Allergy Testing

You have options at HCAA. We learn more about you to discover the best treatment option for your allergies.

Allergy Testing

If you have an allergy, your body is reacting to something you inhaled, touched or ate. The substances that trigger an allergic reaction are called allergens (ie. food, pollen, mold, dust mites, insect stings, animal dander, etc.). Reactions to these allergens range from annoying to life-threatening.

Types of Allergy Tests

Skin Test

Here at Hill Country Allergy & Asthma we determine your degree of allergy through a procedure
called skin testing where the prick test and the intradermal (under the skin) test are used. With each
test, you will be exposed to small amounts of things to which you may be allergic (medications, insect venom, molds, pollens, animal dander, dust mites, foods, etc.). If you are allergic
to a substance a reaction will appear which looks like a mosquito bite. The staff will
examine any reaction that appears to decide whether a positive reaction has occurred indicating

In the prick test, allergens are applied by tiny pokes that penetrate only the very top layer of skin.
These pokes will rarely draw blood. You feel only a slight prick or scraping of the skin. Reactions are
usually seen in ten to thirty minutes if they are going to occur, and you generally won’t have any
other symptoms besides the small hives where the tests were done, which go away typically within a few days.

The intradermal test involves the injection of a small amount of allergen placed with a needle just
under the skin. This pushes the skin up slightly, producing a round whitish, raised area called a
wheal. This procedure is not as painful as the usual injection, because only a small amount of
allergen is injected and the small needle slips barely under the skin surface. Any reaction usually
occurs within ten to twenty minutes.

The prick method has the advantage of letting the provider test a large number of allergens at one
time. Intradermals are used as a confirmatory test. The provider will decide whether to use one or
both methods for the testing. A MULTI-TEST is a sterile disposable, multiple test head applicator
used to administer skin test substances. It provides a quick, convenient, and standardized procedure
and is frequently used for children. There are eight tests heads on each device.

Skin testing is the most common and is least invasive. If you are allergic to ragweed pollen
but not to cats, only the ragweed allergen will cause a little swelling or itching. The spot where the
cat allergen was applied will remain normal.

*A skin test has to be done in an allergist’s office to minimize the risk of rare side effects and reactions to tests.

Challenge Tests

In a challenge test, a very small amount of an allergen is inhaled or taken by mouth. Challenges are
done mostly with potential food or medication allergies, and it is very important that they be
supervised by an allergist.

Blood Tests

This test involves drawing blood, so results are not available as rapidly as with skin tests. Blood tests
are more limited and are generally used when skin tests might be unsafe or won’t work, such as if
you are taking certain medications, or have a skin condition that may interfere with skin testing.

Patch Testing

Patch testing is useful for the evaluation of allergic contact dermatitis.  This test is used to identify whether a substance that comes in contact with the skin is causing inflammation of the skin (contact dermatitis.)  There are essentially two types of contact dermatitis:  irritant contact dermatitis and allergic contact dermatitis

More Information

What is Patch Testing?

Patch testing is useful for the evaluation of allergic contact dermatitis. This test is used to identify
whether a substance that comes in contact with the skin is causing inflammation of the skin (contact
dermatitis.) There are essentially two types of contact dermatitis: irritant contact dermatitis and
allergic contact dermatitis.

Irritant Contact Dermatitis

An irritant substance is one that would cause inflammation in almost every individual if it was applied
in sufficiently high concentration for long enough. An irritant reaction is caused by the direct contact
of an irritant substance with the skin.

Allergic Contact Dermatitis

An allergic reaction is specific to the individual and to a substance (or a group of related substances)
called an allergen. Allergy is a hypersensitivity (oversensitivity) to a particular substance, and always
involves the immune system. All areas of skin that are in contact with the allergen may develop the
rash. The rash will disappear if you avoid contact with the substance.

Why is Patch Testing Done?

If you have a dermatitis that started recently or if you have a persistent or unusual eczema, your
allergist may suspect you have an allergic contact dermatitis. Patch testing is commonly advised for
people who handle chemicals regularly, or on people who have seasonal or patterns of rashes.

