Herpes Simplex virus (HSV) stomatitis is a viral infection that causes the mouth, gums and lips to get swollen and red, causing sores and ulcers.
Signs and symptoms
HSV infection is common, and often children don’t show any symptoms when they first get it. They will develop:
- painful ulcers in the mouth, on the lips and around the mouth
- refusal to eat and drink or low appetite
- irritability, lethargy, fevers and headache may occur before the ulcers appear.
What causes HSV stomatitis?
HSV stomatitis is caused by the herpes simplex virus, which is the same virus that can cause cold sores in adults. HSV stomatitis can develop or get worse because of cold weather, injuries, stress. It can also be more common in people with weak immune systems, and sometimes it can happen for no obvious reason. Future episodes of flare will be shown as cold sores, not stomatitis.
Diagnosis
HSV stomatitis can be diagnosed by a doctor based on your child’s symptoms, and usually doesn’t require any testing. Sometimes swabs may be taken by your child’s doctor, particularly if your child is immunocompromised.
Treatment
HSV stomatitis usually doesn’t need special medicine. Managing the symptoms, giving regular pain relief, and making sure your child drinks sugar-based fluids to stay hydrated will help. If some children can’t drink enough fluids, they might need to go to the hospital to have fluids delivered through a tube in their nose or a drip in their arm.
Doctors might give antiviral medicine to children within 72 hours of the first symptoms if they have weak immune systems or start feeling dehydrated or sick with a lot of pain.
Ulcers from HSV stomatitis may take 10-14 days to completely heal.
Care at home
Give your child paracetamol and ibuprofen to help with their pain and help them to drink.
Encourage your child to drink lots of sugar-based fluids to make sure they do not become dehydrated or low in energy. Over the counter numbing gels can also be used on the ulcers for pain relief — please read instructions for individual products prior to use.
It’s important to remember that your child is contagious until the ulcers have healed.
When to seek help
See your doctor if your child:
- drinks less than half of their usual amount or has less than half the number of wet nappies/passing urine they usually do
- feels light-headed or dizzy, or has dry lips and mouth
- has bad pain that isn’t relieved with paracetamol and ibuprofen
- If your child is an infant with concerns of HSV infection.
A rare complication of HSV stomatitis is encephalitis (inflammation of the brain).
If your child has confusion, a change in behaviour or is very drowsy and hard to wake up, call an ambulance immediately.
In an emergency, always call Triple Zero (000) immediately. Otherwise, visit the emergency department of your nearest hospital. For less urgent medical advice, call 13 HEALTH (13 43 25 84) 24/7 to talk to a registered nurse who can advise on the best course of action.
Developed by the Queensland Paediatric Emergency Care (QPEC), Queensland Children's Hospital. We acknowledge the input of consumers and carers.
Resource ID: FS405. Reviewed: July 2024.
Disclaimer: This information has been produced by healthcare professionals as a guideline only and is intended to support, not replace, discussion with your child’s doctor or healthcare professionals. Information is updated regularly, so please check you are referring to the most recent version. Seek medical advice, as appropriate, for concerns regarding your child’s health.