Oral thrush is a very common infection in infants that causes irritation in and around the baby's mouth. It occurs when the yeast candida overgrows in the child's mouth and leads to infection.

Why Do Babies Get Oral Thrush?

Most infants naturally have the yeast candida albican in their mouths. Because their immune systems are not yet mature, the amount of yeast in the mouth can overgrow and lead to an infection. (Adults and older kids who have weakened immune systems because of an illness or something like chemotherapy also can get oral thrush.)

Oral thrush usually occurs within the first 6 months of life, and a baby with the infection will develop cracked skin in the corners of the mouth, and whitish or yellowish patches on the lips, tongue, or inside the cheeks.

Preventing and Treating Oral Thrush

There's not much that you can do to prevent your infant from getting oral thrush. Most cases go away without medical treatment within a week or two, but your child's doctor may prescribe an antifungal solution for the baby to swallow. And depending on your baby's age, the doctor may also suggest adding yogurt with lactobacilli to your child's diet. The lactobacilli are bacteria that can help eliminate the yeast in your child's mouth.

You can help remedy oral thrush if your child has it. If you are formula-feeding your baby or using a pacifier, it's important to thoroughly clean the nipples and pacifiers in hot water after each use. That way, if there's yeast on the bottle nipple or pacifier, your baby doesn't continue to get reinfected.

If you are breastfeeding and your nipples are red and sore, there's a chance you may have a yeast infection on your nipples, and that you and the baby are passing it back and forth. If so, you may want to talk to the doctor about using an antifungal ointment on your nipples while the baby is being treated with the antifungal solution.

If your child keeps getting oral thrush, or is older than 9 months and is getting oral thrush, talk with your child's doctor because this might be an indication of another health issue.

Reviewed by: Barbara P. Homeier, MD
Date reviewed: October 2005