Which allergy testing option is right for you? Fifty million-plus Americans have allergy symptoms annually, according to the Asthma and Allergy Foundation of America (AAFA). If you think you're one of the millions of allergy sufferers, take a look at what you need to know about testing, diagnosis, and treatment.
Do Foods and Environmental Allergens Have the Same Tests?
Not all allergies are the same. But does that mean allergy tests are different for every possible allergen? If you have a suspected food allergy (such as a nut, gluten, soy, or shellfish allergy), the doctor may order an oral challenge test, a skin prick test, or an IgE antibody blood test, or they may ask you to try an elimination diet. People who may have environmental allergies (such as dust, pet dander, or pollen allergies) may need a skin prick test or an IgE blood test.
How Do Skin Prick Tests Work?
Each type of test will check for specific potential allergies. The medical provider will place a drop of the suspected allergen (either food or environmental) on your skin. They'll then prick or scratch the surface of your skin with a needle. Redness, itchiness, swelling, or another similar response means you may have an allergy to the substance.
The doctor may need to combine the results of this test with other information to make an accurate diagnosis. This could include a physical exam and a history of reactions around specific triggers.
How Do IgE Blood Tests Work?
Instead of applying a suspected allergen to your skin, the medical provider will take a sample of your blood for this type of test. The allergen isn't added until your sample reaches the lab. After your blood sample is mixed with the potential food or environmental trigger, the lab technician will look for and measure antibodies.
The presence and number of antibodies may mean you have an allergy. Like skin prick testing, the doctor may need additional information before making a diagnosis.
Which Test Is Better?
There's no universal answer to this question. A blood test can look for multiple allergens at the same time with only one sample. If you don't like the idea of multiple skin pricks, one blood draw is preferable.
Some medications may interfere with skin prick testing results. Along with your comfort level, you may need to choose a blood test if you take certain medications.
Whether you choose a skin prick or blood draw test, the doctor will use the results (and additional information) to create an allergy treatment plan. The treatment depends on several factors, such as your specific allergies, your ability to avoid triggers, and the severity of your reaction to the allergen.