Development and Validation of a Penicillin Allergy Clinical Decision Rule

Evaluating the PEN-FAST Clinical Decision-making Tool to Enhance Penicillin Allergy Delabeling

This cohort study evaluated the diagnostic accuracy of PEN-FAST as a clinical decision-making tool to enhance penicillin allergy evaluation.

Perceived usefulness of a mnemonic to improve nurses' evaluation of reported penicillin allergies

We surveyed clinicians to evaluate the perceived usefulness of a mnemonic, STORY, to improve penicillin allergy evaluation. Survey responses indicated that the perceived usefulness of STORY was high, and support for nurses' involvement in penicillin allergy assessment was high. Future research may evaluate the feasibility of STORY implementation in clinical care.

Characterizing Antibiotic Allergy Labels in a Large UK Hospital Population to Inform Antimicrobial Stewardship and Delabeling Assessment Strategy

BACKGROUND

Antibiotic allergy labels are important barriers to treatment and antimicrobial stewardship, but their prevalence in UK hospitals is poorly described.

OBJECTIVE

To ascertain the prevalence and characteristics of antibiotic allergy labels in a large UK hospital setting and estimate the proportion of penicillin allergy labels for which point-of-care (POC) delabeling assessment would be appropriate.

METHODS

Electronic health records data were analyzed from all patients treated at Cambridge University Hospitals NHS Foundation Trust in 2019. Validated POC delabeling risk stratification criteria were retrospectively applied to penicillin allergy labels.

RESULTS

Recorded reactions to antibiotics were present in 11.8% of all patients (32,148 of 273,216), 16.3% of inpatients (13,874 of 85,230), and 9.7% of outpatients (18,274 of 187,986). Penicillins were the commonest reaction precipitant described (9.0% of patients; 24,646 of 273,216), followed by sulfonamides/trimethoprim (1.4%; 3869 of 273,216) and macrolides/lincosamides (1.3%; 3644 of 273,216). A total of 3.9% of inpatients had recorded reactions to >1 antibiotic class (3348 of 85,230). Cutaneous manifestations were the most commonly described reaction features (40.7% of labels; 15,821 of 38,902). Of 15,949 labels describing probable or possible penicillin "allergy" with sufficient detail to allow for the retrospective assessment of POC delabeling suitability, 1702 were deemed suitable for removal or downgrading of the label to "intolerance" without further investigation (10.7%), 11,887 were appropriate for POC assessment using an oral penicillin challenge (OPC) or OPC with prior bedside skin testing (74.5%), and 2360 were identified as unsuitable for any form of POC assessment (14.8%).

CONCLUSIONS

Antibiotic allergy labels are highly prevalent in a UK hospital setting. A large proportion of penicillin allergy labels may be suitable for POC delabeling assessment.

Opportunities for Antimicrobial Stewardship Interventions Among Solid Organ Transplant Recipients

Although antimicrobial stewardship programs have excelled over the past decade, uptake and application of these programs to special populations such as solid organ transplant recipients have lagged. Here, we review the value of antimicrobial stewardship for transplant centers and highlight data supporting interventions that are ripe for adoption. In addition, we review the design of antimicrobial stewardship initiatives, targets for both syndromic and system-based interventions.

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 Dutch Working Party on Antibiotic Policy (SWAB) guideline for the approach to suspected antibiotic allergy

OBJECTIVES

Prudent handling of reported antibiotic allergy is an important aspect of antibiotic stewardship. The Dutch Working Party on Antibiotic Policy (SWAB) constituted a multidisciplinary expert committee to provide evidence-based recommendations for bedside decision making in antibiotic therapy in patients that report an antibiotic allergy.

METHODS

The guideline committee generated 12 key questions, most of which were population, intervention, comparison and outcome (PICO) questions relevant for both children and adults with suspected antibiotic allergy. For each question a systematic literature search was performed and reviewed for the best available evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Quality of evidence was graded from very low to high and recommendations were formulated in structured discussions as strong or weak.

RESULTS

Sixty recommendations were provided for suspected allergy to beta-lactam antibiotics (BLA) and non-beta-lactam antibiotics (NBLA). Due to the absence of randomized controlled trials in this field, the underlying evidence was predominantly graded as low or very low. Available data supports that a detailed allergy history should always be performed and critically appraised. When cross-allergy between BLA groups is not to be expected due to absence of molecular similarity of the side chains, the patient can be safely exposed to the alternative BLA. An exception to this rule are severe delayed type reactions, in which reexposure to a BLA should only be considered after consultation of a multidisciplinary team.

CONCLUSIONS

Accumulated scientific data now supports a more liberal approach that better balances benefits of treatment with first choice and usually smaller spectrum antibiotics with appropriate avoidance of antibiotics in case of a truly high risk of a (severe) allergic reaction. In the Netherlands, a formal guideline was developed that provides recommendations for the approach towards suspected allergy to BLA and frequently used NBLA, thereby strongly supporting antimicrobial stewardship.

Penicillin-allergy delabelling resources for clinicians practicing in resource-limited settings: a full educational resource review of the grey literature

Background

The clinical and financial consequences associated with a penicillin-allergy label are increasingly evident and have garnered support from international organizations to prioritize penicillin-allergy delabelling programmes. Most settings lack access to resources including drug allergy specialists and rely on general practitioners (GPs) and pharmacists.

Objectives

The aim of this scoping review was to identify and describe freely available penicillin-allergy delabelling materials to guide clinicians practising in resource-limited settings with initiative application.

Methods

This scoping review searched two grey literature databases, six targeted websites and consulted content experts to identify freely available materials in the English language that provided evidence-based and actionable penicillin-allergy delabelling strategies. Study investigators ranked and voted on which screened resources should be included in the final review. Characteristics of resources were evaluated and compared.

