Your doctor may be able to diagnose your condition from your history, symptoms, and physical exam. However, allergy testing is also used to pinpoint allergy triggers. You need this information if you're going to take allergy shots to reduce your sensitivity to these triggers.
Who does them?
These tests are often performed by a board-certified allergist. This is an allergy specialist who has advanced training in diagnosing and treating allergies and who can handle the rare but potentially dangerous reaction called anaphylactic shock.
Are they safe?
The allergen extracts used in allergy tests are typically made of allergen proteins. Because they are made to the standards and requirements set by the US Food and Drug Administration, these products are safe.
Are they reliable?
Keep in mind that allergy testing isn't perfect. You may have a positive reaction to an allergen in a test but not be bothered by the substance in real life. Also, sometimes allergy tests fail to detect substances to which you are allergic. They do, however, give your allergist important clues to substances that are likely to be causing your symptoms.