You look in your baby's mouth and see little white patches on the tongue or inside the cheeks. It could just be milk, but if they don't go away, it may be oral thrush: a fairly common yeast infection (oral candidiasis) in the first months. It's usually not serious and can be treated, but your pediatrician needs to see it. Here's how to recognize it and what to do in the meantime.
What is oral thrush?
It's an infection caused by a yeast, Candida, which normally lives in the mouth and gut without causing problems. In babies, whose immune system is still maturing, it sometimes overgrows and white patches appear. It's common in the first weeks and months and doesn't mean you're doing anything wrong with hygiene.
It can show up more easily after a course of antibiotics (the baby's or the breastfeeding mother's).
How to recognize oral thrush
- White plaques or patches, like curdled milk or cottage cheese, on the tongue, inner cheeks, gums, roof of the mouth or inner lips.
- They don't wipe off easily with a damp gauze. If scraped, the area underneath may look red or bleed slightly: that's why you shouldn't rub them.
- Discomfort while feeding: some babies get fussier during feeds, pull off or refuse the breast or bottle. If that's happening, also see baby refuses the bottle.
- Sometimes it comes with a red rash in the diaper area that doesn't improve with the usual cream, because the same yeast can affect that skin. More in our diaper rash guide.
Many babies with thrush still eat and sleep as usual: no discomfort doesn't rule it out.
Thrush or milk residue?
It's the most common question, and there's a fairly clear difference:
| Milk residue | Possible thrush | |
|---|---|---|
| Where | Mostly on the tongue | Tongue, cheeks, gums, palate |
| With a gauze | Wipes off easily | Doesn't come off or leaves a red area |
| When it shows | Right after feeding, gone shortly after | Stays for hours or days |
If in doubt, take a photo in good light and show it to your pediatrician.
What to do if you suspect thrush
- See your pediatrician to confirm it. If it is thrush, they usually prescribe a specific antifungal treatment for the baby's mouth, in the right form and for the right length of time.
- Don't use home remedies (baking soda, honey, vinegar, gentian violet) or creams on your own. Honey is also not safe under 1 year.
- Don't scrape the patches: it hurts the lining of the mouth and doesn't make it go away sooner.
- Keep breastfeeding or bottle-feeding as usual, unless your pediatrician says otherwise.
- Wash pacifiers, bottle nipples and teethers well every day and let them dry; follow the manufacturer's sterilizing instructions.
- Wash your hands before and after touching their mouth or changing a diaper.
If you breastfeed: watch your nipples
The yeast can pass from the baby's mouth to the nipple and back. If you have nipple pain that latch doesn't explain, burning, itching, or they look pink and shiny, tell your doctor or lactation consultant: sometimes both of you need treatment at the same time so it doesn't come back. For more, see our breastfeeding guide.
Is it contagious? Does it come back?
It spreads mainly between the baby and the breastfeeding mother, and through objects that go in the mouth. That's why cleaning pacifiers and nipples helps. It can come back; if it recurs often or appears in an older baby, your pediatrician will want to look into it more closely.
When to call the pediatrician
- You see white patches that don't wipe off and you're not sure whether it's milk.
- Your baby eats much less, refuses the breast or bottle, or it hurts to swallow.
- They wet fewer diapers than usual, have a very dry mouth or seem listless.
- They have a fever (under 3 months, always seek care right away).
- The patches spread, bleed or don't improve with the prescribed treatment.
- Thrush keeps coming back, or appears in an older baby.
Pediatric checkups — a real screen from the Alfonso app.
Get to the pediatrician with everything noted
In Alfonso you can note when the patches appeared, how feeds and diapers are going, and keep your pediatric checkups at hand. The visit goes faster and you don't forget anything. No account or password, synced with your partner.
Frequently asked questions
How do I know if it is thrush or milk?
Milk wipes off easily with a damp gauze and disappears shortly after feeding. Thrush doesn't wipe off easily, can be on cheeks, gums or palate, and stays.
Is oral thrush serious?
Usually not, and it can be treated. But your pediatrician should see it to confirm it and decide what to do.
Can I treat it at home?
Don't use home remedies or creams on your own. Treatment is prescribed by the pediatrician; at home, cleaning pacifiers, nipples and hands helps.
Can I keep breastfeeding?
Yes, unless told otherwise. If your nipples hurt, tell your doctor: sometimes mom and baby need treatment at the same time.
Does it come back?
It can. If it recurs often or appears in an older baby, your pediatrician will want to evaluate it.
Keep reading
ℹ️ This article is for information only and does not replace a pediatrician's judgment. If you see patches in your baby's mouth or have any doubts about their health, always check with a health professional.