THURSDAY, Nov. 5, 2015 (HealthDay News) -- Many people who've been told they're allergic to penicillin may be able to safely take the drug, a small study suggests.

Most people who believe they are allergic to penicillin have been told so by a doctor after having a reaction to the antibiotic. Most never take penicillin again, even if they are never tested for the allergy, the researchers said.

The researchers examined the medical records of 15 people who tested negative for penicillin allergy after being told they were allergic. They were then treated with intravenous penicillin multiple times.

The study was to be presented Thursday at the annual meeting of the American College of Allergy, Asthma and Immunology, in San Antonio.

"Of the patients whose records we examined, there were no adverse drug reactions or evidence of recurrence of their penicillin allergy," study author and allergist Dr. David Khan said in a college news release. "There is often thought to be a higher risk in patients who get intravenous penicillin, but we did not find this to be the case."

Previous reported reactions included rash, hives and swollen lips, Khan said. But the study found none of those reactions after allergy testing and treatment with multiple courses of intravenous penicillins.

About 10 percent of Americans believe they are allergic to penicillin. As a result, they're prescribed more risky and expensive antibiotics, according to the news release.

"Recent research has shown that patients who are labeled penicillin-allergic and take other antibiotics are more likely to have poor outcomes, such as development of colitis, longer hospital stays and greater numbers of antibiotic-resistant infections," allergist Dr. Roland Solensky said in the news release.

Khan said patients who've been told they're allergic to penicillin should get tested to be sure.

"An allergist will work with you to find out if you're truly allergic to penicillin, and to determine what your options are for treatment if you are. If you're not, you'll be able to use medications that are safer, often more effective and less expensive," he explained.

Research presented at meetings has not been subject to the same scrutiny as published studies and is typically considered preliminary.

More information

National Jewish Health has more about drug allergies.