Your skin is exposed to suspected allergy-causing substances (allergens) during allergy skin testing, and indicators of an allergic reaction are subsequently examined. Allergy testing, in combination with your medical history, may be able to determine whether a material you touch, breathe, or ingest is causing symptoms.
Allergy testing in Sydney comprises a blood test or a skin test in the evaluation.
Your body’s natural defence system is the immune system. Allergies develop when your immune system overreacts to anything in your surroundings. Pollen, for example, which is usually harmless, may cause the immune system to overreact. These allergic reactions may result in a runny nose, sneezing, sinus congestion, itchy, watery eyes, coughing, or wheezing.
Different types of allergens:
Allergens are chemicals that have the potential to trigger allergic responses. Allergens are classified into three kinds.
- When allergens are inhaled, they influence the body by coming into touch with the lungs, nose, and inside walls of the throat. Pollen is the most frequent allergen breathed.
- Certain foods, such as peanuts, soybeans, and shellfish, have allergies that can be consumed.
- In order for the response to occur, contact allergens must come into touch with the skin. The rash and itching induced by poison ivy is an example of a response to a contact allergen.
Allergy testing is exposing you to a very tiny quantity of a specific allergen and documents your reaction.
Types Of Allergy Tests And What To Expect
Skin Testing
This is used to assess potential environmental or seasonal allergies, food allergies, stinging insect allergies, and drug/medication allergies. The suspected allergen is applied to the skin during skin testing, and the findings are read after 15 minutes. Skin testing is done in two ways: skin prick test and intradermal skin testing.
Prick skin testing: Using a prick instrument, individual solutions containing the probable allergens are applied to the skin.
Intradermal skin testing: Using a tiny needle, individual solutions containing the suspected allergens are put just beneath the skin’s surface.
The results of both these tests are accessible 15 minutes later.
To get ready for the skin testing: 5 days before your appointment, avoid any antihistamines and sleep aids containing antihistamines. The reason for this is that antihistamines will interfere with positive skin test findings, rendering them inaccurate.
Blood Testing
In addition to skin testing, certain individuals may require allergen-specific IgE tests (also known as RAST) to complete their allergy examination. In some cases where allergy skin testing is not acceptable, specific IgE tests can be acquired. Such circumstances include:
- Patients who are unable to discontinue antihistamines or certain other medications that may affect skin test results.
- Patients who have dermatographism (in which scratching the skin causes hives).
- Patients who have skin rashes/lesions that prevent us from accurately reading skin test results.
Blood tests are also used to diagnose the immune system and allergy symptoms such as angioedema (swelling episodes), chronic urticaria (hives), and primary immunodeficiency diseases.
Your allergist will assess if you need blood tests, and the results of these tests will be evaluated by your allergist while taking your medical history and other findings from your evaluation into account.
Food allergies test:
This is done on a small number of people to confirm a food allergy or to see whether they can tolerate a food that they are presently avoiding. The patient is given incremental dosages of the meal, beginning with a very little amount. Each dosage is followed by a time of observation and assessment before the next dose is administered. Following the final dose, the patient is subjected to an extended observation period and final evaluation. All food challenges are undertaken under physician supervision due to the danger of developing an adverse reaction.
What are the risks of having allergy tests?
Mild itching, redness, and swelling of the skin may occur during allergy testing. Wheals, which are tiny lumps on the skin, might emerge at times.
These symptoms usually go away within a few hours, although they might continue for a few days. These symptoms can be relieved by using mild topical steroid creams.
Rarely, allergy tests cause an instant, severe allergic reaction that needs medical treatment. As a result, allergy testing should be performed in a doctor’s office with proper drugs and equipment, including epinephrine to treat anaphylaxis, a potentially fatal acute allergic reaction.
If you have a severe response shortly after leaving the doctor’s office, call your doctor straight away.
How to prepare for an allergy test
Before an allergy test, your doctor will ask you about your lifestyle, family history, and more.
They will tell you to stop taking the next drug before your allergy test because they can affect test results:
- Prescription and over-the-counter antihistamines
- Certain medications used to treat heartburn, such as famotidine (Pepcid)
- Benzodiazepines such as diazepam (Barium) or lorazepam (Atiban)
- Tricyclic antidepressants such as amitriptyline (Elavil)
- Systemic corticosteroids (if you are doing a patch test)
Next step after allergy test:
Once your doctor has discovered which allergens are causing your symptoms, you and your doctor can collaborate to devise a strategy for avoiding and managing them. Your doctor may also recommend drugs to alleviate your symptoms.
