Allergic Asthma Tests
Depending on whether or not you’re already diagnosed with asthma, your doctor may take one or more steps to determine if you have allergic asthma. These include:
- Reviewing the medical history of your asthma symptoms and overall health (including the health of family members)
- Giving you a physical exam that may include examining your ears, eyes, nose, throat, chest, and upper airways (as well as a possible lung X-ray)
- Asking you to perform one or more lung function tests that measure how fast you can force air out of your lungs (“peak airflow” and “spirometry”) and the amount of air you can inhale and exhale (“spirometry”)
After completing these steps and talking to you about your symptoms and triggers, your doctor may begin to suspect allergic asthma. Still, diagnosing allergic asthma can be a challenge. To confirm allergic asthma, an IgE test may be needed. It can be ordered by a primary care doctor or a specialist.
About the IgE Test
An IgE test measures the levels of IgE in your blood. IgE, or immunoglobulin E, is a type of antibody that plays an important role in how your body responds to allergens. For people with allergic asthma, allergen triggers may cause levels of IgE to increase. To find out which specific triggers your body reacts to, a blood test or skin test can be done. This is called “allergen-specific” IgE testing.
Blood tests measure allergen specific IgE in your blood. Specific allergens may include dust mites, pet dander, or cockroaches. If high amounts of IgE are present in lab results, this may mean you have allergic asthma.
If your body has an allergic response to an allergen introduced to your skin, a reaction occurs. Redness, itching, and swelling may be observed at the site after about 15 minutes. Skin tests are done by a health care professional
- With the “prick” or “scratch” test, allergens are pricked or scratched into your skin’s surface
- Another form of skin test is done with an injection of an allergen just below the surface of the skin on your arm