Penicillin allergy label persists despite negative testing

Assessing the rationale of prescribing carbapenems among hospitalized patients with documented penicillin allergy: implications for stewardship

Background

A reported history of penicillin allergy frequently leads to the prescription of carbapenems as a substitute for penicillin to avoid allergic reactions. Such self-reported allergies need to be accurately characterized to identify targeted antibiotic stewardship interventions that potentially minimize unnecessary carbapenem use.

Design

Retrospective cohort study.

Method

The proportion of hospitalized patients with penicillin allergy history receiving carbapenem prescriptions was evaluated between January 1st, 2017 and December 31st, 2018 at the University Hospital Basel, Switzerland. The appropriateness of carbapenem prescription of each patient was evaluated using institutional guidelines based on previously published recommendations.

Results

Our analysis revealed that among 212 patients with recorded penicillin allergy, of the 247 carbapenem treatment episodes, 79 (32%) were unjustified. Abdominal and lower respiratory tract infections were most frequently associated with inappropriate carbapenem use (OR 2.64, 95% CI 1.22-5.71, P = .014 and OR 2.26, 95% CI 1.08-4.73, P = .031). The recorded allergy type was not documented or unclear in 153 patients (72%) and penicillin allergy was only confirmed in 2 patients (0.9%). Inconsistencies in allergic symptom documentation and allergy types were found between the institution's two software programs.

Conclusion

While a multimodal approach to identify and accurately label penicillin allergies remains essential to reduce inappropriate carbapenem use, our findings highlight the need for comprehensive and easily accessible guidelines for carbapenem utilization and structured history-based allergy assessment as an initial screening tool, embedded in a tailored digital allergy record template.

Use of the Electronic Health Record for Monitoring Adverse Drug Reactions

PURPOSE OF REVIEW

Adverse drug reactions (ADRs) are a significant cause of morbidity and mortality. The electronic health record (EHR) provides an opportunity to monitor ADRs, mainly through the utilization of drug allergy data and pharmacogenomics. This review article explores the current use of the EHR for ADR monitoring and highlights areas that require improvement.

RECENT FINDINGS

Recent research has identified several issues with using EHR for ADR monitoring. These include the lack of standardization between EHR systems, specificity in data entry options, incomplete and inaccurate documentation, and alert fatigue. These issues can limit the effectiveness of ADR monitoring and compromise patient safety. The EHR has great potential for monitoring ADR but needs significant updates to improve patient safety and optimize care. Future research should concentrate on developing standardized documentation and clinical decision support systems within EHRs. Healthcare professionals should also be educated on the significance of accurate and complete ADR monitoring.

[Drug allergy: Fundamental aspects in diagnosis and treatment.]

BACKGROUND

Any substance used as a treatment for any disease can produce harmful or unpleasant events called adverse drug reactions (ADRs). They are due to inherent biological effects of the drug and are caused by immunological and non-immunological mechanisms.

OBJECTIVES

To describe the immunological mechanisms of hypersensitivity reactions (HSR) to drugs, their epidemiology, risk factors, classification, clinical manifestations, diagnosis, treatment, and prognosis.

METHODS

A review of the most current literature in English and Spanish was carried out, in the main databases, related to the HSR of various drug groups.

RESULTS

This study describes the terms used to define ADRs and HSRs, their classification and clinical manifestations, current diagnostic tools, treatment algorithms and prognosis of the most frequently used medications and with the highest prevalence of reported adverse events.

CONCLUSION

ADRs are a challenging entity, with a complex pathophysiology that has not been fully understood. Its approach requires a careful consideration since not all drugs have validated tests for their diagnosis nor a specific treatment. When indicating the use of any drug, the severity of the disease, the availability of other treatments and the potential risks of developing future adverse events should always be taken into consideration.

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.

