Acute urticaria is a very itchy raised rash, which appears suddenly and fades within a few hours. It often reappears daily for a few days to weeks. The raised areas of skin are pale with pink borders. It can also present with larger areas of raised, swollen skin (wheals). Rarely, other signs of an acute generalized allergic reaction, such as wheezing, collapse and shock, may occur.

The cause in children is usually unknown but is probably caused by a viral infection. Less commonly, urticaria is a reaction to a specific food. These foods must be avoided.

Urticaria can usually be treated with an oral antihistamine. Local calamine lotion or 1% hydrocortisone cream may help. Local antihistamine cream is not effective. If the urticaria is recurrent, the child should be referred for a specialist opinion.