After eating some big, red strawberries, you decide to walk to
your friend's house. Just as you're turning the corner, you
notice reddish bumps and patches on your arms and chest. What are
these itchy welts or blotches on your skin? Should you turn around
and head home?
What Are Hives?
Hives are pink or red bumps or slightly raised patches of
skin
. Sometimes, they have a pale center. Hives usually itch, but they
also can burn or sting.
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
some more may appear on a person's arms.
Hives are common - between 10% and 25% of people get them at
least once in their lives. They are usually harmless, though they
may occasionally be a sign of a serious allergic reaction. (So,
yes, you should go home and tell your mom or dad.)
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
. Other causes of hives are not related to allergies and these can
include:
- exposure to the cold (like diving into a cold pool)
- exercise
-
sun exposure
- nervousness or
stress
- infections caused by viruses
No matter what the cause, a case of hives can last for a few
minutes, a few hours, or even days.
What Will the Doctor Do?
Doctors usually can diagnose hives just by looking at you and
hearing your story about what happened. The doctor can try to help
figure out what might be causing your hives, although often the
cause will remain a mystery. If you're getting hives a lot, or
your reaction was serious, your doctor might send you to another
doctor who specializes in allergies.
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.
Less often, hives can be a sign of a more serious allergic
reaction that can affect breathing and other body functions. In
these cases, the person needs immediate medical care. 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?
Yes and no. The answer is "yes" if you know what
causes your hives - the strawberries at the start of this article,
for example. If you know they cause you trouble, you can just avoid
them. If you get hives when you're nervous, relaxation
breathing exercises may help. But if you don't know why you get
hives, it's tough to prevent them.
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. The good news is that hives usually aren't
serious and you might even grow out of them. Who wouldn't want
to give hives the heave-ho?
Reviewed by:
Elana Pearl Ben-Joseph, MD
Date reviewed: October 2007
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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