Mouth ulcers and oral thrush in children

Telling them apart

Mouth ulcers are small painful craters with a white or yellow base and a red rim, on the inner cheeks, lips or tongue. They hurt sharply, especially with salty or spicy food, and heal in one to two weeks.

Oral thrush is a fungal infection: creamy white patches on the tongue, inner cheeks and gums that do not wipe off easily — and if you do wipe them, the surface underneath is red and may bleed slightly. Common in babies, particularly after antibiotics.

Milk residue on a baby's tongue, by contrast, wipes off cleanly and leaves normal pink underneath. That is the simplest home test.

Mouth ulcers: causes and relief

Common causes: minor injury from a toothbrush, biting the cheek or a sharp piece of food; viral illness including hand, foot and mouth disease; stress; and deficiencies — iron, vitamin B12 and folate, all of which are common in Indian children.

Relief: soft, cool, bland food — curd, kheer, khichdi, banana, ice lollies; avoiding citrus, tomato, chilli and salty snacks; a straw for drinks; and paracetamol before meals if eating is painful.

Topical gels for ulcers exist; ask your doctor which are appropriate for your child's age rather than using an adult product. Do not apply honey to a baby under one year for any reason.

Recurrent ulcers — several a month, or ulcers with other symptoms — deserve a haemoglobin, B12 and folate check. In Indian children this frequently turns out to be the answer.

Thrush: treating it properly

Thrush needs an antifungal gel or drops prescribed by a doctor, applied after feeds, usually for one to two weeks and continued for a few days after the patches clear — stopping early is why it comes back.

If the baby is breastfeeding, the mother often needs treating at the same time, particularly with nipple pain that is sharp and burning during and after feeds, or shiny or flaky nipple skin. Otherwise it passes back and forth.

Sterilise everything the baby's mouth touches — bottles, teats, soothers, teething toys — daily during treatment.

Thrush that keeps returning, or appears in an older child who is not on antibiotics and does not use an inhaler, is worth investigating rather than treating repeatedly.

When to see a doctor

Same-day: a child who cannot drink or is refusing all fluids, signs of dehydration, high fever with mouth sores, ulcers with a widespread rash, difficulty breathing or swallowing, drooling with an inability to swallow saliva, or swelling of the face or neck.

Book an appointment for: ulcers lasting more than two weeks, recurrent ulcers, thrush that does not clear with treatment, white patches in an older child, bleeding gums, or a child losing weight because eating hurts.

This article is general information, not medical advice, and is no substitute for personal medical advice. For any decision about your or your child's health, please consult your doctor.

Frequently asked questions

Q: Are mouth ulcers caused by heat, as my family says? — The 'body heat' explanation is traditional rather than medical. The actual common causes are minor injury, viral infection and deficiencies — the last of which is worth testing for.

Q: Can I apply honey or ghee to a baby's ulcer? — No honey before one year, ever. Ghee is harmless but does nothing. Ask the doctor for an age-appropriate gel.

Q: Is thrush a sign of poor hygiene? — No. It is extremely common in healthy babies, particularly after a course of antibiotics, and has nothing to do with cleanliness.

Q: My baby has thrush and a nappy rash at the same time. — Common — the same fungus can affect both ends. Both need antifungal treatment, and the nappy area needs a prescribed cream rather than powder.