Allergy Testing and Treatment


Skin Testing For Allergies

Testing vialsSkin testing for allergies is used to identify the substances that are causing your allergy symptoms. It is often performed by applying an extract of an allergen to your skin, scratching or pricking the skin to allow exposure. It may also be done by injection the allergen under the skin. During skin tests, your skin is exposed to suspected allergy-causing substances (allergens) and is then observed for signs of an allergic reaction.

Skin testing can be used for people of all ages. Sometimes, however, skin tests aren’t recommended. Your doctor may advise against skin testing if you:

  • Have ever had a severe allergic reaction. You may be so sensitive to certain substances that even the tiny amounts used in skin tests could trigger a life-threatening reaction (anaphylaxis).
  • Take medication that could interfere with test results. These include antihistamines, many antidepressants and some heartburn medications. Your doctor may determine that it’s better for you to continue taking these medications than to temporarily discontinue them in preparation for a skin test.
  • Have a widespread skin reaction. If severe eczema or psoriasis affects large areas of skin on your arms and back – the usual testing sites – there may not be enough clear, uninvolved skin to do an effective test.

Blood tests (in vitro IgE antibody tests) can be useful for those who shouldn’t undergo skin tests. However these can be more expensive.

Allergy Testing, Treatment and Risks


Prick Testing

Prick 3In this test a device with several sharp prongs is dipped in a liquid with a specific allergen in it. The prongs are then pushed into the skin on the back to introduce the substance just into the surface layer of the skin. This allows the doctor to know what a patient is allergic to, but not necessarily how strongly they react. This test is usually done to identify allergies to pollen, mold, pet dander and dust mites. It checks for immediate allergic reactions to as many as 40 different substances at once. The skin prick is not a shot and doesn’t cause bleeding.

About 20 minutes after the skin pricks, the nurse observes your skin for signs of allergic reactions. If you are allergic to one of the substances tested, you’ll develop a raised, red, itchy bump (wheal) that may look like a mosquito bite. A nurse will then measure the bump’s size.

Intradermal Testing

Prick 2The most frequently used, and most accurate, method of allergy testing is intradermal skin testing. This involves our nurse placing small amounts of many common allergens underneath the skin. This allows us to determine what allergens affect a patient and to what degree.

The allergen placement part of the test takes about 5 to 10 minutes. Then you will have to wait about 15 minutes to see how your skin reacts.

Rast Testing

The second form of testing that we use when skin testing is not possible is a blood test called RAST. This checks the blood for immune molecules that react to certain allergens and allows us to indirectly gauge a patient’s response to those substances.

Results

IntradermalBefore you leave your doctor’s office, you’ll know the results of your skin testing.

A positive skin test means that you may be allergic to a particular substance. Bigger wheals usually indicate a greater degree of sensitivity. A negative skin test means that you probably aren’t allergic to a particular allergen.

Treatment

Once a patient’s allergic disease has been defined, the patient is then ready to begin immunotherapy, commonly referred to as allergy shots. This is a series of injections that, over time, will lead the body to stop overreacting to harmless stimuli and thus stop the annoying and debilitating symptoms of allergic disease.

Risks

Positive resultsThe most common side effect of skin testing is slightly swollen, red, itchy bumps (wheals). These wheals may be most noticeable during the test. They usually go away within a few hours, although they can persist for a few days - even up to a week. A mild cortisone cream can help ease the itching and redness. Systemic (whole body) reactions to skin testing are extremely rare.

Rarely, allergy skin tests can produce a severe, immediate allergic reaction, so it’s important to have skin tests performed at an office where appropriate emergency equipment and medications are available. If you develop a severe allergic reaction in the days after a skin test, call your doctor right away.

What Happens After the Allergy Skin Test?

After the allergy skin test, any extracts will be cleaned off your skin with alcohol. A mild cortisone cream may be applied to your skin to relieve any excessive itching at the sites of the skin pricks.

