Kids Health Info

Hives

  • Hives are slightly raised, red patches of skin called wheals (or welts). They occur in groups on any part of the body, and can look like mosquito bites. They are often itchy, but sometimes also sting. The medical word for hives is urticaria (er-tuh-care-ia).

    Hives are usually a sign of an allergic reaction to things like food or an insect sting. Hives are very common – one out of every five people will have hives at some time in their life.

    Treatment includes medicines and avoiding known triggers. The triggers may be different for each child.

    Signs and symptoms of hives

    If your child has hives, they may have raised round wheals that look like mosquito bites. The wheals are red on the outside and white in the middle.

    • Hives are normally very itchy, but can also sting.
    • A single wheal often lasts around 24 hours before fading without trace.
    • The wheals appear in batches or clusters. New batches may develop as old areas fade away. 
    • Often the wheals join together to form larger swellings. The area of affected skin can vary in size from quite small to as large as a dinner plate. 
    • Hives will usually go away within a few days, but may last weeks.

    Hives can look or feel unpleasant, but usually they are harmless.

    Anaphylaxis

     Sometimes children have a more serious allergic reaction known as anaphylaxis. Symptoms of anaphylaxis include:

    • difficulty with breathing and/or noisy breathing
    • wheeze or persistent cough
    • swelling of the tongue
    • swelling and/or tightness in the throat
    • difficulty talking or hoarse voice
    • loss of consciousness and/or collapse
    • becoming pale and floppy (infants/young children).

    Call an ambulance immediately if your child has symptoms of anaphylaxis.

    If your child has experienced anaphylactic reactions in the past, you may be advised to have an adrenaline autoinjector (e.g. an EpiPen) with you at all times. Your child could also wear a medical alert pendant or bracelet to let other people know what may cause them to have an allergic reaction. Discuss this with your GP.

    What causes hives?

    Hives are a skin rash usually caused by an allergic reaction. Hives can occasionally occur without a trigger, but usually happen when the immune system responds to a substance (such as a food or insect venom) as if it were toxic (poisonous). Hives occur when blood plasma leaks from the blood vessels into the skin. This happens when a chemical called histamine is released. 

    The following can cause histamine release and hives:

    • insect stings or bites
    • viral infections (e.g. a cold or hepatitis)
    • chemicals in foods, medicines or plants.

    For most children, each attack of hives will become more severe and intense if they are repeatedly exposed to the same trigger.

    Usually tests are not performed because often it's impossible to find out what triggers hives in children.

    Care at home

    Most of the time, hives can be safely managed at home, without the need to see a doctor. A pharmacist might provide you with some antihistamine medication for relief of symptoms during an episode. The best treatment for hives is to avoid the cause or trigger, however this is not always possible.

    You can help treat your child’s hives by:

    • avoiding known triggers for your child
    • avoiding things that make the rash worse, such as sunshine, heat and hot showers
    • applying cool compresses (a face washer, cloth nappy or clean tea towel soaked in cool water), which may help relieve the itching and stinging.

    When to see a doctor

     If your child continues to have hives for more than six weeks, take them to see your GP.

    Treatment for severe or frequent hives may include:

    • checking that the rash isn't caused by an underlying disorder
    • medications such as corticosteroids, which can reduce the immune system's response to the triggers
    • prescribing non-sedating antihistamines to provide relief from itching – these can be very useful if taken at bedtime.

    If at any time the hives are associated with other symptoms (high fever, bruising, purple skin discolouration or joint pains), your child should be seen by a doctor.

    Key points to remember

    • Hives are very common and are usually harmless.
    • Hives are a skin rash involving red, raised wheals that are usually very itchy.
    • This type of skin rash is an allergic reaction, which means the immune system responds to a substance as if it were toxic.
    • Treatment options include avoiding known triggers and medications such as antihistamines and corticosteroids.
    • Call an ambulance if your child has symptoms of anaphylaxis.

    For more information

    Common questions our doctors are asked

    How effective are antihistamine medications?

    Antihistamine medication won't treat existing hives, but it will prevent hives from getting worse and prevent new hives from erupting. If your child is exposed to a known trigger, it is best to give them antihistamine medication as soon as you can.

    Are there any creams I can put on my child's hives to stop them itching?

    Talk to your pharmacist about creams and lotions that may help reduce the intensity of the itching. The most effective creams will include antihistamine.

    Should I take my child to see an allergy specialist to find out the cause of his hives?

    If you are unable to determine the trigger, it is useful to keep a food and activity diary. An allergy specialist can also perform further testing to determine the most likely triggers for your child's hives.


    Developed by The Royal Children's Hospital General Medicine and Dermatology departments. We acknowledge the input of RCH consumers and carers.

    Reviewed July 2018.

    Kids Health Info is supported by The Royal Children’s Hospital Foundation. To donate, visit www.rchfoundation.org.au.

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Disclaimer
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.