Results

Out of 1191 total citations, 6 open-access resources were included. Penicillin-allergy toolkits featuring various delabelling strategies were identified in four resources. The toolkits supported a broad range of downloadable and adaptable materials, predominantly targeted towards GPs. Patient educational materials were also provided. Another resource highlighted a point-of-care penicillin-allergy risk assessment calculator via a free mobile app that quickly and accurately identified low-risk penicillin-allergic patients. The final resource, a supplemental instructional video, presented impactful and standardized delabelling strategies that clinicians can adopt into daily practices.

Conclusions

Limited penicillin-allergy delabelling materials are available in the grey literature but existing resources provide broad and diverse opportunities. Additional support from health protection agencies is critical to augment ongoing delabelling efforts.

Digital Antibiotic Allergy Decision Support Tool Improves Management of β-Lactam Allergies

BACKGROUND

Frontline providers frequently make time-sensitive antibiotic choices, but many feel poorly equipped to handle antibiotic allergies.

OBJECTIVE

We hypothesized that a digital decision support tool could improve antibiotic selection and confidence when managing β-lactam allergies.

METHODS

A digital decision support tool was designed to guide non-allergist providers in managing patients with β-lactam allergy labels. Non-allergists were asked to make decisions in clinical test cases without the tool, and then with it. These decisions were compared using paired t tests. Users also completed surveys assessing their confidence in managing antibiotic allergies.

RESULTS

The tool's algorithm was validated by confirming its recommendations aligned with that of five allergists. Non-allergist providers (n = 102) made antibiotic management decisions in test cases, both with and without the tool. Use of the tool increased the proportion of correct decisions from 0.41 to 0.67, a difference of 0.26 (95% CI, 0.22-0.30; P < .001). Users were more likely to give full-dose antibiotics in low-risk situations, give challenge doses in medium-risk situations, and avoid the antibiotic and/or consult allergy departments in high-risk situations. A total of 98 users (96%) said the tool would increase their confidence when choosing antibiotics for patients with allergies.

CONCLUSIONS

A point-of-care clinical decision tool provides allergist-designed guidance for non-allergists and is a scalable system for addressing antibiotic allergies, irrespective of allergist availability. This tool encouraged appropriate antibiotic use in low- and medium-risk situations and increased caution in high-risk situations. A digital support tool should be considered in quality improvement and antibiotic stewardship efforts.

Administration of β-lactam antibiotics to patients with reported penicillin allergy in the emergency department

BACKGROUND

β-lactam antibiotics are amongst the most commonly prescribed medications in the Emergency Department (ED) due to their role in empiric sepsis therapy; however, inferior therapeutic options are often utilized due to a reported allergy; penicillin (PCN) being most frequent. In the United States, 10% of the population endorses an allergic reaction to PCN while <1% experience IgE-mediated reactions. This study aimed to evaluate the frequency and outcome of patients in the ED whose PCN allergies were challenged with β-lactam antibiotics.

METHODS

We conducted a retrospective chart review of patients in the ED at an academic medical center aged ≥18, and who received a β-lactam despite a reported PCN allergy between January 2015 and December 2019. Patients who did not receive a β-lactam or did not report a PCN allergy prior to administration were excluded. The primary outcome was the frequency of IgE-mediated reactions in response to β-lactam administration. A secondary outcome assessed the frequency of continuation of β-lactams upon admission from the ED.

RESULTS

819 patients were included (66% female) with prior reported PCN reactions: hives (22.5%), rash (15.4%), swelling (6.2%), anaphylaxis (3.5%), other (12.1%), or undocumented on medical electronic record (40.3%). No patients experienced an IgE-mediated reaction to the β-lactam administered in the ED. Previously reported allergies had no effect on the continuation of β-lactams when admitted or discharged (OR: 1, 95% CI: 0.7-1.44). Patients who had a history of an IgE-mediated penicillin allergy were frequently continued (77%) on a β-lactam after leaving the ED via admission or discharge.

CONCLUSION

β-lactam administration in patients with previously reported PCN allergies did not result in any IgE-mediated reactions nor in an increase in adverse reactions. Our data contributes to the body of evidence that supports the administration of β-lactams to patients with documented PCN allergies.

Delabelling multiple antibiotic allergy: Practical issues

With the growing incidence of multi-drug resistant organisms, delabelling incorrect antibiotic allergies has become an integral part of antimicrobial stewardship worldwide. For example, around 90% of penicillin allergy labels are found to be inaccurate following a full allergy work-up, which deprive patients the use of effective first-line penicillin antibiotics and increase the risk of antimicrobial resistance with the use of other extended spectrum non-penicillin antimicrobials. Significant numbers of adult and paediatric patients over time are labelled with multiple penicillin and non-penicillin antibiotic allergies often during inappropriate antimicrobial use, resulting in a label of “multiple antibiotic allergy”. In contrast to delabelling penicillin allergy where oral direct provocation tests can be used for low-risk, mild reactions, and sensitivity/specificity/positive and negative predictive values of skin tests have been demonstrated, diagnostic tests for multiple antibiotic allergy often require the use of a combination of in-vivo and in-vitro tests across different antimicrobial classes for evaluation. Shared decision making with patients and informed consent are also needed when prioritising which drugs to delabel first, balancing the risks, benefits of testing vs. interim use of alternative antibiotics. Similar to delabelling penicillin allergy, the cost-effectiveness of delabelling multiple drug allergies is unknown.

Virtually supported penicillin allergy de-labelling during COVID-19

BACKGROUND

Penicillin allergy is a commonly listed medication allergy despite rare overall incidence. Many patients erroneously have this label, which has personal, health, and societal costs. Penicillin allergy delabelling requires an oral challenge, which can be a rate limiting step in the de-labeling process; this is even more relevant with the reduction of in-person visits during the COVID-19 pandemic.

OBJECTIVE

To identify the utility and broader applicability of using a virtually supported platform, initially adopted given COVID-19 restrictions, to expedite penicillin oral provocation challenge and penicillin de-labeling in patients at low to moderate risk of immediate hypersensitivity reaction and based on shared decision making.

