Pathways to improved antibiotic allergy and antimicrobial stewardship practice: The validation of a beta-lactam antibiotic allergy assessment tool

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.

Retrospective study on penicillin allergy delabeling and evaluation of an antibiotic allergy assessment tool

BACKGROUND

It has been reported that 95 % of patients labeled as penicillin-allergic may be mislabeled. However, the process of delabeling has not advanced due to a shortage of allergy specialists capable of conducting accurate assessments. To address this issue, The Antibiotics Allergy Assessment Tool (AAAT) has been proposed as a tool to evaluate patients who can be delabeled by non-specialists.

OBJECTIVE

This study aims to identify patients who can be delabeled and to evaluate patients who are likely to be delabeled using AAAT.

METHODS

Patients admitted to the hospital between January 1, 2017, and December 31, 2021, with documented penicillin allergy labels were included in the study. Patients who demonstrated tolerance to labeled antibiotics or were labeled without explicit allergy declarations were defined as delabeling. Subsequently, patients who did not meet the criteria for delabeling were evaluated for their potential to be delabeled using the AAAT, retrospectively.

RESULTS

530 patients were selected, of which 62 (11.7 %) were delabeled. The AAAT evaluation of the remaining patients indicated that at least an additional 137 (25.8 %) patients could potentially be delabeled.

CONCLUSION

The use of AAAT demonstrated the potential to delabel approximately third as many patients without the need for specialist evaluation. To promote broader delabeling efforts in the future, prospective studies should investigate the safety and effectiveness of evaluation tools such as the AAAT.

First-line treatment with ceftriaxone for Neisseria gonorrhoeae infection less likely to be prescribed to patients with a penicillin allergy label: a retrospective audit of medical records

Background Gonorrhoea notifications have increased substantially in Australia over the past decade. Neisseria gonorrhoeae is already highly resistant to several antibiotics and so, alternatives to first-line treatment are generally strongly discouraged. The penicillin allergy label (AL) on patient medical records has previously been shown to influence prescribing practices, to the detriment of best-practice management and antimicrobial stewardship. This study aimed to understand how the penicillin AL influences antibiotic selection for gonorrhoea treatment at Canberra Sexual Health Centre. Methods A retrospective chart audit of gonorrhoea cases treated at Canberra Sexual Health Centre between January 2020 and October 2023 (n =619 patients, n =728 cases). Antibiotic selection was assessed according to penicillin AL status. Ceftriaxone selection was assessed according to penicillin allergy severity reported in the medical records and as determined using a validated antibiotic allergy assessment tool. Results Cases with a penicillin AL were more likely to receive antibiotics other than ceftriaxone (n =7/41, 17.1%) than cases without the label (n =8/687, 1.2%, P n =28/41, 68.3%) to apply the assessment tool. Those reported as low-severity in the records were more likely to receive ceftriaxone (n =21/22, 95.5%) than those reported as moderate-high (n =7/11, 63.6%) or unreported (n =6/8, 0.75%). Conclusions Treatment of gonorrhoea in outpatient settings requires an understanding of penicillin allergy, and the ability to quickly and accurately identify penicillin-AL patients who can safely tolerate ceftriaxone. Institutionally endorsed penicillin allergy de-labelling protocols and access to easy-to-navigate prescribing advice within national sexually transmitted infection management guidelines would support this.

Improving the performance of machine learning penicillin adverse drug reaction classification with synthetic data and transfer learning

BACKGROUND

Machine learning may assist with the identification of potentially inappropriate penicillin allergy labels. Strategies to improve the performance of existing models for this task include the use of additional training data, synthetic data and transfer learning.

AIMS

The aims of this study were to investigate the use of additional training data and novel machine learning strategies, namely synthetic data and transfer learning, to improve the performance of penicillin adverse drug reaction (ADR) machine learning classification.

METHODS

Machine learning natural language processing was applied to free-text penicillin ADR data extracted from a public health system electronic health record (EHR). The models were developed by training on various labelled data sets. ADR entries were split into training and testing data sets and used to develop and test a variety of machine learning models. The effect of training on additional data and synthetic data versus the use of transfer learning was analysed.

RESULTS

Following the application of these techniques, the area under the receiver operator curve of best-performing models for the classification of penicillin allergy (vs intolerance) and high-risk allergy (vs low-risk allergy) improved to 0.984 (using the artificial neural network model) and 0.995 (with the transfer learning approach) respectively.

CONCLUSIONS

Machine learning models demonstrate high levels of accuracy in the classification and risk stratification of penicillin ADR labels using the reaction documented in the EHR. The model can be further optimised by incorporating additional training data and using transfer learning. Practical applications include automating case detection for penicillin allergy delabelling programmes.

[Penicillin allergy-Truth or duty?]

