Penicillin Allergy Might Not Include Related Antibiotic

SATURDAY, Feb. 27 (HealthDay News) -- Most patients who have a history of penicillin allergy can safely take antibiotics called cephalosporins, U.S. researchers say.

Cephalosporins -- which are related to penicillin in their structure, uses and effects -- are the most frequently prescribed class of antibiotics.

"Almost all patients undergoing major surgery receive antibiotics to reduce the risk of infections. Many patients with a history of penicillin allergy don't get the cephalosporin because of a concern of possible drug reaction. They might get a second-choice antibiotic that is not quite as effective," study author Dr. James T. Li, of the Mayo Clinic in Rochester, Minn., said in a news release from the American Academy of Allergy, Asthma & Immunology.

He and his colleagues conducted penicillin allergy skin tests on 178 patients who reported a history of severe allergic (anaphylactic) reaction to penicillin. The tests yielded 10 unclear results, 12 positive results, and 156 negative results.

Later, 80 of the 156 patients with negative skin tests to penicillin received a cephalosporin when they had surgery. Just one patient experienced a possible mild adverse reaction to the cephalosporin.

"Even patients with a history of a serious reaction to penicillin can receive cephalosporins safely if the allergy tests are negative," Li said. "The main message here is that patients with a history of penicillin allergy who need surgery can benefit from consultation with an allergist. They can get the best antibiotic with the lowest risk of drug reaction."

The findings were scheduled to be presented Saturday at the American Academy of Allergy, Asthma & Immunology annual meeting, in New Orleans.

More information

The U.S. National Library of Medicine has more about allergy testing.