Published on 1st March 2023

When you’re a new parent, the health of your baby is naturally at the very top of your agenda — therefore it’s perfectly reasonable to feel a little concerned when doesn’t something doesn’t look or feel quite right.

If you notice that your little one’s tongue is white instead of perfectly pink, for example, could this be a sign of an infection known as newborn thrush? Or is it something completely harmless like a coating of milk on your baby’s tongue?

In this guide, we’ll take you through the differences between oral thrush and milk tongue, so you can determine if your baby requires treatment or their little tongue is just a milk magnet. 

What is milk tongue?

It’s common for a newborn to have a white coating on their tongue, particularly just after feeding. This is known as “milk tongue”, and it happens for a number of reasons. The main reason is an exclusive milk diet, and the fact that an infant doesn’t fully develop full salivation until 5-6 months of age. This can make the milk more likely to remain on the tongue. The coating may be thicker if your baby is fed using formula rather than breast milk.

In most cases, the milk residue will be wiped away during breastfeeding. However, if breastfeeding is compromised due to a shallow latch your baby may be more likely to present with a milk tongue. 

Factors such as a high arched palate and the presence of a tongue tie may also make your baby more likely to have a milk tongue. A baby’s inability to reach their palate with their tongue at rest due to restricted tongue movements or high palate can prevent the milk being cleared. 

Whatever the cause of your baby’s milk tongue, it’s not permanent and it’s nothing to worry about. At around 5months your baby will reach their maximum saliva production, which should wash away any milk residue from the tongue after feeds. Once they start eating solid foods (typically around 6 months), milk tongue will no longer be a concern.

What is oral thrush?

Oral thrush is a fungal infection that occurs in the mouth. Whilst it is rare in healthy children and adults it can be more common in newborns due to their immature immune system. It is thought to affect 5% of newborns with the number peaking at 14% of babies aged 4 weeks before declining again. It appears as patches of curd-like yellow or white patches which occur in the cheeks, on the palate, tongue and gums.

Fortunately, newborn thrush is usually harmless and can easily be treated. It’s not a result of poor hygiene, but persistent oral thrush can be a sign of an underlying condition, so if it keeps occurring, speak to a doctor.

Thrush is caused by a fungus called Candida albicans, a type of yeast that thrives in warm, moist areas. When too much of this fungus grows inside your baby’s mouth, their underdeveloped immune system can struggle to keep it in check, meaning an infection can spread. 

Thrush may be triggered by mom or baby taking antibiotics, as these can kill off “good” bacteria and allow the fungus to grow. Less commonly, a breastfed baby can develop oral thrush if the mother has a yeast infection on her breast.

So, how can you tell if your baby has thrush? A white tongue may be a sign of infection, but there are other symptoms to keep an eye out for.

Symptoms of oral thrush in babies include:

  • Slightly raised white bumps that appear on the tongue, the gums, the inside of the lips, the roof of the mouth, or the back of the throat. Oral thrush is unlikely to be present solely on the tongue.

  • A white (or sometimes yellowish) ‘coating’ inside the mouth that, when wiped away, reveals a red base.

  • Irritability and restlessness during feeding. This does not occur in all infants and many will have no other symptoms but the white coating in the oral cavity.

  • A co-occurring fungal diaper rash

Does my baby have milk tongue or thrush?

It’s easy to get confused by milk tongue and newborn thrush because they both cause a thick white coating on the tongue (it looks a little like cottage cheese, if you’re wondering). 

The easiest way to distinguish between thrush and milk tongue is to take a warm damp cloth and give your baby’s tongue a gentle wipe. If the white residue wipes off easily — showing a healthy pink tongue underneath — then it’s likely just milk residue. If the white residue remains on your baby’s tongue after wiping it or comes off and reveals a deep red base, then it is more likely to be thrush.

Your baby might also be suffering from thrush rather than milk tongue if other areas of the mouth apart from the tongue are affected— for example, the inside of the lips, the gums, the back of the throat, or the palate.

Milk tongue should go away as soon as your baby starts to produce enough saliva, while oral thrush can usually be treated quickly and easily with oral drops. 

If you’re unsure, you should book an appointment with your doctor, who will be able to diagnose whether your baby has thrush by assessing the clinical features and requesting a swab if required.

Can a baby have a white tongue and not have thrush?

Your baby having a white tongue isn’t necessarily a sign of oral thrush. More likely, it’s a buildup of milk residue from breast or bottle feeding that is easily wiped away with a cloth. You’ll only need to seek medical advice if the white ‘coating’ doesn’t go away when wiped or is also present on the lips, gums, or palate, as this may indicate thrush.

Does milk tongue turn into thrush?

A build up of milk residue on your baby’s tongue will not lead to thrush. Thrush is a fungal infection inside the baby’s mouth, and is relatively common in newborns infants. Milk tongue is not a medical condition, and it rarely leads to other complications or issues. 

How to treat milk tongue in babies

Milk tongue doesn’t require treatment. It will usually come and go, and even if it’s more persistent (for example, because your baby has tongue tie), it won’t cause your little one any pain or discomfort. Either way, milk tongue should go away on its own at the point your baby starts to produce more saliva (around 5 months) or eat solid foods (around 6 months). 

How to treat thrush in babies

Your doctor will determine whether your baby needs medication based on the severity of their symptoms. Mild cases of thrush that aren’t affecting your baby’s feeding may not require any treatment at all, and they’ll likely go away within a week or two.

Moderate to severe cases of thrush, on the other hand, are usually treated with an antifungal medication such as Miconazole. This is applied directly into your baby’s mouth up to 4 times a day.

For younger babies, Nystatin may be prescribed. This is applied directly into the baby's mouth with an applicator or dropper up to 4 times a day.

Depending on the severity of your baby’s thrush, the treatment should start working in a couple of days and completely clear the infection within a week or so.

If you think that your baby might be suffering from oral thrush, book an appointment with your doctor as soon as possible so they can advise the best course of action. Oral thrush is usually pretty harmless and shouldn’t cause your baby too much pain or discomfort, but it’s always best to get it checked by a professional and treated if necessary.

How to prevent oral thrush in babies

Thrush is very contagious, but there are measures you can take to prevent your baby — or you, for that matter — from contracting a yeast infection. To keep thrush at bay, we’d advise the following:

  • If you are breastfeeding and your baby is diagnosed with oral thrush then you will need to treat your breasts due to the high risk of cross infection during nursing. The treatment of choice is Miconazole cream applied sparingly to the nipples after every feed.

  • If you’re breastfeeding and you have painful breasts after a breastfeed, after previously having had pain-free breastfeeding, then speak to your doctor as you may have contracted thrush from your baby.

  • Ensure good hygiene – wash your hands well before and after each nappy change and make sure all members of the family have separate towels.

  • If you’re bottle feeding or pumping, ensure you thoroughly clean all components of your bottle or pump after each use and sterilise at high temperatures.

  • Always store pre-prepared formula or breast milk in the fridge or freezer to keep it fresh and prevent bacteria growth.

The information above was supervised by Stacey Zimmels on 31/03/2023. Stacey is a feeding and swallowing specialist speech therapist (SLT) and International Board-Certified Lactation Consultant (IBCLC).