Urticaria (hives) can take on many different appearances but it always includes an outbreak of pimples known as "nettle rash" which may appear anywhere on the body and is accompanied by itching. It is characterised by red, swollen and very itchy welts that form on the skin.
Some of the main allergic causes of acute urticaria include:
Other than allergic induced urticaria, there are some physical conditions which can cause cute urticaria such as sun, cold, and pressure.