ALLERGY DIAGNOSTIC TESTING AND THERAPY

Allergies have become a common medical issue in today’s world. A lot of people are struggling with allergy symptoms without knowing what they are actually allergic to and how to properly deal with the symptoms. 

The usual allergic reactions include watery eyes, hay fever, skin eczema or rashes and respiratory problems. These symptoms are actually the body’s defense mechanism against allergens or environmental substances. The symptoms can be mild or severe – all depending on how the body reacts to these usually harmless substances.

Allergy testing is beneficial because it can help people identify allergens that cause health issues. There are numerous allergens that people can react to like pet dander, mold, certain food, bee sting, pollen, latex, and others. When people are allergic to food, they usually can’t tolerate milk, soy or peanuts. 

Therefore, during allergy testing, a dermatologist introduces different allergens into the patient’s skin through skin pricking. If the patient reacts with a wheal/raised mark or rash, the dermatologist can determine to which allergens that patient is allergic. There are also blood tests that check IgE antibodies or skin patch test. Once the patient gets the results of the tests, they can find the best way to deal with allergies.

WHY ARE ALLERGY TESTS PERFORMED?

A dermatologist performs an allergy test to see if the patient’s immune system overreacts to some allergens. If there is an allergic reaction, the patient has an allergy. Often, a dermatologist will suggest an allergy test, if the patient has asthma – the test can show which allergens can make asthma symptoms worse or cause an asthma attack.

The patient also needs an allergy test if they’ve had an anaphylaxis or a major allergic reaction. The patient’s medical history together with an allergy test can determine the cause of this serious reaction.

If the patient is allergic to dust, pet dander, pollen or other air allergens, they might develop allergic rhinitis or hay fever. The symptoms include headache, watery and itchy eyes, sore throat, sneezing, runny nose or nasal congestion, wheezing, cough or shortness of breath.

In the case of food allergies, the symptoms generally happen 30 minutes after food ingestion or up to 2 hours. The symptoms will be swelling of the lips, tongue or face, itching and hives, respiratory symptoms like shortness of breath, coughing, wheezing or throat tightness, GI symptoms like cramps, abdominal pain, vomiting, nausea or diarrhea and cardiovascular symptoms like weak pulse, pale skin or dizziness.

If the patient is allergic to latex or metals like nickel, they may develop contact dermatitis or other symptoms like hives and swelling, blisters, rash and itchiness or burning sensation on the skin. These allergic reactions are determined with the use of a patch test.

WHAT ARE THE DIFFERENT TYPES OF ALLERGY TESTS?

Allergy tests are performed to determine which allergens or allergy triggers cause the body to overreact to them. The tests identify if the patient’s immune system produces antibodies called immunoglobulin E or IgE. These antibodies are also known as proteins whose chemicals trigger allergic reactions.

There are different ways to perform allergy tests. The dermatologist chooses the most effective test based on the patient’s allergy symptoms. 

Patch test – this test can identify the cause of contact dermatitis. The dermatologist introduces droplets of various allergens onto the patient’s arm and puts a bandage over the droplets. Or the dermatologist can place a bandage that is already filled with allergens. The patient keeps the bandage for up to 96 hours when the dermatologist removes the bandage to identify if the patient’s skin has developed a rash or other symptoms of applied allergens.

Blood/IgE test – If this test is necessary for identifying allergies, the patient needs to get a blood sample tested in the laboratory. The allergens are introduced into the patient’s blood sample and levels of IgE antibodies are then measured. Sometimes, blood allergy tests can show falsely positive or negative results. 

WHAT ARE THE BENEFITS OF ALLERGY TESTING?

Allergic reactions vary from mild like nasal congestion to severe like anaphylactic shock. Therefore getting a proper allergy test can make the patient’s life much easier. 

There are many benefits of allergic testing.

Allergy test show allergens that trigger allergic reactions so the patient can treat and control those reactions properly. Some treatments include changing diet or avoiding other allergens.

For example, the patient can change his/her diet by avoiding the whole food group that triggers allergic symptoms. The patient can still have a nutritious diet with the rest of the food groups.

After allergy tests, the patient knows which allergens cause his/her allergy reactions and can avoid them. For example, if the patient finds out that they are allergic to animal dander, they may change their mind about having a pet.

When the patient discovers that they are allergic to environmental and air allergens, they can take the medications only when these allergens are high in the air and not all the time. For example, if the patient is allergic to pollen, extensive exposure to it should be avoided in the summer when this allergen is the highest. Also, grass pollen is the major allergen that causes hay fever. Or if the patient is allergic to tree pollen, exposure to it should be avoided in the spring when this allergen is the highest in the count.

Overall, the biggest benefit of getting an allergy test is preventing the risk of developing severe allergic reactions. 

