Kids Health Info

Hives

  • Hives are slightly raised, red patches of skin called wheals. They occur in groups on any part of the body and can look like mosquito bites. They are often itchy, but sometimes also sting. Hives are usually a sign of an allergic reaction to things like food or insect bites. It's the bodies way of saying it is responding or reacting to something it feels or thinks is toxic (poisonous).

    Each wheal lasts a few hours before fading without trace. New areas may develop as old areas fade. 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.

    The medical word for hives is urticaria. Hives are very common - one out of every four people will have hives at some time in their life.

    Hives will usually go away within a few days. If your child continues to have hives for more than six weeks this may need investigation. Treatment includes avoiding known triggers (i.e. things known to cause the hives) and medicines. The triggers may be different for each child.

    Signs and symptoms

    • Raised round wheals that look like mosquito bites.
    • The wheals are red on the outside and white in the middle.
    • They are normally very itchy.
    • A single wheal often lasts around 24 hours.
    • The wheals appear in batches or clusters.
    • One batch fades away as a new batch appears.
    • The rash may last for days or weeks.

    Anaphylactic shock

    Usually, the hives look or feel unpleasant but are harmless. However, sometimes a more serious allergic reaction known as anaphylactic shock can happen. This is a medical emergency and an ambulance should be called immediately by dialling 000.

    Symptoms of anaphylactic shock include:

    • swelling of the tongue and throat
    • breathing difficulties
    • choking
    • collapse.

    If your child has experienced anaphylactic reactions in the past you may be advised to have ready access to adrenaline. Your child should also wear a Medi-alert pendant or bracelet to let other people know what may cause them to have an allergic reaction. Discuss this with your GP.

    Causes

    Often it's impossible to find out what triggers hives in children. Usually no tests are needed. Hives are a type of skin rash that is an allergic reaction. This means the immune system responds to a substance as if it were toxic.

    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:

    • allergic reactions
    • insect bites
    • virus infections
    • chemicals in foods and medicines.

    Treatment

    The best treatment for hives is to find and remove the cause or trigger, however this is not always possible. For most people, each attack of hives will become more severe and intense if they are repeatedly exposed to the same trigger.

    Treatment for severe or frequent hives may include:

    • checking that the rash isn't caused by an underlying disorder
    • avoiding known triggers for your child
    • medications, such as antihistamines and corticosteroids, can reduce the immune system's response to the triggers
    • 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) may help relieve the itching and stinging
    • anti-histamines are often prescribed for your child to provide relief from itching. These can be very useful if taken at bedtime.

    Key points to remember

    • Hives is a skin rash characterised by reddened and raised round wheals.
    • 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 avoidance of known triggers and medications such as antihistamines and corticosteroids.

    Contact Information

    For more information or if you have any concerns, call your GP.

     

    Developed by the RCH General Medicine and Dermatology Departments.  First published 2003. Reviewed November 2010.



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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.