METHODS

Patients in Vancouver catchment area were referred for penicillin allergy and virtually assessed by the consulting allergist between July 2020 and April 2021. Those deemed appropriate for oral challenge based on the allergist consultant were offered the option of a virtual oral provocation challenge to oral amoxicillin in a subsequent virtual visit. Patients who agreed and were consented underwent a virtually supervised oral amoxicillin challenge during the second virtual visit. Findings are summarized in this case series.

RESULTS

Twenty-three patients, both adult and pediatric, ranging from no to significant co-morbidities were consented and underwent the virtual challenge. One hundred percent of patients were successful with no reaction after an hour post virtual oral provocation challenge with amoxicillin.

CONCLUSION

Virtual medicine is likely to remain in the allergist's practice. Virtually supported penicillin allergy delabelling, based on shared decision making and risk stratification, presents another pathway for penicillin allergy delabelling.

Low self-reported penicillin allergy in South Africa-implications for global public health response

Objectives

In high-income countries, up to 25% of inpatients have a self-reported penicillin allergy (PA). After testing, 95% of these self-reported PAs are incorrect. These incorrectly labelled PAs increase the use of broad-spectrum antibiotics, and drive bacterial resistance. The epidemiology of PA in low- and middle-income countries is unknown. We aimed to describe the epidemiology and delabelling outcomes of self-reported PA in South African (SA) inpatients.

Methods

We conducted point prevalence surveys between April 2019 and June 2021 at seven hospitals in Cape Town, South Africa. A team trained in the PEN-FAST allergy decision tool conducted in-person interviews, and reviewed patient notes to identify and risk stratify inpatients with a self-reported PA. These patients were referred to the Groote Schuur Hospital (GSH) allergy clinic for delabelling.

Results

A total of 1486 hospital inpatients were surveyed and 3.2% (n = 48) carried a PA label. Importantly, 64.6% (n = 31) were classified by PEN-FAST as low risk for true penicillin hypersensitivity. Overall, 25% of the self-reported PAs received a β-lactam antibiotic in hospital and were directly delabelled. Delabelling attrition was very high, with 6.3% (3/48) of the self-reported PAs attending the GSH allergy clinic, and only one patient proceeding to a negative oral penicillin challenge.

Conclusions

Inpatient self-reported PA was lower in South Africa hospitals compared with other upper-middle-income countries, and the majority of patients carried a low-risk PA label. Linkage for delabelling with the allergy clinic was very poor, and thus strategies to improve access and delivery of delabelling remains an urgent public health issue.

Self-reported beta-lactam allergy in government and private hospitals in Cape Town, South Africa

BACKGROUND

Up to a quarter of inpatients in high-income countries (HICs) self-report beta-lactam allergy (BLA), which if incorrect,increases the use of alternative antibiotics, worsening individual health outcomes and driving bacterial resistance. In HICs, up to 95% ofself-reported BLAs are incorrect. The epidemiology of BLA in low- and middle-income African countries is unknown.

OBJECTIVES

To describe the epidemiology and de-labelling outcomes of self-reported BLA in hospitalised South African (SA) patients.

METHODS

Point-prevalence surveys were conducted at seven hospitals (adult, paediatric, government and privately funded, district andtertiary level) in Cape Town, SA, between April 2019 and June 2021. Ward prescription records and in-person interviews were conductedto identify and risk-stratify BLA patients using the validated PEN-FAST tool. De-labelling was attempted at the tertiary allergy clinic atGroote Schuur Hospital.

RESULTS

A total of 1 486 hospital inpatients were surveyed (1 166 adults and 320 children). Only 48 patients (3.2%) self-reported a BLA,with a higher rate in private than in government-funded hospitals (6.3% v. 2.8%; p=0.014). Using the PEN-FAST tool, only 10.4% (n=5/48)of self-reported BLA patients were classified as high risk for true penicillin hypersensitivity. Antibiotics were prescribed to 70.8% (n=34/48)of self-reported BLA patients, with 64.7% (n=22/34) receiving a beta-lactam. Despite three attempts to contact patients for de-labelling atthe allergy clinic, only 3/36 underwent in vivo testing, with no positive results, and 1 patient proceeded to a negative oral challenge.

CONCLUSION

Unlike HICs, self-reported BLA is low among inpatients in SA. The majority of those who self-reported BLA were low risk fortype 1 hypersensitivity, but outpatient de-labelling efforts were largely unsuccessful.

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.

Skin testing as a biomarker in drug allergy

Despite the significant negative impact drug allergies can have on patient care, the diagnosis is largely based on clinical history, and there are limited diagnostic tests that can be done at the time of a reaction. Biomarkers are needed to improve the diagnosis and the identification of the culprit medication. Skin testing is the most useful biomarker for immediate- and delayed-type reactions available, but it is limited by its low sensitivity. To improve its accuracy and reproducibility, a standardized procedure must be used. For immediate-type reactions, penicillin skin testing is the most widely studied, and it can be used in patients with history of anaphylaxis or recent immunoglobulin E-mediated reaction or for whom there is a significant risk if a reaction were to occur, such as pregnancy. Skin testing is also important in allergy to platinum agents allowing for continued first-line therapy. For delayed-type reactions, patch testing and delayed intradermal testing, used in conjunction with clinical history, can help to improve identification of the culprit medication depending on the type of reaction. Other biomarkers including in vitro testing for specific immunoglobulin E, basophil activation test, lymphocyte transformation test, ELISpot, and genetic factors that increase the likelihood of reaction are under investigation, and they may be most helpful when used in combination with the clinical history and skin testing results.