WHAT DIFFERENT TYPES OF ALLERGY TESTS EXIST?

Allergy tests are done to measure the patient’s body reactions to different allergens or allergy triggers. They show if the patient’s immune system overreacts and produces antibodies known as immunoglobulin E or IgE. These antibodies or also called proteins release the chemicals that trigger allergic reactions.

Allergies can be tested in different ways. The dermatologist determines which test is the best according to the patient’s symptoms and possible allergens.

Intradermal skin test

This allergy test is done if the skin prick test results are inconclusive or negative. The dermatologist injects a tiny amount of allergens into the patient’s epidermis or top layer of the skin. This way, the dermatologist can determine if the patient is allergic to insect stings, some medications or airborne allergens.

Patch test

This allergy test is performed to determine the origin of contact dermatitis. The dermatologist administers drops of allergen onto the patient’s skin on the arm and places the bandage over the treated area. Or the dermatologist applies a bandage that already has allergens on it. The patient needs to keep the bandage on the skin for up to 48 hours. After that, the dermatologist takes off the bandage to see if the patient’s skin has a rash or other reactions to applied allergens.

Blood/IgE test

For this allergy test, the dermatologist sends a sample of the patient’s blood to a laboratory. The allergens are added to the blood sample and levels of IgE antibodies are measured. In some cases, blood allergy tests can be falsely positive or negative.

WHY ARE ALLERGY TESTS BENEFICIAL?

Allergic reactions can be mild like congestion but also severe like anaphylactic shock. The dermatologist can choose the most suitable allergy test for each patient.

The benefits of allergic tests are numerous.

They can help the patient find a proper treatment solution because allergy tests can show the precise allergens that cause allergic reactions. The patient can change his/her diet or avoid environmental agents that cause his/her allergies and improve his/her quality of life.

Changing diet usually means avoiding the entire food groups that can trigger an allergic reaction. But this doesn’t mean that the patient can’t keep a nutrition diet with other food groups.

Once the patient knows what he/she is allergic to, he/she can avoid situations that can trigger these reactions. For instance, if the patient is allergic to animal dander he/she may reconsider the idea of having a pet.

When the patient is allergic to environmental allergens, he/she can only take medications periodically when these allergens are high in count. For example, pollen is high in the summer and grass pollen is the biggest cause of hay fever. On the other hand, tree pollen is the highest in the spring.

The most important benefit of an allergic test is that the patient can prevent the risks of serious allergic reactions.

FREQUENT QUESTIONS

  • WHAT DOES AN ALLERGY TEST INCLUDE?

    Prior to having an allergy test, the patient needs to have a consultation with the dermatologist. In order to carefully diagnose an allergy problem and recommend proper treatment, the dermatologist needs to get a detailed evaluation of symptoms that can indicate that the patient has an allergy.

    Also, 3 to 7 days before the patient can undergo an allergy test, they need to stop taking allergy medications such as antihistamines because they can corrupt the test results. Antihistamines stop the immune system from responding to allergens. The patient can continue to take medications for asthma.

    During the consultation, the patient talks about their daily habits or they have a diary with written reactions to any allergens. This can help the patient to answer all the questions about their reactions to certain food or environmental agents. For example, the patient can share the usual food allergies they have from personal experience. Keeping an accurate food diary can help with the elimination of certain food that the patient is not allergic to.

  • WHAT TO EXPECT WHILE GETTING AN ALLERGY TEST?

    The dermatologist will find out how the patient’s body reacts to allergens according to an allergy test. If the patient has an allergic reaction, they develop a mild reaction at the site where the allergen was introduced. They can get itchy skin, red skin, congestion or watery eyes. Most of the reactions will disappear after 2 hours.
    An allergy test can be positive or negative.

    If it is negative that means that the patient is not allergic to the introduced allergens. In some rare cases, the test can be a false negative which means that the patient doesn’t have an allergy when they actually do
    .
    If it is positive it means that the patient is allergic to the allergen.

  • ARE THERE ANY RISKS OF GETTING AN ALLERGY TEST?

    There aren’t any special risks of getting an allergy test, except a rare one called an anaphylactic reaction. However, the dermatologist will offer emergency care in case of this serious reaction.

  • HOW CAN THE PATIENT TREAT HIS/HER ALLERGIES?

    It all depends on the type of allergy that the patient has. The dermatologist can interpret the results of the allergy test and recommend proper treatment.

    The treatment may include:

    - Minimizing exposure to allergens that cause the allergy, especially if the allergens are certain food.

    - Taking allergy medications regularly, especially antihistamines because they can minimize allergic rhinitis.

    - Getting allergy shots because this immunotherapy can lower the reaction of the immune system to some allergens. Allergy shots provide long-term results.