How to Test Different Types of Allergy
Allergy tests are tests conducted by an allergist specialist to determine whether your body has an allergic reaction to a known substance. The test can be a blood test, skin test, or food elimination.
Allergies occur when your immune system overreacts to something in your environment. For example, pollen, which is usually harmless, can cause your body to overreact. The body's excessive reaction to substances that can cause symptoms such as colds, sneezing, sinus blockages, and watery eyes.
Types of allergens
There are three types of allergens (substances that can cause allergic reactions):
- Inhaled allergens: These allergens affect the body when they come in contact with the lungs or the lining of the nose. Pollen is the most common inhalation allergen.
- Ingested allergens: These allergens are present in certain foods such as peanuts, soybeans, and gluten.
- Skin allergens: These allergens come in contact with your skin to produce reactions, such as rashes and itching caused by poison ivy.
Allergy testing involves giving a person's exposure to a very small amount of a particular allergen and seeing the reaction that occurs.
Why allergy testing is done
The World Allergy Organization estimates that allergies are responsible for 250,000 deaths annually (WAO).
Allergy tests are performed to determine whether certain pollen, fungus, or other allergens are causing a person to be allergic. You might need medication to treat your allergies or you might just try to avoid triggering your allergies.
How to prepare for allergy testing
Before your allergy test, your doctor will ask about your lifestyle, family history, and more.
You will most likely be told to stop taking the following medication before your allergy test because the drug can affect the results of the test:
- Antihistamines (both prescription drugs and drugs on the market)
- Certain heartburn medications
- Omalizumab (Xolair) (asthma medication)
- Antidepressant tricyclic
How allergy testing is carried out
Allergy testing may be done with a skin test or blood test. In cases of suspected food allergies, you can eliminate the diet.
Skin test
Skin tests are used to identify various potential allergens. This includes airborne allergens, food and contact allergens.
Your doctor will usually try the initial test first. During this test, allergens are placed on the part of your skin. A technician uses a special tool to scratch the surface of the skin. You will be watched closely to see how your skin reacts to foreign substances. If there is no swelling or redness of the skin, you are not allergic to the allergen.
If the initial test is not conclusive, your doctor may order an intradermal skin test. This test is done by injecting a small amount of allergen into your skin. Once again, the doctor will monitor your reaction.
Another form of allergic skin test is the patch test. This test is carried out using an adhesive patch that is affixed with a suspected allergen. The patch will remain on your body after you leave your doctor's office. The patch is then examined 24 hours after application and again at 48 hours if needed.
Blood test
In the case of a severe allergic reaction, the doctor can determine that the skin test will not be effective. Therefore, he can choose to take a sample of your blood. The blood is then tested in a laboratory to check for antibodies against certain allergens. This test, called ImmunoCAP, is very successful in detecting antibodies to major allergens.
Food elimination
Food elimination can help your doctor determine the foods that cause you to have an allergic reaction. This method requires someone to avoid food from his diet and then consume them again. Your reaction will help determine the foods that cause allergies.
Risk of allergy testing
Allergy tests can cause mild itching, redness, or swelling of the skin. Occasionally, small lumps called patches to appear on the skin. These symptoms often disappear within a few hours, but can last for several days. Mild cortisone cream can relieve these symptoms.
In rare cases, allergy tests cause an immediate allergic reaction that requires medical attention. In anticipation of such reactions, allergy tests must be carried out in clinics that are equipped with adequate drugs and equipment. This includes epinephrine to treat anaphylaxis (a life-threatening allergic reaction).
If you experience a severe reaction after you leave the doctor's office, contact your doctor immediately. If you experience symptoms of anaphylaxis - such as swelling of the throat, difficulty breathing, or low blood pressure, rush to the hospital immediately because this is a medical emergency.
After testing for allergies
After your doctor determines the allergens that cause your symptoms, he will instruct you on how to avoid allergens. Your doctor can also suggest drugs that can relieve your symptoms.
