Penicillins are widely used antibiotics that have important roles in treating bacterial infections. The label of penicillin allergy is commonly attached in childhood where common childhood infections may themselves contribute to or be confused with allergy. In addition, even in those with true allergy, over 90% will lose this tendency over a 10 year period. Consequently, although approximately 10% of the population is labeled as being allergic to penicillin, over 90% of these individuals actually are negative on allergy testing and can tolerate penicillin. Overall penicillins are the safest and most effective antibiotics for many infections, and therefore it is important to find out if a patient is really penicillin allergic.

From AAAAI