Implementation of a pharmacist-led penicillin allergy de-labelling service in a public hospital

Direct Single-Dose Drug-Provocation Test Is Safe for Delabelling Penicillin Low-Risk Reactions in Adults

BACKGROUND

Penicillins (PENs) are the most frequent drug-allergic reactions trigger. However, diagnostic work-up is complex and time-consuming: it requires skin testing (ST) and drug-provocation test (DPT), needing faster delabelling strategies. Although direct DPT without previous STs has shown to be safe, most of the studies are performed in children or in North American, Asian, or Oceanian adults, with few studies in the European adult population. We explored its safety in European adult patients with low-risk PEN allergy history and, additionally, analysed ST role and T-cell involvement by lymphocyte transformation test (LTT).

METHODS

We prospectively evaluated > 16 years of PEN-allergic labelled patients referred to Málaga Regional University Hospital during 2023. They reported non-immediate reactions without alarm signs and unknown reactions. Direct-single-dose DPT was performed in all patients. If positive, ST and LTT were carried out after reaction resolution.

RESULTS

We included 269 patients with the culprits being an unidentified PEN (36%), amoxicillin (AX) (32%), and AX-clavulanic acid (AX-CLV) (31%); and the symptoms maculopapular exanthema (MPE) (34%) and unknown reaction during childhood (23%). Only 16 (5.9%) had positive DPT, being 56% for AX and 44% for AX-CLV, 81% developing MPE, none severe. Most DPT-reacting patients reported cutaneous non-immediate reactions in the index reaction, and only one had an unknown childhood reaction. The mean day interval between drug administration and symptom development was lower (p = 0.002) in positive DPT than in the index reaction (2 vs 5 days). Moreover, ST was positive in only 19% and LTTs in 86.7% of positive DPT patients.

CONCLUSIONS

Direct-single-dose DPT is safe for delabelling PEN allergy in non-immediate reactions without alarm signs and unknown reactions. ST had a poor diagnostic value and LTT had a high one, confirming a T-cell involvement.

Unpacking Oral Challenge Protocols: A Descriptive Epidemiologic Study of Reactions, Predictors, and Practices for Delabeling Low-Risk Penicillin Allergies Leveraging Data from a Systematic Review and Meta-Analysis

Background: Oral challenges with amoxicillin or other penicillins are safe and effective for delabeling low-risk penicillin allergy histories. While approximately 90% of reported penicillin allergies can be safely delabeled, detailed data on reaction frequency, types, and timing during and after delabeling interventions remain limited. Such data are crucial to optimizing protocols and integrating oral challenges into routine practice. This study aims to characterize the interventions commonly used for oral challenge, classify reported reactions, and identify reported predictors of hypersensitivity reactions in randomized controlled trials and quasi-experimental studies involving an oral challenge for patients with low-risk penicillin allergies. Methods: This study leverages data from a systematic review and meta-analysis assessing the effectiveness of oral challenge interventions in patients with low-risk penicillin allergies. This descriptive analysis summarizes the adverse reactions experienced among patients in published studies who received oral challenge. Participant demographics, intervention protocols, frequency, type, and timing of post-challenge adverse reactions are reported. Reactions are categorized as immediate, delayed, or other, with frequencies summarized using descriptive statistics. A random effects meta-analysis quantifies a pooled adverse reaction rate. Predictors of hypersensitivity reactions were synthesized narratively. Results: Across 26 studies (2 randomized trials, 24 quasi-experimental studies) evaluating an oral challenge for patients with a low-risk penicillin allergy, the average participant age was 56 years, with a predominance of females (61%) and limited ethnic diversity with 88% reported or identifying as White. Amoxicillin was the most frequenty used oral challenge agent, typically administered as a single 250 mg oral dose. The incidence of reaction or non-delabeling was 4% (95% Confidence Interval 3%, 6%), I 2 = 43%, P = .0001. Cutaneous manifestations, such as rashes, were the most frequent reactions. Delayed reactions, primarily mild maculopapular rashes, were uncommon and managed with antihistamines or topical steroids. Risk factors for oral challenge reactions included higher baseline allergy burden and shorter intervals to oral challenge since the index reaction. Conclusion: Oral challenge strategies to delabel low-risk penicillin allergies can involve single doses of amoxicillin or other penicillins with monitoring protocols that can be managed in ambulatory settings. However, although these delabeling strategies are becoming more prevalent, continued study of standardized protocols and follow-up are essential for effective and replicable delabeling strategies. Future research should prioritize diverse populations and equity-driven frameworks to improve generalizability to all individuals and to resource limited settings.

Implementation of a proposed algorithm to assess and de-label false penicillin allergy labels in the community

BACKGROUND

Community pharmacists could have a pivotal role to play in de-labelling false penicillin allergies or preventing false penicillin allergy labels from occurring to reduce inappropriate prescribing of less effective and broader-spectrum antibiotics.

METHODS

A quasi-experimental study aimed at implementing and evaluating an algorithm to assess and de-label false penicillin allergy labels in the community. Between April and May 2024, the algorithm was rolled out to five community pharmacies in Victoria, Australia. De-labelling outcomes of Type A reactions were recorded. Barriers and enablers to implementing the penicillin allergy assessment algorithm were also collected through semi-structured interviews.

RESULTS

Of 18,646 patients who presented to the pharmacies, 163 individuals (0.87 %) had a penicillin allergy label. Of these 163 patients, 30 (18.4 %) patients were assessed as having a Type A reaction (a non true allergy; non-immune related). All patients with Type A reactions were engaged in an attempt to de-label their allergy; 77 % of patients were accepting whilst 23 % were hesitant or non-receptive, due to time restraints or disbelief that their allergy is not a true allergy. Qualitative interview data revealed there remains a public misconception that antibiotic allergy labels do not impact the appropriateness of antibiotic prescribing or affect patient safety through increased risk of adverse drug events and antimicrobial resistance.

CONCLUSIONS

The proposed algorithm was able to support the de-labelleling of false penicillin allergies. Future research could implement the use of the algorithm in other primary care settings and ascertain the long-term retention of the initiation of de-labelleling in the community.

Penicillin Allergy Management in India and Sri Lanka: Current Challenges

Data regarding Penicillin allergy labels (PALs) from India and Sri Lanka are sparse. Emerging data suggests that the proportion of patients declaring an unverified PAL in secondary care in India and Sri Lanka (1%-4%) is lesser than that reported in High Income Countries (15%-20%). However, even this relatively small percentage translates into a large absolute number, as this part of the world accounts for approximately 25% of the global population. There is a huge unmet need for allergy specialists in India and Sri Lanka. Penicillin allergy management is further compromised by unavailability of skin test reagents, lack of formal training in drug allergy, pre-emptive, non-standardised and unregulated skin testing by untrained operators and a weak health service framework. This has an adverse impact on antimicrobial stewardship, particularly in the management of rheumatic fever, rheumatic heart disease, bacterial endocarditis, syphilis and other sexually transmitted infections. This narrative review highlights the burden of PALs in India and Sri Lanka, as well as gaps in the published literature. It describes current challenges and a pragmatic, cautious and staged bespoke mitigation approach to improve and standardise antimicrobial stewardship in accordance with the World Health Organisation AWaRe guidance.

Impact of Parent-Reported Antibiotic Allergies on Pediatric Antimicrobial Stewardship Programs

BACKGROUND

Antimicrobial stewardship (AMS) is crucial for optimizing antimicrobial use and restraining emergence of antimicrobial resistance. The overall increase in reported antibiotic allergies in children can pose a significant barrier to AMS, but its impact on clinical AMS care in children has not been addressed.

OBJECTIVE

To compare the clinical outcomes for children with a reported antibiotic allergy label (AAL) with those with no AAL reviewed by AMS.

METHODS

A retrospective cohort study was conducted in a pediatric tertiary hospital, capturing 1590 inpatient admissions reviewed under the AMS between 2017 and 2019. Logistic, log-binomial, and Cox regression analyses were undertaken. Data collected included a documented AAL, antibiotic prescriptions, principal diagnosis, admitting specialty, hospital length of stay, intensive care admissions, and hospital readmissions.

RESULTS

All 1590 pediatric patients were prescribed at least 1 antibiotic. AALs were recorded in 6.6% of patients; majority were β-lactam (82%), mostly penicillins (71%). AALs increased with age (P < .001); no gender effect was seen. Patients with AALs received more quinolones (P < .001), lincosamides (P = .001), aminoglycosides (P < .001), and metronidazole (P = .015) than patients with no AALs. In contrast, children with no AAL received more penicillin (P < .001). Children with any AAL had marginally longer hospital length of stay, median (interquartile range [IQR]) 7.0 (4.0, 15.0) days, than those without, median (IQR) 5.0 (3.75, 11.0) days, P = .027.

