Symptoms and causes

Symptoms and causes

What is it?

With hives, certain white blood cells release a substance, histamine, en masse in your blood unnecessarily.


The substance that is released in your blood, histamine, suddenly causes bright itchy red lumps. In the centre, they sometimes become so thick that they are whiter. They may also have a white edge around them. Blotches can also appear very quickly. These blotches can change places or quickly disappear again. If you have blotches that go away within 24 hours, chances are that you have hives.

You can also develop quincke oedema, in which case a piece of skin will quickly swell up like a balloon, e.g. a lip or eyelid. This can occur together with hives.

How often does it happen?

Twenty per cent of the population develops hives once in their lifetime, so do not panic, even if you are sometimes full of red spots.


The white blood cells that release histamine into your blood are overstimulated, which often happens after you have been ill, even after a common cold.

Inhibitors of inflammation often cause hives; this is a kind of painkiller that you can also get without a prescription. A few weeks may pass between taking this painkiller and the itchy bumps, so you do not always make the link yourself.

Sometimes a clear cause for the hives cannot be found. Even with prolonged forms, it occurs spontaneously.

Diagnosis and treatment

Diagnosis and treatment

Hives are not allergies, so allergy tests are rarely useful. Your physician will usually prescribe an antihistamines treatment. These are harmless pills. With hives, it is important that you take them daily at fixed times, whether you have itching or not, and sometimes you have to take many pills a day until everything heals.

Difficult, prolonged forms of urticaria can be treated with special medication or injections.

Treatment centres and specialisations

Treatment centres and specialisations

Latest publication date: 14/12/2022
Supervising author: Dr Van Autryve Els