SSM Cardinal Glennon Children's Medical Center
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Help With Hives


What Are Hives?


Hives can occur anywhere on the body and vary in size and shape. They can be small like a mosquito bite or big like a dinner plate. Hives also might look like rings or groups of rings joined together. Hives can appear in clusters and might change locations in a matter of hours. A bunch of hives might be on a person's face, then those might go away. Later, more may appear on a person's arms.


The medical term for hives is urticaria (say: ur-tuh-kar-ee-uh). When a person is exposed to something that can trigger hives, certain cells in the body release histamine (say: his-tuh-meen) and other substances. This causes fluid to leak from the small blood vessels under the skin. When this fluid collects under the skin, it forms the blotches, which we call hives.

Why Do I Get Hives?

People can get hives for lots of different reasons. Often, the cause is not known.

One common reason for getting hives is an allergic reaction. Some common allergic triggers are certain foods (like milk, shellfish, berries, and nuts), medications (such as antibiotics), and insect stings or bites.


  • exercise
  • sun exposure
  • nervousness or stress
  • infections caused by viruses


What Will the Doctor Do?


Sometimes, doctors will suggest you take a type of medication called an antihistamine to relieve the itchiness. In many cases, hives clear up on their own without any medication or doctor visits.


Some people who know they have serious allergies carry a special medicine to use in an emergency. This medicine, called epinephrine, is given by a shot. Ordinarily, a nurse gives you a shot, but because some allergic reactions can happen really fast, many adults and kids carry this emergency shot with them and know how to use it, just in case they ever need it in a hurry.

Can I Prevent Hives?


Some kids get hives when they have a virus, such as a bad cold or a stomach flu. Other than washing your hands regularly, there's not much you can do to avoid getting sick occasionally.


Reviewed by: Christopher C Chang, MD
Date reviewed: June 2011