In this section
Herpes simplex gingivostomatitis (jin-juh-voe-sto-ma-tie-tis) is inflammation of the gums and lips caused by the herpes virus – the same virus that later causes cold sores. This inflammation damages the skin, resulting in painful ulcers in the mouth and blisters on the lips.
Infections in children are common, and they often go unnoticed. However, about one in four children will develop mouth ulcers after their first infection. Your child may have a fever and become irritable, then a day or two later develop blisters on their lips and ulcers on
their gums. These are painful and often lead to drooling and a refusal to eat or drink. Your child may then become dehydrated.
If your child has been infected with herpes simplex gingivostomatitis, they may show no symptoms. If they do have symptoms, they may include:
The ulcers/blisters usually take 10 to 14 days to go away. The blisters never leave scars.
Encourage your child to drink their normal amount of fluids to prevent them becoming dehydrated. There's no need to worry about them not eating, but it is important that they get enough fluids.
Signs that your child is mildly dehydrated include:
If your child is showing these signs, encourage them to drink more. This can be in the form of water, milk, jelly, icy poles or oral rehydration solutions.
It is important to reduce the pain caused by the blisters so that your child is more likely to want to drink. Give your child pain relief medication (paracetamol or ibuprofen) – see our fact sheet
Pain relief for children. The pain usually goes away after three to four days.
No other medications are needed, because antibiotics and antiviral medications do not work and are of no use in treating this condition.
If your child is refusing to drink and you think they may be dehydrated, take them to your GP or to your nearest hospital emergency department.
Signs of severe dehydration include:
Call an ambulance if it is difficult to wake your child up.
See your GP if your child's pain is not relieved with medication. The doctor may prescribe a numbing gel, which can safely be swallowed. Also see the GP if your child is becoming increasingly unwell, with high fever or vomiting.
A rare but serious complication of herpes simplex infection is inflammation of the brain (encephalitis). Symptoms include confusion, significant behaviour change and being very drowsy. If your child has herpes simplex gingivostomatitis and is showing these symptoms, call an ambulance
Once my child has had gingivostomatitis can she get it
Once someone has been infected with the herpes simplex virus, the virus will
stay in their body for life. Your child may have other episodes of herpes
reactivation (when the virus affects the body again), but the first instance is
usually the worst, and they may not experience symptoms such as painful
blisters again. Future episodes of herpes is often referred to as cold sores.
How can I get more fluids into my child?
Offer small amounts to drink often. Gastrolyte, HYDRAlyte,
Pedialyte and Repalyte are different types of oral rehydration fluid that can
be used to replace fluids and body salts. These are the best option if your
child is becoming dehydrated. They are also available as icy poles, which
children are often happy to have.
Developed by The Royal Children's Hospital General Medicine and Infectious Diseases departments. We acknowledge the input of RCH consumers and carers.
Reviewed May 2018.
This information is awaiting routine review. Please always seek the most recent advice from a registered and practising clinician.
Kids Health Info is supported by The Royal Children’s Hospital Foundation. To donate, visit
This information is intended to support, not replace, discussion with your doctor or healthcare professionals. The authors of these consumer health information handouts have made a considerable effort to ensure the information is accurate, up to date and easy to understand. The Royal Children's Hospital Melbourne accepts no responsibility for any inaccuracies, information perceived as misleading, or the success of any treatment regimen detailed in these handouts. Information contained in the handouts is updated regularly and therefore you should always check you are referring to the most recent version of the handout. The onus is on you, the user, to ensure that you have downloaded the most up-to-date version of a consumer health information handout.