Allergy testing is usually done at an allergist’s office. Typically, testing takes between 20 and 40 minutes, depending on the type of test being administered and the complexity of your condition. These tests generally detect immediate allergic reactions, which are those that develop within minutes of exposure to an allergen, and delayed allergic reactions, which may take several days to develop.   The most common allergy tests administered by allergy physicians are: • The skin prick test • Intradermal test • Blood test • Patch test • Food challenge test   Depending on the type of test administered, you may have your results the same day or within a couple of weeks. Talk to your allergist or primary physician about what type of allergy test is best for you.