A toddler with a fever, red swollen gums that bleed easily and a mouth full of small ulcers most often has herpetic gingivostomatitis, the first infection with the cold sore virus; it clears on its own in about 10 to 14 days, and the parents' job is pain relief, fluids and knowing the dehydration warning signs. The Royal Children's Hospital Melbourne reports that about one in four children develop mouth ulcers with their first herpes simplex infection, usually between six months and five years of age. A GP or child health nurse confirms the diagnosis; what follows is what I tell parents who ring worried it is a tooth problem.
Written by Dr James Tran, BDent (University of Sydney), MICOI, GradDip (Oral Implants), general dentist at Lumi Dental in Melrose Park.
The short version
- Herpetic gingivostomatitis is the first encounter with herpes simplex virus type 1, the virus behind lip cold sores. It is not a dental infection.
- Fever and misery come first, then swollen bleeding gums and ulcers on the gums, tongue, palate and lips a day or two later.
- The pain usually eases within three to four days; the ulcers take about 10 to 14 days to heal and do not scar.
- Dehydration is the main risk because drinking hurts. Small, frequent, cool drinks and pain relief per the packaging and your child's weight are the treatment.
- Antiviral medicine is a GP decision, considered early and in severe cases only. Adult cold sore creams do not belong inside a child's mouth.
- Our guide to cold sores versus mouth ulcers covers the difference in older children and adults.
What herpetic gingivostomatitis is
The RCH clinical practice guideline describes a first herpes simplex infection as usually silent: gingivostomatitis, the painful mouth version, occurs in about 15% to 30% of first infections. Contact with the virus happens roughly a week before symptoms, usually through saliva or skin contact with someone shedding it, often with no visible cold sore. After the illness the virus stays in the nerves for life, which is why some of these children later get recurrent lip cold sores.
The usual timeline, day by day
The RCH guideline describes a prodrome of fever, poor appetite and general misery, followed by blisters that break into yellow ulcers with a red halo on the cheeks, tongue, gums, palate, throat, lips and the skin around the mouth. The gums bleed easily, lip blisters can crust, and drooling and refusing food are typical because swallowing hurts.
| Stage | What you may see | What helps |
|---|---|---|
| Days 1 to 2 | Fever, irritability, off food, before anything shows in the mouth | Pain relief per the packaging and weight, fluids, GP if unsure |
| Days 2 to 4 | Red, swollen gums that bleed with a touch; blisters, ulcers, drooling, lip blisters | Cool drinks little and often, soft cold food, barrier cream on lips |
| Days 3 to 5 | Pain at its worst, then easing | Keep fluids going; GP if not drinking or pain uncontrolled |
| Days 5 to 14 | Ulcers shrink, lip crusts fall off, appetite returns | Normal brushing again; childcare once sores have dried |
Raising Children Network says symptoms are gone within seven to ten days in most children; the RCH allows 10 to 14 days, and up to three weeks in severe cases.
Is it teething, hand foot and mouth, ulcers or thrush?
Teething does not cause high fever or a mouth full of ulcers. Hand, foot and mouth disease also brings mouth blisters and fever, but the blisters usually sit on the tongue and cheeks rather than the gums, with matching spots on the palms, soles or nappy area; our article on hand, foot and mouth disease covers it. Oral thrush shows white patches that wipe off to leave a red base, usually without fever; see our guide to oral thrush.
| Feature | Herpetic gingivostomatitis | Hand, foot and mouth | Teething | Aphthous ulcers |
|---|---|---|---|---|
| Fever | Yes, often first | Often, usually mild | No true fever | No |
| Gums | Red, swollen, bleed easily | Usually normal | Sore over the erupting tooth only | Normal |
| Ulcers | Many, small; gums, tongue, palate, lips | Few to many; tongue and cheeks | None | One or two; cheeks or lips |
| Skin | Blisters and crusts on the lips | Spots on palms, soles, nappy area | Dribble rash on chin | None |
The single rule: pain relief, fluids and a dehydration watch
Nothing a parent does shortens the illness much, so the goal is comfort and hydration. The RCH puts it plainly: give pain relief so your child is more likely to drink, encourage their normal amount of fluids, and treat refusing to drink as the signal to see a doctor.
What helps at home
- Paracetamol or ibuprofen, dosed per the packaging and your child's weight. Never give aspirin to a child; Raising Children Network warns of the risk of Reye's syndrome.
- Cool fluids in small amounts, often. Raising Children Network suggests oral rehydration solution as liquid or ice blocks for children over six months, and a cup and spoon if a bottle teat hurts.
- Soft, bland, cold food such as yoghurt or custard; skip salty, acidic or crunchy food until the ulcers settle.
- A smear of petroleum jelly on the lips; the RCH guideline notes a barrier cream stops crusted lips sticking together.