Documented Penicillin Allergies Should Not Preclude Use of Preoperative Cefazolin in Hip and Knee Arthroplasty

INTRODUCTION

Perioperative cefazolin administration for total joint arthroplasty is a first-line antibiotic recommended by the American Academy of Orthopaedic Surgeons (AAOS) guidelines for the prevention of periprosthetic joint infections (PJIs). We aim to analyze the clinical viability of giving patients with a documented penicillin allergy (PA) a perioperative full-strength cefazolin "test dose" under anesthesia.

METHODS

This is a retrospective chart review of 2,451 total joint arthroplasties from a high-volume arthroplasty orthopaedic surgeon over a 5-year period from January 2013 through December 2017. This surgeon routinely gave patients with a documented PA a full-strength cefazolin test dose while under anesthesia instead of administrating a second-line antibiotic. The primary outcomes examined were allergic reaction and postoperative infection.

RESULTS

Cefazolin was given to 87.1% of all patients (1,990) and 46.0% of patients with a PA (143). The total rate of allergic reactions among all patients was 0.5% (11). Only one patient with a documented PA who received cefazolin had an allergic reaction. The reaction was not severe and did not require any additional treatment. In patients who had no reported allergies and received cefazolin, 0.3% (6) had an allergic reaction. There was no statistically significant difference in the rate of allergic reaction when comparing patients with and without a PA (P = 0.95). Patients receiving cefazolin had an overall PJI rate of 2.9% (57) versus those patients receiving antibiotics other than cefazolin who sustained a 5.5% PJI rate (16), which was statistically significant (P = 0.02).

CONCLUSION

This study found that utilization of a full-strength test dose of cefazolin in patients with a documented PA is a feasible, safe, and effective way of increasing the rate of cefazolin administration and thus mitigating the risk of PJIs.

Cofactors of drug hypersensitivity-A monocenter retrospective analysis

Background

Drug hypersensitivity reactions (DHRs) are major medical problems that influence the treatment of patients by both under- and overdiagnosis. Still, little is known about the role of predisposing or protecting cofactors of DHR.

Objective

This study aims to determine drug-specific cofactors in patients with DHR.

Methods

Retrospective file chart analysis of inpatients with suspected DHR in our department between 2015 and 2020 was performed. Descriptive statistics and multiple logistic regression were conducted for the estimation and statistical interference.

Results

DHRs were suspected in 393 patients with 678 culprit drugs. In 183 cases, drug hypersensitivities were confirmed, mostly against nonopioid analgesic drugs and antibiotics. Multiple logistic regression analysis identified a positive association of antibiotic hypersensitivity with obesity [odds ratio (OR) 5.75, average marginal effect (AME) +24.4%] and age and a negative association with arterial hypertension, female sex, elevated immunoglobulin E (IgE), and allergic rhinitis. Hypersensitivity to nonopioid analgesics was associated with atopic dermatitis (OR 10.28, AME +28.5%), elevated IgE, and arterial hypertension.

Conclusions

Drug-specific cofactors of DHR include obesity for antibiotics and atopic dermatitis for nonopioid analgesics, the knowledge of which may improve the risk calculation for drug provocation tests.

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.

Beta-lactam hypersensitivity diagnosis in ambulatory and hospitalized settings require different approaches

BACKGROUND

Data on beta-lactam hypersensitivity (BLH) are mainly focused on immediate or mild nonimmediate reactions in the ambulatory setting, but limited in patients with concurrent illness and moderate-to-severe nonimmediate reactions in the hospitalized setting.

OBJECTIVE

To investigate the entire spectrum of BLH in Thai tertiary hospital.

METHODS

Clinical characteristics of 357 patients with suspected BLH were evaluated in a 7-year period. Culprit drug identification was performed in 335 patients by combined skin testing, in vitro testing, or drug provocation tests.

RESULTS

The predominant BLH presentations were non-immunoglobulin (Ig)E-mediated reactions with severe cutaneous adverse reactions of 18.9%, and BLH status was definitively confirmed in 18.1%. The most common verified culprits were cephalosporins (34.8%), particularly in hypersensitivity type IV reactions. Natural penicillins were the main implicated drugs in 48.5% of ambulatory patients. In contrast, cephalosporins and carbapenems were the main implicated drugs in hospitalized patients. Non-IgE-mediated anaphylaxis and serum sickness-like reaction remained diagnostically challenged. New generations of beta-lactams, hospitalized patients, recent allergic history, and underlying malignancies or autoimmune diseases were associated with increased BLH risk.

CONCLUSION

At present, cephalosporins are the leading causes of BLH, particularly in non-IgE-mediated reactions. More research on the verification of non-IgE hypersensitivity reactions from new generations of beta-lactams should be better emphasized.

CLINICAL TRIAL REGISTRATION

The registry was approved by the Ethics and Research Committee of the Faculty of Medicine, Chulalongkorn University, and listed on ClinicalTrials.gov (Identifier: NCT01667055; https://www.

CLINICALTRIALS

gov/ct2/show/NCT01667055).

Advances in the Understanding of Drug Hypersensitivity: 2012 Through 2022

Over the last decade there have been key advances in understanding mechanisms, risk, and consequences of both true immunological drug hypersensitivity and unverified drug allergy labels that have changed clinical practice. This has been facilitated by the widespread adoption of electronic health records (EHRs). The vast majority of EHR drug allergy labels are unverified and cause significant morbidity from unnecessary avoidance of optimal drug therapy. There has also been significant movement in our understanding of mechanisms of drug hypersensitivity that, in addition to advancing our understanding of the pathogenesis of immediate and delayed reactions, have guided preventive efforts, diagnostic procedures, and clinical management. More widespread adoption, including scale-up of "allergy" delabeling and appropriate management, specifically for antibiotics, opiates, radiocontrast, chemotherapeutics, biologics, and nonsteroidal anti-inflammatory medications, will be necessary to improve patient outcomes over the next decade. This will require further engagement and collaboration between primary care health care providers, allergists, and other specialists.