CONCLUSION

This study is the first to show how AALs impact clinical outcomes in children under an AMS program. With recent advances in delabeling, early intervention in cases of AAL should target children under AMS services who are in immediate need of optimal antibiotic management.

An Economic Evaluation of Direct Oral Penicillin Challenge for De-Labelling Low Risk Patients With a Penicillin Allergy Label

BACKGROUND

Removing inaccurate penicillin allergy labels (PALs) can reduce unnecessary exposure to 'watch' and 'reserve' groups of antibiotics and thereby reduce antimicrobial resistance. The most efficient model for a non-allergy-specialist-led penicillin allergy de-labelling (PADL) service has not been established.

OBJECTIVE

To determine the costs to the UK National Health Service of a direct oral penicillin challenge (DPC) for low-risk patients with a PAL in three hospitals in England, each with a different non-allergy-specialist delivery model: pharmacist-led, nurse-led, and mixed multidisciplinary.

METHODS

Cost analysis of the DPC pathway, including resources related to staff time and antibiotics. The effect of de-labelling on healthcare utilisation over 5 years was modelled using data from the published literature.

RESULTS

In total, 2257 patients from the Acute Medical or Infectious Disease Unit (AMU/IDU), Pre-surgical, and Haematology-Oncology departments were screened. Subsequently, 126 underwent DPC, and 122 were de-labelled. Twenty-two of these were de-labelled in time to affect their antibiotic regimen; 6 from AMU/IDU and 16 Pre-surgery. The DPC represented 22%-23% of the pathway cost in the pharmacist-led and mixed models, and 15% in the nurse-led model. Across departments and models, the cost per de-labelled patient varied between £577 (95% Credible Interval: 370, 633) for haematology-oncology patients to £2329 (947, 19,504) for AMU/IDU patients, both under the nurse-led model. After 5 years, recouping costs was unlikely for AMU/IDU patients under any model or for all patients combined under the mixed model.

CONCLUSIONS

The penicillin allergy de-labelling pathway cost was  ≥ 4-fold that of the DPC alone. Costs were up to 3 times higher in an acute compared to an elective setting. No short-term cost savings were identified from proactive or opportunistic penicillin allergy de-labelling in this study.

Direct oral penicillin challenge in secondary care with low-risk patients: the SPACE mixed-methods study with cost-effectiveness analysis

Background

One in five inpatients carries a penicillin allergy label. However, 90-95% of labels are incorrect. Penicillin allergy labels lead to increased risk for serious hospital infections and longer hospital stay and are associated with higher estimated healthcare costs. Penicillin allergy testing is onerous and requires a specialist. Routine inpatient testing is not available. Recent evidence suggests that a direct oral penicillin challenge delivered by non-allergy specialists is safe in 'low risk' patients, who are highly unlikely to be allergic based on history.

Aims

To explore behaviour, attitudes and acceptability of patients, healthcare professionals and managers regarding a direct oral penicillin challenge in 'low risk' patients. To inform development of an implementation framework and determine potential cost-effectiveness.

Methods

This study (1 May 2021-30 April 2023) involved delivery of direct oral penicillin challenge by non-allergy specialists across three clinical settings (medical/infectious diseases wards, presurgical and haematology-oncology units) at three hospitals. The study had three workstreams: Workstream 1: Screening for potential suitability. Patients were stratified into 'low risk' and 'high risk'. 'Low-risk' patients underwent direct oral penicillin challenge. Workstream 2: One-to-one semistructured interviews with patients (N = 43) and focus group (N = 28) discussions with stakeholders. Workstream 3: Care pathway mapping, decision-analytic modelling and value of information analysis were carried out to determine potential cost-effectiveness of direct oral penicillin challenge.

Results

One thousand and fifty-four of 2257 screened patients were eligible, 270 of 643 approached patients consented (42%). Two hundred and fifty-nine patients were risk-stratified (155 'low risk'; 104 'high risk'). Of the 155 'low risk' patients, 126 underwent direct oral penicillin challenge, 122 (97%) were de-labelled with no serious allergic reactions and 43 patients were interviewed. Low-risk patients accepted their allergy labels, had limited knowledge of the adverse impact and most were keen to have their labels reviewed. Healthcare professionals demonstrated a risk-averse approach, although would engage in the intervention with training, resource availability and a governance framework in place. The total costs of the direct oral penicillin challenge pathway were higher than the costs of direct oral penicillin challenge alone (£940 vs. £98-288 per patient). There were minimal expected savings in antibiotic and hospital costs in the short term and potentially large healthcare cost savings over 5 years.

Limitations

Relatively small sample size for direct oral penicillin challenge, poor conversion rate, particularly in acute settings, patients with limited English language proficiency could not be included and the study was not sufficiently powered and controlled to conduct a cost-effectiveness evaluation.

Conclusions

This first multicentre United Kingdom study showed that non-allergy specialist-led direct oral penicillin challenge is feasible in secondary care. A high proportion of direct oral penicillin challenges were successful, with positive feedback from patients. Majority of screened patients did not progress through the study pathway. Going forward, a multipronged approach is needed to enhance equitability of direct oral penicillin challenge in routine practice. Follow-up mechanisms to consider the intervention during a clinically stable state and a governance framework for those lacking capacity to consent are needed. The cost of delivering a direct oral penicillin challenge pathway in its entirety is significantly higher than the costs of performing direct oral penicillin challenge per se.

Future work

A randomised controlled trial with long-term follow-up is needed to determine the cost-effectiveness of direct oral penicillin challenge.

Study registration

This study is registered as ISRCTN55524365.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme (NIHR award ref: NIHR129069) and is published in full in Health and Social Care Delivery Research; Vol. 13, No. 9. See the NIHR Funding and Awards website for further award information.

The burden of β-lactam allergy labels in health care: a systematic review and meta-analysis

BACKGROUND

Unverified β-lactam allergy labels (BALs) pose a considerable barrier to optimal antimicrobial treatment and represent a growing public health concern. However, no comprehensive meta-analysis has been conducted to explore the associations between BALs and clinical outcomes. We aimed to evaluate existing evidence on the clinical outcomes associated with BALs to determine their global burden.

METHODS

In this systematic review and meta-analysis, we searched PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), and Embase from Jan 1, 2000, to Nov 30, 2024. We included observational and interventional studies that compared clinical outcomes related to the presence or absence of a BAL (as reported or documented in any clinical record), irrespective of patient age or clinical setting. The outcomes assessed included the incidence of surgical site infections, the incidence of infections or colonisation due to multidrug-resistant organisms (MDROs) or Clostridioides difficile, mortality, and length of hospital stay. Pooled estimates were calculated using random-effects models, with subgroup analyses conducted by region, country income level, type of BAL, hospital setting, sample size, age group, and quality of evidence. Publication bias was assessed using Begg's funnel plots and Egger's regression test. This study is registered with PROSPERO (CRD42023484030).

FINDINGS

63 studies were included in this systematic review, of which 60 (95%) were from high-income countries. Studies were done in the Americas (41 [65%]), Europe (15 [24%]), and the Western Pacific region (seven [11%]). Seven studies were of moderate quality and none were classified as low quality. No significant publication bias was detected for most outcomes, except for length of hospital stay (p=0·0062). Overall, BALs were associated with increased rates of surgical site infection (OR 1·60, 95% CI 1·27-2·01; p<0·0001; I2=70·3%), rates of infection or colonisation with both MDROs (1·42, 1·22-1·64; p<0·0001; I2=84·4%) and C difficile (1·26, 1·16-1·37; p<0·0001; I2=56·4%), and length of hospital stay (standardised mean difference 0·06 days, 95% CI 0·05-0·08; p<0·0001; I2=86·1%). BALs were also associated with death at or after 180 days but not with overall, in-hospital, or 30-day mortality.

INTERPRETATION

BALs are associated with an array of adverse health outcomes, especially surgical site infection and infection or colonisation with MDROs and C difficile. Although BALs were associated with longer hospital stays, the observed difference was unlikely to be clinically relevant. The heterogeneity and methodological limitations of the included studies could limit the robustness of some of our conclusions. However, these findings underscore the need to develop and evaluate public health initiatives to curb inaccurate allergy labelling, thereby reducing unnecessary avoidance of first-line β-lactam antibiotics.

