Millions Wrongly Think They Have Penicillin Allergy

BOSTON (CBS) - Claire Branman is among the millions of Americans who think they have a penicillin allergy.

It's something that's been listed on her medical records since she was a kid, "because my mom told me when I was a baby I had an allergic reaction," she told WBZ-TV.

At 26 years old, Claire is now getting an allergy test to find out for sure.

And here's why: "Ten-to-fifteen percent of the U.S. population thinks that they are allergic to penicillin. But, in actuality less than one-percent are truly allergic to penicillin," explained Dr. Aleena Banerji, an allergist at Massachusetts General Hospital.

"When we're children and we have this added to our medical record then over time as we get repeated infections we don't ever address the issue again," said Dr. Kim Blumenthal, also an allergist at Mass General.

Doctors have been prescribing penicillin reliably for years.

But, when they can't, the alternatives are often more expensive, less effective, and can cause serious side effects.

For Claire, the alternative antibiotic for a minor dental procedure led to much bigger health problems.

"It was nightmare and I actually ended up having my stomach kind of messed up for a few years," she said. "When I was given clindamycin I got C. diff, which I thought maybe if I wasn't allergic to penicillin I could have avoided that."

A penicillin allergy prevents patients from taking any of the penicillins, including amoxicillin and Augmentin.

Allergists at Mass General have now developed an app to help doctors quickly identify patients who should get tested. It's now being used at MGH and Brigham and Women's Hospital.

"It helps the doctor or the nurse... ask more detailed questions that are usually, sort of, allergy specialist knowledge... at the palm of your hands," said Dr. Blumenthal.

"People should get tested when they are actually healthy and when they're not sick," said Dr. Banerji.

After two skin tests and a dose of the pink medicine, doctors determined, as suspected, that Claire is not allergic to penicillin. And that could make a world a difference the next time she gets sick.