Evaluation of a pharmacist-led penicillin allergy testing service in a community health system

Prospective, Multicenter, Head-to-Head Comparison Between Allergists Versus Nonallergists in Low-Risk Penicillin Allergy Delabeling: Effectiveness, Safety, and Quality of Life (HK-DADI2)

BACKGROUND

Penicillin "allergy" labels are prevalent but frequently misdiagnosed. Mislabelled allergies are associated with adverse outcomes and increased antimicrobial resistance. With an urgent need to delabel the overwhelming number of mislabeled allergies, nonallergist evaluations have been advocated for low-risk individuals. Despite growing interest in non-allergist-led initiatives, evidence on their effectiveness, safety, and impact by direct comparisons is lacking.

OBJECTIVE

To assess the comparative outcomes of penicillin allergy evaluations conducted by allergists versus nonallergists.

METHODS

A prospective, multicenter, pragmatic study was conducted at 4 tertiary hospitals (1 allergist- vs 3 non-allergist-led) for low-risk penicillin allergy patients in Hong Kong-the Hong Kong Drug Allergy Delabelling Initiative 2 (HK-DADI2).

RESULTS

Among 228 low-risk patients who underwent testing (32.9% by allergists, 67.1% by nonallergists), only 14 (6.1%) had positive penicillin allergy testing results. Delabeling rates (94.1% vs 93.3%; P = .777), positive skin test results (2.6% vs 2.7%; P > .99), and drug provocation test results (3.3% vs 2.7%; P = 1.000) were similar between allergists and nonallergists. There were no systemic reactions in either cohort. All patients had significant improvements in health-related quality of life (Drug Hypersensitivity Quality of Life Questionnaire scores -5.00 vs -8.33; P = .072). Nonallergist evaluations had shorter waiting times (0.57 vs 15.7 months; P < .001), whereas allergists required fewer consultations with higher rate of completing evaluations within a single visit (odds ratio, 0.04; P < .001).

CONCLUSIONS

With training and support, nonallergists can independently evaluate low-risk penicillin allergies. Compared with allergists, evaluation of low-risk penicillin allergy by nonallergists can be comparably effective, safe, and impactful on quality of life. More multidisciplinary partnerships to empower nonallergists to conduct allergy evaluations should be encouraged.

Low-risk penicillin allergy delabeling: a scoping review of direct oral challenge practice, implementation, and multi-disciplinary approaches

INTRODUCTION

Penicillin allergy is common, and there is increased clinician interest in direct oral challenge (DOC) as a testing strategy for low-risk penicillin allergy. To aid wider implementation of DOC, consensus definitions of low-risk penicillin allergy phenotypes, and standardized approaches to assessment, DOC procedures, and evaluation, are required.

AREAS COVERED

This review systematically reviews studies that have utilized penicillin DOC in healthcare settings to identify heterogeneity in implementation approaches and synthesize low-risk definitions, procedures, and evaluation.

EXPERT OPINION

Opportunity exists to standardize penicillin DOC procedures in patients with a low-risk penicillin allergy to optimize antimicrobial prescribing and reduce the burden of penicillin allergy. Standardizing the definitions of 'low-risk' and 'positive challenge,' and improving the evaluation of patient safety, alongside the development of a unified approach to the structure of undertaking an oral challenge, is likely to increase uptake and confidence among non-allergist clinicians.

A new clinical opportunity: Rechallenging penicillin allergy in an outpatient pharmacy

In the United States, approximately 27 million people have a documented penicillin allergy, but 90% of the allergies are falsely labeled. By rechallenging suspected allergies, a pharmacist can optimize patient care, fulfill antimicrobial stewardship objectives, and educate patients on true allergies. We suggest a protocol that allows pharmacists to investigate the presence of an allergy and conduct a challenge when indicated. The protocol consists of a patient interview, a risk assessment, an oral rechallenge, and the potential for a skin test. The testing and delabeling of penicillin allergies will enhance the practice of antimicrobial stewardship in the outpatient setting. In the changing landscape of pharmacy, community pharmacists can increase their services and improve patient care. Owing to limited documented experience in the outpatient pharmacy, an opportunity to set the standard and be a leader in the field is present.