FUNDING

National Natural Science Foundation of China.

A systematic review and meta-analysis of interventions to delabel low-risk penicillin allergies with consideration for sex and gender

AIMS

Sex and gender may influence penicillin allergy label (PAL) prevalence and outcomes. This review evaluates the effectiveness and safety of direct delabelling (DD) and oral challenge (OC) for low-risk patients and examines sex and gender differences in reporting and outcomes.

METHODS

We searched PubMed, Database of Abstracts of Reviews and Effects, ClinicalTrials.gov, Cochrane Database of Systematic Reviews, International Pharmaceutical Abstracts, medRxiv, Ovid MEDLINE, and Ovid EMBASE until February 2024 for studies including DD or OC compared to no intervention, skin testing or other methods. Two reviewers assessed quality. Meta-analyses were conducted, and subgroup analyses were carried out if I2 >   75%. Descriptive data was analysed using NVivo 14 and reported narratively.

RESULTS

From 1046 screened studies, 28 met inclusion criteria (two RCTs, 26 quasi-experimental studies). Sex at baseline was reported in 86% of studies, with 61% females: 18% disaggregated outcomes by sex with a female mean delabelling rate of 66%. Gender variables were not reported. OC was not found to be more or less as effective comparaed to skin testing in RCTs (risk ratio [RR] 1.04; 95% confidence interval [CI] 0.95, 1.13, I2 = 74%). DD interventions had a 27% delabelling rate (95% CI 10%, 50%, I2 = 96%), with nursing staff achieving 29% (95% CI 15%, 47%, I2 = 63%) and allergists/immunologists 6% (95% CI 0.00, 0.00, I2 = 20%). Quasi-experimental studies reported 90% delabelling for OC, with 59% by allergists/immunologists and 90% by pharmacists. Adverse events averaged 4% and were non-severe.

CONCLUSIONS

DD and OC are effective for delabelling low-risk penicillin allergies. Comprehensive data is lacking on sex and gender differences, indicating a need for further research.

Effectiveness analysis of a pharmacist-led intervention for orthopedic perioperative use of antibiotics: a retrospective cohort study

Background

Following the Chinese guidelines' recommendation to completely cancel routine cephalosporin skin tests, the choice of cephalosporin as surgical prophylactic medication was affected. This was due to the limited cognition of the predictive value of cephalosporin skin test or the desire to avoid medical disputes. The aim of this retrospective study was to evaluate whether the pharmacist-led perioperative antibiotic prophylaxis model could improve clinicians' medical behavior in choosing cephalosporin antibiotics for surgical prophylaxis.

Methods

From July 2021 to May 2022, a retrospective analysis was conducted on the selection of surgical preventive medication, skin test, postoperative infection and adverse drug reactions in foot and ankle surgery. The study was divided into three period: the rountine cephalosporin skin test period (Period I: Skin Test), the period when the routine cephalosporin skin test was cancelled but the pharmacist did not intervene (Period II: Cancel Skin Test), and the period when the pharmacist-led perioperative antibiotic prophylaxis was implemented after the cancellation of the cephalosporin skin test (Period III: Pharmacist Intervention).

Results

A total of 1,583 patients were enrolled in this study. There was no significant difference in the utilization rate of cefuroxime between the routine skin test stage and the skin test cancelled stage [74.92% (Period I) vs. 74.54% (Period II), P > 0.05]. However, in the pharmacist intervention stage, the usage rate of cefuroxime significantly increased compared to the initial stage when the skin test was cancelled [87.07% (Period III) vs. 74.54% (Period II), P < 0.05]. The use of cephalosporins also increased in patients with self-reported beta-lactam allergies between these stages [41.94% (Period III) vs. 3.22% (Period II), P < 0.05)]. There was no significant difference in the incidence of postoperative infection and adverse drug reactions among the three periods.

Conclusion

The pharmacist-led perioperative antibiotic prophylaxis model can significantly improve the medical behavior of clinicians in choosing cephalosporin antibiotics as surgical prophylactic medication and optimize the perioperative medication plan.

Exploring Antibacterial Usage and Pathogen Surveillance over Five Years in a Tertiary Referral Teaching Hospital Adult General Intensive Care Unit (ICU)

Antimicrobial resistance is a globally recognised health emergency. Intensive care is an area with significant antimicrobial consumption, particularly increased utilisation of broad-spectrum antibacterials, making stewardship programmes essential. We aimed to explore antibacterial consumption, partnered with pathogen surveillance, over a five-year period (2018 to 2023) in a tertiary referral adult general intensive care unit (ICU). The mean number of admissions was 1645 per annum. A comparison between the ICU populations admitted before and after the COVID-19 pandemic peak (2020/21) identified several notable differences with increased average daily unit bed occupancy (21.6 vs. 25.2, respectively) and a higher proportion of admissions with sepsis (28.4% vs. 32.5%, respectively) in the post-pandemic period. Over the entire five years, the overall proportion of antibacterial use by the WHO AWaRe classification was 42.6% access, 54.7% watch and 2.6% reserve. One hundred and forty-seven positive blood culture isolates were reported, with the most concerning antibacterial resistance identified in 7.5% (9 Escherichia coli and 2 Klebsiella pneumoniae isolates). The COVID-19 pandemic peak year was associated with increased ICU bed occupancy, as well as a greater number of positive blood cultures but lower antibacterial consumption. Despite an increasingly complex workload, a large proportion of overall antibacterial consumption remained within the access category. However, the mortality rate and the incidence of most concerning antimicrobial resistance with respect to pathogens remained satisfyingly consistent, suggesting the positive consequences of real-world antibiotic stewardship in an intensive care setting.

Adult penicillin allergy programmes in Australian hospitals: a practical guide from the National Antibiotic Allergy Network

Penicillin allergy is a significant burden on patient, prescribing and hospital outcomes. There has been increasing interest in the incorporation of penicillin allergy testing (i.e. delabelling) into antimicrobial stewardship (AMS) programmes to reduce the burden of penicillin allergy labels and improve prescribing. In particular, there has been a focus on point-of-care penicillin allergy assessment and direct oral challenge for low-risk phenotypes. The National Antibiotic Allergy Network has provided a guide to assist AMS clinicians with the incorporation of penicillin allergy programmes, in particular direct oral challenge, into Australian hospitals.

Evaluation of Antibiotic Allergy in the Ambulatory Setting Using a Standardized Questionnaire

Patients are sometimes mislabeled as having an immune-mediated antibiotic allergy in their medical records. Therefore, the aim of this study was to investigate the prevalence of subjects with non-immune mediated reactions to antibiotics using a standardized questionnaire. Subjects aged 18 years and older with a documented antibiotic allergy were identified and recruited from 2 outpatient clinics in the greater Chicago area. Subjects completed a standardized questionnaire during a single visit regarding their previous adverse reaction to an antibiotic. For subjects with multiple documented antibiotic allergies, 1 questionnaire was filled out for each antibiotic allergy. Investigators subsequently evaluated the questionnaire responses to determine whether the adverse reaction was a true immune-mediated allergic reaction or an adverse drug reaction. A total of 98 subjects were recruited with completion of 159 questionnaires. Eighteen subjects (18.37%, 95% CI: 10.7%, 26.3%) had antibiotic allergy labels with no corresponding immune-mediated reaction history. There were 35 allergy labels (22.0%, 95% CI: 14.7%, 29.4%) that were unlikely to be immune-mediated. Antibiotics with the highest percentage of clinical histories that were unlikely to be immune-mediated were macrolides (8 of 11 subjects), nitrofurantoin (1 of 2 subjects), and amoxicillin/clavulanate (2 of 8 subjects). The most common antibiotic allergy labels were penicillin (43 of 159 subjects), sulfonamides (25 of 159 subjects), and fluoroquinolones (21 of 159 subjects). Identification of adverse reactions to antibiotics that are unlikely to be immune-mediated can be accomplished using a standardized questionnaire in the outpatient setting. Improved identification of low-risk antibiotic allergy labels can guide de-labeling initiatives to improve antibiotic prescribing.

Effectiveness of direct delabelling of allergy labels in type A adverse drug reactions to penicillin: a multicentre hospitalwide prospective cohort study

BACKGROUND

Patient-reported penicillin allergy labels (PALs) are associated with adverse patient outcomes and inappropriate antibiotic prescribing. Removal of PALs via direct oral challenge (DOC) is associated with increased penicillin utilization post removal.

OBJECTIVES

To assess the impact of direct delabelling (allergy label removal via medical reconciliation alone) of type A adverse drug reaction (ADR) PALs on inpatient prescribing.

