An algorithm for safe de-labelling of antibiotic allergy in adult hospital in-patients

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.

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.

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.

Antimicrobial Stewardship in the Frail Elderly

Antimicrobial therapy is essential to modern healthcare practice. However, years of injudicious use has contributed to the development of population and individual level harm from antimicrobial resistance. The frail elderly are particularly at risk from infection as well as antimicrobial adverse effects due to multimorbidity, polypharmacy and declining physiological reserve. Diagnosis and management decision making may be challenging in this vulnerable group due to subtle or absent symptoms and signs. Antimicrobial stewardship is the systematic approach to safe and effective use of antimicrobials to optimise outcomes, minimise harm and preserve future therapies. Herein, we consider the significance and importance of antimicrobial stewardship in the frail elderly and suggest ten steps to assist clinicians in the recognition, investigation and management of infection in this group.

Patient-related factors impact the implementation of inpatient antibiotic allergy delabeling

Background

The clinical consequences of an antibiotic allergy label are detrimental, impacting health care delivery and patient outcomes. We assessed hospital inpatients with intent to offer free antibiotic allergy labeling (AAL) assessment within a randomized controlled trial.

Objective

We sought to determine the feasibility of establishing an adult antibiotic allergy delabeling service in a Western Australian tertiary public hospital.

Methods

Inpatients (N = 1503) with AAL were identified through medical records and screened for eligibility to participate in a randomized controlled trial. Those recruited were randomized to undergo assessment by skin testing ± oral challenge, or direct oral challenge. A control group received usual care.

Results

Of the 1503 inpatients with an AAL, 429 (28.5%) were eligible for AAL assessment. The primary excluding factor (1074 [71.5%]) was contraindicated medication use (387 [36.0%]), followed by cognitive impairment (298 [27.9%]). Thirty-nine patients were randomized, of which 20 received allergy testing and 19 usual care; all patients were followed up for 5 years. Older patients were less likely to be eligible (10-year increase: odds ratio, 0.82; 95% CI, 0.77-0.88; P < .0001), whereas surgical patients were more likely to be eligible than medical patients (odds ratio, 2.49; 95% CI, 1.97-3.16; P < .0001).

Conclusions

Antibiotic allergy delabeling in the acute care context is not straightforward. Competing clinical concerns and patient acceptance are some barriers to an inpatient service. Nor is it apparent that inpatient versus outpatient testing is cost saving although select patient groups may benefit. Testing younger people and those with predicted high antibiotic usage will derive maximal individual and health system benefits.

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.

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.

EAACI/ENDA position paper on drug provocation testing

In drug hypersensitivity, drug provocation testing (DPT), also called drug challenge, is the gold standard for investigation. In recent years, risk stratification has become an important tool for adjusting the diagnostic strategy to the perceived risk, whilst still maintaining a high level of safety for the patient. Skin tests are recommended before DPT but may be omitted in low-risk patients. The task force suggests a strict definition of such low-risk patients in children and adults. Based on experience and evidence from studies of allergy to beta-lactam antibiotics, an algorithm on how to adjust DPT to the risk, and when to omit skin tests before DPT, is presented. For other antibiotics, non-steroidal anti-inflammatory drugs and other drugs, skin tests are poorly validated and DPT is frequently necessary. We recommend performing DPT with chemotherapeutics and biologicals to avoid unnecessary desensitization procedures and DPT with skin tests negative contrast media. We suggest DPT with anesthetics only in highly specialized centers. Specifics of DPT to proton pump inhibitors, anticonvulsants and corticosteroids are discussed. This position paper provides general recommendations and guidance on optimizing use of DPT, whilst balancing benefits with patient safety and optimizing the use of the limited available resources.

Non-allergist healthcare workers views on delivering a penicillin allergy de-labelling inpatient pathway: identifying the barriers and enablers

Background

Non-allergist delivered PADL is supported by UK and World Health Organization guidelines but is not yet routine in UK hospitals. Understanding the views of healthcare workers (HCWs) on managing patients with penA records and exploring perspectives on delivering a PADL inpatient pathway are required to inform the development of non-allergist delivered PADL pathways.

