Allergens are substances that are typically harmless but that the immune system mistakes for a dangerous intruder. To fight this intruder, the immune system releases antibodies called Immunoglobulin E (IgE), which causes your cells to release histamine. Histamine increases mucus production and triggers inflammation, resulting in your allergy symptoms.
An allergy test can identify what exactly you’re allergic to so you can more easily manage symptoms.
Types of Allergy Tests
There are two types of allergy tests: skin testing and blood testing.
Skin tests are the gold standard for identifying triggering allergens. There are two ways a skin test can be administered: the skin prick method and the intradermal method.
The skin prick method entails placing a drop of an allergen extract onto the skin and pricking the area underneath, while the intradermal method involves injecting a diluted allergen extract into the top layer of skin.
If you’re allergic to the particular substance, a red raised bump resembling a mosquito bite, known as a wheal, will appear.
The wheal is then compared to a positive control, usually histamine, and a negative control, usually saline.
Blood tests are typically reserved only for testing for food allergies, as they measure the amount of allergic antibodies to various substances.
The enzyme-linked immunosorbent assays (ELISA) test has come to be preferred over the radioallergosorbent testing (RAST) in many cases.
Blood tests are higher in cost, the results take days to weeks and there is a greater risk of false-negatives and false-positives, which makes skin testing preferable to blood testing in most cases.
Are Allergy Tests Safe?
Allergy tests are extremely safe, as they are performed by allergists in medical clinics. This means that in the extremely rare case that anaphylaxis occurs, the medical team can respond promptly. Allergy tests are safe even for young children and infants.
Some people cannot undergo a skin test, including those who cannot stop their antihistamine medications, have extremely sensitive skin, take beta blockers or have serious heart or lung conditions. In these cases, blood testing is the preferred method.
The main risks blood testing poses are related to drawing blood, like fainting. For more information about blood testing or to schedule an appointment with an allergy expert, call Charleston ENT & Allergy today.