Mouth Ulcers in Toddlers: Causes and Soothing | Parenting Hub

Painful mouth ulcers are common in toddlers — often from viral infections like hand-foot-mouth or herpes. Here's how to soothe and feed.

Painful mouth sores are common in toddlers — usually from a virus like hand-foot-mouth or first cold-sore infection. The challenge is getting fluids in.

Common causes

  • Hand, foot and mouth disease (see our dedicated article)
  • Primary herpes (cold-sore) infection — large numbers of ulcers, swollen red gums, very sore
  • Trauma (bitten cheek, sharp toy)
  • Mouth thrush in babies — white patches that don't wipe off
  • Rarely: iron/B12 deficiency, coeliac, hand-foot-mouth aftermath

Soothing

  • Cold drinks, ice blocks, smoothies, yoghurt
  • Avoid acidic (orange juice), salty or spicy food
  • Paracetamol or ibuprofen for pain (age-appropriate) — give 20 minutes before meals
  • Soft food: custard, jelly, mashed potato
  • Topical SM-33 or similar in older toddlers (check with pharmacist for age)

Primary herpes (gingivostomatitis)

First cold-sore infection can be intense — many ulcers, fever, drooling, refusing food. See your GP — antiviral medicine (aciclovir) helps if started early. Watch hydration closely.

When to seek help

  • Refusing all fluids, fewer wet nappies
  • Drooling and unable to swallow
  • Sleepy, hard to rouse
  • Painful joints, persistent fever >3 days

Common questions

Can my baby still go to daycare?

Usually no while there are open mouth ulcers — saliva spreads the virus. Check current daycare policy.

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