Your Allergist Will Ask You a Series of Questions

First your provider will discuss your skin problem with you. Subjects include:

● The site where your rash began and how it developed
● The treatments you have tried
● Previous skin disease
● The general health of you and your family, especially any tendency to get one or a
combination of asthma, hay fever, or eczema
● Cosmetics and toiletries used
● Your occupation – this will focus on materials used at work and the effect of weekends and
holidays on your dermatitis (if it settles during these times, it is likely that you are in contact
with an allergen at work.) If other workers are affected with a similar rash then tell your
● Your hobbies or seasonality of the rash
● Foods you feel may be aggravating your dermatitis

If you can think of anything that you were in contact with around the time the rash first appeared, tell
your provider. Do not assume that just because you have been using something previously without a
problem, it will not be the cause. Sometimes a cosmetic that you have been using for some time
can become the cause of a rash. Your provider will then examine your skin. The dermatitis is usually
most severe at the site of exposure, but can be widespread (for example, if a patient with an allergy
to a substance in nail polish touches her face, the dermatitis may spread.)

Your Allergist Recommends Allergens to be Tested

Your allergist will suggest for which allergens you should be tested. The standard selection of
allergens used consists of the majority of allergens that are implicated in contact dermatitis.
Together, the allergens in this panel cause over 85 percent of all allergic skin reactions. In addition,
the allergist may suggest additional patch tests using other allergens specific to your occupation or
site of the rash as well as your own cosmetics. Foods and airborne allergens can also cause
contact reactions and are used in certain situations to evaluate specific rashes.

Conducting the Patch Test

Patch testing should be done on a skin site where the dermatitis is not apparent. The allergens are
mixed with a non-allergenic material (base) to a suitable concentration. They are then placed in
direct contact with the skin, usually on the upper back, within small plastic discs. Adhesive tape
is used to fix them in place, and the test sites are marked. The patches are left in place for 48 hours.

Preparing for Patch Testing

It is important that you are not taking any steroid medications by mouth (such as prednisone) within
the month of your patch test. You should not receive a cortisone injection within one month of your
test as well. Do not apply lotions or powders prior to the application of your patch tests. In addition,
it is very important you are not applying any cortisone-containing creams to your back within two
weeks preceding your patch test. Antihistamines may be taken if needed, or unless otherwise
instructed. Avoid sun exposure to your back for 3 weeks preceding your patch test. The test may
possibly stain clothing. Choose your clothing carefully with this in mind. You must not be pregnant
or nursing. No showering, swimming, sweating, rubbing, or scratching.

What to Expect at the First Visit:

● Application of the patch tests (approximately 90 minutes)
● This is when the application of the patches is done.

What to Expect at the Second Visit:

● First reading after 48 hours (approximately 60 minutes)
● This first reading will allow us to assess the degree of the reactions and remove any
significantly positive patches.

What to Expect at the Third visit:

● Delayed reading after 72-96 hours (approximately 60 minutes)
● Oftentimes a delayed reaction occurs. This means that during your third visit, a substance
that was originally negative has since produced a response on your skin. At this visit you will
be informed of the compounds that showed reactions. This will be reviewed with you, and a
list of safe products or products that these compounds are in so you can avoid them will be
emailed to you.

What Should I Do if A Patch Test Reaction is Positive?

● You should be given detailed information about sources of the allergen
● Carefully avoid any further contact with the allergen
● Carefully read ingredients of new products, especially cosmetics
● Use barrier creams and protective clothing to avoid the allergen
● If the allergen is at work, then discuss the options with your employer. They should provide
materials to protect you from the allergen, or, if this is not possible, consider how to change
your work.


Immunotherapy (allergy drops) is aimed at increasing your tolerance to allergens that trigger your symptoms every time you are exposed to them. Allergy Shots are in essence a series of injections to control allergy symptoms. Allergy shots are not a medication, they are a serum made up of the very same proteins that you are allergic to and inhale.
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Allergies and Your Immune System

Your immune system responds to allergies by producing antibodies called Immunoglobulin E (IgE).
These antibodies travel to cells that release chemical mediators, causing an allergic reaction.

What is Immunotherapy?

Immunotherapy (allergy shots/drops) is aimed at increasing your tolerance to allergens that trigger your
symptoms every time you are exposed to them. Allergy Shots are in essence a series of injections to
control allergy symptoms. Allergy shots are not a medication, they are a serum made up of the very
same proteins that you are allergic to and inhale. This serum is also known as a vaccine to the allergen to which you
have a sensitivity. Receiving allergy shots desensitizes allergy patients to their specific allergens and
is the only way to “turn off” the immune system’s reactions.

