Thrush is a yeast infection of the tongue and mouth. This common infection can be passed between a mother and baby during breastfeeding.
Certain germs normally live in our bodies. While most germs are harmless, some can cause infection.
Thrush occurs when too much of a yeast called Candida albicans grows in a baby's mouth. Germs called bacteria and fungi naturally grow in our bodies. Our immune system helps keep these germs in check. But babies don't have fully formed immune systems. That makes it easier for too much yeast (a type of fungus) to grow.
Thrush often occurs when mother or baby has taken antibiotics. Antibiotics treat infections from bacteria. They can also kill "good" bacteria, and this allows yeast to grow.
The yeast thrives in warm, moist areas. The baby's mouth and the mother's nipples are perfect places for a yeast infection.
Babies can also get a yeast infection on the diaper area at the same time. The yeast gets in the baby's stool and can cause a diaper rash.
Symptoms of thrush in the baby include:
- White, velvety sores in the mouth and on the tongue
- Wiping the sores may cause bleeding
- Redness in the mouth
- Diaper rash
- Mood changes
- Refusing to nurse because of soreness
Some babies may not feel anything at all.
Symptoms of thrush in the mother include:
- Deep-pink, cracked, and sore nipples
- Tenderness and pain during and after nursing
Exams and Tests
Your pediatrician can usually diagnose thrush by looking at your baby's mouth and tongue. The sores are easy to recognize.
Your baby might not need any treatment. Thrush often goes away on its own in a few days.
Your pediatrician may prescribe antifungal medicine to treat thrush. You paint this medicine on your baby's mouth and tongue.
If you have a yeast infection on your nipples, your doctor may recommend an over-the-counter or prescription antifungal cream. You put this on your nipples to treat the infection.
If both you and your baby have the infection, you both need to be treated at the same time. Otherwise, you can pass the infection back and forth.
Thrush in babies is very common and can easily be treated. However, let your pediatrician know if thrush keeps coming back. It may be a sign of another health issue.
When to Contact a Medical Professional
Call your doctor if:
- Your baby has symptoms of thrush
- Your baby refuses to eat
- You have symptoms of a yeast infection on your nipples
You may not be able to prevent thrush, but these steps may help:
- If you bottle feed your baby, clean and sterilize all equipment, including nipples
- Clean and sterilize pacifiers and other toys that go in baby's mouth
- Change diapers often to help prevent yeast from causing diaper rash
- Be sure to treat your nipples if you have a yeast infection
Candidiasis - oral; Oral thrush; Fungal infection - mouth; Candida - oral
Edwards JE Jr. Candida species. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2009:chap 257.
Kauffman CA. Candidiasis. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 346.
Wright DA, Cohen BA. Infections of the skin. In: Gleason CA, Devaskar SU. Avery's Diseases of the Newborn. 9th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 99.
Update Date 11/7/2013
Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.