Patients Physicians Employers News Media Urticaria Urticaria, commonly known as hives, usually strikes suddenly. First the skin itches, then it erupts into red welts. The itching may be severe, keeping people from working or sleeping. It's a distressing disorder which affects an estimated 20 percent of the population at one time or another in their lives. Most cases of urticaria are acute, lasting from a few hours to less than six weeks.
Some cases are chronic, lasting more than six weeks.
The welts may appear in one place, disappear after a short time, then erupt at another spot, then another. They are made worse by scratching. Each individual hive lasts no more than 24 hours. In some people, pressure caused by belts and constricting clothing causes eruption. Urticaria may be a response to infection including the common cold, strep throat and infectious mononucleosis.