Hives are red, itchy spots on the skin, otherwise known as urticaria. According to the American Academy of Dermatology, approximately 10 to 20 percent of Americans are affected by hives during their lifetime. Hives usually occur as an allergic reaction to certain medications or foods, although sometimes they occur without an easily identifiable cause.
Features
Hives occur as raised, itchy, pink to red bumps on the skin that may produce a burning or stinging feeling. According to Dr. Tiffany Young, a hives specialist, on her website Hives.org, hives can be as small as a pencil eraser or as large as a dinner plate. They can change shape, location or color, and sometimes disappear before reappearing several hours later.
Causes
Hives occur as an allergic reaction. Your body releases chemical substances known as antihistamines in order to attack the suspected allergen. Hives develop as a way for your body to let you know that it has a problem with the allergen. According to the American Academy of Dermatology, common food triggers of hives include chocolate, nuts shellfish and milk. Drug allergies, pet dander, stress, anxiety, pollen, bacteria and other factors can also cause hives, according to Dr. Young.
Types
There are several types of hives. Acute urticaria lasts for six weeks or less, and usually resolves after the underlying cause is eliminated. Chronic urticaria lasts longer than six weeks, and usually occurs because the underlying cause is difficult to determine. The American Academy of Dermatology notes that solar urticaria is a type of acute urticaria that occurs to some people within minutes of exposure to the sun, but generally resolves in a few hours. Heat hives, another form of acute urticaria, can occur in extremely hot conditions or due to excessive sweating.
Treatment
Eliminating the cause is the first step in treating hives. Your doctor may recommend an allergy test, especially if this is your first outbreak of hives. According to the American Academy of Dermatology, antihistamines, cortisone and injections of epinephrine, especially in severe cases, are often used to treat hives.
Misconceptions
Hives are not contagious, according to Dr. Young, so you cannot contract hives from someone else. You can use the same toilet, towels, bed linens and other everyday items without the risk of contracting hives, as it is an allergic reaction and not an infection or virus.
