PARK CITY, UTAH – When attendees at the annual scientific meeting of the Infectious Diseases Society for Obstetrics and Gynecology were asked if their institutions test to confirm alleged penicillin allergies, the only hands that went up were from clinicians at Duke University.
That’s a problem, according to Robert Heine, MD, a maternal-fetal medicine specialist at Duke, in Durham, N.C. “We, as a group, need to be doing [penicillin] allergy testing,” he said.
Dr. Robert Heine
It’s become clear in recent years that patients who say they have a penicillin allergy often don’t have one, or remember a mild reaction from childhood that doesn’t preclude the use of beta-lactam antibiotics as adults. For decades, however, clinicians have taken those claims at face value, and duly noted them in charts and switched patients to non–beta-lactam antibiotics that don’t work as well.
That’s what happened at Duke in 2014. A total of 81 women with documented penicillin allergies were put on gentamicin and clindamycin to protect against cesarean wound infections and 16% ended up with infections anyway. Among the 864 women who received cefazolin – the first-line cesarean prophylaxis choice at Duke – the infection rate was 7%.
“Beta-lactam antibiotic prophylaxis reduced the risk of surgical site infections after cesareans by 60%,” said Benjamin Harris, MD, the lead investigator and an ob.gyn. resident at Duke, who presented the findings at the meeting.
Dr. Benjamin Harris
When the investigators took a closer look at the 81 women who reported penicillin allergies, most of them had rashes and other mild reactions noted in their charts.
Findings such as those led Dr. Heine to push for routine testing. “I brought Duke into it kicking and screaming,” he said. The biggest obstacle was concern over liability, specifically that pregnant women would go into anaphylaxis and deliver prematurely, he said.
After a lot of lobbying, Dr. Heine and his colleagues started routine penicillin allergy testing in March 2016. There hasn’t been a single reaction among the 80-plus pregnant women tested so far, he reported.
Duke administrators were also concerned about reimbursement, but it hasn’t turned out to be a problem. Reimbursements from public and private payers “cover our costs,” a little over $100 per test, Dr. Heine said.
Dr. Heine said he can imagine outpatient testing at some point, but for now women are checked into triage. They get a fetal heart tone before 24 weeks, and a fetal heart rate monitor afterward. “We try to do it before 20 weeks so we don’t have to worry about the fetus,” he said.
When penicillin allergies are in the chart, or women say they are allergic, ask what type of reaction they had in the past. Type 1 reactions should be confirmed with testing. It’s okay to skip testing and give beta-lactams for non–type 1 reactions, but “if a woman has a non–type 1, and they’re already set up for testing, I’m going to do it anyway because getting the penicillin allergy off her chart is good for her and her life,” Dr. Heine said.
Dr. Heine and Dr. Harris reported having no financial disclosures.