Skin Tests
An allergy skin test may help diagnose the cause of the allergy. Skin tests are done on the arms or back using either the prick or intradermal method.
Prick Technique: In the prick technique, a drop of an allergy-producing substance (allergen) is applied to the skin, then the skin pricked.
Intradermal Technique: In the intradermal technique, a tiny amount of allergen is injected into the skin.
Skin tests are safe, and the results are available in 20 to 30 minutes. Antihistamine and antidepressant medications affect skin tests and must be stopped before tests are begun. Some antihistamines can interfere with allergy skin tests for weeks. Check with Dakota Allergy & Asthma about stopping medications.
Note: Skin tests for tobacco smoke allergy are not useful because tobacco smoke is an irritant, not an allergen.
Blood Allergy Tests
Allergies can also be diagnosed using a blood test. Examples include the radioallergosorbent test (RAST) or the ImmunoCap. They give information similar to the skin test, however, they are more expensive, may miss identifying some allergies, and also take longer to determine the results.
The blood test can be useful, however, when a skin test is not possible. For example, it can be used when a person has a skin disease which does not allow skin tests to be done, or when taking an antihistamine or other medication that might affect skin test results.
Both skin and blood allergy test results must be interpreted by a physician who is experienced in diagnosing and treating allergies and who is familiar with your medical history.
Step 4
After your testing, we will schedule a Summary Visit for you to review the test results, give you your diagnosis, and plan out your treatment course.
If you’d like, feel free to bring other family members involved in your care to this appointment. Together, you can learn more about your particular type of allergy and its specific treatment. We encourage you to write down questions before you come, and bring that list with you.