Department of Pharmacy and Department of Infectious Diseases — James Curtis, PharmD, MHA; Shafinaz Akhter, MD, PhD; Michael Edleman, PharmD; Ricky DiPasquale, PharmD, BCPS; and Melissa Ilano, PharmD, BCPS
Chester County Hospital, Penn Medicine
The Department developed a protocol that uses penicillin skin testing (PST) to identify patients who truly have an allergy to penicillin, as a thorough allergy history from the patient isn't always accurate, and an incorrect reporting of hypersensitivity to penicillin may unnecessarily limit the patient's treatment options.
In the new protocol, a clinician identifies patients who would benefit from PST based upon allergy history and may order PST by placing a consult to pharmacy. The pharmacist provides the stewardship ID physician with the patient information, who orders PST once patient consent has been obtained. A pharmacist prepares, administers, and documents the skin test. After completing the test, a progress note is left in the patient's chart explaining the interpretation of the results; the attending physician is notified; and a letter is sent to the patient's primary care provider and primary outpatient pharmacy. The documented penicillin allergy is removed and replaced by either “Penicillin Skin Test Negative," or “Penicillin Skin Test Positive," along with who conducted the test, when, and any details regarding the results.
Since June 2018, 48 patients have received PST. All of them had a negative result, and the allergy was removed from each patient's profile. To assess the impact on patient outcomes, a cohort of patients who received PST was compared to a cohort of patients who were treated with aztreonam for more than 24 hours. There were fewer readmissions in the PST group when compared to the group that did not receive PST (9.1% vs 18%, respectively), suggesting that 12 patients would need to receive PST to prevent a 30-day readmission.
The reduction in readmissions demonstrates that removing or clarifying a penicillin allergy benefits the patient not only for the acute episode, but also for the rest of their lives when antimicrobials may be prescribed.