The stress hyperglycemia ratio improves the predictive ability of the GRACE score for in-hospital mortality in patients with acute myocardial infarction

BACKGROUND

The Global Registry of Acute Coronary Events (GRACE) score is a powerful tool used to predict in-hospital mortality after acute myocardial infarction (AMI) and does not include a glycometabolism-related index. We investigated whether the addition of the stress hyperglycemia ratio (SHR) provides incremental prognostic value in addition to the GRACE score.

METHODS

A retrospective cohort of 613 AMI patients was enrolled in the present analyses. The patients were stratified according to the primary endpoint (in-hospital mortality) and the tertiles of the SHR.

RESULTS

During hospitalization, 40 patients reached the primary endpoint, which was more frequently observed in patients with a higher SHR. The SHR, but not admission blood glucose (ABG), adjusted for the GRACE score independently predicted in-hospital mortality [odds ratio 2.5861; 95% confidence interval (CI), 1.3910-4.8080; P = 0.0027]. The adjustment of the GRACE score by the SHR improved the predictive ability for in-hospital death (an increase in the C-statistic value from 0.787 to 0.814; net reclassification improvement, 0.6717, 95% CI 0.3665-0.977, P < 0.01; integrated discrimination improvement, 0.028, 95% CI 0.0066-0.0493, P = 0.01028). The likelihood ratio test showed that the SHR significantly improved the prognostic models, including the GRACE score. Adding the SHR to the GRACE score presented a larger net benefit across the range of in-hospital mortality risk than the GRACE score alone.

CONCLUSION

The SHR, but not the ABG, is an independent predictor of in-hospital mortality after AMI even after adjusting for the GRACE score. The SHR improves the predictability and clinical usefulness of prognostic models containing the GRACE score.

Advances in immunoglobulin E mediated antibiotic allergy

PURPOSE OF REVIEW

The purpose of this review is to identify recent advances in our understanding and management of immunoglobulin E (IgE)-mediated antibiotic allergy.

RECENT FINDINGS

Antibiotics remain a leading cause of fatal anaphylaxis reported to the FDA. However, recent advances have defined the features of adult and pediatric patients without true IgE-mediated allergy or any mechanism of anaphylaxis when tested. This has created opportunities to use direct challenges to disprove these allergies at the point-of-care and improves antibiotic stewardship. Additional advances have highlighted cross-reactive structural considerations within classes of drugs, in particular the R1 side-chain of cephalosporins, that appear to drive true immune-mediated cross-reactivity. Further advances in risk-based approaches to skin testing, phenotyping, and re-exposure challenges are needed to standardize antibiotic allergy evaluation.

SUMMARY

Recent advances in defining true IgE-mediated drug allergy have helped to identify patients unlikely to be skin-test positive. In turn, this has identified patients who can skip skin testing and proceed to direct ingestion challenge using history risk-based approaches. The ability to identify the small number of patients with true IgE-mediated allergy and study their natural history over time, as well as the vast majority without true allergy will facilitate important and novel mechanistic discoveries.

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.

Improving antimicrobial stewardship with penicillin allergy testing: a review of current practices and unmet needs

Penicillin allergy, the most frequently reported drug allergy, has been associated with suboptimal antibiotic therapy, increased antimicrobial resistance, increased rates of Clostridioides difficile colonization and infection, as well as extended hospital length of stay and increased cost. Although up to 10% of all patients may report penicillin allergy, most penicillin allergies are not confirmed. As such, most patients with a penicillin allergy can still safely use penicillin and related drugs following a more precise assessment. Herein, we review the current practices and unmet needs in penicillin allergy testing. The diagnostic algorithm is mostly based on a clinical history assessment followed by in vivo testing, i.e. skin test and/or drug challenge. As these tests are labour and resource intensive, there is increased interest in point-of-care penicillin allergy de-labelling solutions incorporated into Antimicrobial Stewardship Programmes including digital assessment tools. These can be locally parameterized on the basis of characteristics of target populations, incidence of specific allergies and local antibiotic usage to perform clinical risk stratification. Safely ruling out any residual risk remains essential and in vivo drug challenge and/or skin testing should be systematically encouraged. Gradual understanding and convergence of the risk stratification of the clinical presentation of penicillin allergy is enabling a wider implementation of this essential aspect of antimicrobial stewardship through digitalized decision tools and in vivo testing. More research is needed to deliver point of care in vitro diagnostic tools to democratize this de-labelling practice, which would be highly beneficial to patient care. This progress, together with better education of patients and clinicians about the availability, efficacy and safety of penicillin allergy testing, will increase the dissemination of penicillin allergy assessment as an important component of Antimicrobial Stewardship Programmes.

Distinct Characteristics and Chronology of Amoxicillin-Associated Reactions in Pediatric Acute Care Settings

BACKGROUND

Amoxicillin-associated reactions (AARs) in children presenting as rashes are common, and recent data suggest that >90% tolerate amoxicillin on re-exposure. However, additional data would help pediatricians and allergists gain confidence in referring and testing children who experienced systemic symptoms perceived as "worrisome," thus leading to urgent medical evaluations. By characterizing the entire spectrum of AAR symptoms in pediatric patients presenting to emergency department (ED)/urgent care (UC) settings, we sought to increase our diagnostic acumen to guide subsequent allergy evaluations.

OBJECTIVE

To fully characterize clinical features of rash and systemic symptoms in children presenting to the ED/UC with AARs.

METHODS

A retrospective chart review of children seen in the ED/UC from July 1, 2015, to June 30, 2017, was conducted. Clinical features, chronology, and seasonality were detailed, and cases were classified into 3 previously described AAR phenotypes: maculopapular exanthem (MPE), urticaria, and serum sickness-like reactions (SSLRs), if they experienced joint symptoms.

