Symptoms and causes

What is it?

Urticaria, also known as 'hives', is a rapidly onset and intensely itchy rash. The ‘hives’ are red spots that turn into thickened, pale patches. They can vary in size from a few millimetres to several centimetres and can also merge into larger surfaces.

Urticaria can be caused by an allergy, but there are also other triggering factors for urticaria, such as:

  • a quick change in temperature
  • infections
  • pressure
  • hypersensitivity to sunlight
  • effort

Diagnosis and treatment


Urticaria is treated with antihistamines, which are medications that suppress allergic reactions. They block the action of the body's own histamine. Histamine is a substance released after the body has been in contact with an allergen, which is a substance to which a person is allergic.

Treatment centres and specialisations


Latest publication date: 21/01/2021
Supervising author: Dr Degraeuwe Jelle