If you notice a white patch on your baby's tongue or mouth that won't rub off, it could be thrush. Learn more about this common infection and how to treat thrush in babies.


Is that little patch of white around baby's mouth leftover milk, or something more? One possible culprit is thrush, an infection in and around the mouth caused by an overgrowth of the Candida fungus (aka yeast). Though it can happen to anyone, thrush is especially common in newborns and usually appears in infants under six months of age. Learn more about how babies get thrush and some of the common symptoms of this oral infection.

baby with square marking its mouth
Credit: Illustration by Parents Staff; Getty Images (1)

How Do Babies Get Thrush?

It's normal to have some Candida in the mouth and digestive systems—it indicates a healthy immune system. But the fungus can overgrow and infection can set in when the immune system is weakened or not fully developed, as is the case with infants.

Taking steroids or antibiotics can put you or your baby at a higher risk, since the medicines strip the "good" bacteria that keeps the yeast in check, says Preeti Parikh, M.D., a board-certified pediatrician, assistant clinical professor in the Pediatrics Department at the Mount Sinai School of Medicine, and an American Academy of Pediatrics fellow and spokesperson.

And though there's no evidence that breastfeeding your little one increases her chances of getting thrush, it's not unusual for the infection to be passed between Baby and mom during nursing sessions, says Dr. Parikh. (Candida passes easily through cracked nipples, a common issue for breastfeeding mamas.)

Thrush Symptoms in Babies

The tell-tale signs of yeast overgrowth are painful white patches on your baby's tongue, lips, gums, inner cheeks, and roof of the mouth that do not wipe off with a wet washcloth. The infection can also spread to the esophagus, making swallowing especially painful for her.

For some babies, thrush is no big deal. But for others, the excess yeast can lead to a sore mouth, and your baby may shun feedings because it's too painful. Though thrush is usually a mild condition, it can also affect the skin, mucus membranes, and the diaper region, so keep an eye out for diaper rashes.

Thrush Symptoms in Moms

Thrush presents differently in breastfeeding moms. Your nipples may be red, flaky, crusty, itchy or burning, and you may also feel an intense stabbing or burning pain in one or both breasts during or shortly after feedings. "This can indicate a fungal infection within the milk ducts," Dr. Parikh says.