• Different Uses of Allergy Testing

    Allergy testing is a very common procedure performed to detect the specific substance/s to which an individual is allergic. Some of the conventional methods that are used for allergy testing are:

    • Skin tests
    • Elimination-type test
    • Blood tests (including the radioallergosorbent, or RAST, test)

    An allergy test is useful for diagnosing food allergy; penicillin allergy; venom allergy; allergic contact dermatitis; and mold, pollen, animal, and other allergens that can cause allergic rhinitis and asthma. In some cases, an individual may test “allergic” to a certain food and yet no symptoms appear when s/he eats that food. There are also people who would show allergic reactions in just 1 to 2 hours after exposure to certain allergens, such as dairy or shellfish.

    Sources of allergens can be categorized by food and non-food. Top food allergens include dairy, eggs, fish, shellfish, peanuts, tree nuts, wheat, soy, and sesame. Some examples of the popular food allergy testing that are done today are egg allergy, wheat allergy, tree nut allergy, peanut allergy, gluten allergy. On the other hand, non-food allergens may range from pollen to mold to animal dander.

    Skin test can be done in the form of skin prick test, intradermal test, and skin patch test. The blood test can be in the form of enzyme-linked immunosorbent assay (ELISA, EIA), radioallergosorbent testing (RAST), or immunoassay capture test (ImmunoCAP, UniCAP, or Pharmacia CAP). Skin test results are usually seen within 15 to 20 minutes, whereas, blood allergy tests result may take a few days to 1 or 2 weeks.

    The allergy tests listed below are examples of lab-based blood tests that allergists may recommend and perform to determine the specific substances that cause an allergic reaction in a person. Hypersensitivity to the following allergens is assessed using a qualitative allergen specific IgE test.

    Food Allergy Test

    Non-Food Allergy Test

    • Avocado Allergen
    • Egg White Allergen
    • Milk Allergen
    • Peanut Allergen
    • Shrimp Allergen
    • Sesame Allergen
    • Gluten Allergen
    • Chestnut Allergen
    • Bahia Grass Allergen
    • Olive Tree Allergen
    • Ash Tree Allergen
    • Oak Tree Allergen
    • Japanese Cedar Allergen
    • Honeybee Allergen
    • Hymenoptera Allergy (Bee Sting) Panel
    • False Ragweed Allergen
    • Cocksfoot Weed Allergen
    • Rough Marshelder Allergen
    • Dermatophagoides farinae Allergen
    • Stachybotrys chartarum (mold) Allergen
    • Penicillin G & V Allergens
    • Penicillin G Allergen
    • Allergy Region 1 Respiratory Panel (CT, MA, NJ, PA, VT, ME, NH, NY, RI)
    • Allergy Region 13 Respiratory Panel (So. Coastal CA)
    • Allergy Region 3 Respiratory Panel (GA, SC, N. FL)
    • Allergy Region 5 Respiratory Panel (IN, OH, WV, KY, TN)
    • Allergy Region 7 Respiratory Panel (MI, MN, WI)
    • Allergy Region 8 Respiratory Panel (IL, MO, IA)

    Reason for Performing Blood Allergy Test
    A doctor may prescribe blood allergy test if:

    1. The person is taking a medicine that cannot be stopped for a few days and can interfere with skin testing.
    2. The person suffers from a severe skin condition, such as eczema or psoriasis.
    3. Testing with a strong allergen might cause severe allergic reaction.
    4. For babies and very young children (a single needle stick for allergy blood testing may be better than several skin tests)
    5. The person has had positive skin tests to many foods. Enzyme-linked immunosorbent assay (ELISA) can find out the foods that a person is most allergic to.

    Pros and Cons of Blood Allergy Test

    When done properly, the blood allergy test is reliable and useful in diagnosing and managing certain types of allergies. It measures the amount of allergic antibody to the food or other allergens. Unlike skin test, blood allergy test is less sensitive that’s why it is usually recommended to people with sensitive skin or skin problems. Furthermore, it does not cause allergic reaction (except perhaps a small bruise that may develop at the punctured area), as well as not affected by medications such as antihistamines or tricyclic antidepressants.

    Meanwhile, for people with low tolerance on needle prick, a blood allergy test may experience a bit of discomfort. The person may feel a brief sting or pinch when the needle penetrates the skin. Another drawback of the lab-based blood allergy test is that the result may take a few days or even one to two weeks.


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