The beta-lactam antibiotics are some of the safest and best-tolerated antibiotic agents; however, many patients have reported allergies against penicillin. All beta-lactam antibiotics are only restrictively prescribed for these patients and alternative antibiotics are increasingly given, which carries the risk of negative clinical results and socioeconomic sequelae; however, over 95% of patients who reported an allergy to penicillin show a negative result in the allergy tests for penicillin and this antibiotic can safely be prescribed. The use of sensitive and specific instruments for identification of false penicillin allergies should be an important topic within the framework of antibiotic stewardship. Anesthesists can play a central role in the reduction of the enormous individual and public health burden associated with the classification of penicillin allergy by taking an appropriate medical history and a risk stratification for the identification of patients with a penicillin allergy. This overview article presents a possible delabelling algorithm within the framework of the clarification of a beta-lactam antibiotic allergy. The focus is on a structured allergy anamnesis using the penicillin allergy, five or fewer years ago, anaphylaxis/angioedema, severe cutaneous adverse reaction (SCAR) and treatment required for allergy episode (PEN-FAST) score.

The appropriateness of penicillin allergy de-labelling by non-allergist clinical ward teams

OBJECTIVES

We aimed to assess the appropriateness of penicillin allergy (PenA) assessment conducted by clinical teams and to review the safety of subsequent exposure of these patients to penicillin.

METHODS

Opportunistic, prospective observational study of usual clinical care, between 16 May 2023 and 14 August 2023, of inpatients with a PenA and requiring antibiotics, in a 750-bed hospital in England. To assess the appropriateness of management, PenA patients prescribed penicillins were grouped into risk categories using a validated antibiotic allergy assessment tool: eligible for de-label on history alone (direct de-label; DDL), eligible for direct oral challenge (DOC), high risk or unable to obtain history.

RESULTS

Of the 123 patients admitted with a PenA (or sensitivity record) and exposed to a penicillin, data were collected for 50. Their PenA records were grouped follows: eligible for DDL 34 (68%), eligible for DOC 11 (22%), high risk 4 (8%) and unable to obtain history 1 (2%). In 14/50 (28%) patients there was no evidence of a current PenA assessment in the medical notes.

CONCLUSIONS

Using the allergy risk tool, most patients with PenA records were exposed to penicillin appropriately. However, patients meeting high-risk criteria were also exposed to penicillin when the tool excluded them. PenA assessment needs to be carried out with appropriate training and governance structures in place.

Beta-lactam allergy in patients: an antibiotic stewardship challenge

BACKGROUND

Patients are commonly reported as being allergic to beta-lactam (BL) antibiotics. However, many patients with this reported allergy are able to receive BL treatments because they do not have true allergies. In many cases these are simply intolerances due to side effects reported as an allergy. Delabelling these patients leads to better clinical outcomes, optimal antibiotic usage, decreased bacterial resistance and reduced healthcare costs. Therefore, the aims of this study were to identify incorrectly labelled BL allergies in hospitalised patients and to assess antibiotic use in delabelled patients in order to establish a quality indicator to optimise antimicrobial treatments.

METHODS

A prospective study was conducted in which hospitalised patients treated with antimicrobial drugs and labelled as 'BL-allergic' were identified by clinical pharmacists. An allergist assessed whether patients were suitable candidates for a skin test or oral challenge. The Allergy Service removed 'BL-allergic' labels if negative results were obtained. Delabelled patients were followed up by clinical pharmacists to study the use of BL antibiotics as a result of the delabelling programme.

RESULTS

A total of 176 suspected allergic patients were identified and 91 (51.7%) were tested either by a skin test or oral challenge based on the patient indicators. Seven (16.4%) patients tested were allergic to BL antibiotics, 76 (83.5%) were totally delabelled and eight (0.1%) were partially delabelled. Thirty-two (38.1%) delabelled patients required antibiotic treatment in another inpatient or outpatient setting, of whom 27 (84.3%) patients with a new infectious episode received BL treatments while five (15.7%) continued to receive antimicrobial treatments without BL.

CONCLUSION

After the implementation of a protocol to detect incorrect BL allergy labels, 83.5% of the patients in this cohort were completely delabelled. This shows that there is a clear opportunity to optimise the use of antibiotics by delabelling 'BL-allergic' patients.

Oral challenge vs routine care to assess low-risk penicillin allergy in critically ill hospital patients (ORACLE): a pilot safety and feasibility randomised controlled trial

PURPOSE

Critically ill patients are vulnerable to penicillin allergy labels that may be incorrect. The validity of skin testing in intensive care units (ICUs) is uncertain. Many penicillin allergy labels are low risk, and validated tools exist to identify those amenable to direct oral challenge. This pilot randomised controlled trial explored the feasibility, safety, and validity of direct enteral challenge for low-risk penicillin allergy labels in critical illness.

METHODS

Consenting patients with a low-risk penicillin allergy label (PAL) (PEN-FAST risk assessment score < 3) in four ICUs (Melbourne, Australia) were randomised 1:1 to penicillin (250 mg amoxicillin or implicated penicillin) direct enteral challenge versus routine care (2-h post-randomisation observation for each arm). Repeat challenge was performed post -ICU in the intervention arm. Patients were reviewed at 24 h and 5 days after each challenge/observation.

RESULTS

We screened 533 patients. 130 (24.4%) were eligible and 80/130 (61.5%) enrolled (age median 64.5 years (interquartile range, IQR 53.5, 74), PEN-FAST median 1 (IQR 0,1)), with 40 (50%) randomised to direct enteral challenge. A positive challenge rate of 2.5% was identified. No antibiotic-associated serious adverse events were identified. 32/40 (80%) received a repeat challenge (zero positive). Post-randomisation, 13 (32%) of the intervention arm and 4 (10%) of the control arm received penicillin (odds ratio, OR 4.33 [1.27, 14.78] p = 0.019).

CONCLUSION

These findings support the safety, validity, and feasibility of direct enteral challenge for critically ill patients with PEN-FAST assessed low-risk penicillin allergy. The absence of false negative results was confirmed by subsequent negative repeat challenges. A relatively low recruitment to screened ratio suggests that more inclusive eligibility criteria and integration of allergy assessment into routine ICU processes are needed to optimise allergy delabelling in critical illness.

How to Define and Manage Low-Risk Drug Allergy Labels

Risk stratification in drug allergy implies that specific risk categories (eg, low, moderate, and high) classify historical drug hypersensitivity reactions. These risk categories can be based on reaction phenotypic characteristics, the timing of the reaction and evaluation, the required reaction management, and individual characteristics. Although a multitude of frameworks have been described in the literature, particularly for penicillin allergy labels, there has yet to be a global consensus, and approaches continue to vary between allergy centers. Immune-mediated drug allergies can sometimes be confirmed using skin testing, but a negative drug challenge is required to demonstrate tolerance and remove the allergy from the electronic health record ("delabel" the allergy). Even for quintessential IgE-mediated drug allergy, penicillin allergy, recent data reveal that a direct oral challenge, without prior skin testing, is an appropriate diagnostic strategy in those who are considered low-risk. Drug allergy pathogenesis and clinical manifestations may vary depending on the culprit drug, and as such, the optimal approach should be based on risk stratification that considers individual patient and reaction characteristics, the likely hypersensitivity reaction phenotype, the drug class, and the patient's clinical needs. This article will describe low-risk drug allergy labels, focusing on β-lactam and sulfonamide antibiotics, nonsteroidal anti-inflammatory drugs, iodinated contrast media, and common chemotherapeutics. This review will also address practical management approaches using currently available risk stratification and clinical decision tools.

The importance of clinical history in the diagnosis of drug hypersensitivity in children

BACKGROUND

In case of suspected hypersensitivity reactions (HRs) to drugs, a challenging area for pediatricians is detecting relevant elements in the parent-reported history, in order to reach a definite diagnosis. We analyzed the concordance between the description of the HR and the medical reports documented at the time of the event. Furthermore, we studied any correlation between clinical history variables and the prediction of true allergy.

METHODS

We retrospectively collected 50 charts of children referred to our Allergy Unit, after a previous access to the Emergency Department. We compared the description of the HR at acute phase to the history told by parents. Type and timing of the HR and culprit drug were classified as "known" or "unknown." The diagnosis was confirmed or excluded at the end of the investigations. Logistic regression analysis was performed to find any significant association.

RESULTS

The type of the HR was known in 74%, the timing in 28%, and the culprit drug in 98%. We showed that having had a severe HR had an increased odds of remembering the timing; being older >6 years and having had an immediate HR had an increased odds of remembering the type; time to diagnostic was lower in patients whose parents remembered the type of HR.

CONCLUSION

Our paper underlines the importance of an accurate anamnesis at the time of the event. Providing the physicians with a standardized Case Report Form could be a useful tool to simplify the diagnostic work-up and minimize mistakes due to lack of memory.

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.

A new pathway for penicillin delabeling in Norway

Background

Penicillin allergy is self-reported by 3-10% of patients admitted to hospital. The label is wrong in 90% of the cases and has severe health implications. Penicillin-delabeling can reverse the negative effects of the label, and pathways adapted to local practice are needed. No tools are available in Norway for penicillin delabeling outside an allergy clinic.

Objective

To create and validate the first penicillin delabeling pathway applicable outside an allergy clinic in Norway.

Methods

An interdisciplinary taskforce created a penicillin allergy delabeling program (PAD) adapted to the Norwegian health care system. This was validated in a prospective, single-center study. Very low-risk and low-risk patients underwent a direct oral penicillin challenge and high-risk patients were referred for allergologic evaluation.

Results

One-hundred forty-nine patients declaring penicillin allergy were included. Seventy-four (50%) were very-low- and low risk patients suitable for a direct oral penicillin challenge resulting in only 1 mild reaction. Sixty high-risk patients were eligible for an oral penicillin challenge after allergologic evaluation; 3 patients reacted non-severely.

Conclusion

We have created and demonstrated feasibility of the first penicillin delabeling program (PAD) applicable in a hospital setting outside an allergy clinic in Norway. Our data suggest this is safe and beneficial, with 49% patients delabeled through a direct oral penicillin challenge, performed without any serious adverse events, and an overall 87% delabeling rate.

Artificial intelligence-enabled penicillin allergy delabelling: an implementation study

Inaccurate penicillin allergy labels may be delabelled following evaluation. The intervention in this study was an email-based notification system regarding the appropriateness for penicillin allergy evaluation, with a view to delabelling, as identified by a deep learning artificial intelligence algorithm. Of the intervention group (n = 59), three (5.1%) individuals had their penicillin allergies delabelled, which was significantly more than the control group (0%, P = 0.002). Further research to optimise such approaches is required.

Prevalence of Trimethoprim-Sulfamethoxazole Adverse Reaction Mislabelling in Australia

INTRODUCTION

Trimethoprim-sulfamethoxazole (TMP-SMX) is an important antibiotic, with the most compelling indications for Pneumocystis jirovecii pneumonia prophylaxis and methicillin-resistant Staphylococcus aureus treatment. Previous adverse reactions (AR) to TMP-SMX may limit the usability of TMP-SMX. Electronic medical record (EMR) of AR for other antibiotics has previously been shown to be inaccurate; however, the extent to which this occurs for TMP-SMX is unknown.

METHODS

A multi-centre retrospective observational study was conducted for consecutive inpatient admissions over a 2.5-year period commencing 2020. Adverse reactions to TMP-SMX recorded in the EMR were collected and reviewed by two independent medical officers using pre-defined expert criteria for the classification of allergies and intolerances.

RESULTS

TMP-SMX AR were present in the EMR of 759 individuals (prevalence 0.6%). The majority were labelled as allergy (725, 95.5%) rather than intolerance (34, 4.5%). Most common AR were rash, vomiting, and swelling. When classified against the gold-standard expert criteria, there were 437 allergies (57.6%) and 159 intolerances (21.0%). Overall, the number of incorrect EMR AR labels was 133/759 (17.5%). Both medical and surgical specialties had significant numbers of patients with TMP-SMX AR labels and incorrectly classified EMR AR labels.

CONCLUSION

TMP-SMX AR labels affect inpatients admitted under multiple specialty units. The user-entered categorization as allergy or intolerance labels in EMRs are frequently used incorrectly. These incorrect labels may inappropriately contraindicate the use of TMP-SMX, and formal evaluation of TMP-SMX ARs with immunological assessment and relabelling where appropriate may increase the use of this agent.

A pharmacist-led penicillin allergy de-labelling project within a preoperative assessment clinic: the low-hanging fruit is within reach

BACKGROUND

Having a false penicillin-allergy label is linked to longer hospital stays and to an increased risk of Clostridioides difficile and meticillin-resistant Staphylococcus aureus infection.

AIM

To assess a penicillin-allergy de-labelling tool designed for use by the non-allergist.

METHODS

Patients attending the surgical preoperative assessment clinic (POAC) at a large UK teaching hospital, who reported a penicillin allergy, were directly de-labelled by nursing or pharmacy staff, where appropriate. A penicillin-allergy de-labelling tool designed for use by the non-allergist was adapted and applied; nursing staff were provided with supporting information and education to enable removal of spurious labels. Antimicrobial pharmacists (AMPs) provided follow-up, cross-checked prophylactic antibiotics administered, interrogated clinical notes, and telephoned patients following their surgery, for details of any adverse reactions suffered.

FINDINGS

A total of 163 patients reporting a penicillin allergy were identified for intervention. Twenty-nine (17.8%) patients reported a penicillin-allergy history appropriate for direct de-labelling, of whom eight (27.6%) declined to consent. The remaining 21 patients (12.8%) were directly de-labelled, with 12 (7.4%) patients consenting during their POAC appointment; the remaining nine (5.5%) patients were consented and de-labelled after their surgery by an AMP.

CONCLUSION

The POAC was identified as an appropriate location and time-point in the patient pathway to enable the direct removal of spurious penicillin-allergy labels prior to surgery. Results suggest that this could be undertaken by nursing staff, although support from AMPs enabled a greater number of patients to be de-labelled.

Drug allergy in primary care: systematic review to support quality improvement initiative of management and optimization of healthcare pathways

PURPOSE OF REVIEW

The aim of this study was to review the practice of general practitioners (GPs) in regard to the diagnosis and management of drug hypersensitivity reactions (DHRs) to identify major challenges and to facilitate the development of decision support tools to GPs confronted with DHRs patients.

RECENT FINDINGS

DHRs are still a challenge in the GPs clinical practice, which implies difficulties in clinical decisions and referral to allergy specialists.

SUMMARY

DHRs can range from mild to severe and even life-threatening. Drugs are the main cause of anaphylaxis deaths in most countries. Most DHRs are firstly seen by GPs, paediatricians or emergency doctors. However, our systematic review demonstrated difficulties in differentiating DHRs from other drug side effects. Most DHRs epidemiological data are from hospital and emergency departments, which may not reflect the real-life experience in primary care. GPs should be aware of the alert signs of DHRs: the involvement of other systems beyond the skin and/or atypical skin/ mucosal involvement, which mandated immediate referral to an emergency department. Data still stress difficulties in the recognition of DHRs clinical manifestations and highlight the need for decision aids to support their management by GPs. Structured clinical history and clinical examination are key diagnostic tools. Reasons for referring to allergy specialists based on the literature are to investigate cause, to undergo specific procedure, such as desensitization and to identify well tolerated, alternative drugs.

