What is acute urticaria in children?
What is acute urticaria?
Urticaria (sometimes called hives) is an itchy rash caused by tiny amounts of fluid that leak from blood vessels just under the skin surface. Urticaria is classed as:
- Acute urticaria - if it develops suddenly and lasts less than six weeks. Most cases last 24-48 hours. About 1 in 6 people will have at least one bout of urticaria in their life. It can affect anyone at any age. Some people have recurring bouts of acute urticaria.
- Chronic urticaria - if it persists longer than six weeks. (Chronic means persistent or ongoing.) This is uncommon.
This rest of this leaflet deals only with acute urticaria. See a separate leaflet for information about chronic urticaria.
What does the rash of acute urticaria look like?
The rash usually appears suddenly and can affect any area of skin. Small raised areas called weals develop on the skin. The weals look like mild blisters and they are itchy. Each weal is white or red and is usually surrounded by a small red area of skin which is called a flare. The 'weal and flare' rash of urticaria looks similar to the rash caused by a nettle sting.
The weals are commonly 1-2 cm across but can vary in size. There may be just a few but sometimes many develop over various parts of the body. Sometimes weals that are next to each other join together to form larger ones. The weals can be any shape but are often circular.
As a weal fades, the surrounding flare remains for a while. This makes the affected area of skin look blotchy and red. The blotches then fade gradually and the skin returns to normal.
Each weal usually lasts less than 24 hours. However, as some fade away, others may appear. It can then seem as if the rash is moving around the body. The rash may appear quite dramatic if many areas of skin are suddenly affected.
Average rating:
