Are You Really Allergic to Penicillin?

By Jane Farrell

A new study shows many physicians who treat patients with “penicillin allergy” listed in their charts may not fully understand important facts about penicillin allergy. They may not be aware penicillin allergy can resolve over time and they don’t fully understand the importance of allergy testing to make sure a penicillin allergy currently exists.

The study in Annals of Allergy, Asthma and Immunology, the scientific publication of the American College of Allergy, Asthma and Immunology (ACAAI) examined 276 surveys completed by non-allergist physicians, physician assistants, nurse practitioners and pharmacists at Rochester Regional Health, in Rochester, NY. They found more than 80 percent of the general practitioners surveyed in their system knew a referral to an allergist for testing is appropriate for someone with a reported penicillin allergy. Despite that, the physicians had either never referred their patients to an allergist, or had only done so with one patient a year. In addition, pharmacists surveyed in their system had a better overall understanding of penicillin allergy.

“We were not surprised pharmacists understood the course of penicillin allergy better than other clinicians, given more extensive pharmacology education,” says infectious diseases pharmacist Mary Staicu, PharmD, lead author of the study. “Of those surveyed, 78 percent of pharmacists knew penicillin allergy can resolve over time. Only 55 percent of the remaining respondents (non-allergist physicians, physician assistants and nurse practitioners) did.” The survey also showed a limited understanding among internists and general practitioners regarding the large numbers of people who report penicillin allergy but have never been tested.” Most of the physicians surveyed had been in practice more than 10 years.

Between 10-20 percent of Americans believe they have a penicillin allergy. But previous research has found only 10 percent of those people are truly penicillin allergic. In other words, 9 out of 10 people who think they have penicillin allergy are avoiding it for no reason. Even in people with documented allergy to penicillin, only about 20 percent are still allergic ten years after their initial allergic reaction.

“Our research found a poor understanding of penicillin allergy among non-allergists,” says allergist Allison Ramsey, MD, study co-author and ACAAI member. “This was not a surprising finding given the clinical experience of most allergists, but it does provide an excellent opportunity for education on the topic – not just for patients, but for all health care professionals.”

People who are labeled penicillin allergic are often prescribed second-line antibiotics, which may have a higher risk of side effects and increased cost. “More than 90 percent of people labeled with a penicillin allergy can tolerate penicillin-based antibiotics,” says Dr. Ramsey. “Our survey showed only 30 percent of physician survey respondents knew that. It’s important that doctors understand the importance of confirming penicillin allergy. But it’s even more important that those who carry the label be educated and tested.”

An allergist can work with you to find out if you have a true drug allergy and determine what antibiotics are available for safe and effective treatment. If you’re not allergic, you’ll be able to safely use antibiotics that are often more effective and less expensive.