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Herpes simplex gingivostomatitis

  • 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.

    Signs and symptoms of gingivostomatitis

    If your child has been infected with herpes simplex gingivostomatitis, they may show no symptoms. If they do have symptoms, they may include:

    • fever
    • irritability
    • painful mouth ulcers and lip blisters
    • poor appetite or reluctance to drink.

    The ulcers/blisters usually take 10 to 14 days to go away. The blisters never leave scars.

    Care at home

    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:

    • dizziness or light-headedness
    • nausea or headaches
    • dark yellow or brown wee (urine should be pale yellow)
    • not going to the toilet much (in younger children, fewer wet nappies or nappies not as wet/heavy as usual)
    • dry lips, tongue, mouth or throat.

    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.

    When to see a doctor

    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:

    • not passing urine
    • being pale and losing weight
    • dry lips and mouth
    • sunken eyes
    • cold hands and feet
    • no tears when they cry.

    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 immediately.

    Key points to remember

    • Herpes simplex gingivostomatitis is a very common condition.
    • Infection can often go unnoticed, but symptoms may include painful mouth blisters.
    • Encourage your child to drink plenty of fluids to avoid dehydration.
    • The only medications that should be used are pain relievers.

    For more information

    Common questions our doctors are asked

    Once my child has had gingivostomatitis can she get it again? 
    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


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