METHODS

From January 2019 to December 2022 at two tertiary hospitals in Melbourne, patients aged ≥18 years with type A ADR PALs, as defined by the validated Antibiotic Allergy Assessment Tool, were offered direct delabelling or single-dose DOC. The primary endpoint was antibiotic use pre- and post-assessment (during index admission and 90 days post assessment). The secondary endpoint was the proportion of patients delabelled in the direct delabelling and DOC cohorts in the electronic medical record at 90 days post assessment.

RESULTS

Allergy labels (n = 4108) were assessed for 488 participants, with 490 individual type A ADR PAL assessments included. Three hundred and thirty-seven patients were directly delabelled, 69 underwent DOC and 84 were not delabelled. There was increased use of any penicillin following direct delabelling (OR 19.19, 95% CI 2.48-148.36) and DOC (OR 56.98, 95% CI 6.82-476.19) during the index admission, higher in the DOC group compared with direct delabelling (OR 2.97, 95% CI 1.39-6.37). Relabelling at 90 days was low with no statistically significant difference between direct delabelling (5/337; 1.5%) and DOC (0/69; 0%).

CONCLUSIONS

Both direct delabelling and DOC of type A ADR PALs increased penicillin usage; however, the impact was greatest with DOC. Most patients remain delabelled at 90 days.

Factors influencing implementation and adoption of direct oral penicillin challenge for allergy delabelling: a qualitative evaluation

BACKGROUND

Over 95% of penicillin allergy labels are inaccurate and may be addressed in low-risk patients using direct oral penicillin challenge (DPC). This study explored the behaviour, attitudes and acceptability of patients, healthcare professionals (HCPs) and managers of using DPC in low-risk patients.

METHODS

Mixed-method, investigation involving patient interviews and staff focus groups at three NHS acute hospitals. Transcripts were coded using inductive and deductive thematic analysis informed by the Theoretical Domains Framework.

FINDINGS

Analysis of 43 patient interviews and three focus groups (28 HCPs: clinicians and managers) highlighted themes of 'knowledge', 'beliefs about capabilities and consequences', 'environmental context', 'resources', 'social influences', 'professional role and identity', 'behavioural regulation and reinforcement' and a cross-cutting theme of digital systems. Overall, study participants supported the DPC intervention. Patients expressed reassurance about being in a monitored, hospital setting. HCPs acknowledged the need for robust governance structures for ensuring clarity of roles and responsibilities and confidence.

CONCLUSION

There were high levels of acceptability among patients and HCPs. HCPs recognised the importance of DPC. Complexities of penicillin allergy (de)labelling were highlighted, and issues of knowledge, risk, governance and workforce were identified as key determinants. These should be considered in future planning and adoption strategies for DPC.

Narrative review of recent developments and the future of penicillin allergy de-labelling by non-allergists

This article outlines recent developments in non-allergist delivered penicillin allergy de-labelling (PADL), discusses remaining controversies and uncertainties and explores the future for non-allergist delivered PADL. Recent developments include national guidelines for non-allergist delivered PADL and validation of penicillin allergy risk assessment tools. Controversies remain on which penicillin allergy features are low risk of genuine allergy. In the future genetic or immunological tests may facilitate PADL.

Management and Implications of Beta-Lactam Allergies

Beta-lactam antibiotics are essential components in the current antimicrobial treatment strategy, playing a crucial role in ambulatory patients and hospitalized patients. Despite their prominent therapeutic index, the use of beta-lactam can lead to adverse effects, with allergic reactions being the most concerning because of their severity. Additionally, the phenomenon of cross-reactivity may occur among various beta-lactam families, with side chains significantly contributing to immunological recognition, making these structures often responsible for the cross-allergic reactivity of beta-lactams. Tools to assess beta-lactam allergy include taking a patient's medical history, performing skin tests, and conducting provocation tests. This research aims to analyze the relevant aspects related to the safe administration of beta-lactam antibiotics in hospitalized patients as well as provide knowledge on the proper management of patients with such hypersensitivity, by doing systemic research. This research was made using Google Scholar and keywords such as "Beta-lactam allergy," "Hypersensitivity," "Cross-reactivity," "Desensitization," and "Beta-lactam allergy management." In conclusion, substituting a beta-lactam antibiotic with an alternative antibiotic may not always be the best management option for these patients, as it may lead to more adverse effects, be less effective, and prolong hospitalization time. It may also result in higher rates of antibiotic-resistant infections and increased medical costs, as these alternatives are often more expensive. However, an alternative within the beta-lactam family can be sought by conducting the appropriate analyses. Although cross-reactivity does not always occur among all beta-lactams, potential cross-reactivity should always be considered.

[Precision medicine in infectious diseases]

Infectious medicine faces a variety of challenges, such as the increase in antibiotic resistance and the emergence and spread of infectious diseases fueled by climate change and globalization. Precision medicine can provide solutions to many of these challenges. Since an untargeted request for diagnostic tests can lead to test results without clinical relevance, which can increase the use of non-indicated antibiotics, the principle aimed at is: targeted diagnostics (the right test) and consideration of patient characteristics (the right person) to optimize management (the right action). At the same time, one must always decide whether empirical therapy must be immediately initiated, even if the results of the initiated diagnostics are not yet available. In addition, many new diagnostics as well as therapies have recently been developed for the rapid detection and more specific treatment of bacterial infections. Molecular genetic methods, which offer more rapid results than classical bacterial cultures, are gaining ground as new diagnostics. New therapeutics such as bacteriophages, antibodies or antibacterial peptides allow increasingly precise treatment of certain bacterial infections. Precision medicine will also play an increasingly important role in infectious medicine in the future.

A multicentre observational study to investigate feasibility of a direct oral penicillin challenge in de-labelling 'low risk' patients with penicillin allergy by non-allergy healthcare professionals (SPACE study): Implications for healthcare systems

OBJECTIVE

The huge burden of inaccurate penicillin allergy labels (PALs) is an important driver of antimicrobial resistance. This is magnified by insufficient allergy specialists and lack of 'point-of-care' tests. We investigated the feasibility of non-allergy healthcare professionals (HCPs) delivering direct oral penicillin challenges (DPCs) for penicillin allergy de-labelling.

METHODS

This prospective observational study was conducted in three hospitals in England across three settings (acute medical, pre-surgical and haematology-oncology). Patients with a PAL were screened and stratified as low risk/high risk. Low risk patients (non-immune mediated symptoms, benign rash, tolerated amoxicillin since and family history) underwent a DPC.

RESULTS

N = 2257 PALs were screened, 1054 were eligible; 643 were approached, 373 declined, 270 consented and 259 risk stratified (low risk = 155; high risk = 104). One hundred and twenty-six low risk patients underwent DPC, 122 (96.8%) were de-labelled with no serious allergic reactions. Conversion rate from screening-to-consent was 12% [3.3% and 17.9% in acute and elective settings respectively; odds ratios for consent were 3.42 (p < 0.001) and 5.53 (p < 0.001) in haematology-oncology and pre-surgical setting respectively. Common reasons for failure to progress in the study included difficulty in reaching patients, clinical instability/medical reasons, lacking capacity to consent and psychological factors.

INTERPRETATION

DPCs can be delivered by non-allergy HCPs. A high proportion of patients with PALs did not progress in the study pathway. Strategies to deliver DPC at optimal points of the care pathway are needed to enhance uptake. Elective settings offer greater opportunities than acute settings for DPC. The safety and simplicity of DPCs lends itself to adoption by healthcare systems beyond the UK, including in resource-limited settings.

Antibiotic Stewardship: A Handshaking Strategy Among Physicians and Pharmacists to Improve therapeutic Outcomes in Hematology-Oncology

Background: Infections are highly susceptible in patients with hematological malignancies due to immune suppression, immunosuppressive therapies and disease progression. Rational use of antibiotics following Antimicrobial Stewardship (AMS) guidelines in early detection and response to infection is significant to improve patient care. Objectives: The present study was conducted to determine the impact of clinical pharmacists' interventions (PIs) on antibiotics usage in hematology-oncology set up in Karachi, Pakistan. Methodology: An observational prospective study was conducted for a period of 4 months in a well-known 75-bed teaching hospital, specializing in bone marrow transplantation in Karachi, Pakistan without a structured Antimicrobial stewardship programs (ASPs). The information was gathered from patient medical histories, laboratory, and microbiological records. Results: A total of 876 PIs (1 to 5 per patient) were implemented. Dose modifications or interval changes accounted for the major interventions (n = 190, 21.6%). The majority of all recommendations were related to antipseudomonal β-lactams, aminoglycosides, sulfamethoxazole-trimethoprim and vancomycin. Overall, 94.3% (n = 876) of the 928 PIs were accepted. Conclusion: The PIs and the high physician acceptance rate may be useful for improving the safe use of antibiotics, lowering their toxicity, lowering the need for special-vigilance medications and potentially improving patient care.

