Oral Thrush in Babies—Why Does It Happen?

If your baby seems cranky or uncomfortable when feeding, take a look in her mouth. White patches on the tongue, or anywhere else in the mouth or throat, could mean that a common fungal infection called oral thrush has taken hold.

But what exactly is oral thrush? Read on to learn more about thrush and what might cause it in your baby, how to spot the symptoms, how to treat or prevent this kind of infection, and how oral thrush might affect you if you’re breastfeeding.

What Is Thrush?

Thrush is a fungal infection of the mouth that can affect anyone at any age, but it’s especially common in newborns and small babies, especially those younger than 6 months.

The fungus that causes thrush is a kind of yeast called candida that can live anywhere on the body, even in the mouth and digestive tract.

There’s a good chance that your baby has already come into contact with candida. For example, it can be transferred in saliva through hand-to-mouth contact, or your newborn might have picked it up while in the birth canal if he was born vaginally.

When the fungus grows out of control in your baby’s mouth, it can develop into oral thrush, which can cause sore patches in or around your little one’s mouth. These may be uncomfortable or painful, especially when feeding.

Thrush may also be transferred from your baby’s mouth to your nipples if you breastfeed, which can cause you discomfort or pain, particularly when you’re nursing your baby.

What Causes Oral Thrush in Your Baby?

Most of the time, the presence of candida isn’t a problem, as it’s kept in check by your baby’s immune system and “good bacteria.” But if your baby is still quite young, especially before 6 months of age, his immune system isn’t fully developed yet. This “weaker” immune system can result in an overgrowth of candida, causing oral thrush in your baby.

If your baby is being given antibiotics for an infection, this might also increase the risk of thrush because antibiotics, which are great at fighting bacterial infections, can also kill off some of those “good bacteria” at the same time. This means your baby’s natural defenses against the candida are down, and the fungus can grow out of hand.

Signs and Symptoms of Oral Thrush in Your Baby

If you suspect your baby has oral thrush, it’s important to see your healthcare provider to get a diagnosis and treatment. Here are some signs and symptoms to watch out for:

• Difficulties with feeding. One of the first signs you notice could be that your baby isn’t feeding as well as usual, or he seems to be finding it uncomfortable or painful.

• White patches. These spots may look a little like cottage cheese, and can appear on your baby’s tongue, lips, gums, or the roof of his mouth. Try wiping them gently away—if they can’t be removed in this way, your little one might have oral thrush. Because these patches aren’t always obvious from the outside, it’s a good idea to check in your little one’s mouth from time to time.

• Cracked skin at the corners of the mouth. This is another possible symptom of oral thrush in your baby.

• Diaper rash. As the fungus is swallowed and passed out of your little one’s system, it can cause diaper rash around your baby’s bottom.

• Telltale signs on your own body. If you’re breastfeeding and have itchy, cracked, or sore nipples, or intense shooting pains in the nipples or breasts, these symptoms could indicate that you have thrush. Thrush can be passed between your nipples and your baby’s mouth during breastfeeding. We cover how thrush can affect breastfeeding later on.

How to Treat Oral Thrush in Your Baby

If you notice any possible symptoms of thrush in your baby or yourself, check in with your healthcare provider to get a diagnosis. Your provider can explain your treatment options.

Thrush occasionally goes away by itself in a few weeks, but your healthcare provider may prescribe an antifungal treatment.

Over-the-Counter and Home Remedies for Thrush

Various over-the-counter treatments are available for thrush in your baby, but always check with your provider before using any of these.

Some moms believe that home remedies like rinsing nipples in a solution of vinegar and water or baking soda and water solution can help, as can cutting down on the amount of sugar, yeast, and dairy products in your diet.

These measures aren’t medically proven to work, and should only be used alongside any medication that’s prescribed by your healthcare provider, and not as a substitute for it. Always check with your provider before using any home remedies or over-the-counter medicines.

