Hives is a skin condition that causes red rashes that are raised above the skin, and is frequently very itchy. The rashes can change size, and move from location to location within hours. They can appear suddenly and very quickly, and will also fade quickly. This pattern can last for several weeks or longer.
They occur when histamine is produced in the skin, which leads to the rapid swelling of the skin. Some cases are a result of allergies to foods, insect bites, or medications, but in many cases, no specific cause can be found. In some cases, the causes of hives are physical. Direct stimulation of the skin causes the rashes. Dermatography is one of the more well known cases of physical hives.
Fortunately, although hives are very common, they are rarely dangerous, or otherwise hinder a person's life. Up to 1 in 5 people will experience hives at least once in their lives, and it tends to occur in women more often. In the cast majority of cases, hives are simply ignored, or antihistamines are taken to relieve symptoms when they flare up. Most cases of hives will resolve on their own within 6 weeks or less.
- Wheals that vary in size
- Rashes come and go rapidly, often within hours
- Areas affected can move rapidly
- Can be mild to bright red