The role of clinical pharmacists in patients with suspected allergy to β-lactams: A systematic review

OBJECTIVE

To analyze the role played by the clinical pharmacist and its impact in antibiotic stewardship facing suspected allergy to beta-lactam antibiotics.

METHOD

We performed two different independent bibliographic searches. A total of 35 articles were found, and the final number included in the study was 12. We analysed the articles and collected variables of efficacy, safety and applicability of evaluation tools applied to patients with suspected allergy to beta-lactams. Also, the variation in the consumption and prescription profile of alternative antibiotics was analyzed.

RESULTS

The selected studies analysed questionnaires, allergy delabeling, intradermal tests and oral challenge tests performed by pharmacists. Significant differences in the efficacy endpoint were found in 4 studies in favour of pharmaceutical intervention. In the study of Kwiatkowski et al, cefazolin use increased in surgical patients after pharmacist intervention (65 vs. 28%; p < 0.01). In a quasi-experimental study, the mean defined daily dose of aztreonam and the mean days of therapy per 1000 patients/day decreased (21.23 vs 9.05, p <0.01) and (8.79-4.24, p = 0.016), pre and post-intervention, respectively, increasing antibiotic de-escalations (p ≤ 0.01). In another quasi-experimental study, the prescription of restricted-use antibiotics decreased (42.5% vs. 17.9%, p < 0.01) and the use of pre-surgical prophylactic antibiotics alternative to cefazolin (81.9% vs 55.9%, p<0.01) in another study. Other study showed that the mean time per interview was 5.2 minutes per patient. No adverse events were reported in any study.

CONCLUSION

The pharmacist intervention in the evaluation of the patient with suspected allergy to beta-lactams is effective, safe and feasible to implement on daily clinical practice. The standardization of protocols to clarify the history of allergies and development of evaluation tools represent simple screenings to perform delabelling or refer to the Immunoallergology service, improving penicilins use and reducing the need for second line antibiotics. More studies are needed to standardize the desensitization tests made by pharmacists. However, despite these results, the involvement and leadership of the pharmacist in this area is limited and constitutes a future challenge for the profession.

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.

Inpatient allergy delabeling of pediatric patients with low-risk penicillin allergy status through direct oral amoxicillin challenge

Background: Less than 5% of children who report penicillin allergy have clinically pertinent type 1 immunoglobulin E mediated hypersensitivity reaction by using direct oral amoxicillin challenge. Several pathways have been developed to delabel penicillin allergy by using direct oral amoxicillin challenge, mostly in the outpatient settings, but there is relative scarcity on published outcomes of these pathways, especially in the inpatient pediatric settings. Objective: This study aimed to evaluate the performance of an institutionally derived inpatient penicillin allergy screening tool. Methods: Patients were stratified into three penicillin allergy risk categories by using an institutional screening questionnaire. Patients with a no-risk status were delabeled without challenge testing. Patients with low-risk status underwent direct graded oral amoxicillin challenge and delabeled based on their response. Patients with high-risk status were referred to allergy service. Results: Ninety-two patients were identified with penicillin allergy. Forty of the 92 patients (43%) were screened. Of the 40 patients screened, 6 (15%) were identified as no risk, 28 (70%) were identified as low risk, and 6 (15%) were identified as high risk. Twenty-four of the 28 patients at low risk (86%) were eligible for direct amoxicillin oral challenge. Seventeen of the 24 (71%) consented to oral challenge but only 12 (71%) underwent direct amoxicillin oral challenge. Eleven of the 12 who underwent oral challenge (92%) were successfully delabeled. Five of the six patients at no risk (83%) were successfully delabeled. Three of the six patients at high risk (50%) were referred for further allergy evaluation. Overall, 16 of the 40 patients screened (40%) were successfully delabeled. Conclusion: In this small pediatric inpatient study, our institutional risk stratification screening tool identified patients at low risk for penicillin allergy and direct graded oral amoxicillin challenge was safely administered to delabel penicillin allergy in these patients.Clinical trial NCT05020327, www.clinicaltrials.gov.

[Translated article] The role of clinical pharmacists in patients with suspected allergy to β-lactams: A systematic review

OBJECTIVE

To analyze the role played by the clinical pharmacist and its impact in antibiotic stewardship facing suspected allergy to beta-lactam antibiotics.

METHOD

We performed 2 different independent bibliographic searches. A total of 35 articles were found, and the final number included in the study was 12. We analyzed the articles and collected variables of efficacy, safety, and applicability of evaluation tools applied to patients with suspected allergy to beta-lactams. Also, the variation in the consumption and prescription profile of alternative antibiotics was analyzed.

RESULTS

The selected studies analyzed questionnaires, allergy delabeling, intradermal tests, and oral challenge tests performed by pharmacists. Significant differences in the efficacy endpoint were found in 4 studies in favor of pharmaceutical intervention. In the study of Kwiatkowski et al., cefazolin use increased in surgical patients after pharmacist intervention (65% vs 28%; P < .01). In a quasi-experimental study, the mean defined daily dose of aztreonam and the mean days of therapy per 1000 patients/day decreased (21.23 vs 9.05, P <.01) and (8.79-4.24, P = .016), pre- and post-intervention, respectively, increasing antibiotic de-escalations (P = < .01). In another quasi-experimental study, the prescription of restricted use antibiotics decreased (42.5% vs 17.9%, P < .01)and the use of pre-surgical prophylactic antibiotics alternative to cefazolin (81.9% vs 55.9%, P < .01)in another study. Other study showed that the mean time per interview was 5.2 min per patient. No adverse events were reported in any study.

CONCLUSION

The pharmacist intervention in the evaluation of the patient with suspected allergy to beta-lactams is effective, safe, and feasible to implement on daily clinical practice. The standardization of protocols to clarify the history of allergies and development of evaluation tools represent simple screenings to perform delabeling or refer to the Immunoallergology service, improving penicilins use and reducing the need for second-line antibiotics. More studies are needed to standardize the desensitization tests made by pharmacists. However, despite these results, the involvement and leadership of the pharmacist in this area is limited and constitutes a future challenge for the profession.

Penicillin allergy de-labelling by non-allergists: a comparison of testing protocols

Optimizing penicillin allergy de-labelling (PADL) to ensure patients with an incorrect penicillin allergy record are de-labelled with minimal patient harm is important for antibiotic stewardship. The heterogeneity of inclusion and exclusion criteria in the published penicillin allergy testing protocols risks suboptimal delivery of PADL. We compared the similarities and the differences between non-allergist-delivered PADL testing protocols and make suggestions for harmonization. The observed variation in testing practice has two broad elements: (i) definitions and terminology; and (ii) differences in the acceptability of perceived risk. All direct drug provocation testing (DDPT) protocols included patients with benign delayed rash as eligible for testing, although the remoteness of the rash, and the terminology used to describe the rash, differed. Patients with features of potential IgE reactions were excluded from most DDPT protocols, but not all of them. There was differing advice on how to manage patients who had subsequently tolerated penicillin since the index reaction and differences in which patients were considered ineligible for DDPT due to acuity of illness, comorbidities and concomitant medications. Standardization of the terminology used in penicillin allergy testing protocols and consensus on inclusion and exclusion criteria are required for safe and efficient PADL delivery at scale by non-allergists.

Penicillin Allergy Impact and Management

There is international evidence that penicillin allergies are associated with inferior prescribing and patient outcomes. A host of tools now exist from assessment (risk assessment tools, clinical decision rules) to delabeling (the removal of a beta-lactam allergy via testing or medical reconciliation) to reduce the impact of these "labels" in the hospital and community setting, as a primary antimicrobial stewardship intervention.

The Burden of Self-Reported Antibiotic Allergies in Health Care and How to Address It: A Systematic Review of the Evidence

BACKGROUND

Antibiotics are the first-line treatment for bacterial infections; however, overuse and inappropriate prescribing have made antibiotics less effective with increased antimicrobial resistance. Unconfirmed reported antibiotic allergy labels create a significant barrier to optimal antimicrobial stewardship in health care, with clinical and economic implications.

