What Is Thrush in Babies?

A yeast infection that causes velvety, white patches in the mouth

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Thrush is a common yeast infection in the mouths of babies caused by the fungus Candida. It typically causes white patches on a baby's inner cheeks, tongue, and top of the mouth. It can also occur in other areas, such as the diaper area. Candida is the fungus that is perhaps better known for causing vaginal yeast infections in adults.

Yeast thrives in warm, moist areas like a baby's mouth or mother's nipples. Thrush is particularly common in young babies since they do not yet have a fully formed immune system. It is not dangerous and doesn't always need to be treated. A healthcare provider can prescribe anti-fungal medication to help clear up a more severe case.

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Signs and Symptoms of Thrush in Babies

Thrush in babies usually appears as white, velvety patches on the tongue and inner cheeks that may bleed when wiped.

It may also cause:

  • Redness inside the mouth
  • Oral pain
  • Loss of taste
  • Dry mouth
  • Crying or fussiness
  • Refusing to feed or us a pacifier due to pain

A white tongue alone does not mean that your baby has thrush. Many babies have white tongues after drinking milk. The white patches from thrush usually cover multiple surfaces in your child’s mouth and cannot be easily wiped away. When you attempt to wipe them away, the sores may bleed. Oral thrush will usually also have a red border around the white patch.

Thrush in babies doesn't always appear just in the mouth, however. It can also affect the:

  • Fingernails 
  • Eyes
  • Diaper area (the vagina or groin)
  • Skin folds (armpits or folds in the neck)

If the yeast enters a baby’s digestive tract and their stool, it may lead to a yeast infection in the diaper area. If you notice that your baby has a diaper rash in addition to oral symptoms, they may two yeast infections rather than just one.

Is Baby Thrush Serious?

Thrush in babies can be a nuisance, but it is not a serious condition.

However, since its symptoms can prompt some babies to refuse to eat, it may lead to dehydration.

See a healthcare provider about oral thrush in babies if:

  • It seems to be causing pain or your baby becomes inconsolable
  • It doesn't seem to be getting better on its own
  • Your baby is refusing to eat
  • You notice a decline in the number of wet diapers your baby has

Causes of Thrush in Babies

Candida albicans is the yeast responsible for thrush in babies. Antibiotic use is the most common reason why this yeast, which is normally present on the body without causing problems, can grow out of control and cause an infection.

A baby could also become infected with the yeast during childbirth.

Since yeast thrives in warm, moist places, a baby's mouth is a perfect place for it to flourish.

Antibiotic Use

As antibiotics kill off harmful bacteria, they kill off healthy bacteria right along with it. This means that the good bacteria that normally keep yeast in check die off, allowing it to grow.

This can lead to different types of yeast infections, including a yeast infection of the nipples. Once this happens, it’s likely that the infection will pass on to a nursing baby’s mouth during feedings.

Likewise, a baby's own use of antibiotics can also cause them to develop thrush that can then get passed along to a nursing person during feedings.

Frequent signs of a yeast infection of the nipples include nipple skin that is darker in color, cracked, and/or sore, as well as pain with breastfeeding.


Though less common, thrush in babies can also occur during vaginal childbirth.

If a parent has a vaginal yeast infection, the yeast can pass on to a baby as it moves through the birth canal and is delivered.


Fortunately, thrush is quick and simple to diagnose. Most pediatricians can identify it by looking in your baby’s mouth. The velvety, white patches that cannot be wiped away are classic signs of thrush.

Occasionally, your healthcare provider may recommend scraping off a sample of the white patch for lab testing.

If you notice that your baby is getting frequent thrush infections, talk with your pediatrician to find out if further testing is needed. 

How Thrush in Babies Is Treated

Thrush in babies does not always require treatment and sometimes goes away on its own after a few days. It is still beneficial to have your pediatrician confirm that the sores in your baby’s mouth are caused by thrush and not another infection.

Your pediatrician may prescribe an antifungal medication to treat your child’s infection. This medication can be painted onto the sores in your baby’s mouth. If the mother has a yeast infection on her nipples as well, her healthcare provider will most likely recommend an over-the-counter antifungal cream to be applied directly to the nipples. The healthcare provider could also recommend an oral antifungal prescription such as Diflucan (fluconazole). 

Most cases of thrush in babies resolve within two weeks of starting treatment.

Preventing Thrush in Babies

Taking a regular probiotic may help prevent thrush and other types of yeast infections. Probiotics help support the good bacteria, which keep yeast growth under control.

Talk with your pediatrician before beginning a supplement regimen for your infant. If you are breastfeeding, hold off on starting any natural remedies until you’ve talked with your healthcare provider. 

Aside from that, these strategies can help you reduce the risk of infection:

  • Thoroughly clean and sterilize anything that goes into your baby’s mouth, such as a pacifier or bottle nipple.
  • Change your baby’s diaper often to help prevent a yeast infection in their diaper area.
  • If both you and your baby are experiencing a yeast infection at the same time (or think you might be), be sure to evaluated and have both infections treated right away. If you nurse and only one of you is treated, it’s likely that you will continue to pass the infection back and forth each time you breastfeed. 

Frequently Asked Questions

  • How do I know if my baby has thrush?

    Signs of thrush in a baby include white, velvety patches over their tongue and inner cheeks, redness or bleeding in the mouth, crying or fussiness, difficulty feeding, and, sometimes, a diaper rash. Nursing mothers may also develop a yeast rash on their nipples.

  • Is oral thrush painful for babies?

    Yes, oral thrush can be very uncomfortable and even painful for babies. If your baby has thrush, they will likely be fussy and have difficulty feeding. If the infection has spread to the esophagus, it may hurt to swallow.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. MedlinePlus. Thrush in newborns.

  2. Seattle Children’s. Thrush.

  3. American Academy of Pediatrics. Thrush and other Candida infections.

  4. Matsubara VH, Bandara HM, Mayer MP, Samaranayake LP. Probiotics as antifungals in mucosal candidiasis. Clin Infect Dis. 2016;62(9):1143-53. doi:10.1093/cid/ciw038

Additional Reading

By Carrie Madormo, RN, MPH
Carrie Madormo, RN, MPH, is a health writer with over a decade of experience working as a registered nurse. She has practiced in a variety of settings including pediatrics, oncology, chronic pain, and public health.