Urticaria is a nasty rash also known as hives. It's quite common - estimates are that 10-20% of people will have at least one episode in their lifetime. It's usually caused by an allergic reaction. Antihistamines may be taken to relieve symptoms of urticaria, and LadyDay notes that a mixture of camomile tea and flour can also help soothe the skin.
Most outbreaks are acute: they disappear quickly in a few days to a few weeks, and it's relatively easy to trace the cause of the outbreak, usually a food or a medication. Occasionally, however, a person will continue to have chronic urticaria for many years, and the causes are much more difficult to discern. See also living with chronic urticaria.
I understand that when swelling or hives form around the eyes, lips, or genitals, the tissue may swell excessively. Although frightening, the swelling usually goes away in less than 24 hours. However, if you have difficulty breathing or swallowing you should go to the emergency room. (I'm glad I don't work in an emergency room, where things like excessively swollen genitals are just part of the daily regimen of pretty sights.)