Machine learning models automate classification of penicillin adverse drug reaction labels

There is a growing interest in the appropriate evaluation of penicillin adverse drug reaction (ADR) labels. We have developed machine learning models for classifying penicillin ADR labels using free-text reaction descriptions, and here report external and practical validation. The models performed comparably with expert criteria for the categorisation of allergy or intolerance and identification of high-risk allergies. These models have practical applications in detecting individuals suitable for penicillin ADR evaluation. Implementation studies are required.

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.

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.

Penicillin allergy delabeling: Opportunities for implementation and dissemination

Although existing as a safety measure to prevent iatrogenic harm, unconfirmed penicillin allergy labels have a negative impact on personal and public health. One downstream effect of unconfirmed penicillin allergy is the continued emergence and transmission of resistant bacteria and their associated health care costs. Recognizing the consequences of inaccurate penicillin allergy labels, professional and public health organizations have started promoting the adoption of proactive penicillin allergy evaluations, with the ultimate goal of removing the penicillin allergy label when the allergy is disproved, also known as penicillin allergy "delabeling." A penicillin allergy evaluation includes a comprehensive allergy history often followed by drug challenge, sometimes with preceding skin testing. Currently, penicillin allergy delabeling is largely carried out by allergy specialists in outpatient settings. Penicillin allergy delabeling is performed on inpatients, albeit rarely, often at the time of need, as a point-of-care procedure. Access to penicillin allergy evaluation services is limited. Recent studies demonstrate the feasibility of expanding penicillin allergy evaluations and delabeling to internists, pediatricians, emergency medicine physicians, infectious diseases specialists, and clinical pharmacists. However, reducing the impact of mislabeled penicillin allergy will require comprehensive efforts and new investments. In this review, we summarize the current practices of penicillin allergy delabeling and discuss expansion opportunities for penicillin allergy delabeling as quality improvement.

An overview of penicillin allergies for nurses

ABSTRACT

Antibiotics are frequently reported as allergies by patients, particularly antibiotics from the penicillin family. Most of these reported allergies are benign, and the consequences of alternative therapies can be significant. This article provides background information on penicillin allergies and serves as a guide to penicillin allergy management.Reprinted with permission from Wrynn, A.F. An overview of penicillin allergies for nurses. Nurse Pract 2022; 47(9): 30-36. Copyright Wolters Kluwer. All rights reserved.

Study protocol for PREPARE: a phase II feasibility/safety randomised controlled trial on PeRiopErative Penicillin AlleRgy TEsting

INTRODUCTION

Patient-reported antibiotic allergy labels (AALs) are common. These labels have been demonstrated to have a negative impact on use of appropriate antibiotics and patient-related health outcomes. These patients are more likely to receive suboptimal antibiotics, have increased rates of surgical site infections and are more likely to be colonised with multidrug-resistant organisms. Increasing recognition that antibiotic allergy forms a key part of good antimicrobial stewardship has led to calls for greater access to antibiotic allergy assessment.PREPARE is a pilot randomised controlled trial of beta-lactam allergy assessment and point of care delabelling in perioperative patients utilising a validated antibiotic allergy assessment tool that has been repurposed into a smartphone application. The aim of the study is to assess the feasibility and safety of this approach in the perioperative outpatient setting.

METHODS AND ANALYSIS

Adult participants requiring elective surgery and are likely to require prophylactic intravenous antibiotics will be recruited. During the intervention phase, participants will be randomised to the intervention or control arm, with control patients receiving usual standard of care. Those randomised to intervention undertake a risk assessment via the smartphone application, with those deemed low risk proceeding to direct oral provocation with either a penicillin or cephalosporin. Study outcomes will be evaluated in the postintervention phase, 30 and 90 days after surgery.Feasibility of intervention delivery and recruitment will be reported as proportions with respective 95% CIs. Participants who experience an antibiotic adverse event will be reported by group with respective 95% CIs and compared using modified Poisson regression model with robust SE estimation.

ETHICS AND DISSEMINATION

This protocol has received approval from the Austin Health human research and ethics committee, Heidelberg, Victoria, Australia (HREC/17/Austin/575). Results will be disseminated via publication in peer-reviewed journals as well as presentation at international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12620001295932.

Artificial intelligence and the potential for perioperative delabeling of penicillin allergies for neurosurgery inpatients

PURPOSE OF THE ARTICLE

Patients with penicillin allergy labels are more likely to have postoperative wound infections. When penicillin allergy labels are interrogated, a significant number of individuals do not have penicillin allergies and may be delabeled. This study was conducted to gain preliminary evidence into the potential role of artificial intelligence in assisting with perioperative penicillin adverse reaction (AR) evaluation.

MATERIAL AND METHODS

A single-centre retrospective cohort study of consecutive emergency and elective neurosurgery admissions was conducted over a two-year period. Previously derived artificial intelligence algorithms for the classification of penicillin AR were applied to the data.

RESULTS

There were 2063 individual admissions included in the study. The number of individuals with penicillin allergy labels was 124; one patient had a penicillin intolerance label. Of these labels, 22.4% were not consistent with classifications using expert criteria. When the artificial intelligence algorithm was applied to the cohort, the algorithm maintained a high level of classification performance (classification accuracy 98.1% for allergy versus intolerance classification).

