on the visible symptoms.

Taking swabs does not help with diagnosis as healthy babies carry the fungus in their mouths.

Page last reviewed: 13/07/2011

Mild oral thrush infections in babies can often clear up after a few days without treatment. However, if you are concerned, visit your GP.

Antifungal medicine

If your GP decides that your baby needs treatment, they will probably prescribe an antifungal medicine called miconazole, which kills the fungus in your baby's mouth.

The dose of miconazole will vary depending on your baby's age. Your GP will be able to recommend the correct dosage for your baby and advise you how long to use the treatment.

In 2008, the manufacturers of miconazole recommended that the gel no longer be used in babies younger than four months, because of the risks of choking if it is not applied carefully.

If the infection has not cleared after seven days, visit your GP again. They may continue treatment with miconazole for a further seven days, or they may prescribe another antifungal medicine called nystatin.

Your GP may also prescribe nystatin for initial treatment, if your baby cannot take miconazole.

If the infection still does not clear up, your GP may consider seeking advice from a specialist.

How to use your baby's medicine

Miconazole gel is used for babies. Using a clean finger, smear the gel, a little at a time, on the affected areas of your baby's mouth. To avoid the risk of choking (even though this risk is low), do not apply too much at once and do not try to apply it to the back of your baby's throat.

You can buy miconazole gel over the counter, but ask your pharmacist for advice first.

Nystatin comes as a liquid medicine (suspension). You put the liquid directly on the affected area using a dropper (oral dispenser) supplied with the medicine.

When to use the medicine

Your GP will tell you how much medicine to use and how often to apply it.

Whichever medicine is prescribed, it will be most effective if you use it after your baby has had a feed or drink. That way, the medicine will be in contact with the affected areas of your baby's mouth for as long as possible.

Continue to use the medicine for two days after the infection has cleared up.

Breastfeeding and thrush

Read about the signs of thrush in breastfeeding women and how to treat it.

Page last reviewed: 13/07/2011

In most cases, there is no known cause for oral thrush infections in babies. Some doctors suggest that the steps below may help to prevent infection:

  • If your baby uses a dummy, sterilise all their dummies regularly, as well as any toys designed to be put in their mouth, such as teething rings.
  • If you bottle feed your baby, sterilise the bottles and other feeding equipment regularly, especially the teats.

Some doctors also suggest giving your baby a drink of sterilised water after a feed, to rinse away any milk left in their mouth.

Content provided by NHS Choices and adapted for Ireland by the Health A-Z.

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