RESULTS

Children (n = 668; median age: 1.8 years) presented to the ED/UC with urticaria (44%), MPE (36%), and SSLRs (11%) typically on days 7 to 10 of amoxicillin. Although children with SSLRs were more frequently treated with corticosteroids (28%, P < .0001) and exhibited higher rates of "worrisome" features (fever, angioedema, or gastrointestinal symptoms; 73%, P < .0001), delayed-onset systemic symptoms were identified frequently in all 3 groups. ED/UC reutilization was unexpectedly high with 66 children (10%) returning to the ED/UC for re-evaluation.

CONCLUSION

"Worrisome" symptoms are common in children presenting to the ED/UC with AARs. Future studies are needed to determine the impact on subsequent referral and allergy testing.

Tools to improve the diagnosis and management of T-cell mediated adverse drug reactions

Delayed drug T-cell immune-mediated hypersensitivity reactions have a large clinical heterogeneity varying from mild maculopapular exanthema (MPE) to severe cutaneous adverse reactions (SCARs) such as acute generalized exanthematous pustulosis (AGEP), drug reaction with eosinophilia and systemic symptoms (DRESS) and severe skin necrosis and blistering as seen in Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Given the knowledge gaps related to the immunopathogenesis of these conditions, the absence of validated diagnostic tools and the significant associated morbidity and mortality, patients with SCARs often have limited drug choices. We performed a comprehensive review aiming to evaluate in vivo diagnostic tools such as delayed intradermal skin and patch testing and ex vivo/in vitro research assays such as the lymphocyte transformation test (LTT) and the enzyme-linked ImmunoSpot (ELISpot) assay. We searched through PubMed using the terms “drug allergy,” “in vivo” and “ex vivo” for original papers in the last 10 years. A detailed meticulous approach adapted to the various clinical phenotypes is recommended for the diagnostic and management of delayed drug hypersensitivity reactions. This review highlights the current diagnostic tools for the delayed drug hypersensitivity phenotypes.

Safety and value of pretransplant antibiotic allergy delabeling in a quaternary transplant center

BACKGROUND

Self-reported antibiotic allergies, also known as antibiotic allergy labels, are common and may lead to worse patient outcomes. Within immunocompromized patients, antibiotic allergy labels can lead to inappropriate use of antimicrobials and may limit options for prophylactic and therapeutic options in the posttransplant period. While antibiotic allergy delabeling is considered an important aspect of antibiotic stewardship protocols, evidence and awareness of its application in transplant recipients is limited.

METHODS

We describe our experience with an antibiotic allergy delabeling intervention in the pretransplant evaluation period and its impact on posttransplant antimicrobial utilization. This was a retrospective analysis of patients with an antibiotic allergy label who underwent evaluation for solid organ or stem cell transplantation between 2015 and 2020. Patients included in this analysis were those who completed pretransplant antibiotic allergy delabeling through our Drug Allergy Clinic and were retained in care for 6 months after transplant.

RESULTS

Twenty-six of 27 patients underwent pretransplant antibiotic allergy delabeling and safely received the delabeled antibiotic posttransplant. There were no reported side effects to the delabeled antibiotic within 6 months posttransplant. Specific examination of sulfonamide (sulfa)-antibiotic delabeling showed cost savings of $254 to $2910 per patient in the posttransplant period compared to the use of alternative antibiotics for prophylaxis protocol.

CONCLUSION

Antibiotic allergy delabeling prior to transplant is safe, is of high value, and should be considered in the pretransplant evaluation period. More resources are needed for the development of delabeling guidelines and support for broad implementation of pretransplant antibiotic allergy delabeling programs.

Validation of the PEN-FAST Score in a Pediatric Population

This cohort study examines a clinical decision model for penicillin allergies among pediatric patients; the model considers when reactions occurred; whether patients experienced angioedema, anaphylaxis, or a severe cutaneous adverse reaction; and whether treatment was required.

Use of a penicillin allergy clinical decision rule to enable direct oral penicillin provocation: an international multicentre randomised control trial in an adult population (PALACE): study protocol

INTRODUCTION

Penicillin allergies are highly prevalent in the healthcare setting and associated with the prescription of second-line inferior antibiotics. More than 85% of all penicillin allergy labels can be removed by skin testing and 96%-99% of low-risk penicillin allergy labels can be removed by direct oral challenge. An internally and externally validated clinical assessment tool for penicillin allergy, PEN-FAST, can identify a low-risk penicillin allergy without the need for skin testing; a score of less than 3 has a negative predictive value of 96.3% (95% CI, 94.1 to 97.8) for the presence of a penicillin allergy. It is hypothesised that PEN-FAST is a safe and effective tool for assessing penicillin allergy in an outpatient clinic setting.

METHODS AND ANALYSIS

This is an international, multicentre randomised control trial using the PEN-FAST tool to risk-stratify penicillin allergy labels in adult outpatients. The study's primary objective is to evaluate the non-inferiority of using PEN-FAST score-guided management with direct oral challenge compared with standard care (defined as prick and intradermal skin testing followed by oral penicillin challenge). Participants will be randomised 1:1 to the intervention arm (direct oral penicillin challenge) or standard of care arm (skin testing followed by oral penicillin challenge, if skin testing is negative). The sample size of 380 randomised patients (190 per treatment arm) is required to demonstrate non-inferiority.

ETHICS AND DISSEMINATION

The study will be performed according to the guidelines of the Helsinki Declaration and is approved by the Austin Health Human Research Ethics Committee (HREC/62425/Austin-2020) in Melbourne Australia, Vanderbilt University Institutional Review Board (IRB #202174) in Tennessee, USA, Duke University Institutional Review Board (IRB #Pro00108461) in North Carolina, USA and McGill University Health Centre Research Ethics Board in Canada (PALACE/2022-7605). The results of this study will be published and presented in various scientific forums.

TRIAL REGISTRATION NUMBER

NCT04454229.

