Diagnosing an allergy does not usually require allergy testing. A physical exam and careful medical history are sufficient. Based on that information, a health care professional can usually suggest some strategies to reduce your exposure to likely allergy triggers, as well as medication to try. An allergy diagnosis is often confirmed if you feel better after using allergy medications.

Allergy testing is helpful when the diagnosis is not clear or when you and your health care professional have trouble identifying your allergens. A visit to an allergy specialist may also be helpful if your symptoms are hard to control, if you and your doctor are considering allergy shots (immunotherapy), or if medication side effects make your allergies difficult to treat.

An allergy specialist can perform allergy testing if it is needed. Allergy tests may speed the identification of your most likely allergy triggers. However, an allergy specialist needs to interpret the test results along with your experience after exposure to allergens in real life, because allergy tests may have falsely positive or falsely negative results. In other words, you may have a positive test result for substances that you do not think you react to or you may have a negative result for substances that definitely make your symptoms worse. Positive test results that go along with your history can help identify and justify aggressive interventions to eliminate allergens in your environment, such as removing wall-to-wall carpeting to eliminate mold. They can also help you decide whether allergy shots (immunotherapy) would be right for you, and to provide a “recipe” for the doctor who prepares the injections for you.