How Does Immunotherapy Work?

By gradually increasing the dose of your allergen, your body develops an immunity and/or tolerance
to that allergen. In essence, immunotherapy turns off an inappropriate immune response –your allergic
reaction to a plant, tree, pet, insect venom or mold –while still allowing your immune system to respond normally to
infectious agents, especially viruses. Allergy patients are frequently able to get rid of their allergies
and become medication “free” by gradually developing a stronger tolerance to his or her allergens.
With immunotherapy, your allergy symptoms can be decreased, minimized or even eliminated through
this process that slowly makes your body less responsive to inhaled allergens over the course of
several months to years.

Types of Immunotherapy Protocols

Hill Country Allergy & Asthma offers several different protocols for achieving desensitization to
aeroallergens and venom from stinging insects. These include traditional protocols with weekly
injections, cluster protocol consisting of 2-3 sets of injections at each visit, as well as rush (rapid
desensitization) immunotherapy which is a rapid desensitization taking place over two days.

Immunotherapy consists of 2 phases: Build up and Maintenance. Each method has different steps
that can be further explained once you make an appointment.

Immunotherapy Subcutaneous (shots) and Sublingual (under the tongue) are both offered by Hill
Country Allergy & Asthma. FDA Studies are ongoing with sublingual immunotherapy.
For more Info on Sublingual Immunotherapy visit the American Academy of Allergy, Asthma &
Immunology website.

Shot Clinic

Shot clinic is the area in which patients receive their immunotherapy or “Allergy Shots”. Shot hours are posted at the individual offices and vary by location. The allergy shot visits do not require an appointment. We offer them on a “walk in” basis. Minors must be accompanied by a parent or legal guardian in order to receive an injection. You may not be able to receive your injections if you are acutely ill, have a fever or increased asthma symptoms.  If you are experiencing severe allergy symptoms, please notify the staff prior to your injection. For your safety, there is a 20-30 minute waiting period following each injection, so please be prepared to stay for that waiting period.  Feel free to help yourself to a snack, read a book, catch up on emails by connecting to our free WiFi, or watch your favorite TV shows while you wait!

“My son has been going to Dr. Mery for over a year.  I always appreciate how attentive the nurses are to him when checking him out before he is released after his shot.  This office is very clean and organized as well.”

Stephanie H.

“My whole family goes to Dr. Mery.  He has been a major factor in our family’s health and well-being.  Dr. Mery is compassionate and understanding.  He is determined to help those who come to see him and truly cares for his patients.”

Susan D.

“Hill Country Allergy has been a very good experience for me these last few weeks. A great team has been providing me with a thorough job of evaluating my allergy needs and implementing a specific plan to reach my specific goal of setting my allergies under control. All staff is efficient, courteous, and very knowledgeable of my specific concerns. I am very pleased with my current service.”

Sandra B.

“The staff at Hill Country Allergy & Asthma is nothing short of amazing. They greet you with a smile and they actually remember my name; you are not just another face. They are patient and take the time to explain things even if you ask them the same questions every other time you are there. The technicians providing the shots are extremely careful and service is usually quick due to the check in system they utilize. They are well organized, with excellent customer service.”

Ditrell B.

“Whenever Julie is the one who gives me my shot, I almost look forward to getting the shot. Her sunny disposition brightens my day. I did say that it almost makes me want to get a shot!”

Bob B.

“I have been very pleased with the great care I have received from Dr. Mery, as well as his entire staff. They are all great!”

Cindy M.

“I look forward to getting my allergy shots every month. The office staff is so friendly and professional. It is a very nice and relaxed atmosphere too.”

Maria B.

“Dr. Mery saved me! I struggled for months with a skin reaction that three other doctors were unable to get under control.  It was clear from the onset that Dr. Mery is truly invested in his patients as he spent so much time with me trying to understand my situation and helped me tremendously with my condition.  Dr. Mery and his staff genuinely care for their patients!”

Krista H.

“My son saw Dr. Mery years ago for his bad allergies.  He was tested, started shots and has been on shots for a couple of years now.  We cannot begin to express our gratitude to HCAA for helping our family.  Our son is completely different kid – he can now play on sports teams and enjoy playing outside with his buddies!  THANK YOU DR. MERY!”

Sandy H.