Follow-up of penicillin allergy labels 1 year after successful penicillin delabeling

BACKGROUND

Penicillin allergy delabeling confers many benefits, including reduced patient morbidity and mortality and improved health economics. Reports suggest that both patients and clinicians often remain hesitant to take and prescribe penicillins, respectively, after penicillin delabeling. However, follow-up of an individual's penicillin allergy label and incorporation of this into relevant health care records after delabeling have not been well studied in the Australian population.

OBJECTIVE

To evaluate the status of penicillin allergy labels in the community 1 year after penicillin delabeling at a tertiary hospital in Australia.

METHODS

A cross-sectional study was performed using follow-up interviews with patients and community primary care providers after 1 year from the date of patients' penicillin delabeling at a tertiary hospital in New South Wales, Australia. The main outcome measures that were evaluated included patient willingness to accept penicillin for future infections, patient self-reported receipt of penicillin-based antibiotics after delabeling, accuracy of penicillin allergy labels in the records of the primary care provider, and prescription of penicillin-based antibiotics by the general practitioner.

RESULTS

A total of 86 patients were included in this study. The percentage of patients with a correct penicillin allergy status at 1-year follow-up was 94% in the hospital electronic medical record but only 37% in primary care records. At 1-year follow-up, 14% of delabeled patients continued to reject penicillin prescriptions.

CONCLUSION

Better strategies are required to increase patient confidence in receiving penicillins after penicillin delabeling and to ensure that penicillin allergy labels are translated into the medical records at the primary care level.

Allergy Electronic Health Record Documentation: A 2022 Work Group Report of the AAAAI Adverse Reactions to Drugs, Biologicals, and Latex Committee

The allergy section of the electronic health record (EHR) is ideally reviewed and updated by health care workers during routine outpatient visits, emergency room visits, inpatient hospitalizations, and surgical procedures. This EHR section has the potential to help proactively and comprehensively avoid exposures to drugs, contact irritants, foods, and other agents for which, based on an individual's medical history and/or genetics, there is increased risk for adverse outcomes with future exposures. Because clinical decisions are made and clinical decision support is triggered based on allergy details from the EHR, the allergy module needs to provide meaningful, accurate, timely, and comprehensive allergy information. Although the allergy section of the EHR must meet these requirements to guide appropriate clinical decisions and treatment plans, current EHR allergy modules have not achieved this standard. We urge EHR vendors to collaborate with allergists to optimize and modernize allergy documentation. A work group within the Adverse Reactions to Drugs, Biologicals, and Latex Committee of the American Academy of Allergy, Asthma & Immunology was formed to create recommendations for allergy documentation in the EHR. Whereas it is recognized that the term "allergy" is often used incorrectly because most adverse drug reactions (ADRs) are not true immune-mediated hypersensitivity reactions, "allergy" in this article includes allergies and hypersensitivities as well as side effects and intolerances. Our primary objective is to provide guidance for the current state of allergy documentation in the EHR. This guidance includes clarification of the definition of specific ADR types, reconciliation of confirmed ADRs, and removal of disproved or erroneous ADRs. This document includes a proposal for the creation, education, and implementation of a drug allergy labeling system that may allow for more accurate EHR documentation for improved patient safety.

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.

Mixed-methods evaluation of a behavioural intervention package to identify and amend incorrect penicillin allergy records in UK general practice

OBJECTIVES

About 6% of the UK general practice population has a record of a penicillin allergy but fewer than 10% of these are likely to be truly allergic. In the ALABAMA (Allergy Antibiotics and Microbial resistance) feasibility trial, primary care patients with penicillin allergy were randomised to penicillin allergy assessment pathway or usual care to assess the effect on health outcomes. A behavioural intervention package was developed to aid delabelling. This study aimed to investigate patients' and clinicians' views of penicillin allergy testing (PAT).

DESIGN

We conducted a mixed-methods process evaluation embedded within the ALABAMA trial, which included a clinician survey, a patient survey (at baseline and follow-up) and semistructured interviews with patients and clinicians.

