Urticaria- what causes hives and how is it treated?
What is Urticaria?
- Urticaria (commonly known as “hives”) is a common itchy rash- around 20% of people get it at some point in life.
- It usually leads to raised pink itchy skin lesions, which can look a bit like mozzie bites.
- These spots can vary in size, from quite small to much larger “welts”- and they can fluctuate quickly- appearing, disappearing and reappearing over minutes hours or days.
- Urticaria is NOT a crusty or blistering rash, and it should always go pale (blanche) when pressure is applied to the lesions.
- An antihistamine may relieve the symptoms.
- If it goes on for more than 6 weeks, it’s considered to be Chronic Urticaria.
What causes Urticaria?
Urticaria (hives) happen when a substance called histamine is released from cells in your skin, leading to swelling and irritation. It’s not known exactly why this happens, but the following may be triggers for urticaria:
- Viral illness- this is a very common trigger in children
- Certain foods
- A side effect of a medicine
- Insect stings or bites
- Exposure to certain plants or animals
- Less commonly it can be caused by physical triggers like cold weather, sunlight, rubbing or pressure on the skin, exercise,
Occasionally, urticaria is part of a more serious allergic reaction – this possibility should be considered if any of the following occur:
- It’s always within 2 hours of a meal
- Tightness of breathing
- Nausea, vomiting and/or tummy pain
- Light-headedness
- Swelling of the throat and/or tongue
If there is breathing difficulty, tongue and mouth swelling, or abdominal pains with the rash it could mean it’s Anaphylaxis, which is a life-threatening allergic reaction- immediate medical attention should be sought.
What is the treatment for urticaria?
- If you know the trigger, avoid it.
- Antihistamines may ease the rash and the itch- these are available over the counter from your pharmacist.
- Avoid anything that makes the rash more prominent – like stress, alcohol, getting too hot or hot spicy food.
- It seems anti-inflammatories can make urticaria worse in some people- so these should be avoided. Paracetamol (Panadol) is still OK.
- Sometimes oral steroid medication (cortisone) is prescribed- but it’s often not very helpful, and there are many possible side effects of this treatment.
- People who have chronic urticaria may need to see an allergy specialist or dermatologist for further advice- sometimes they may try medications which act on the immune system.
Are there any tests for urticaria?
- Tests are not usually needed- as they usually don’t offer any helpful information.
- However, if urticaria goes on for more than 6 weeks, or if a person has other unexplained symptoms apart from the rash (eg fevers, pain or feeling generally unwell), blood tests may be advised.
- If there are symptoms suggestive of Anaphylaxis, further allergy testing will usually be recommended.
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Clinical review & governance
Medically reviewed by Dr AIFRIC BOYLAN
CEO
About Dr Aifric Boylan MB BCh BAO MICGP FRACGP DRCOG DCH Fellow of the Royal Australian College of General Practitioners, Dr Aifric Boylan is a general practitioner with more than 20 years' experience. She graduated in medicine from…
This health information has been clinically reviewed by an Australian doctor. Qoctor health pages are reviewed to support clear, evidence-informed guidance; they do not replace individual medical advice.
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