OBJECTIVE

A systematic review was conducted to summarize the impact of patient-reported antibiotic allergy on clinical outcomes and various strategies that have been employed to effectively assess and remove these allergy labels, improving patient care.

METHODS

The review was undertaken using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A critical appraisal was conducted on all studies and a narrative synthesis was performed to identify themes.

RESULTS

Four themes emerged: the prevalence of antibiotic allergy, impact of antibiotic allergy on antimicrobial prescribing, impact of antibiotic allergy on clinical outcomes, and delabeling strategies to improve clinical outcomes. Of the 32 studies, including 1,089,675 participants, the prevalence of reported antibiotic allergy was between 5% and 35%. Patients with a reported antibiotic allergy had poorer concordance with prescribing guidelines in 30% to 60% of cases, with a higher use of alternatives such as quinolone, tetracycline, macrolide, lincosamide, and carbapenem and lower use of beta-lactam antibiotics. Antibiotic allergy delabeling was identified as an intervention and recommendation to advance the state of the science.

CONCLUSIONS

There is substantial evidence within the literature that antibiotic allergy labels significantly impact patient clinical outcomes and a consensus that systematic assessment of reported antibiotic allergies, commonly referred to as delabeling, improves the clinical management of patients.

Facilitators and Barriers to Verifying Penicillin Allergies in a Veteran Nursing Home Population

BACKGROUND

Unconfirmed penicillin allergies are common and may contribute to adverse outcomes, especially in frail older patients. Evidence-based clinical pathways for evaluating penicillin allergies have been effectively and safely applied in selected settings, but not in nursing home populations.

OBJECTIVE

To identify potential facilitators and barriers to implementing a strategy to verify penicillin allergies in Veterans Health Administration nursing homes, known as Community Living Centers (CLCs).

METHODS

We conducted semistructured interviews with staff, patients, and family members at 1 CLC to assess their understanding of penicillin allergies and receptiveness to verifying the allergy. We also asked staff about the proposed allergy assessment strategy, including willingness to delabel by history and feasibility of performing oral challenges or skin testing on their unit.

RESULTS

From 24 interviews (11 front-line staff, 4 leadership, 3 patients, 6 family members), we identified several facilitators or barriers. Staff recognized the importance of allergy verification and were willing to support and assist in implementing verification strategies. The CLC residents were willing to have their allergy status verified. However, some family members expressed reluctance to verifying their relative's allergy status owing to safety concerns. Front-line staff also expressed concern over having the necessary resources, including time and expertise, to implement the strategy. Staff suggested involving clinical pharmacists and educating staff, patients, and family members as ways to overcome these barriers.

CONCLUSIONS

Concerns about safety and staff resources are important potential barriers to implementing verification strategies. Involvement of pharmacists and education of both staff and patients and family members will be important components of any successful intervention.

The Who, What, When, and Where of Inpatient Direct Oral Penicillin Challenge-Implications for Health Services Implementation

Inpatient direct oral challenge programs are increasingly deployed as part of antimicrobial stewardship initiatives to reduce the burden and impacts of penicillin allergy labels on antibiotic prescribing. Using data from a prospective, multicenter cohort inpatient penicillin allergy program, we identify the key targets for delabeling to aid health service implementation.

Delabeling of Penicillin Allergy: Room for Improvement

BACKGROUND

Penicillin allergy labels have been shown to be associated with suboptimal treatment, negative health outcomes, and increased antibiotic resistance. Many inpatients claim to have penicillin allergy, but studies show that allergy can be disproved and the label removed in up to 90% of cases.

OBJECTIVES

The purpose of the study was to investigate the proportion of patients with a penicillin allergy label in a Danish hospital and to classify patients according to the risk of having penicillin allergy in "no risk," low, and high risk.

METHODS

For 22 days, inpatients with penicillin allergy labels were interviewed, had their dispensed penicillin prescriptions examined, and were subsequently categorized into risk groups based on the risk evaluation criteria in national guidelines.

RESULTS

In total, 260 patients had a penicillin allergy label (10% of the inpatients). Out of 151 included patients, 25 were "no risk" patients (17%), who could potentially have their penicillin allergy label removed without testing. 42 were low-risk patients (28%). 10 "no risk" patients and 20 low-risk patients had been prescribed and dispensed one or more penicillins despite an allergy label.

CONCLUSION

Ten percent of inpatients have a penicillin allergy label in a Danish hospital. 17% of these could potentially have their penicillin allergy label removed without allergy testing.

Impact of Penicillin Allergy Label on Clinical Outcomes of Pneumonia in Children

BACKGROUND

Penicillin (PCN) allergy label, reported in approximately 5% of children, influences antibiotic choice and prolongs hospital stay. To our knowledge, the impact of PCN allergy label on clinical outcomes of pneumonia in children is not well characterized.

OBJECTIVES

To investigate the impact of PCN allergy label on clinical outcomes of pneumonia in children.

METHODS

In this propensity score-matched cohort study, we used the TriNetX research network, a population-based database, to compare the 30-day risk of hospitalization, need for intensive level of care, and acute respiratory failure from pneumonia between pediatric patients (aged 1-17 years) with and without a PCN allergy label after matching the 2 cohorts for demographic and medical comorbidities. Antibiotic prescription patterns were also contrasted.

RESULTS

When comparing 3793 pediatric patients with pneumonia labeled with a PCN allergy with matched children without a PCN allergy label, PCN allergy label was associated with a higher risk of hospitalization (relative risk [RR], 1.15; 95% confidence interval [CI], 1.07-1.23), acute respiratory failure (RR, 1.27; 95% CI, 1.17-1.39), and need for intensive level of care (RR, 1.46; 95% CI, 1.15-1.84). PCN allergy label resulted in overutilization of broader-spectrum antibiotics and increased complications including cutaneous drug reactions (RR, 2.43; 95% CI, 1.31-4.52) and Clostridioides difficile infection (RR, 2.25; 95% CI, 1.14-4.44).

CONCLUSION

Children with a PCN allergy label are more likely to be hospitalized, receive broader-spectrum antibiotics, and develop acute respiratory failure from pneumonia. Delabeling may offer a way to lessen morbidity from pneumonia in children.

Penicillin de-labelling in vancouver, British Columbia, Canada: comparison of approaches, outcomes and future directions

BACKGROUND

Inaccurate penicillin allergy labels lead to inappropriate antibiotic prescriptions and harmful patient consequences. System-wide efforts are needed to remove incorrect penicillin allergy labels, but more health services research is required on how to best deliver these services.

METHODS

Data was extracted from five hospitals in Vancouver, British Columbia, Canada from October 2018-May 2022. The primary outcomes of this study were to outline de-labelling protocol designs, identify the roles of various healthcare professionals in de-labelling protocols and identify rates of de-labelling penicillin allergies and associated adverse events at various institutions. Our secondary outcome was to describe de-labelling rates for special populations, including pediatric, obstetric and immunocompromised subpopulations. To achieve these outcomes, participating institutions provided their de-labelling protocol designs and data on program participants. Protocols were then compared to find common themes and differences. Furthermore, adverse events were reviewed and percentages of patients de-labelled at each institution and in total were calculated.

RESULTS

Protocols demonstrated a high level of variability, including different methods of participant identification, risk-stratification and roles of providers. All protocols used oral and direct oral challenges, heavily involved pharmacists and had physician oversight. Despite the differences, of the 711 patients enrolled in all programs, 697 (98.0%) were de-labelled. There were 9 adverse events (1.3%) with oral challenges with mainly minor symptoms.

CONCLUSIONS

Our data demonstrates that de-labelling programs effectively and safely remove penicillin allergy labels, including pediatric, obstetric and immunocompromised patients. Consistent with current literature, most patients with a penicillin allergy label are not allergic. De-labelling programs could benefit from increasing clinician engagement by increasing accessibility of resources to providers, including guidance for de-labelling of special populations.

The effectiveness of interventions that support penicillin allergy assessment and delabeling of adult and pediatric patients by nonallergy specialists: a systematic review and meta-analysis

OBJECTIVES

Penicillin allergy records are often incorrect and may result in harm. We aimed to systematically review the effectiveness and safety of nonallergist health care worker delivery of penicillin allergy delabeling.

METHODS

We searched EMBASE/MEDLINE/CINAHL (Ovid), PsycInfo, Web of Science, and Cochrane CENTRAL from inception to January 21, 2022 and unpublished studies and gray literature. The proportion of patients allergic to penicillin delabeled and harmed was calculated using random-effects models.

