1924. Most Patients Tolerate Penicillin Administration Despite History of Nonanaphylactic Penicillin Allergy: A Systematic Review and Meta-Analysis

BACKGROUND: True allergy to penicillin is rare, despite the high frequency with which it is reported. Misrepresented allergy drives unnecessary use of alternative antibiotics which may be less effective, more toxic, and more expensive than the penicillins. While most patients reporting penicillin allergy are not prone to anaphylaxis, it is not currently known what percentage of these patients go on to fully tolerate systemic doses of penicillin-based antibiotics. This review aims to determine the tolerance rate in patients with non-anaphylactic penicillin allergy when challenged with systemic doses of penicillin-based antibiotics. METHODS: We searched MedLine, Embase, and Cochrane Library for publications with English language translations between the years 2000 and 2017. We included controlled trials, quasi-experimental, and observational studies of reportedly penicillin-allergic subjects who received at least one systemic dose of a penicillin in the form of a challenge. At least two independent reviewers extracted data from included studies, and assessed the quality of each included study. To generate primary outcome data, we calculated a summary estimate rate of penicillin tolerance from a pooled fraction of subjects receiving a penicillin with no adverse effects, among all subjects receiving a penicillin challenge. RESULTS: Initial literature search yielded 5,554 studies, of which 22 studies were ultimately included in our review. A total of 4,572 study participants, each with a history of penicillin allergy low risk for anaphylaxis, were challenged with systemic dosing of a penicillin. After weighting for sample size, an average of 94.8% [95% CI 93.3%, 96.3%] of these patients tolerated penicillin challenge without any adverse reaction. CONCLUSION: In addressing the problem of penicillin allergy over-diagnosis, evaluation should go beyond risk for type 1 hypersensitivity. Our data suggest that 94.8% of 4,572 subjects with reported penicillin allergy determined to be low risk for anaphylaxis tolerated repeat administration of penicillin-based antibiotics without any adverse reactions. This review generates meaningful information useful to clinical predictive analytics, in evaluating and managing patients with a reported history of penicillin allergy. DISCLOSURES: All authors: No reported disclosures.