Adjustment of the GRACE score by the triglyceride glucose index improves the prediction of clinical outcomes in patients with acute coronary syndrome undergoing percutaneous coronary intervention

Background

The Global Registry of Acute Coronary Events (GRACE) score derived from clinical parameters at the time of hospital discharge is a powerful predictor of long-term mortality and reinfarction after acute coronary syndrome (ACS). The triglyceride glucose (TyG) index, which is a simple and reliable surrogate marker of insulin resistance, has been demonstrated to be an independent predictor of long-term adverse major adverse cardiac events, irrespective of diabetes mellitus. We investigate whether the addition of the TyG index improves the predictive ability of the GRACE score after percutaneous coronary intervention (PCI) in ACS patients regardless of diabetes mellitus.

Method

A retrospective cohort of 986 ACS patients undergoing PCI was enrolled in the present analyses. The GRACE score for discharge to 6 months and the TyG index were calculated. The primary endpoint was the composite of MACEs, including all-cause death and nonfatal myocardial infarction. Patients were stratified according to the primary endpoint and the tertiles of the TyG index. Cumulative curves were calculated using the Kaplan–Meier method. Multivariate Cox regression was adopted to identify predictors of MACEs. The predictive value of the GRACE score alone and combined with the TyG index or fasting blood glucose (FBG) was estimated by the area under the receiver‑operating characteristic curve, likelihood ratio test, Akaike’s information criteria, continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI). Internal validation was assessed using the means of bootstrap method with 1000 bootstrapped samples.

Results

During a median follow-up of 30.72 months ((interquartile range, 26.13 to 35.07 months), 90 patients developed MACEs, more frequently in the patients with a higher TyG index. Multivariate Cox hazards regression analysis found that the TyG index, but not FBG was an independent predictor of MACEs (hazard ratio 1.6542; 95% CI 1.1555–2.3681; P = 0.006) in all types of ACS regardless of diabetes mellitus when included in the same model as GRACE score. Furthermore, Kaplan–Meier analysis revealed that the incidence of the primary endpoint rose with increasing TyG index tertiles (log-rank, P < 0.01). Adjustment the GRACE score by the TyG index improved the predictive ability for MACEs (increase in C-statistic value from 0.735 to 0.744; NRI, 0.282, 95% CI 0.028–0.426, P = 0.02; IDI, 0.019, 95% CI 0.004–0.046, P = 0.01). Likelihood ratio test showed that the TyG index significantly improved the prognostic ability of the GRACE score (χ² = 12.37, 1 df; P < 0.001). The results remained consistent when the models were confirmed by internal bootstrap validation method.

Conclusion

The TyG index, but not FBG is an independent predictor of long-term MACEs after PCI in all types of ACS patients regardless of diabetes mellitus after adjusting for the GRACE score, and improves the ability of the GRACE score to stratify risk and predict prognosis of ACS patients undergoing PCI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01582-w.

Antibiotic Allergy De-Labeling: A Pathway against Antibiotic Resistance

Antibiotics are one of the most frequently prescribed drugs. Unfortunately, they also are the most common cause for self-reported drug allergy, limiting the use of effective therapies. However, evidence shows that more than 90% of patients labeled as allergic to antibiotics are not allergic. Importantly, the label of antibiotic allergy, whether real or not, constitutes a major public health problem as it directly impacts antimicrobial stewardship: it has been associated with broad-spectrum antibiotic use, often resulting in the emergence of bacterial resistance. Therefore, an accurate diagnosis is crucial for de-labeling patients who claim to be allergic but are not really allergic. This review presents allergy methods for achieving successful antibiotic allergy de-labeling. Patient clinical history is often inaccurately reported, thus not being able to de-label most patients. In vitro testing offers a complementary approach but it shows limitations. Immunoassay for quantifying specific IgE is the most used one, although it gives low sensitivity and is limited to few betalactams. Basophil activation test is not validated and not available in all centers. Therefore, true de-labeling still relies on in vivo tests including drug provocation and/or skin tests, which are not risk-exempt and require specialized healthcare professionals for results interpretation and patient management. Moreover, differences on the pattern of antibiotic consumption cause differences in the diagnostic approach among different countries. A multidisciplinary approach is recommended to reduce the risks associated with the reported penicillin allergy label.

Penicillin Allergy and Perioperative Anaphylaxis

Penicillin allergy is the most commonly reported drug allergy, while perioperative anaphylaxis is overall rare. This review covers the epidemiology of both penicillin allergy and perioperative anaphylaxis both separately and taken together. Considerations regarding anaphylaxis to penicillin during pregnancy are also discussed, since penicillin is the drug of choice for Group B Streptococcus prophylaxis. The minimal cross reactivity between penicillins and cephalosporins is addressed, since the vast majority of patients with a penicillin allergy label can receive perioperative cephalosporins. The management of the patient who has experienced perioperative anaphylaxis, including the importance of allergy referral is covered. Approaches to pre-operative penicillin allergy evaluations and opportunities for education are highlighted.

Standards for practical intravenous rapid drug desensitization & delabeling: A WAO committee statement

Drug hypersensitivity reactions (DHRs) to intravenous drugs can be severe and might leave patients and doctors in a difficult position where an essential treatment or intervention has to be suspended. Even if virtually any intravenous medication can potentially trigger a life-threatening DHR, chemotherapeutics, biologics, and antibiotics are amongst the intravenous drugs most frequently involved in these reactions. Admittedly, suspending such treatments may negatively impact the survival outcomes or the quality of life of affected patients.

Delabeling pathways and rapid drug desensitization (RDD) can help reactive patients stay on first-choice therapies instead of turning to less efficacious, less cost-effective, or more toxic alternatives. However, these are high-complexity and high-risk techniques, which usually need expert teams and allergy-specific techniques (skin testing, in vitro testing, drug provocation testing) to ensure safety, an accurate diagnosis, and personalized management. Unfortunately, there are significant inequalities within and among countries in access to allergy departments with the necessary expertise and resources to offer these techniques and tackle these DHRs optimally.