Objective

To explore the perspectives of non-allergist HCWs working in medical specialties on managing patients with penA records, and to explore the enablers and barriers to embedding PADL as a standard of care for inpatients.

Methods

Semi-structured interviews with doctors, nurses, pharmacists and medicines optimization pharmacy technicians working in a district general hospital in the UK. Thematic analysis was used to analyse the data.

Results

The PADL pathway was considered a shared responsibility of the multidisciplinary team, which needed to be structured and supported by a framework. PADL aligns with HCW roles but time to deliver PADL was a barrier. Training for HCWs on the benefits of PADL and delivering PADL for those patients where a penicillin might be beneficial during the current episode of care would both motivate HCWs to deliver PADL.

Discussion and conclusion

The PADL pathway was acceptable to HCWs and aligned with their roles and current healthcare processes but their capacity to deliver PADL in a time pressured environment was a significant barrier.

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.

Removal of incorrect penicillin allergy labels in a UK hospital

OBJECTIVES

Penicillin allergy records are common, often incorrect and are associated with broad spectrum antibiotic use. We piloted a pharmacist-led multidisciplinary penicillin allergy de-labelling daily ward round to determine the opportunity for penicillin allergy de-labelling in a UK hospital.

METHODS

A daily ward round, delivered by antibiotic pharmacists or junior doctors, identified adult medical and surgical patients between 7 November 2022 and 31 January 2023 with a penicillin allergy record that was preventing first-line penicillin use. An allergy history was taken before risk stratifying likelihood of future harm from penicillin re-exposure and an allergy testing method was determined (direct de-label on history alone or after direct drug provocation testing). After successful allergy de-label, the antibiotic was switched to a penicillin antibiotic.

RESULTS

Of 7214 inpatients during the study period, 1133 (15.7%) had a penicillin allergy record. Of 285 allergy histories taken, 105 (36.8%) met high-risk criteria, 45 (15.8%) met low-risk criteria eligible for direct de-label and 73 (25.6%) met criteria eligible for direct drug provocation testing. We were unable to obtain a history for 61 (21.4%) patients. Of 45 low-risk patients eligible for direct de-label, 40 (88.9%) were de-labelled of whom 24 (53.3%) were switched to a penicillin antibiotic. Of 73 patients with a low-risk allergy history eligible for direct drug provocation testing, 16 (21.9%) received direct drug provocation testing, of whom 9 were switched to a penicillin antibiotic. Two direct de-label patients experienced harm (thrush within 5 days and delayed skin reaction after day 5); none of the direct drug provocation testing patients had a reaction by day 5. The switches resulted in reduced alternative antibiotic use by 173 Daily Defined Doses (DDDs).

DISCUSSION

Penicillin allergy de-labelling patient pathway delivered by pharmacists and junior doctors was safe and effective and well accepted by patients and the wider clinical teams.

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.

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.

Parent-reported penicillin allergies in children: A qualitative study

BACKGROUND

Penicillin allergies are commonly reported in children. Most reported penicillin allergies are false, resulting in the unnecessary selection of alternative antibiotic treatments that promote antibiotic resistance. While formal allergy testing is encouraged to establish a diagnosis of penicillin allergy, children are rarely referred for allergy testing, and study of parents' experiences and perceptions of their child's reported penicillin allergy is limited. We aimed to describe parents' experiences and perceptions of their child's penicillin allergy and attitudes towards penicillin allergy testing to identify opportunities to engage parents in antimicrobial stewardship efforts.

METHODS

This was a qualitative descriptive study.

RESULTS

Eighteen parents participated in this study. Parents' children were on average 2 years old when the index reaction occurred, and 7 years had passed since the reaction. Transcripts revealed that participants were receptive to penicillin allergy testing for their child after learning the consequences of penicillin allergy and availability of allergy testing. Four major themes emerged from data (1) parents' making sense of allergy; (2) parents' impressions of allergy label, (3) parents' attitudes towards allergy testing, and (4) parents' desire to be informed of testing availability.

CONCLUSIONS

Efforts are needed to engage parents in addressing spuriously reported penicillin allergies.