Key findings

This scoping review suggests that pharmacist-directed interventions may support improved management of penicillin (and broader beta-lactam) allergy labeling and strengthen AMS efforts. Across the included studies, pharmacist involvement was generally associated with improved antibiotic selection, particularly increased use of guideline-recommended beta-lactams and decreased use of alternative broad-spectrum agents, improved allergy documentation, favorable utilization and cost outcomes, and generally reassuring safety findings. The evidence base consists primarily of hospital-based studies published between 2016 and 2024, most of which were conducted in the United States and utilize observational designs, predominantly cohort and prepost quasi-experimental studies.

Interpretation in the context of existing literature

The results of this scoping review are consistent with existing evidence that most reported penicillin allergy labels do not reflect current IgE-mediated hypersensitivity. ^{Reference Graudins, Ly, Trubiano and Aung5,Reference Krishna, Vedanthan and Vedanthan6,Reference Blumenthal, Peter, Trubiano and Phillips12} Previous studies suggest that IgE-mediated penicillin sensitivity declines over time, with approximately 80% of patients losing sensitivity after 10 years; however, inaccurate labeling may persist due to misclassification of childhood reactions, nonallergic adverse reactions, and incomplete histories as allergy. ^{Reference Graudins, Ly, Trubiano and Aung5,Reference Samarakoon, Accarino, Wurcel, Jaggers, Judd and Blumenthal40} Consistent with the literature, persistent penicillin allergy labels are associated with avoidance of first-line beta-lactams and increased prescribing of broader-spectrum, less effective, more toxic, and more costly alternatives. ^{Reference Kardos and Demain2,Reference Lee3,Reference Luque, Rei, Capoulas, Santos and Raimundo7} These patterns have been associated with antimicrobial resistance, Clostridioides difficile infection, longer hospital stays, higher readmission rates, and increased mortality. ^{Reference Luque, Rei, Capoulas, Santos and Raimundo7–Reference Knezevic, Sprigg and Seet9}

In this context, pharmacist-led approaches identified in the included studies ranged from history-based delabeling in low-risk patients to facilitating PST and drug provocation testing pathways in moderate-risk patients. ^{Reference Shenoy, Macy, Rowe and Blumenthal14,Reference Devchand and Trubiano15,Reference Wall, Peters, Leaders and Wille41,Reference Chen, Tarver, Alvarez, Tran and Khan42} Evidence from pharmacist-managed PST services suggests that these models are feasible and safe and are associated with increased beta-lactam use and decreased reliance on alternative agents, even in settings without on-site allergists. ^{Reference Park, McClimon and Ferguson43–Reference Mattingly, Fulton and Lumish45} Beyond testing services, pharmacists’ expertise in beta-lactam cross-reactivity and side-chain structure can also support safer cephalosporin selection in patients with penicillin allergy labels. ^{Reference Devchand and Trubiano15,Reference Park, McClimon and Ferguson43,Reference DePestel, Benninger and Danziger46,Reference Omer, Hodson, Thomas and Coleman47} Finally, pharmacist-led education and stewardship efforts may improve multidisciplinary understanding of penicillin allergy assessment and support more appropriate antimicrobial prescribing decisions. ^{Reference King, Challa, Curtin and Bielory48,Reference Chen and Khan49}

Strengths and limitations

A key strength of this scoping review is the synthesis of pharmacist-led interventions for penicillin allergy, primarily in hospital-based settings. By capturing a wide range of intervention models and stewardship-relevant outcomes, this review provides insight into the feasibility and potential impact of pharmacist involvement in the assessment and management of penicillin allergy in different clinical contexts.

The included studies were heterogeneous in terms of study design, patient populations, intervention components, and outcome measures, limiting direct comparability and precluding quantitative synthesis. Most of the available evidence was derived from observational or prepost study designs, with relatively few randomized controlled trials. In addition, the literature focused predominantly on adult populations and hospital-based services, with limited evidence from pediatric populations and community pharmacy-based interventions.

Knowledge gaps and future research

Despite growing evidence supporting pharmacist-led penicillin allergy assessment, important knowledge gaps remain. Standardized, evidence-based protocols are needed to better define the role of pharmacists in allergy assessment, delabeling, and diagnostic testing in various healthcare settings. Future studies should evaluate the sustainability and long-term impact of pharmacist-led delabeling programs, including effects on patient safety, healthcare utilization, and antimicrobial resistance-related outcomes and cost-effectiveness across different healthcare systems. Additional research is also needed in pediatric populations and community pharmacy settings where access to allergy specialists may be limited. ^{Reference Li, Krishna, Razaq and Pillay13,Reference Sobrino-García, Muñoz-Bellido and Moreno50}

Despite growing interest in pharmacist-assisted penicillin allergy evaluation, several barriers to implementation remain. ^{Reference Mann, Cox, Gorman and Calissi19,Reference Alagoz, Saucke, Balasubramanian, Lata, Liebenstein and Kakumanu51} Time constraints and competing priorities often limit pharmacists’ ability to obtain a structured allergy history, provide patient counseling, coordinate observation for direct oral challenge/skin testing, and ensure accurate electronic record updates. ^{Reference Mann, Cox, Gorman and Calissi19,Reference Alagoz, Saucke, Balasubramanian, Lata, Liebenstein and Kakumanu51,Reference Powell, Upton, Kent, Sandoe and Tonkin-Crine52} In addition, unclear role definitions and governance (eg, who is responsible for initiating delabeling, authorizing reexposure, and documenting the outcome as “allergy label removal”) and the lack of reliable local protocols may limit pharmacists’ operational authority in practice. ^{Reference Mann, Cox, Gorman and Calissi19,Reference Foong, Erdil, Campion, Doron and Alsoubani53,Reference Joost, Tometten and Barry54} Finally, gaps in delabeling knowledge/skills, limited experience, and low confidence, as well as fear of triggering reactions or medicolegal concerns, may further limit engagement. ^{Reference Alagoz, Saucke, Balasubramanian, Lata, Liebenstein and Kakumanu51,Reference Foong, Erdil, Campion, Doron and Alsoubani53,Reference Joost, Tometten and Barry54} These findings support implementation strategies that combine clear institutional pathways and role delineation, adequate resources, and competency-based training/credentialing aligned with robust EHR documentation workflows. ^{Reference Mann, Cox, Gorman and Calissi19,Reference Powell, Upton, Kent, Sandoe and Tonkin-Crine52,Reference Bland, Bookstaver and Griffith55,Reference Kufel, Justo, Bookstaver and Avery56}

This scoping review suggests that pharmacist-led penicillin allergy assessment may support AMS by improving the accuracy and completeness of allergy documentation, facilitating structured assessment pathways, and enabling more appropriate beta-lactam prescribing. Although the evidence base was heterogeneous and largely derived from nonrandomized, observational, and prepost study designs, the findings suggest that pharmacists may play a practical role in multidisciplinary penicillin allergy assessment pathways. Integrating pharmacists into these pathways may represent a pragmatic, evidence-based strategy to mitigate the impact of inaccurate penicillin allergy labeling on antimicrobial prescribing and healthcare utilization. Further research, particularly well-designed randomized controlled trials, is needed to strengthen the evidence base, increase confidence in these findings, and support wider implementation.