You might be allergic to penicillin; then again, you might not

Many people have been told, incorrectly, that they're allergic to penicillin, but have not had allergy testing. These people are often given alternative antibiotics prior to surgery to ward off infection. But when antibiotic choices are limited due to resistance, treatment alternatives may be more toxic, more expensive and less effective.

According to two studies presented at the American College of Allergy, Asthma and Immunology (ACAAI) Annual Scientific Meeting, people who believe they have a penicillin allergy would benefit from consultation from an allergist and penicillin allergy skin testing.

Once they know if they are allergic, they can be given appropriate -- and not more resistant -- treatment prior to surgery. Of the 384 people in the first study who believed they were allergic to penicillin, 94 percent tested negative for penicillin allergy.

"A large number of people in our study who had a history of penicillin allergy were actually not allergic," said allergist and ACAAI member Thanai Pongdee, MD, lead study author.

"They may have had an unfavorable response to penicillin at some point in the past, such as hives or swelling, but they did not demonstrate any evidence of penicillin allergy at the current time. With that in mind, their doctors prescribed different medications prior to surgery."

In the second study, 38 people who believed they were allergic to penicillin were given penicillin skin testing to see if it was possible to help reduce the use of high-cost antibiotics. Of the 38 people tested, all of them tested negative to an allergy for penicillin.

Once it was known they weren't allergic to penicillin, the medical center was able to change the medications of 29 of the patients, thereby significantly lowering prescription costs.

"When you are told you have an allergy to something, it's important to be seen and tested by an allergist, who has the specialized training needed for accurate diagnosis and treatment," said allergist James Sublett, ACAAI president-elect. "If you're truly allergic to a medication, your allergist will counsel you on an appropriate substitute.