CONCLUSIONS

Penicillin allergy labels are common among neurosurgery inpatients. Artificial intelligence can accurately classify penicillin AR in this cohort, and may assist in identifying patients suitable for delabeling.

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.

Implementing Preoperative Penicillin Allergy Testing in Surgical Patients

Penicillin allergy is the most reported immunoglobulin E (IgE)-mediated reaction. About 10% of the general population and 20% of hospitalized patients have a history of penicillin allergy. Unconfirmed penicillin allergy with subsequent administration of second-line antibiotics has been associated with increased morbidity. However, when penicillin allergy testing is performed, the incidence of IgE-mediated reactions is extremely low; in fact, the negative predictive value of penicillin allergy testing exceeds 99%. This article aims to briefly describe implementing safe penicillin allergy testing as a routine test during the preoperative evaluation of surgical patients.

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.

Penicillin allergies: A guide for NPs

ABSTRACT

Antibiotics are frequently reported as allergies by patients, particularly antibiotics from the penicillin family. Most of these reported allergies are benign, and the consequences of alternative therapies can be significant. This article will deliver background information on penicillin allergies and serve as a guide to penicillin allergy management.

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.

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).

Genetic Association of Beta-Lactams-Induced Hypersensitivity Reactions: A Protocol for Systematic Review and Meta-Analysis

Beta-lactam (BL) antibiotics are among the drugs commonly related to hypersensitivity reactions. Several candidate gene studies and genome-wide association studies have reported associations of genetic variants and hypersensitivity reactions induced by BL antibiotics. However, the results were inconclusive. This protocol details a comprehensive systematic review of genetic factors associated with BL-induced hypersensitivity. A systematic search of literature related to genetic associations of BL-induced hypersensitivity will be performed through PubMed, Medline, Scopus, EMBASE, Web of Science, CINAHL, and the Cochrane central register of Controlled Trials (CENTRAL) from their inception dates with no language restrictions. Two reviewers will independently screen, extract, and appraise the risk of bias. Frequencies of genetic variants that comply with Hardy–Weinberg equilibrium will be extracted and pooled. Genetic models will be applied to variant effect calculation as per allele and genotype analysis. Based on statistical heterogeneity among studies, common effect estimation (odds ratio) and its corresponding 95% confidence interval will be analyzed. Sensitivity and subgroup analyses will be performed to determine the robustness of eligible studies. This systematic review and meta-analysis will provide comprehensive evidence of genetic effects regarding BL-induced hypersensitivity. The findings will enlighten the determination of disease-related genotypes that would potentially reveal allergy profiling in patients.

Assessment of the validity of the beta-lactam antibiotic allergy assessment tool for use in the rural context, QLD

OBJECTIVE(S)

The objective of the study was to validate a clinical aid to guide the assessment and management of a patient's listed beta-lactam antibiotic allergy for use in rural areas of Australia.

DESIGN

Rural generalists, pharmacists and junior doctors completed an online assessment of eight patient case studies using the tool.

SETTING

The study was conducted in the Southern Downs, QLD.

PARTICIPANTS

Twenty-seven rural generalists, nine pharmacists and eight junior doctors.

MAIN OUTCOME MEASURES

The sensitivity of the selected allergy phenotype and management option for each case study was calculated by profession and overall. Hazardous responses were reported by management category and profession.

RESULTS

The sensitivity overall for phenotype selection was 82.4% (95% CI, 78.0-86.2) and for management 88.1% (95% CI, 84.2-91.2). The sensitivity for phenotype selection was lower for junior doctors than other professions 73.4% (95% CI, 60.9-83.7), but did not reach statistical significance (p = 0.08). A total of 10/308 responses for management recommended the least restrictive option of direct delabelling or oral challenge, where the correct answer was skin prick testing or referral to an allergist.

CONCLUSION(S)

With further education the tool could be a key component of increased antimicrobial stewardship in rural areas in Australia.

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.

Patients with questionable penicillin (beta-lactam) allergy: Causes and solutions

BACKGROUND

In Europe, North America, and Australia, 5% to 10% of the population are now classified as penicillin (β-lactam) allergic. Only ~ 10% of these questionable diagnoses, mostly made in childhood, can be confirmed by allergy diagnostics.

MATERIALS AND METHODS

The aim of this review is to show causes and consequences as well as recommendations for dealing with the often questionable diagnosis of penicillin (β-lactam) allergy (BLA).

RESULTS

An incorrect BLA diagnosis may negatively impact antibiotic treatment needed in the future, by using a less effective antibiotic or using a broad-spectrum antibiotic, for example, further exacerbating the problem of increasing antibiotic resistance. Accordingly, there is growing pressure from antibiotic stewardship programs to critically challenge the BLA diagnosis. Conservatively, a suspected BLA is reviewed by an allergist using medical history, skin testing, laboratory testing, and provocation. This clarification is costly and is not remunerated in the German health care system; that is the reason why this testing is only offered in a few specialized clinics and practically not at all in general practice. In view of thousands of affected patients, additional strategies are needed to treat patients with a low risk of hypersensitivity reaction despite suspected allergy with a β-lactam antibiotic. In recent years, various methods have been proposed to eliminate suspected allergy as promptly as possible and directly before necessary treatment with a β-lactam antibiotic, including standardized history (also in the form of an algorithm), skin test with immediate reading after 15 minutes, or administration of a small test dose. Investigations of small case series and also multi-center studies to date have yielded promising results in terms of feasibility and safety.

