Hives: Causes, Symptoms, Treatments

Hives are skin welts that can range from tiny spots to blotches that span a dozen inches in diameter. These welts often itch terribly, and are occasionally painful. Hives commonly appear in clusters and may be accompanied by skin swelling. Most hives go away within 24 hours, though new ones can form in their place. An acute case of hives is one in which a hive cycle ends within six weeks, while chronic hives can last for years. Many people can develop fixed hives, which can arise again and again in a single spot.

The Causes of Hives

The most common trigger for hives—especially acute ones—is an allergy. Foods, medicine, and insect bites or stings can often cause hives, along with infection and illness, chemicals, sun exposure, extreme temperatures, stress, and exertion. Reactions to these triggers may occur immediately or may take up to two hours, making it harder to isolate the cause. Chronic hives in particular are often not ascribed to a particular cause, though they are often associated with autoimmune disorders.

Treating Hives

Some hives will go away on their own quickly, but if they persist for several days or don't respond to over-the-counter treatment, it's important to talk to your doctor. A dermatologist may perform allergy and blood tests as well as a skin biopsy to figure out what's triggering the hives. Most frequently, hives are treated with an antihistamine. Certain anti-inflammatory medicines may also be used.

When Hives Are Dangerous

Hives are not usually serious; however, they can indicate an underlying health condition or be accompanied by severe swelling called angioedema. According to the Mayo Clinic, about 40 percent of people with chronic hives experience some kind of angioedema along with them. Anyone suffering from angioedema should receive urgent care, since the swelling can increase to the point where it blocks off airways.

Managing Chronic Hives

The most obvious way to manage hives is to steer clear of what triggers them. However, for those with unknown triggers or chronic hives, maintenance medications, or self-injectors may be available from a doctor. 


Sources: "Hives" American Academy of Dermatology. Web. 2012. "Chronic Hives (Urticaria)" The Mayo Clinic. Web. September 17, 2011.