RESULTS

Overall, 5019 patients were delabeled. Using allergy history alone, 14% (95% confidence interval [CI], 9-21%) of 4350 assessed patients were delabeled without reported harm. Direct drug provocation testing resulted in delabeling in 27% (95% CI, 18-37%) of 4207 assessed patients. Of the 1373 patients tested, 98% were delabeled (95% CI, 97-99%), and nonserious harm was reported in 1% (95% CI, 0-2%). Using skin testing, followed by drug provocation testing, 41% (95% CI, 24-59%) of 2890 assessed patients were delabeled. Of the 1294 tested patients, 95.0% (95% CI, 90-99%) were delabeled, and the reported harm was low (0%; (95% CI 0-1%).

CONCLUSION

Penicillin allergy delabeling by nonallergists is efficacious and safe. The proportion of assessed patients who can be delabeled increases with the complexity of testing method, but substantial numbers can be delabeled without skin testing.

Comparative Effectiveness, Safety, and Real-World Outcomes of a Nurse-Led, Protocol-Driven Penicillin Allergy Evaluation From the Hong Kong Drug Allergy Delabelling Initiative (HK-DADI)

BACKGROUND

There is a high prevalence of unconfirmed penicillin allergy, which is associated with a multitude of adverse clinical outcomes. With the overwhelming burden of currently incorrect labels and the lack of allergy specialist services, new delabeling strategies are urgently needed.

OBJECTIVE

To assess the effectiveness, safety, and real-world outcomes of a nurse-led, protocol-driven evaluation of penicillin allergy, the Hong Kong Drug Allergy Delabelling Initiative (HK-DADI).

METHODS

Adult patients with suspected penicillin allergy were recruited into HK-DADI. Allergy and postdelabeling outcomes were retrospectively compared between patients evaluated via HK-DADI or traditional allergist evaluation.

RESULTS

A total of 312 completed penicillin allergy evaluation: 84 (27%) and 228 (73%) via HK-DADI and traditional pathways, respectively. Overall, 280 penicillin allergies were delabeled (90%). The delabeling rate between HK-DADI and traditional pathways was similar (90% vs 89%; P = .796). Among patients of the HK-DADI pathway, the delabeling rate was significantly higher among low-risk (LR) compared with non-LR patients (97% vs 77%; P = .010). Skin tests did not add diagnostic value among LR patients. No patients developed severe or systemic reactions during the evaluation. Upon 6- to 12-month follow-up (median, 10 months), 123 patients experienced infective episodes (44%) and 63 used penicillins again after delabeling (23%). This proportion was significantly higher in patients who were delabeled via HK-DADI compared with the traditional pathway (32% vs 19%; P = .026).

CONCLUSIONS

The Hong Kong Drug Allergy Delabelling Initiative, a nurse-led, protocol-driven evaluation, was safe and effective in penicillin allergy delabeling. It led to an even higher rate of future penicillin use after delabeling and mitigated the need for unnecessary skin testing among LR patients.

Addressing the Challenges of Penicillin Allergy Delabeling With Electronic Health Records and Mobile Applications

Allergy labels are common, often incorrect, and potentially harmful. There are many opportunities for clinical decision support (CDS) tools integrated in the electronic health record (EHR) and mobile apps to address the challenges with drug allergy management, including penicillin allergy delabeling (PADL). Effective delabeling solutions must consider multidisciplinary clinical workflow and multistep processes, including documentation, assessment, plan (eg, allergy testing and referral), record update, drug allergy alert management, and allergy reconciliation over time. Developing a systematic infrastructure to manage allergies across the EHR is critical to improve the accuracy and completeness of a patient's allergy and avoid inadvertently relabeling. Improving the appropriateness and relevancy of drug allergy alerts is important to reduce alert fatigue. Using alerts to guide clinicians on appropriate antibiotic use may reduce unnecessary β-lactam avoidance. To date, EHR CDS tools have facilitated non-allergists to provide PADL at the point of care. A mobile app was shown to support PADL and provide specialist support and education. Future research is needed to standardize, integrate, and evaluate innovative CDS tools in the EHR to demonstrate patient safety and clinical utility and facilitate wider adoption.

Barriers to paediatric penicillin allergy de-labelling in UK secondary care: a regional survey

BACKGROUND

Incorrect penicillin allergy labels result in the use of inappropriately broad-spectrum antibiotics. De-labelling inaccurate penicillin allergy promotes antimicrobial stewardship and optimises prescribing practices. The objectives were to evaluate paediatric clinicians' knowledge and understanding of penicillin allergy and to identify barriers in tackling incorrect penicillin allergy labels.

METHODS

Paediatric clinicians from across the West Midlands of the UK were surveyed using an online, anonymised questionnaire between 1 August and 30 September 2021. Domains explored were (1) approach to penicillin allergy clinical vignettes, (2) knowledge of the impact of penicillin allergy labels, (3) frequency of allergy-focused history questions and (4) barriers in tackling incorrect penicillin allergy.

RESULTS

Responses were received from 307 paediatric clinicians across 12 hospitals. Sixty-one per cent would not prescribe a penicillin-based antibiotic if a family history of penicillin allergy was reported. There was an overall deficit in taking an allergy-focused history with only 36.5% inquiring about diagnostic confirmation. Absence, or lack of awareness of a referral pathway for antibiotic allergy evaluation (58.6%) and unfamiliarity of the indications for oral provocation testing (55%) were the most common reported barriers to penicillin allergy de-labelling. Fifty-one per cent would rather 'play it safe' than explore penicillin allergy confirmation as it is felt that alternative treatments were readily available.

CONCLUSIONS

The deficiency in antibiotic allergy-focused history among paediatric clinicians highlights the need for better allergy education across all clinical grades. Pragmatic algorithms and clear referral pathways could address barriers faced by non-allergists in de-labelling incorrect penicillin allergy.

Improving drug allergy label accuracy by supervised safety- and protocol-driven evaluation

Introduction: Drug allergies are often self-reported but of unknown accuracy. We carried out a prospective study to examine the utility and safety of formal allergology evaluation, and to identify factors associated with accurate drug allergy labels. Method: All patients who underwent drug allergy evaluation in our clinic during the study period were recruited. Baseline demographics, characteristics of index hypersensitivity reaction and outcomes of evaluation were recorded. Results: A total of 331 patients from March 2019 to June 2021 completed drug allergy evaluation to index drugs of concern. There were 123 (37%) male patients, and the mean age was 49 years (standard deviation 17). There were 170 beta-lactam antibiotics, 53 peri-operative drugs, 43 others, 38 non-steroidal anti-inflammatory drugs, and 27 non-beta-lactam antibiotic evaluations. Index reaction occurred within 5 years in 165 (50%) patients, with latency of less than 4 hours in 125 (38%) patients. The most common index reactions were rash, angioedema and urticaria. There were 57 (17%) evaluations stratified as low risk, 222 (67%) moderate risk, and 52 (16%) high risk based on multidisciplinary consensus. Allergy label was found to be false (negative drug evaluation) in 248 (75%) patients, while 16/237 (7%) skin tests, 44/331 (13%) in-clinic graded challenge, and 23/134 (17%) home prolonged challenges were positive (true drug allergy). The most common evaluation reactions were rash and urticaria. No cases of anaphylaxis were elicited. Conclusion: Seventy-five percent of drug allergy labels are inaccurate. Risk-stratified, protocolised allergy evaluation is safe. Prolonged drug challenge increases the sensitivity of drug allergy evaluation and should therefore be performed when indicated. Keywords: Drug allergy, drug hypersensitivity, graded challenge, prolonged drug provocation, skin testing

Differences in beta-lactam and penicillin allergy: Beyond the West and focusing on Asia-Pacific

Beta-lactam (BL) antibiotic "allergy" labels are common, but often overdiagnosed. Although much research has been focused on the BL allergy and the delabelling process in the West, studies from other parts of the world remain sparse. This review outlines the contrasting global epidemiology, shifting clinical practices and disparities of BL allergy in the Asia-Pacific region compared with the West. Innovative strategies to overcome barriers in BL allergy workup are discussed and potential directions for future research and service development are also proposed.

