Urticaria, commonly known as ‘hives', is an itchy rash with swelling that appears on the surface of skin. The red raised bumps on the skin become white if pressed on. The hives can appear on any parts of the body and vary in size. They usually disappear within hours to days, but occasionally will come back. Less than 10 percent of cases become chronic.
Angioedema is a swelling from the deeper layers of the skin. It often shows as a big area of swelling on the body part(s) affected (e.g. lips, around the eyes).
The swelling in angioedema usually appears on the fingers, toes, face, head, neck and, in men, the reproductive organs. It can also occur in the gut, resulting in nausea and abdominal discomfort. The swelling may or may not be itchy and it can be painful or cause a burning feeling. It is not considered to be dangerous, unless your tongue or throat swell and close your airways. This is considered an emergency and requires urgent medical intervention.
Urticaria and angioedema can happen together or alone.
They are common. 10 percent to 20 percent of the population is affected by acute urticaria at some point in their lives but only three percent will have chronic urticaria. One in three will have angioedema as well. It is less common to have angioedema alone.
Most cases are not considered dangerous, but can cause severe discomfort and affect quality of life.