Testing for allergies in your child

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Testing for allergies in your child

http://www.mayoclinic.com/home?id=AA00016

Your child always seems to have more sniffles and sneezes than most kids do.

Although you are concerned, you pass them off as simply another cold.

But now your pediatrician suspects that your child's colds really may be due

to allergies and has recommended allergy testing. You're not sure what these

tests are and what your child will go through. What are these tests and what

do they involve?

Knowing what to expect

" It's natural to have these concerns, " says Li, M.D., an allergy and

asthma specialist at Mayo Clinic, Rochester, Minn. " Many parents feel that

same way when they bring their child in for testing. " But Dr. Li is quick to

reassure parents that allergy tests are safe, involve little if any

discomfort and usually are over quickly. " Millions of children have

allergies and many of them have undergone allergy testing, " he adds. By

knowing what the tests are and what to expect, Dr. Li says, you can feel

less anxious. And that will help you reassure and prepare your child for the

tests.

What to expect at the appointment

At the doctor's appointment, he or she will ask you and your child a series

of questions. These questions will guide the doctor in diagnosis and may

provide clues to what your child is allergic. In addition, they may help the

doctor understand how much the symptoms interfere with your child's typical

activities.

Next, the doctor will examine your child. The physical exam may provide the

doctor with additional clues about what is causing your child's symptoms.

During the exam, the doctor may check your child's eyes, ears, nose and

lungs.

Two main types of tests

The two primary kinds of tests for respiratory allergies are a skin test and

a blood test. Because interpreting results can be challenging, an allergy

specialist may need to perform them. Your family doctor can help you find

one.

The skin test. During a skin test, tiny drops of about 40 diluted allergens

(substances that may cause an allergic reaction) are applied to your child's

skin, usually on the forearm or back. The allergist or nurse also will write

on the skin with ink to create a map of where allergens are applied. After

applying each substance directly onto the skin, the allergist or a nurse

will use an instrument to press down on your child's skin. This indentation,

which is similar to what you'd make if you pressed on your skin lightly with

a ballpoint pen, helps ensure that each substance interacts with your

child's skin.

" The prick is not a shot and doesn't cause bleeding, " says Dr. Li. " It just

penetrates the surface of the skin and although not painful, it can be a

little uncomfortable. "

If your child's response to an allergen is positive, a skin reaction like a

mosquito bite or a small hive (a wheal or a flare) appears at the test site

within about 20 minutes. A positive skin test means only that your child

might be allergic to a particular substance. To pinpoint the cause of your

child's symptoms, your doctor considers the results of your child's skin

test in addition to your child's history and physical examination. Following

the test the nurse will wash your child's arm to remove the ink and the

remaining extracts. The nurse also may apply cortisone cream to reduce any

itching. From start to finish, the skin test takes about 30 minutes.

The blood test. If your child is on medication or has a skin disorder, your

allergist may need to perform a blood test. A small amount of blood from a

vein in your child's arm is analyzed to see if your child has abnormally

high levels of antibodies that cause allergies. If your child's blood

contains more of these antibodies than normal, your child likely has an

allergy to a particular substance.

Breathing easier

" The benefit of allergy testing is that it not only can confirm the initial

diagnosis of allergies, but it can pinpoint the exact cause, " says Dr. Li.

" Using that information, the doctor can suggest the most effective methods

for controlling your child's symptoms. " For example, if your child is

allergic to pollen, the doctor may suggest that you run an air conditioner

at home as much as possible during pollen season. Your doctor also may

suggest allergy shots based on your child's test results.

Your doctor also may suggest, however, that you skip the allergy tests and

go directly to allergy medications. If the allergy medications work and

don't cause side effects, then allergy testing may not be necessary. If the

allergy medications don't work or cause side effects, then you may want to

consult with an allergist and proceed with allergy testing.

Both the skin and blood tests take relatively little time and usually are

covered by your health insurance provider. If you're concerned about your

child's allergies, testing can help you breathe easier about your child's

health and, if necessary, help get your child's allergies under control.

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Allergy tests: Prickly but not painful

http://www.mayoclinic.com/home?id=HQ00206

Allergy testing on the skin is a simple procedure that can yield important

information about your allergic sensitivities. We ask Judith Blomgren, an

allergy and immunization registered nurse at Mayo Clinic, Rochester, Minn.,

to tell you what to expect if you're referred for allergy testing.

What happens during an allergy test?

Blomgren: First, we clean your forearm with alcohol, then we mark it with an

ink pen according to each substance that we're going to test. We have

extracts of potential allergens in small vials. We put a drop from each of

these vials on the corresponding mark on your skin, and then we use a little

device to prick the skin. It isn't a shot. It doesn't cause bleeding. We

just breaking the surface of your skin so that the extract can enter. If an

extract provokes an allergic reaction, you will develop an irritation that

may look like a mosquito bite.

Does it hurt?

Blomgren: It's a little irritating, but most people say it doesn't hurt too

much.

Is there anything I should do, or not do, before coming in for the test?

Blomgren: There are certain medications that will interfere with this test -

primarily antihistamines. Many antidepressants, certain heartburn

medications and some sleeping medications also may interfere. These

medications need to be out of your system from 2 days to 6 weeks or more

before an allergy test, depending on the medication. You should check with

your physician and report all medications that you are taking. Of course,

some people can't stop taking certain types of medications. In those cases,

we use 'control' tests to determine whether medications may be interfering.

How long does the test take?

Blomgren: The application only takes from 5 to 10 minutes, then there is a

15-minute wait. If there is a reaction, it will usually show up during the

waiting period.

What if I get a reaction?

Blomgren: We measure each reaction in millimeters and record it for the

doctor. When we're finished, we wash your arm with alcohol and remove all of

the ink and the extract. You may experience some itching at the sites of the

skin pricks. We apply mild cortisone cream to your arm to help relieve that.

How long do reactions stay irritating?

Blomgren: It varies depending on the extent of the reactions. If you have

many, you may have some redness the next day. Generally, the itching is

worst during the 15-minute waiting time, and then it fades fairly quickly.

Can I scratch it?

Blomgren: The more you scratch, the more it will itch.

What's the bottom line for allergy testing?

Blomgren: Everybody is different regarding allergies. Your doctor or

allergist may use the testing results to help in developing a management

plan for you.