How do you treat thrush in a baby’s mouth?

Oral thrush is a common yeast infection in babies, caused by Candida, that leaves creamy white patches on the tongue, gums, inner cheeks and roof of the mouth. Unlike milk residue, the patches don't wipe away easily and may bleed slightly if rubbed. Pediatricians usually treat it with an antifungal medicine. Cleaning anything that goes in the mouth helps keep it from coming back.

Key takeaways

• Milk coating wipes off; thrush patches don't.
• It's most common in the first months, when immune systems are new.
• Breastfeeding parents and babies can pass it back and forth.
• A diaper rash that won't heal may be the same yeast.

Signs

• White or yellowish patches inside the mouth.
• Redness or cracking at the corners of the mouth.
• Fussiness during feeds or pulling off the breast or bottle.
• A bright red diaper rash with small red spots at the edges.

Many babies have no discomfort at all.

Causes

Candida lives on skin and in the mouth normally. It overgrows when:

• The immune system is still developing.
• A baby or parent recently took antibiotics.
• Bottle nipples or pacifiers aren't cleaned well.
• Moisture and warmth create a good environment.

Diagnosis

Your pediatrician can usually tell by looking. Call if you see patches, because other conditions can look similar.

Treatment

• Antifungal medicine such as nystatin liquid, painted on the patches several times a day, usually for 7 to 14 days. Use as prescribed even after patches fade.
• Your doctor may suggest a different medicine if it doesn't improve.
• Diaper rash from yeast needs an antifungal cream.

For breastfeeding parents

Signs on the breast include itchy, shiny or flaky nipples, and burning or shooting pain during or after feeds. Talk with your own doctor; treating parent and baby at the same time prevents passing it back and forth. Change nursing pads often and wash bras in hot water.

Cleaning at home

• Boil bottle nipples, pacifiers and teething toys for 5 to 10 minutes daily during treatment, or run them through a dishwasher sanitize cycle.
• Replace pacifiers and nipples once treatment ends.
• Wash breast pump parts thoroughly after every use.
• Wash your hands before and after feeds and diaper changes.
• Store expressed milk properly and don't reuse leftover milk.

Feeding during thrush

Keep feeding. If your baby's mouth is sore, shorter, more frequent feeds may help. Watch for fewer wet diapers, which can mean your baby isn't drinking enough.

Preventing it

• Clean feeding equipment well.
• Let nipples air-dry after breastfeeding.
• Use antibiotics only when needed.
• Limit long pacifier sessions while thrush is active.

When to call the doctor

• White patches that won't wipe off.
• Your baby isn't feeding well or has fewer wet diapers.
• Thrush lasts more than two weeks with treatment.
• Thrush keeps returning or appears after the first year, which may need more checking.
• Fever or other signs of illness.

Thrush in toddlers

Thrush is less common after infancy, but toddlers who use inhaled steroids for asthma, or who have taken antibiotics, can develop it. Rinsing the mouth after inhaler use helps.

Common questions

Is thrush contagious? It can pass between baby and nursing parent, and through shared items.

Does it hurt? Sometimes, especially during feeds.

Can I use home remedies? Ask your pediatrician before using anything other than prescribed treatment.

Thrush vs. milk tongue

	Thrush	Milk residue
Location	Tongue, cheeks, gums, lips	Mostly tongue
Wipes off?	Not easily; may bleed	Yes, with a damp cloth
Fussiness	Often during feeds	No
Timing	Any time	Right after feeds

Diaper area connection

The same yeast can cause a bright red diaper rash with small spots at the edges. If both appear, mention it so your doctor can treat both at once.

How long it takes to clear

With antifungal treatment, white patches often fade within a week, but doctors usually advise finishing the full course. If patches return, ask whether a parent's nipples or pump parts also need treatment.

Later, when your child is ready to let the binky go, the pacifier book tells an illustrated goodbye story made from one photo.

When it is time to say goodbye: a goodbye story many families read

Look through a sample pacifier book, then start from a photo.

Sources

1. Thrush, KidsHealth (Nemours), accessed November 4, 2026
2. Pacifiers and Thumb Sucking, HealthyChildren.org (American Academy of Pediatrics), accessed November 4, 2026