What to do if your baby gets thrush

Feeding a baby — whether from a bottle or breast — can be a wonderful experience. But feeding a baby can also be challenging if your baby doesn’t want to eat or is having trouble eating.

Thrush is one feeding challenge that can affect newborns. It’s a yeast infection caused by a fungus called Candida albicans, which can grow out of control in the baby’s mouth. ¹

Thrush often affects breastfeeding babies. It also can show up as a diaper rash.²

While thrush isn’t usually dangerous, it can be uncomfortable for babies and can affect their feeding. Find out what causes this yeast infection and how it’s treated.

Our bodies and skin are home to millions of organisms, including fungi (such as candida) and bacteria. This is true of babies too. An adult’s immune system usually keeps these organisms in check. But a baby’s immune system is still developing, so they’re more susceptible to infections such as thrush.²

Babies can get thrush from:

• A vaginal delivery. This is especially true if the mother has an overgrowth of Candida albicans in her vagina.³
• Antibiotics. If mom or baby is taking antibiotics, they can kill off the “good” bacteria that help keep the fungi population in check. This allows candida to flourish in a vulnerable baby.³
• A yeast infection on the mother’s nipples. An infection in this area can keep getting passed back and forth between a nursing mother and her baby. It can be painful for both.
• Bottle nipples or pacifiers. If not cleaned properly, these can breed fungi.⁴

“Most commonly, thrush tends to be pretty mild,” says Rebekah Diamond, M.D., a pediatrician in New York City. She is the author of Parent Like a Pediatrician: All the Facts, None of the Fear. But you still need to be aware of the signs, since you’ll want to bring them to your pediatrician’s attention.

The symptoms of thrush in a baby include:^3,4

• White or yellow patches on the tongue, lips or gums
• A dry or red mouth, including on the inner cheeks and roof of the mouth
• Refusing to nurse or seeming fussy at feeding time
• Diaper rash

In moms, cracked, tender, red or sore nipples are signs of thrush.⁵

It depends how bad the case is, explains Dr. Diamond. “Thrush isn’t something you have to panic about, but because treatment is so case-specific, it’s a good idea to talk with the pediatrician,” she says. This can be done during an in-person visit or via telehealth, she adds.

If your baby is fussy or is refusing to feed or has short feeds, it’s important to ask your pediatrician how your baby can stay hydrated and nourished. Then the course of treatment depends on your infant’s symptoms.

You and your baby will both need treatment. The baby’s medicine will likely be drops that you’ll place in their mouth. There will be an additional antifungal cream for your breasts and nipples, so you don’t pass the infection back and forth with your baby. Thrush typically clears up within 2 weeks.³

During the time that a breastfeeding mom is treating thrush, it’s also important to be careful about cleaning and sterilizing any feeding equipment, including pump parts and any bottles. It’s also a good idea to let the breasts and nipples air out after feedings, notes Dr. Diamond.

“Candida loves moist, soft environments. Obviously, the mouth has lots of crannies, and it’s very moist. The same with the folds on the nipple or breast — they’ll often collect moisture on the skin,” she says.

There’s no need to stop nursing while you both heal, explains Dr. Diamond. “If it’s really painful to breastfeed, then you should talk with the pediatrician or a lactation consultant for strategies,” she says.

When you don’t have thrush and your baby’s symptoms are minor, your pediatrician may decide to let the thrush infection clear up on its own, which can take a week or two.¹ "If it doesn’t seem too uncomfortable and it’s not causing feeding issues, your doctor might recommend monitoring things over time,” says Dr. Diamond. “If it’s more extensive though and covering the gums or the palate, the provider may recommend medication.”

Regardless of whether your baby is prescribed medication for thrush, you’ll want to be mindful of what’s going on in your baby’s mouth as it clears. For example, any toys, pacifiers or bottle nipples will need to be sterilized before giving them to your baby.

Thrush doesn’t just affect your baby’s mouth. It may also occur in the diaper area. The symptoms of a yeast infection in the diaper area include:

• Bright red rash
• Pimples or lesions
• Red or scaly areas

Your pediatrician can diagnose a diaper rash caused by a yeast infection by looking at the skin. If your baby does have a yeast infection, your doctor might recommend antifungal creams.⁶

Of course, you’ll want to keep your baby’s diaper area clean and dry. That means changing your baby as soon as possible after a poop or pee. It can also help to attach the diaper loosely so there's more airflow.⁶ And Dr. Diamond recommends airing out your baby’s bottom regularly when you're at home.

Don’t be too alarmed if your baby develops thrush. It’s common and treatable, no matter where it develops.