The main objective of this consensus document is to create a great benefit for patients worldwide by aiding allergists to expand the scope of their practice and support them with evidence, data, and experience from leading groups from around the globe.

This statement of the Drug Hypersensitivity Committee of the World Allergy Organization (WAO) aims to be a comprehensive practical guide on the technical aspects of implementing acute-onset intravenous hypersensitivity delabeling and RDD for a wide range of drugs. Thus, the manuscript does not only focus on clinical pathways. Instead, it also provides guidance on topics usually left unaddressed, namely, internal validation, continuous quality improvement, creating a healthy multidisciplinary environment, and redesigning care (including a specific supplemental section on a real-life example of how to design a dedicated space that can combine basic and complex diagnostic and therapeutic techniques in allergy).

Outcome of a de-labelling algorithm compared with results of penicillin (β-lactam) allergy testing

Background

Penicillin allergy labels frequently impede guideline-directed treatment with a penicillin or other β-lactam antibiotics. Despite presumed allergy, targeted questioning may indicate a low probability of sensitization and permit reasonably safe administration of the antibiotic in question. In this study, we evaluated a standardized algorithm aiming to differentiate non-allergic patients from those with true allergic β-lactam hypersensitivity.

Methods

We retrospectively applied a de-labelling algorithm in 800 consecutive patients with suspected β-lactam hypersensitivity. All had undergone complete allergy work-up permitting to definitely exclude or diagnose β-lactam allergy between 2009 and 2019.

Results

In 595 (74.4%) out of 800 cases evaluated, β-lactam allergy could be excluded by negative challenge testing. IgE-mediated anaphylaxis was diagnosed in 70 (8.7%) patients, delayed-type hypersensitivity in 135 (16.9%). In 62 (88.6%) anaphylaxis cases, the algorithm correctly advised to use an alternative antibiotic. Accuracy was higher in patients with moderate to severe anaphylaxis (97.7%) compared to those with a history of mild reactions (73.1%). The algorithm correctly identified 122 (90.4%) patients with proven delayed-type hypersensitivity. It permitted de-labelling in 330 (55.5%) out of 595 patients with diagnostic exclusion of penicillin hypersensitivity, but failed to identify the remaining 265 (44.5%) as low-risk cases.

Conclusions

The algorithm detected 89.8% of cases with penicillin (β-lactam) allergy, sensitivity was optimal for moderate to severe anaphylaxis. Study data justify the implementation of a standardized de-labelling algorithm under close supervision in order to permit guideline-directed treatment and reduce the use of broad-spectrum antibiotics as part of an antibiotic stewardship program.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-022-00659-1.

New diagnostıc perspectives in the management of pediatrıc beta-lactam allergy

Since overdiagnosis of beta-lactam (BL) allergy is common in the pediatric population, delabeling is a critical part of antimicrobial stewardship. Undesirable consequences of inaccurate BL allergy labeling can be handled by incorporating traditional delabeling or newer risk-based strategies into antibiotic stewardship programs. Conventional assessment of BL allergy relies upon a stepwise algorithm including a clinical history with skin testing followed by drug provocation tests (DPTs). However, a growing number of studies highlighted the suboptimal diagnostic value of skin testing in children. Recently, there has been a paradigm shift in the practice of BL allergy assessment due to recent challenging data which emphasize the safety and accuracy of direct DPTs in children with a suspicion of non-immediate mild cutaneous reactions such as maculopapular eruption, delayed urticaria, and possibly also for benign immediate reactions such as urticaria/angioedema. Identifying low-risk BL allergy patients, in whom skin tests can be skipped and proceeding directly to DPTs could be safe, has become a hot topic in recent years. New risk stratification and predictive modeling studies that have the potential to better predict BL allergy risk status have recently been introduced into the field of drug allergy, particularly in adults. However, in contrast to adults, risk assessment studies in children are rare, and optimal risk definitions are controversial. In the coming years, promising potential methods to elucidate the predictors of BL allergy in children will require multidimensional approaches that may include predictive analytics, artificial intelligence techniques, and point-of-care clinical decision tools.

Promoting β-lactam utilization through suppression of electronic medical record cross-allergy alerts

DISCLAIMER

In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

Current literature surrounding management of patients with reported β-lactam allergies focuses on allergy delabeling. Standard clinical decision support tools have not been optimized to be compatible with the currently accepted cross-reaction rate of 1% to 2%. This potentially promotes use of non-β-lactam antibiotics, which are often not first-line therapy and may carry increased risks. The impact of electronic medical record (EMR) clinical decision support tool optimization on utilization of β-lactam antibiotics in β-lactam-allergic patients was evaluated.

METHODS

A retrospective pre-post β-lactam cross-allergy EMR alert suppression quality improvement intervention cohort study of β-lactam-allergic adult inpatients prescribed antibiotics was conducted. Preintervention baseline data were collected for an initial cohort admitted during September 2018. The intervention, in which clinical decision support rules were updated to display β-lactam cross-sensitivity allergy alerts only for β-lactam-allergic patients with documentation of organization-defined high-severity reactions of anaphylaxis, hives, and shortness of breath, was implemented August 20, 2019. The postintervention cohort included patients admitted during September 2019.

RESULTS

A 91% increase in the percentage of β-lactam-allergic patients who received a β-lactam agent at any time during their admission was noted after the intervention (26.6% vs 51%, P < 0.001). Statistically significant decreases in prescribing of alternative antibiotic classes were seen for fluoroquinolones (decrease from 45.3% to 26%, P < 0.001), aminoglycosides (decrease from 9.4% to 2.9%, P = 0.002), and aztreonam (decrease from 30% to 16.7%, P < 0.001).

CONCLUSION

EMR β-lactam cross-allergy alert optimization consistent with current literature significantly improved the utilization of alternative β-lactam subclasses, mostly through β-lactam prescribing as initial therapy in β-lactam-allergic patients.

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.