Urticaria / Angioedema

Urticaria, also known as hives or nettle rash is characterised by a lumpy, itchy rash. It is the rash you get when you have been stung by nettles. However, it can also be caused by a reaction to certain foods and occasionally, by a viral infection.

If the rash lasts less than six weeks it is called acute urticaria. Acute urticaria is common and usually clears up within 24 hours. Approximately 20% of people will have at least one attack of urticaria in their lifetime. Occasionally, a persistent form called chronic urticaria develops which may last for several months or even years. Chronic urticaria is much less common; approximately one in 1000 people develops chronic urticaria in their lifetime.

Sometimes urticaria occurs at the same time as the more serious condition called angioedema. Angioedema involves swelling in the deeper layers of the skin. The swelling causes a burning sensation and often occurs on the neck and face, the fingers and toes, and, in men, the genitals. The lining of the mouth and windpipe may swell and breathing may become difficult.

Angioedema occurs in approximately half of people with chronic urticaria, it also occurs without urticaria and with acute urticaria. Angioedema commonly lasts 1-2 days and occurs from time to time. Occasionally the tongue or throat swells.

Allergy Services and Research