Beneficial Outcomes of an Inpatient Penicillin Allergy Testing Protocol
Saturday, March 5, 2016: 2:00 PM
Room 515A (Convention Center)
Justin R Chen, MD, , , ,
Rationale: More than 90% of patients reporting a penicillin allergy are not actually allergic.  We present the findings of a protocol aimed at systematically evaluating penicillin allergy in hospitalized patients. 

Methods: Our approach employed a dedicated clinical pharmacist to test inpatients with penicillin allergy documented in the electronic medical record (EMR).  Potential subjects were flagged daily through the EMR or referred by their primary physician.  A cohort deemed likely to benefit from penicillin therapy was prioritized for inpatient testing.  These patients received skin prick (SPT) and intradermal testing with benzylpenicilloyl polylysine (Pre-Pen) and penicillin G followed by oral amoxicillin challenge if both were nonreactive.  Those with a negative evaluation had the penicillin allergy label removed from their EMR.  All patients were individually informed of their result.

Results: Over 9 months approximately 800 applicable charts were detected by our system leading to 135 formal tests.  119 of 135 subjects (88.1%) had their listed penicillin allergy removed.  Of the remainder, only 2 (1.5%) had positive skin test results to penicillin, 8 (5.9%) did not react to a histamine control, 2 were not challenged due to β-blocker use, and 4 (3%) did not subsequently complete the challenge due to personal or physician preference.

Conclusions: An inpatient penicillin skin-testing protocol can lead to removing the penicillin allergy label in the vast majority of patients and serves to educate clinicians and patients alike.  Widespread implementation of this practice may potentially benefit healthcare systems by reducing the expense of alternative antibiotics and the risk of antimicrobial resistance.