NurseWeek: Penicillin allergy? Maybe not

Penicillin allergy?
Maybe not

December 13, 2000


	You've read the article. Now tell us what you think.

Many people who think they're allergic to penicillin may actually not be. In many cases, a person is assumed to be allergic because some sort of reaction occurred after taking penicillin or a related drug.

Doctors at the Cleveland Clinic Foundation estimate that only 0.3 percent to 1.2 percent of the general population ever test positive for penicillin sensitivity. About half of those with a confirmed penicillin allergy lose their sensitivity to the drug after five years, so it's important to get retested.

The term "penicillin allergy" is somewhat vague. People allergic to penicillin will also usually react to synthetic forms of penicillin, such as ampicillin and amoxicillin. And they're more likely to be allergic to other chemically related drugs, known as beta-lactam antibiotics. The "beta-lactam" is a five-sided chemical ring that forms a key part of the structure of these drugs.

Antibiotics known as cephalosporins – chemical cousins of penicillin – also contain this ring. Some doctors avoid prescribing cephalosporins to patients with a penicillin allergy. However, only 5 percent to 20 percent of those allergic to penicillin also react to cephalosporins.

The first of three health briefs from the Jerusalem Post says that as many as 70 percent to 80 percent of people who think they're sensitive to penicillin actually are not. Dr. Harold Oster describes the tests for penicillin allergy in his column from allHealth.com.

The Mayo Clinic has additional information on true penicillin reactions and describes what allergic persons can do to avoid problems.

~ Jeff Johnston

This is a WebSCOUT story from HealthScout, a service of Rx Remedy, Inc.