The Immunoglobulin E (IgE) test measures your immune system's underlying reactivity to certain allergens. It is a widely-accepted allergy diagnostics method used by clinicians in the U.S. and Europe. No allergy test, however, is a 100% diagnosis of your allergies. Diagnosis of an allergy is done by our clinicians during a consultation, after reviewing your allergy and medical history, as well as, your test results.