If the thrush doesn’t clear up in a few weeks with treatment, or if it keeps coming back—especially if your little one is over 9 months old—see your healthcare provider to investigate whether any other health issues are at play.

How to Prevent Oral Thrush in Your Baby

These are some of the steps you can take to help prevent your little one from developing oral thrush:

  • Wash your baby’s hands frequently, especially if your little one sucks her thumb or fingers. Wash your own hands often, too.

  • Regularly sterilize pacifiers, teething rings, the nipples of feeding bottles, and anything else that goes in your baby’s mouth.

  • Put any towels or clothing that may have been in contact with the yeast through a hot wash cycle (at least 50 degrees Celsius).

  • If you use a breast pump, make sure all the parts that come into contact with your breasts or breast milk are sterilized after every use.

  • Store breast milk refrigerated until just before use to prevent the growth of yeast.

  • You may need to throw away any expressed breast milk that you have in storage, if there’s a chance that it’s been contaminated with the yeast.

  • Keep your breasts dry and free of potential sources of yeast by changing any disposable nursing pads frequently and wearing a clean bra every day.

Preventing Reinfection

Oral thrush in babies can be hard to get rid of, especially if you’re breastfeeding, partly because it is so contagious. It can spread from you to your little one and back again via your nipples, and even to and from other members of the family if you share bedding, cups, or utensils.

This is why it’s essential to ensure that both you and your baby (and anyone else who has it in your household) are treated at the same time.

It also helps to take all the preventive measures you can while treating an existing case of thrush.

How Thrush Can Affect You if You’re Breastfeeding

If you’re breastfeeding your baby, thrush can be a real pain—often literally—for you, as well as for your baby.

It’s important to get prompt treatment, so head to your healthcare provider for diagnosis and treatment as soon as you can. Keep in mind that the symptoms may not clear up straight away.

In the meantime, experts advise that you keep on breastfeeding. Here are some ways you might be able to ease the discomfort and keep that breast milk flowing:

  • Try offering shorter, but more frequent feeds. Start with the least painful breast every time.

  • Rinse your nipples with clean water after every feed, and air-dry them before they go back in your bra.

  • If cracked nipples are making it too painful to breastfeed directly, consider expressing milk and offering it to your baby in a small cup.

  • An over-the-counter pain medication might help ease the pain a little. Ask your healthcare provider what’s safe to take while you’re breastfeeding.

Why It Might Not Be Thrush

Not all breast pain or nipple soreness is caused by thrush. If you experience sharp pains in your breast during or after feeds, and severe pains in the nipple, try changing your baby’s breastfeeding position or getting her to latch on again. This might be all that’s needed to help alleviate the pain you’re feeling.

If cold compresses or air-drying make your nipple or breast pain worse, the pains could be caused by a contraction of the blood vessels in and around your nipples.

Another cause of breast pain can be a bacterial infection called mastitis.

These conditions are commonly confused with thrush, so reach out to your healthcare provider, who will be able to find the underlying cause of your discomfort.


Oral thrush can give some babies a sore mouth and make it painful or uncomfortable to feed, but many babies don’t feel anything.

Having a new baby can be unpredictable sometimes. One minute you’re basking in that first toothless smile, the next you’re trying to wipe away a white patch from the inside of your little one’s mouth.

Oral thrush can be one of those challenges that parenthood throws up from time to time, but with treatment from your healthcare provider it’ll clear up in due course, and you and your baby will soon be back to enjoying peaceful bonding when nursing your little one.

In the meantime, take some time out to give yourself or your baby a little treat by turning your diapers into great gifts, coupons, and discounts. Download the Pampers Rewards app to find out how.

How We Wrote this Article

The information in this article is based on the expert advice found in trusted medical and government sources, such as the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists. You can find a full list of sources used for this article below. The content on this page should not replace professional medical advice. Always consult medical professionals for full diagnosis and treatment.