This test, similar to ELISA, measures IgE antibodies that mediate most environmental allergies.
Other Blood Tests
Other lab testing methods, such as radioallergosorbent testing (RAST) or an immunoassay capture test (ImmunoCAP, UniCAP, or Pharmacia CAP), may be used to provide more information. Similar to the ELISA and EIA tests, these tests use laboratory methods to isolate antibodies and test them against known allergens for reaction.
Because skin testing is not particularly useful for food allergies and certain medications, an allergist might recommend a challenge test for these substances. To perform the test, a very small amount of a potential allergen is inhaled or ingested by the patient. It is critical that this type of test be supervised by a doctor in a medical setting where emergency procedures are in place, as even a small amount of a substance that is ingested or inhaled can cause anaphylactic shock and death in a highly susceptible patient.
Electrodermal Screening (EDS)
Although few clinical studies have been done to test the effectiveness of this method, it is widely used in Europe to screen for both food and environmental allergies, and to determine the proper remedy. In a couple of very small clinical trials done in the late 1990s, the test was 82% and 96% accurate, respectively, in differentiating between specific allergens and in discriminating between allergenic and non-allergenic substances, leading researchers to state that it is a reliable method for detecting allergy triggers. At this time, the FDA has not approved any device of this nature for marketing in the US, has warned several manufacturers to stop making false claims, and has disciplined some practitioners for their use and claims for this type of testing due to lack of clinical trials supporting the claims.
To perform this test, the doctor introduces a small current of electricity at specific acupuncture points on the patient. The doctor then introduces various allergens into the circuitry, enabling the physician to determine any change in the patient?s reaction to the current. In this type of testing, the circuitry is also used to deliver treatment doses when an allergy reaction is determined. The full battery of tests can be completed in one hour.