SETTINGS

The study was conducted in primary care, as part of the feasibility stage of the ALABAMA trial.

PARTICIPANTS

Patients and primary care clinicians.

RESULTS

Clinicians (N=53; 52.2%) were positive about PAT and its potential value but did not have previous experience of referring patients for a PAT and were unsure whether patients would take penicillin after a negative allergy test. Patients (N=36; 46%) were unsure whether they were severely allergic to penicillin and did not fear a severe allergic reaction to penicillin. Clinician interviews showed that they were already aware of the benefit of PAT. Interviews with patients suggested the importance of safety as patients valued having numerous opportunities to address their concerns about safety of the test.

CONCLUSIONS

This study highlights the positive effects of the ALABAMA behavioural intervention for both patients and clinicians.

TRIAL REGISTRATION NUMBER

NCT04108637; ISRCTN20579216; Pre-results.

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.

Type B adverse drug reactions to antibiotics and antibiotic allergy in infants and children

BACKGROUND

Distinguishing allergic reactions from non-allergic type B adverse drug reactions (ADRs) to antibiotics is challenging, particularly in children, because we lack epidemiological information that can be used in primary care situations. This study aimed to investigate the characteristics of type B ADRs to antibiotics and antibiotic allergy (AA) in previously healthy children.

METHODS

This was a retrospective cohort study of previously healthy children admitted for treating urinary tract infections over a 10 year period. The primary outcome was the frequency of type B ADRs and AAs that were assessed by pediatricians. Secondary outcomes include demographic data about patients' backgrounds, infections, treatments, ADRs, and action against ADRs. All the data were collected via patients' medical records.

RESULTS

Out of 791 participants, type B ADRs were reported in 77 children (9.7%), and AA labeling was performed in six children (0.8%). Physicians assessed 30.4% of type B ADRs as severe or life-threatening symptoms. All patients were discharged without long-term complications. Physicians detected the primary cause (individual patient host factors or environmental risks) in 39 cases of type B ADRs.

CONCLUSION

Type B ADRs to antibiotics were frequently reported even in previously healthy children. Physicians should use appropriate techniques (e.g., specialist consulting and skin testing) when they suspect that a type B ADR might be an AA. Labeling and de-labeling programs and tools for type B ADRs related to antibiotics should be implemented to prevent the mislabeling of AA.

Betalactam hypersensitivity: The importance of delabelling in primary care

PATIENTS AND METHODS

An allergy work-up was performed on adult patients with a history of a penicillin allergy seen by primary medical care in Monastir (Tunisia) between July 2016 and February 2018. Patients with negative skin tests were challenged with amoxicillin. Patients who were delabelled were contacted by phone after 6 months to determine outcomes after any therapeutic penicillin-class antibiotic intake.

RESULTS

A total of 39 patients were evaluated and 33 (84.6%) were delabelled. Five patients were penicillin skin-test positive and one was oral challenge positive. We succeeded in contacting 33 delabelled patients at 6 months. Twenty-two patients tolerated a subsequent therapeutic course of amoxicillin, eight patients did not retake penicillin due to a lack of therapeutic indication, and three patients refused an indicated penicillin use fearful of another reaction.

CONCLUSION

This study highlights the importance of allergy work-up in the diagnosis of beta-lactam hypersensitivity. Most patients were excessively labelled as beta-lactam allergic and this mislabelling could increase healthcare costs and lead to the development of drug resistance by the use of wide-spectrum antibiotics.

Drug Allergy Labels Lost in Translation: From Patient to Charts and Backwards

The current method of defining, reporting, assessment, labeling, delabeling, and reconciliation of adverse drug reactions (ADRs), and specifically immunologically mediated drug hypersensitivity reactions (HSRs), in electronic health records (EHRs) is inadequate and compromises care quality and safety. It is critical to accurately and succinctly report the signs and symptoms associated with ADRs and suspected HSRs to enable clinicians to determine the plausible reaction type and help guide appropriate future management plans. Despite the current limitations of the EHR allergy module, we must encourage improved clinical documentation and demand technological improvements. Telehealth methods have been shown to be valuable in the assessment of ADRs and HSRs, particularly in the case of penicillin allergy evaluation and delabeling. The implementation, assessment, and refinement of advanced technologies, including clinical informatics and artificial intelligence, along with continued education of health care providers have potential to improve EHR documentation and communication, thereby advancing patient safety efforts.