- Gentle cleaning with a soft cloth or the softest brush once a day until the pain eases.
- Numbing gels only on your GP's or pharmacist's advice. The RCH notes topical antiviral cream is not effective in this illness, and adult cold sore creams should not go inside a toddler's mouth.
Dehydration red flags: when to see a GP or go to emergency
The RCH lists mild dehydration signs as dark urine, fewer or lighter wet nappies, and dry lips, tongue or mouth; give more fluids and see the GP. Severe signs are not passing urine, sunken eyes, no tears, cold hands and feet, pale skin and drowsiness; these mean the nearest emergency department. Call an ambulance if your child is hard to wake, confused or behaving very strangely, because a rare complication is inflammation of the brain. Raising Children Network notes that babies under three months and children with weakened immunity are at higher risk.
Antiviral medicine: a GP decision
The RCH clinical guideline says children with a normal immune system generally do not need antiviral treatment; aciclovir may be considered when the illness is severe or the child is dehydrated and the doctor sees them within 72 hours of the first symptoms, and it is given to children with weakened immunity. That decision belongs to your GP or paediatric team, not the dentist, and the window is short, so see the GP early if your child looks unwell.
Keeping it from spreading
The virus is in saliva and blister fluid. Do not share cups, spoons, dummies or towels; wash hands after wiping dribble; and do not kiss your child on the mouth while sores are present. Keep your toddler away from newborns, because the NHS warns that herpes simplex in a newborn can be very dangerous, and away from anyone with eczema, since the RCH lists eczema herpeticum among the complications that need a paediatric team. The RCH advises keeping children who cannot control their drool home from childcare until the sores have dried. Thumb-suckers can spread it to a fingertip, a painful blistered herpetic whitlow.
Where the dentist fits in
A dentist is not the right first stop for a feverish toddler, but we help at three points. The first is ruling out a dental cause: a tooth abscess can also bring fever and a swollen gum, usually over one tooth, and our article on whether a tooth infection can cause a fever explains the difference. The second is a check a few weeks later, since gums that bled for a fortnight have usually had little brushing. The third is the first dental visit: if your child has not had one by about 12 months, our guide to a child's first dental visit explains what happens.
How we approach this at Lumi Dental
When a parent calls about a feverish toddler with a sore mouth, the team at Lumi Dental asks about drinking and nappies first, and points families to their GP or child health nurse when the picture sounds viral rather than dental. At the check that follows, the dentist examines and diagnoses, confirming the gums have healed and checking for decay, while the hygiene team of oral health therapists helps parents with cleaning and diet. The whole practice accepts the Child Dental Benefits Schedule for eligible children, and children who need specialist care are referred to a paediatric dentist; see children's dentistry at Lumi Dental.
Questions patients ask
Is herpetic gingivostomatitis the same as a cold sore?
Same virus, different stage. Gingivostomatitis is the first infection, which affects the whole mouth and brings a fever; cold sores are later reactivations on the lip.
How long is my toddler contagious, and when can they go back to daycare?
The RCH advises keeping children who cannot control their drooling away from childcare until the sores have dried, often about a week to ten days.
Can I put cold sore cream on my toddler's mouth ulcers?
No. Adult cold sore creams are made for lip skin, not the inside of the mouth, and the RCH guideline notes topical antiviral cream is not effective in this illness.
Should I keep brushing my child's teeth when their gums are bleeding?
Yes, gently. Use a soft cloth or the softest brush once a day while the mouth is sore, then return to twice-daily brushing as the ulcers heal. Our guide to mouth ulcers covers the ordinary ulcers that turn up later in childhood.
Will my child keep getting cold sores after this?
Possibly. The virus stays in the body for life and can reactivate with colds, sun or stress, usually as a lip cold sore.
Worried about your child's mouth? Children's dentistry at Lumi Dental in Melrose Park
If your toddler has had a mouth infection or it is time for a first visit, the team at Lumi Dental sees families from Melrose Park, Ryde, Parramatta, Ermington and Rydalmere at Melrose Central, with on-site parking. Read about children's dentistry at Lumi Dental, check eligibility under the Child Dental Benefits Schedule, or contact the practice to book.
Sources
- The Royal Children's Hospital Melbourne, Kids Health Info: Herpes simplex gingivostomatitis
- The Royal Children's Hospital Melbourne, Clinical Practice Guidelines: HSV gingivostomatitis
- Raising Children Network: Herpes simplex mouth infection in children
- NHS: Cold sores
About the author
Dr James Tran is a general dentist at Lumi Dental in Melrose Park. He holds a BDent from the University of Sydney and a Graduate Diploma in Oral Implants, and is a Member of the International Congress of Oral Implantologists (MICOI).
This article is general information only and is not a substitute for an examination and individual advice from a registered dental practitioner. Suitability for any treatment varies from person to person.
