When you have an allergy, your immune system overreacts to a substance (allergen) to which you are exposed. Allergy testing can provide useful information which an allergist can then use to treat your symptoms.

Medications affect each of us in different ways, and reactions to drugs are very common. However, not all reactions are allergies. This is important because the type of reaction you are having (an allergy, a side effect, or intolerance) will determine what medications you can take in the future.

Penicillin is one of the most commonly reported drug allergies. However, at least 80% of people who were penicillin allergic will no longer be allergic 10 years after the reaction. In fact, 95% of people labeled allergic turn out to have negative testing and can take penicillin again without problems. Simply avoiding penicillin anyway may sound simple, but there are risks: