番茄社区

LOS ANGELES -- Among a group of inpatients who had a penicillin allergy listed in their electronic health records (EHR), 97.6% did not actually have an allergic reaction to a penicillin antibiotic, researchers reported here.

All of the patients in the study received a skin prick test, and intradermal testing with benzylpenicilloyl polylysine (Pre-Pen). Over the course of 15 months, 225 inpatients reporting a penicillin allergy, who were likely benefit from penicillin therapy, were recruited based off of the allergy profile in their EHR, and after exclusions, 201 out of 206 were able to tolerate penicillin medications, according to , of University of Texas Southwestern Medical Center in Dallas, and colleagues.

He noted that "10% of U.S. patients report an allergy to penicillin, but only 1% are actually allergic on skin testing," during a presentation at the American Academy of Allergy, Asthma & Immunology annual meeting.

For this study, a dedicated clinical pharmacist tested inpatients with EHR-documented penicillin allergies. Patients on antihistamines and beta-blockers were excluded from the trial.

A cohort deemed likely to benefit from penicillin therapy was prioritized for inpatient testing. In patients who were nonreactive to both tests, a penicillin G test with 500 mg of oral amoxicillin challenge was administered.

All of the patients in this trial were observed for 1 hour after administration of penicillin. "Observed challenges are an important part of testing protocols," Chen stressed.

There were 10 patients who had a negative histamine test and one who had a positive saline test, and these patients were removed from the challenge.

Overall, 201 patients had a negative evaluation and were able to have the penicillin allergy label removed from their EHR. Only five of the patients who completed the protocol had a positive skin test.

Chen said that there was one patient who had a positive challenge to the amoxicillin despite having a negative penicillin prick and intradermal testing.

Prior to the penicillin testing, Chen's group reported 189 days of powerful non-penicillin antibiotics: 95 patient-days were on vancomycin, 81 were on fluoroquinolone, 43 on clindamycin, 21 on carbapenem, and 15 on aztreonam.

After the implementation of penicillin allergy testing, 425 days of unnecessary exposure to the previous agents were avoided, Chen said. The most common antibiotics in use after removal of the penicillin allergy labels were third generation cephalosporin, and piperacillin-tazobactam.

"Most people who think they have an allergy to penicillin actually aren't allergic to it," , of Children's Mercy in Kansas City, Mo., said in an interview with 番茄社区. "If you have penicillin allergy, it's reasonable to ask to be tested. Penicillin is one of the most effective, least expensive, medicines."

Portnoy, who was not involved in the study, said that the confusion over allergy typically sparks from an interaction between penicillin being used to treat a viral infection. "You're likely to end up with a reaction like hives. That's how most people ended up with the allergy diagnosis," he added.

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