Your doctor will use the results of the test to help develop a management plan for you.

Does An Allergy Skin Test Hurt?

The allergy skin test may be mildly irritating, but most people say it doesn’t hurt too much.

When Should I Call My Doctor?

If you’re having an allergy skin test, call your doctor or emergency number immediately if you experience any of the following symtoms:

  • Fever
  • Lightheadedness
  • Wheezing
  • Shortness of breath
  • Extensive rash
  • Swelling of the face, lips or mouth
  • Difficulty swallowing

How Long Does an Allergy Skin Test Take?

If you’re having an allergy skin test, plan to spend about an hour for the entire appointment.

How Should I Prepare for an Allergy Skin Test?

Complete instructions are presented on our Allergy Instructions page.

Inform the health care provider who is going to perform your allergy skin test about all medicines you are taking, including over-the-counter drugs.

Since allergy medicines (including over-the-counter antihistamines) stop allergic reactions, you should not take them up to a week before the test. Talk to your doctor about discontinuing your allergy medicines prior to the test.

Allergy Shots

Allergy shots help your body get used to allergens, the things that tirgger an allergic reaction. They don’t cure allergies, but eventually your symptoms will get better and you may not have allergic reactions as often. Allergy shots, also called “immunotherapy,” may work for you if allergy medicines don’t work well.

How Often Do You Get Allergy Shots?

At first, you’ll go to your doctor once a week for several months. You’ll get the shot in your upper arm. It will contain a tiny amount of the things your allergic to – pollen, pet dander, mold and dust mites for example.

The dose will go up gradually until you get to what’s called a maintenance dose. After that, you’ll usually get a shot every 2 weeks for months. Then your doctor will gradually increase the time between shots until you’re getting them about once a month for 3-5 years. During that time, your allergy symptoms will get better and may even go away.

How Should I Prepare for Allergy Shots?

You will need to avoid exercise or doing anything strenuous for two hours before and after your appointment. That’s because exercise may increase blood flow to the tissues and cause the allergens to get into your blood faster. It’s not likely to cause a serious problem, but it’s best to be safe.

Tell your doctor about any other medicines or herbs and supplements you are taking. Some medications interfere with the treatment or increase your risk of side effects. You may need to stop allergy shots if you are taking these medications.

If you’re pregnant or planning to get pregnant, ask you doctor whether you should continue to get allergy shots.

What Should I Expect After Allergy Shots?

Both The American Academy of Otolaryngic Allergy (AAOA) and The American Academy of Allergy, Asthma, and Immunology (AAAAI) recommend that a patient receiving allergy injections wait in the doctor’s office for at least 30 minutes after receiving the allergy injection. Tucson ENT follows these guidelines.

Usually, you’ll stay at the doctor’s office for about 30 minutes after receiving an allergy shot to make sure that you don’t develop side effects like itchy eyes, shortness of breath, runny nose or tight throat. If you get these symptoms after you leave, go back to your doctor’s office or go to the nearest emergency room.

Redness, swelling, or irritation right around the site of the injection is normal. These symptoms should go away in 4 to 8 hours.

Do Allergy Shots Work for All Allergies?

A lot depends on how many things you are allergic to and how severe your symptoms are. Generally, allergy shots work for allergies to dust mites, mold, pollen and pet dander.

When Should I Call My Doctor?

Call your doctor and go to the nearest emergency room if you develop shortness of breath, tight throat, or any other symptoms that worry you after getting your shot.

Do I Have to Get a Shot?

Some offices offer drops under the tongue instead of shots. It’s called oral or sublingual immunotherapy (SLIT). Like allergy shots, it exposes your body to an allergen, so you can gradually get used to it. You can do it at home.

Who Should Not Get Allergy Shots?

They may be more risky for people with heart or lung disease, or who take certain medications. Be sure to tell your doctor about your health and any medications you take, so you can decide if allergy shots are right for you.