Approximately 20 percent of the U.S. population gets hives, also called urticaria, at least one time in their life. Hives are red, swollen welts and can appear anywhere on your body. They are sometimes itchy. Hives can last anywhere from a few minutes to several weeks, however, each individual welt should disappear within 24 hours.
Causes of Hives
Usually, hives are caused by an allergic reaction to either a drug or certain foods. If you have other allergies, you are more likely to get hives. For some, the cause of the hives is obvious. An allergic reaction to certain foods, such as peanuts or shellfish, may cause hives within minutes or hours of eating the food.
In other cases, the cause is not so obvious. Some of the other reasons hives may occur are:
- Insect bites
- Allergies to pollen, animals, latex or other substances
- Infections and illnesses, such as thyroid disease or hormonal problems
- Sun exposure or exposure to heat or cold
You may need to work closely with your doctor to determine the cause of your hives.
Diagnosing the Cause of Hives
If you have one episode, your doctor probably will not dig too deep to find out what caused the hives, however, if you have chronic hives, he may refer you to an allergy specialist for testing. In addition to taking a detailed medical history, the specialist may request the following:
- Details on substances in your home and work environment
- A list of all medication you are taking, including vitamins, over-the-counter medications and supplements
- Lab tests, including blood or urine analysis
- Allergy skin testing
There are many possible causes of hives. According to the American College of Allergy, Asthma and Immunology, approximately 20 percent of all cases of hives can be attributed to a specific cause. The other cases either require testing and research or will never be known.
Many cases of hives need no treatment at all. The red welts often disappear on their own, sometimes within minutes or a few hours. If your hives are itchy, cool compresses or taking a cool shower will often relieve the itch. Antihistamines may also be recommended to control the allergic reaction and to reduce the itchiness.
If you have more than one episode or if you have chronic hives (lasting more than six weeks), the best treatment is to find the cause and avoid the triggers. For some people, a daily dose of antihistamine is needed to help control the hives. Because some antihistamines can make you drowsy, it is important to talk with your doctor about the different antihistamines and their side effects. Your doctor may also recommend cortisone treatment or other medications that reduce inflammation.
Some who experience hives may be diagnosed with Chronic Idiopathic Urticaria (CIU). In this case, the hives last more than six weeks, but there is no known diagnosable cause. Since a known trigger is absent, finding the right treatment is a bit more challenging to achieve. But working closely with your doctor and experimenting with different treatment combinations (home remedies, injectable medications, antihistmines etc.) can help you find relief from sypmtoms.
In a few cases, complications, such as trouble breathing can occur. If this happens, you should immediately seek medical help.
"All About Hives," Date Unknown, Staff Writer, American College of Allergy, Asthma & Immunology
"Hives: Diagnosis, Treatment and Outcome," Date Unknown, Staff Writer, American Academy of Dermatology
"Hives: Who Gets and Causes," Date Unknown, Staff Writer, American Academy of Dermatology