CONCLUSION

Of the large number of patients with (questionable) BLA, most have never been tested and - if antibiotic treatment becomes necessary - simply receive an alternative antibiotic. The diagnosis of BLA therefore requires new approaches besides classical allergy testing to critically question BLA.

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.

ESCAPE-Allergy: Evaluating screening for children and adolescents with penicillin allergy

AIM

Penicillin allergy labels are frequently encountered in children and are associated with significant harms. Most children are falsely labelled and can safely tolerate a penicillin but delabelling strategies are underutilised and paediatric-specific resources are lacking. The aim of this study was to evaluate an allergy assessment tool for children in hospital.

METHODS

We evaluated a paediatric-adapted penicillin allergy assessment tool, using an online survey of clinicians in a tertiary paediatric hospital, with 10 hypothetical potential penicillin allergy or adverse reaction cases (including non-allergy reactions). For each case, respondents were asked to use the tool to assign a reaction phenotype and recommend management. We determined the tool's sensitivity, specificity and acceptability to end users.

RESULTS

We evaluated 30 complete survey responses from senior and junior medical staff, nurses and pharmacists. The tool's overall sensitivity was 80.7% (95% confidence interval (CI) 74.2-87.1%) for assigning the correct reaction phenotype and 85.3% (95% CI 79.4-91.3%) for appropriate management. The tool had high sensitivity for identifying immediate hypersensitivity reactions at 95.6% (95% CI 90.2-100%). Most respondents agreed or strongly agreed that they would use the tool in their practice (22/30, 73.3%).

CONCLUSION

This survey evaluated a paediatric-adapted penicillin allergy assessment tool in a tertiary paediatric hospital among multidisciplinary clinician groups. The tool performed well overall and had high safety in identifying immediate hypersensitivity reactions. Further research to support implementation of allergy assessment and delabelling programmes among children is required.

Completeness and accuracy of adverse drug reaction documentation in electronic medical records at a tertiary care hospital in Australia

Background: A large proportion of patients presenting to hospitals have experienced a previous adverse drug reaction (ADR). Electronic medical records (EMRs) present an opportunity to accurately document ADRs and alert clinicians against inadvertent rechallenge where there is a pre-existing reaction. However, EMR systems are imperfect and rely on the accuracy of the data entered. Objective: To ascertain the completeness of ADR documentation and the accuracy of the classification of ADRs as allergy versus intolerance in the EMR at a major metropolitan hospital in Australia. Method: Cross-sectional audit of the ADR field of the EMR for a sample of patients on four different wards over 3 weeks to ascertain the completeness of ADR documentation and the accuracy of classification of ADRs. Results: Of the 264 patients assessed, 102 (38.6%) had a total of 210 ADRs documented in the EMR. Of these, 105 (50%) were considered to have complete documentation; 63/210 (30.0%) were missing a reaction description and 88/210 (41.9%) were missing severity information. For those ADRs with a reaction description (n = 147), 97 (66.0%) were considered to be appropriately classified as allergy or intolerance. Conclusion: Incomplete and inaccurate ADR documentation was common. These findings highlight a need for optimising ADR documentation to improve appropriate medication use in hospital. Implications: Improved EMR design and education of healthcare workers on the importance of complete and accurate documentation of reactions are needed to improve completeness and accuracy of ADR classification.

Immediate and Delayed Hypersensitivity Reactions to Beta-Lactam Antibiotics

Beta-lactam antibiotics are the most commonly reported drug allergy in adults and children. More than 95% of those with reported allergy labels to beta lactams are not confirmed when subjected to allergy testing. Beta lactam antibiotics are associated with a wide spectrum of immediate and delayed drug hypersensitivity reactions. The latency period to symptoms and clinical presentation aids in the causality assessment. Risk stratification based on diagnosis and timing then allows for appropriate management and evaluation. Skin prick testing, intradermal testing and oral challenge are well established for evaluation of immediate reactions. Delayed intradermal testing, patch testing and oral challenge can also be considered for evaluation of mild to moderate delayed reactions. Cross-reactivity between beta-lactams appears to be driven most commonly by a shared R1 side-chain. Standardized algorithms, protocols and pathways are needed for widespread implementation of a pragmatic and effective approach to patients reporting beta lactam allergy.

The Penicillin Allergy Delabeling Program: A Multicenter Whole-of-Hospital Health Services Intervention and Comparative Effectiveness Study

BACKGROUND

Penicillin allergies are associated with inferior patient and antimicrobial stewardship outcomes. We implemented a whole-of-hospital program to assess the efficacy of inpatient delabeling for low-risk penicillin allergies in hospitalized inpatients.

METHODS

Patients ≥ 18 years of age with a low-risk penicillin allergy were offered a single-dose oral penicillin challenge or direct label removal based on history (direct delabeling). The primary endpoint was the proportion of patients delabeled. Key secondary endpoints were antibiotic utilization pre- (index admission) and post-delabeling (index admission and 90 days).