BSACI guideline for the set-up of penicillin allergy de-labelling services by non-allergists working in a hospital setting

The Standards of Care Committee of the British Society for Allergy and Clinical Immunology (BSACI) and a committee of experts and key stakeholders have developed this guideline for the evaluation and testing of patients with an unsubstantiated label of penicillin allergy. The guideline is intended for UK clinicians who are not trained in allergy or immunology, but who wish to develop a penicillin allergy de-labelling service for their patients. It is intended to supplement the BSACI 2015 guideline "Management of allergy to penicillin and other beta-lactams" and therefore does not detail the epidemiology or aetiology of penicillin allergy, as this is covered extensively in the 2015 guideline (1). The guideline is intended for use only in patients with a label of penicillin allergy and does not apply to other beta-lactam allergies. The recommendations include a checklist to identify patients at low risk of allergy and a framework for the conduct of drug provocation testing by non-allergists. There are separate sections for adults and paediatrics within the guideline, in recognition of the common differences in reported allergy history and likelihood of true allergy.

Drug Allergy Delabeling Programs: Recent Strategies and Targeted Populations

Drug allergy delabeling programs have become an essential element of antibiotic stewardship. Development of delabeling programs involves careful selection of target patient population, thoughtful design of delabeling approach, stakeholder engagement, assembly of key team members, implementation, and evaluation of clinical and safety outcomes. Recent programs have targeted patients thought to be most likely to benefit from removal of inaccurate antibiotic allergy labels, those with β-lactam antibiotic allergies and high-risk populations likely to need β-lactam antibiotics as first-line treatment. This review provides an overview of current risk stratification methods and β-lactam cross-reactivity data and summarizes how different inpatient and outpatient delabeling programs have used these concepts in delabeling algorithms. β-Lactam delabeling programs for inpatients, pediatric patients, and programs utilizing telehealth have been implemented with good outcomes. This review also focuses on delabeling programs for high-risk populations likely to benefit from first-line β-lactam antibiotics. These populations include perioperative, prenatal, and immunocompromised patients. Delabeling programs have been successful in the inpatient and outpatient settings at enabling appropriate antibiotic use. This article reviews delabeling strategies utilized by these programs with a focus on highlighting elements key to their success and future areas for innovation.

Effectiveness of interventions that support penicillin allergy assessment and de-labelling of patients by non-allergy specialists: a systematic review protocol

OBJECTIVE

This review will systematically examine and synthesize the evidence evaluating the effectiveness and safety of interventions that enable non-allergy specialist health care workers to assess allergy risk in patients with reported penicillin allergies and subsequently remove erroneous allergy records.

INTRODUCTION

The potential benefits of removing erroneous penicillin allergy labels (de-labeling) are wide-ranging. Penicillin allergy assessment and de-labeling is an antibiotic stewardship priority. Delivery of such assessment and de-labeling by non-allergy specialists has been reported in several studies, but the effectiveness and safety have not been formally synthesized. This is a necessary step in the upscaling of penicillin allergy assessment services.

INCLUSION CRITERIA

This review will consider quantitative studies using appropriate designs. The studies will include adults and pediatric patients who have undergone penicillin allergy assessment and de-labeling by non-allergy specialists in any health care setting.

METHODS

A range of databases will be searched to identify studies published in English, with no date limit. Unpublished studies and gray literature will also be searched. Title and abstract screening, and assessment of selected full texts against the inclusion criteria will be conducted by at least two independent reviewers. Identified studies will be assessed for methodological quality using standardized critical appraisal instruments. Data will be extracted and categorized using the EPOC taxonomy, and the effectiveness and safety of the intervention will be determined. Where possible, data will be pooled to facilitate meta-analysis. Data from heterogeneous studies will be reported narratively. The GRADE approach for grading the certainty of evidence will be followed.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42020219044.

Development and Validation of a Mobile Clinical Decision Support Tool for the Diagnosis of Drug Allergy in Adults: The Drug Allergy App

BACKGROUND

Penicillin allergy overdiagnosis has been associated with inappropriate antibiotic prescribing, increased antimicrobial resistance, worse clinical outcomes, and increased health care costs.

OBJECTIVE

To develop and validate a questionnaire-based algorithm built in a mobile application to support clinicians in collecting accurate history of previous reactions and diagnosing drug allergy appropriately.

METHODS

A survey was completed by 164 medical and nonmedical prescribers to understand barriers to best practice. Based on the survey recommendations, we created a 10-item questionnaire-based algorithm to allow classification of drug allergy history in line with the National Institute for Health and Care Excellence guidelines on drug allergy. The algorithm was incorporated into a mobile application and retrospectively validated using anonymized clinical databases at regional immunology and dermatology centers in Manchester, United Kingdom.

RESULTS

A total of 55.2% of prescribers (95% confidence interval, 47% to 63.4%) thought it impossible to draw a firm conclusion based on history alone and 59.4% (95% CI, 51.4% to 67.5%) believed that regardless of the details of the penicillin allergy history, they would avoid all β-lactams. A drug allergy mobile application was developed and retrospectively validated, which revealed a low risk for misclassification of outcomes compared with reference standard drug allergy investigations in the allergy and dermatology clinics.

CONCLUSIONS

Perceived lack of time and preparedness to collect an accurate drug allergy history appear to be important barriers to appropriate antimicrobial prescribing. The Drug Allergy App may represent a useful clinical decision support tool to diagnose drug allergy correctly and support appropriate antibiotic prescribing.

Burden of antibiotic allergy labels in Australian aged care residents: Findings from a national point-prevalence survey

OBJECTIVE

To determine the prevalence of antibiotic allergy labels (AALs) in Australian aged care residents and to describe the impact of labels on antibiotic prescribing practices.

DESIGN

Point-prevalence survey.

SETTING

Australian residential aged care facilities.

PARTICIPANTS

We surveyed 1,489 residents in 407 aged care facilities.

METHODS

Standardized data were collected on a single day between June 1 and August 31, 2018, for residents prescribed an antibiotic. An AAL was reported if it was documented in the resident's health record. Resident-level data were used to calculate overall prevalence, and antibiotic-level data were used to report relative frequency of AALs for individual antibiotics and classes.

RESULTS

Among 1,489 residents, 356 (24%) had 1 or more documented AALs. The AALs for penicillin (28.3%), amoxicillin or amoxicillin/clavulanic acid (10.5%), cefalexin (7.2%), and trimethoprim (7.0%) were most commonly reported. The presence of an AAL was associated with significantly less prescribing of penicillins (OR, 0.43; 95% CI, 0.31-0.62; P < .001) and significantly more prescribing of lincosamides (OR, 4.81; P < .001), macrolides (OR, 2.03; P = .007), and tetracyclines (OR, 1.54; P = .033). Of residents with AALs, 7 residents (1.9%) were prescribed an antibiotic that was listed on the allergy section of their health record.

CONCLUSIONS

A high prevalence of AALs was observed among residents of Australian aged care facilities, comparable to the prevalence of AALs in high-risk hospitalized patients. Significant increases in prescribing of lincosamide, macrolide, and tetracycline agents poses a potential risk to aged populations, and future studies must evaluate the benefits of AAL delabelling programs tailored for aged care settings.

Impact of Antibiotic Allergy Labels on Patient Outcomes in a Tertiary Paediatric Hospital

OBJECTIVES

Antibiotic allergies are reported in 5 to 15% of children. This study aimed to evaluate the impact of common β-lactam antibiotic allergy labels (AALs) on hospital treatment, focussing on length of stay and appropriateness of antibiotic prescribing.

STUDY DESIGN

Retrospective cohort study over 21-months at the Royal Children's Hospital Melbourne, Australia. A subset of children with the most common β-lactam allergies, and who required admission for intravenous antibiotics over a 12-month period, was analysed for appropriateness of prescribing. Non-allergic patients were matched to evaluate associations between AALs and hospital treatment.

RESULTS

There were 98,912 children admitted over the study period, of whom 938 (1%) had at least one AAL on first admission. Of all encounters, 5145 (2.5%) were for children with AALs. The most common AALs were to amoxicillin and amoxicillin-clavulanic acid combinations (40.8%), cefalexin (14.4%) and trimethoprim-sulfamethoxazole (9.7%). For the subset, there were 66 admissions for children who required intravenous antibiotics. Documentation was adequate for 27% of AALs. Inappropriate prescribing occurred in almost half (47%). Hospital stay was longer for children with AALs (median 4.7 days; IQR 2.3 to 9.2) compared to non-allergic controls (median 3.9 days; IQR 1.9 to 6.8; P=0.02). Children with AALs were more likely to receive restricted antibiotics (aOR 3.03; 95%CI, 1.45 to 6.30; p=0.003).

CONCLUSION

This is the first study to demonstrate high rates of inappropriate prescribing in children with AALs. Children with AALs were significantly more likely to receive restricted antibiotics and had a longer length of stay compared with non-allergic controls.