Penicillin Skin Testing Can Delabel Misidentified Allergic Patients

In an era of growing concerns over antibiotic stewardship, there is renewed interest in delabeling misidentified penicillin allergies as part of quality improvement efforts. Most patients who report being allergic to penicillin actually test negatively, according to a presentation at the American College of Allergy, Asthma and Immunology meeting (Oct. 26-30, 2017; Boston; Mass.). The study also showed that penicillin skin testing (PST) is feasible in real-world outpatient allergy practice.

The researchers obtained a penicillin allergy history from new and existing patients of an outpatient allergy practice. All qualifying patients were offered PST, followed by an amoxicillin challenge with 30-minute observation if PST was negative.

Nearly 16 percent of all patients seen (119 of 755) reported a penicillin allergy. Forty-eight patients completed a PST, with 85.4 percent testing negative. In the remaining 65 patients reporting penicillin allergies, but not undergoing PST, 20 were on interfering medications, seven reported a delayed reaction, five reported anxiety or needle fear, five experienced time constraints, five had a recent reaction, four had a recent positive PST, and eight were scheduled for future PST or challenge. An additional 11 were not tested for other reasons.

“Our analysis provides a real world representation of the feasibility of PST and illustrates that quality improvement projects aimed at PST can improve its utilization,” wrote S. Shahzad Mustafa, from University of Rochester in New York, in the conference abstract.

Takeaway: Verifying patient-reported penicillin allergies with PST is feasible in routine care and can improve antibiotic stewardship.