RESULTS

Between 21 January 2019 and 31 August 2019, we assessed 1791 patients reporting 2315 antibiotic allergies, 1225 with a penicillin allergy. Three hundred fifty-five patients were delabeled: 161 by direct delabeling and 194 via oral penicillin challenge. Ninety-seven percent (194/200) of patients were negative upon oral penicillin challenge. In the delabeled patients, we observed an increase in narrow-spectrum penicillin usage (adjusted odds ratio [OR], 10.51 [95% confidence interval {CI}, 5.39-20.48]), improved appropriate antibiotic prescribing (adjusted OR, 2.13 [95% CI, 1.45-3.13]), and a reduction in restricted antibiotic usage (adjusted OR, 0.38 [95% CI, .27-.54]). In the propensity score analysis, there was an increase in narrow-spectrum penicillins (OR, 10.89 [95% CI, 5.09-23.31]) and β-lactam/β-lactamase inhibitors (OR, 6.68 [95% CI, 3.94-11.35]) and a reduction in restricted antibiotic use (OR, 0.52 [95% CI, .36-.74]) and inappropriate prescriptions (relative risk ratio, 0.43 [95% CI, .26-.72]) in the delabeled group compared with the group who retained their allergy label.

CONCLUSIONS

This health services program using a combination of direct delabeling and oral penicillin challenge resulted in significant impacts on the use of preferred antibiotics and appropriate prescribing.

Predictive factors of amoxicillin immediate hypersensitivity and validation of PEN-FAST clinical decision rule

BACKGROUND

The challenge of delabeling amoxicillin allergy is an important issue for patients and clinicians, especially when anaphylaxis is reported. A recent study has proposed a clinical decision rule, PEN-FAST, to identify low-risk penicillin allergies.

OBJECTIVE

To validate the PEN-FAST clinical decision rule in a population with high risk of suspected immediate amoxicillin allergy and to identify clinical predictive factors of amoxicillin immediate hypersensitivity.

METHODS

We retrospectively analyzed medical records of patients with a suspected immediate amoxicillin allergy who carried out an allergologic evaluation by a specialist in the Allergy Unit of Strasbourg University Hospital from 2015 to 2020.

RESULTS

A total of 142 adult patients (88 women [62.0%]; median age, 52 [interquartile range, 40.3-62.0] years) were analyzed. Most of them reported anaphylaxis (68.8%). Internal validation of PEN-FAST score revealed a good discrimination with area under the curve of 0.86 (95% confidence interval, 0.79-0.92). A cutoff of less than 3 points for PEN-FAST was used to classify 29 from 142 patients at low risk of allergy, of whom only 2 (6.9%) received positive results of allergy testing. The negative predictive value for successful delabeling was 0.93 (95% confidence interval, 0.77-0.99). Predictive clinical features for immediate amoxicillin hypersensitivity were time since reaction (P < .001), time elapsed between drug intake and first symptom (P < .001), severity grade reaction (P < .001), and treatment or hospitalization required (P < .001).

CONCLUSION

PEN-FAST has been validated to identify low-risk penicillin allergies in our European cohort of patients mainly reporting anaphylaxis. This is the first reported external validation of a penicillin allergy clinical decision rule internationally.

Exploring the practice, confidence and educational needs of hospital pharmacists in reviewing antimicrobial prescribing: a cross-sectional, nationwide survey

BACKGROUND

Antimicrobial stewardship (AMS) programs are usually limited in resources and scope. Therefore, wider engagement of hospital pharmacists in reviewing antimicrobial orders is necessary to ensure appropriate prescribing. We assessed hospital pharmacists' self-reported practice and confidence in reviewing antimicrobial prescribing, and their knowledge in making AMS interventions.

METHODS

We conducted an Australia-wide, cross-sectional survey in October 2017. A link to the online survey was emailed to hospital pharmacists via the Society of Hospital Pharmacists of Australia. Factors associated with higher knowledge scores were explored using linear regression models.

RESULTS

There were 439 respondents, of whom 272 (61.7%) were from metropolitan public hospitals. Pharmacists were more likely to assess the appropriateness of intravenous, broad-spectrum or restricted antibiotics than narrow-spectrum, oral antibiotics within 24-72 h of prescription; p < 0.001. Fifty percent or fewer respondents were confident in identifying AMS interventions related to dose optimization based on infection-specific factors, bug-drug mismatch, and inappropriate lack of spectra of antimicrobial activity. The median knowledge score (correct answers to knowledge questions) was 6 out of 9 (interquartile range, 5-7); key gaps were noted in antimicrobials' anaerobic spectrum, beta-lactam allergy assessment and dosing in immunocompromised patients. Clinical practice in inpatient areas, registration for 3-5 years and receipt of recent AMS education were associated with higher knowledge scores. More interactive modes of education delivery were preferred over didactic modes; p ≤ 0.01.

CONCLUSION

Gaps in practice, confidence and knowledge among hospital pharmacists were identified that could inform the design of educational strategies to help improve antimicrobial prescribing in Australian hospitals.