Tips to Remember:
If you are allergic, you are reacting to a
particular substance. Any substance that can trigger an allergic reaction is
called an allergen. To determine which specific substances are
triggering your allergies, your allergist/immunologist will safely and
effectively test your skin, or sometimes your blood, using tiny amounts of
commonly troublesome allergens.
Allergy tests are designed to gather the most
specific information possible so your doctor can determine what you are
allergic to and provide the best treatment.
Who should be tested for allergies?
Adults and children of any age who have symptoms that suggest they have an
allergic disease. Allergy symptoms can include:
- Respiratory symptoms: itchy eyes, nose, or throat; nasal congestion,
runny nose, watery eyes, chest congestion or wheezing
- Skin symptoms: hives, generalized itchiness or atopic dermatitis
- Other symptoms: anaphylaxis (severe life-threatening allergic
reactions), abdominal symptoms (cramping, diarrhea) consistently following
particular foods, stinging insect reactions other than large local
swelling at the sting site.
Generally, inhaled allergens such as dust
mites, tree, grass or weed pollens will produce respiratory symptoms and
ingested (food) allergies will produce skin and/or gastrointestinal symptoms
or anaphylaxis but both types of allergens (ingested and inhaled) can
produce the spectrum of allergy symptoms.
What are the reasons for undergoing
allergy skin testing?
To help you manage your allergy symptoms most effectively, your allergist/immunoloigst
must first determine what is causing your allergy. For instance, you don't
have to get rid of your cat if you are allergic to dust mites but not cats.
Allergy tests provide concrete specific
information about what you are and are not allergic to. Once you have
identified the specific allergen(s) causing your symptoms, you and your
physician can develop a treatment plan aimed at controlling or eliminating
your allergy symptoms. With your allergy symptoms under control you should
see a considerable improvement in the quality of your life. Improved sleep
quality because of less congestion, days without constant sneezing and
blowing your nose, improved ability to exercise, and better control of your
atopic dermatitis (eczema) are some of improvements you may gain from your
allergy treatment plans.
Which allergens will I be tested for?
Because your physician has made a diagnosis of allergies, you know that one
or more allergens is causing your allergic reaction - itching, swelling,
sneezing, wheezing, and other symptoms. Your symptoms are probably caused by
one of these common allergens:
- Products from dust mites (tiny bugs you can't see) that live in your
- Proteins from furry pets, which are found in their skin secretions
(dander), saliva and urine (it's actually not their hair);
- Molds in your home or in the air outside;
- Tree, grass and weed pollen; and/or cockroach droppings.
More serious allergic reactions can be caused
- Venoms from the stings of bees, wasps, yellow jackets, fire ants and
other stinging insects;
- Natural rubber latex, such as gloves or balloons; or
- Drugs, such as penicillin.
All of these allergens are typically made up
of proteins. Allergy tests find which of these proteins you may be reacting
The allergen extracts or vaccines
used in allergy tests are made commercially and are standardized according
to U.S. Food and Drug Administration (FDA) requirements. Your
allergist/immunologist is able to safely test you for allergies to
substances listed above using these allergen extracts.
Types of Allergy Tests
Prick Technique: The prick technique involves introducing a small amount of
allergen into the skin by making a small puncture through a drop of the
allergen extract. If you have an allergy, the specific allergens that you
are allergic to will cause a chain reaction to begin in your body.
People with allergies have an allergic
antibody called IgE (immunoglobulin E) in their body. This chemical,
which is only found in people with allergies, activates special cells called
mast cells. These mast cells release chemicals called mediators,
such as histamine, the chemical that causes redness and swelling.
With testing, this swelling occurs only in the spots where the tiny amount
of allergen to which you are allergic has been introduced. So, if you are
allergic to ragweed pollen but not to cats, the spot where the ragweed
allergen touched your skin will swell and itch a bit, forming a small
dime-sized hive. The spot where the cat allergen scratched your skin will
remain normal. This reaction happens quickly within your body.
Test results are available within 15 minutes
of testing, so you don't have to wait long to find out what is triggering
your allergies. And you won't have any other symptoms besides the slightly
swollen, small hives where the test was done; this goes away within 30
Intradermal: involves injecting a
small amount of allergen under the skin with a syringe. This form of testing
is more sensitive than the prick skin test method. This form of allergy
testing may be used if the prick skin tests are negative.
Other Allergy Testing Techniques
Scratch tests: The term scratch test
refers to a technique not commonly used at the present, which involves
abrading the skin and then dropping the allergen on the abraded site.
Challenge testing: Involves
introducing small amounts of the suspected allergen by oral, inhaled or
other routes. With the exception of food and medication, challenges are
rarely performed. When they are performed, they must be closely supervised
by an allergist/immunologist.
Blood (RAST) test-Sometimes your
allergist/immunologist will do a blood test, called a RAST (radioallergosorbent)
test. Since this test involves drawing blood, it costs more, and the results
are not available as rapidly as skin tests. RAST tests are generally used
only in cases in which skin tests cannot be performed, such as on patients
taking certain medications, or those with skin conditions that may interfere
with skin testing.
Other types of allergy testing methods the
American Academy of Allergy, Asthma and Immunology considers to be
unacceptable are: applied kinesiology (allergy testing through muscle
relaxation), cytotoxicity testing, urine autoinjection, skin titration (Rinkel
method), provocative and neutralization (subcutaneous) testing or sublingual
provocation. If your physician plans to conduct any of these tests on you,
please see an AAAAI member allergist/immunologist for appropriate allergy
Who can be tested for allergies?
Adults and children of any age can be tested for allergies. Because
different allergens bother different people, your allergist/immunologist
will take your medical history to determine which test is the best for you.
Some medications can interfere with skin testing. Antihistamines, in
particular, can inhibit some of the skin test reactions. Use of
antihistamines should be stopped one to several days prior to skin testing.
Your allergist/immunologist can provide
you with more information on allergy testing.
Tips to Remember are created by the
Public Education Committee of the American Academy of Allergy, Asthma and
Immunology. This brochure was updated in 2003.
The content of this brochure is for
informational purposes only. It is not intended to replace evaluation by a
physician. If you have questions or medical concerns, please contact your
American Academy of Allergy,
Asthma and Immunology
555 East Wells Street
Milwaukee, WI 53202-3823
Physician Referral and
AAAAI Web site