There are many different types of allergy tests available that can be used to pinpoint different allergens. Each test serves a different purpose to identify the type of allergen and the severity of the reaction. The different tests that can be performed are: • Skin prick test. This is the most common test available, as well as the most cost-effective that is also incredibly accurate. The doctor performing the test will place a drop of a specific allergen onto the skin’s surface and then prick or scratch the skin where the drop was placed. If there is an allergic reaction, it will show within about 15 minutes. Multiple allergens can be tested at a time using this method. • Intradermal skin test. This test can be performed to identify drug or venom allergies or as a follow-up test to the skin prick test if the doctor wants to challenge a negative result. In this case, a small amount of an allergen is injected under the top layers of the skin, then monitored for any signs of a reaction. • Blood tests can be used to test for allergies in infants. A blood sample is taken from the patient and sent to a laboratory, where it is exposed to various allergens. The sample is then analysed for antibodies, with the presence and number of antibodies being the determinant of an allergy. • A physician-supervised challenge test can be performed in a closely monitored setting under the supervision of an allergist or doctor. This test involves the patient ingesting a small amount of the allergen, either a food or medication, through their mouth and then monitoring for a reaction. As anaphylaxis can be a form of a reaction with this type of test, it is imperative that the doctor is readily available to administer emergency treatment, should it be needed. • A patch test is like a skin prick test in that an allergen is placed directly onto the skin. In this case, the spot is covered over with a patch and checked after 2 to 4 days for any signs of an allergy.