Paediatric Dentistry
Children's mouth sores
Mouth sores in children are usually minor and clear up within a week or two.
Usually
Minor
Heals in
1–2 weeks
Helps
Soft, cool food
Check if
Severe or lasting
Overview
Children often get mouth ulcers, cold sores or sore gums from minor knocks, viral illness or biting the cheek. Most are harmless and short-lived.
The main aim is to keep your child comfortable and drinking enough. See your dentist or doctor if sores are severe, spreading or last beyond about two weeks.
What to know
- Most mouth sores are minor and brief
- Keep your child comfortable and hydrated
- Soft, cool foods are easier to manage
- Check sores that last beyond two weeks
Common questions
What causes mouth sores in children?
Common causes include ulcers, viral illness and small knocks or bites.
How can I ease the pain?
Offer soft, cool foods and plenty to drink. Ask your pharmacist about suitable relief.
When should I see someone?
If your child cannot drink, has a high fever, or sores last beyond two weeks.
Are cold sores contagious?
Yes. Avoid sharing cups or kissing while a cold sore is present.
Related topics
Mouth ulcers & lesions
Common sore spots in the mouth, and when they need checking.
Teething
Teething is the normal, temporary discomfort as baby teeth come through.
Your child's first visit
An early, friendly first visit helps your child feel at ease at the dentist.
Children & tooth grinding
Grinding during sleep is common in children and usually settles on its own.
Dr Rick Iskandar · Reviewed June 2026