Penicillin Allergy De-labeling Results in Significant Changes in Outpatient Antibiotic Prescribing Patterns

Unverified penicillin allergies are common but most patients with a penicillin allergy label can safely use penicillin antibiotics. Penicillin allergy labels are associated with poor clinical outcomes and overuse of second-line antibiotics. There is increasing focus on penicillin allergy "de-labeling" as a tool to improve antibiotic prescribing and antimicrobial stewardship. The effect of outpatient penicillin allergy de-labeling on long-term antibiotic use is uncertain. We performed a retrospective pre- and post- study of antibiotic dispensing patterns, from an electronic dispensing data repository, in patients undergoing penicillin allergy assessment at Auckland City Hospital, New Zealand. Over a mean follow-up of 4.55 years, 215/304 (70.7%) of de-labeled patients were dispensed a penicillin antibiotic. Rates of penicillin antibiotic dispensing were 0.24 (0.18-0.30) penicillin courses per year before de-labeling and 0.80 (0.67-0.93) following de-labeling with a reduction in total antibiotic use from 2.30 (2.06-2.54) to 1.79 (1.59-1.99) antibiotic courses per year. In de-labeled patients, the proportion of antibiotic courses that were penicillin antibiotics increased from 12.81 to 39.62%. Rates of macrolide, cephalosporin, trimethoprim/co-trimoxazole, fluoroquinolone, "other" non-penicillin antibiotic use, and broad-spectrum antibiotic use were all lower following de-labeling. Further, antibiotic costs were lower following de-labeling. In this study, penicillin allergy de-labeling was associated with significant changes in antibiotic dispensing patterns.

Subsequent MRI of pediatric patients after an adverse reaction to Gadolinium-based contrast agents

Background

Gadolinium-based contrast agent (GBCA)-enhanced magnetic resonance imaging (MRI) scans often must be used repeatedly in pediatric oncologic patients. Although GBCAs are usually well tolerated, severe and life-threatening allergic reactions might occur, which can result in overly cautions adherence to special precautions in patients.

Purpose

To evaluate the management of the reported GBCA-associated adverse reactions in subsequent contrast-enhanced MRIs in pediatric patients, distinguishing non-allergic and allergic reactions.

Materials and methods

In this retrospective, cross-sectional study, consecutive pediatric neurooncological patients who underwent GBCA-enhanced MRI at our university hospital, between 2007 and 2016, were eligible. The patients’ history was evaluated with regard to any adverse events after GBCA administration. In a subset of patients with reported adverse reactions, the institutional premedication regime or an allergy work-up in clinical practice were performed, using either skin-prick tests or intravenous provocation tests in a double-blind procedure.

Results

Included were 8156 contrast-enhanced MRI scans in 2109 patients. Nineteen acute adverse events (19/8156; 0.23%) in 17 patients (17/2109; 0.81%) were reported. Despite a premedication regime in 14 patients, three patients (3/14; 21.4%) reported a breakthrough reaction. None of the 12 patients who underwent skin-prick tests or intravenous provocation tests showed allergic reactions. At least one well-tolerated GBCA was identified in almost every tested patient.

Conclusion

A fast-track allergy work-up can help to distinguish non-allergic and allergic reactions and to identify a well-tolerated GBCA, thus avoiding unnecessary premedication for subsequent GBCA administrations.

Children with reported penicillin allergy: Public health impact and safety of delabeling

OBJECTIVE

To review the relevant literature related to children with reported penicillin allergy and highlight the different ways in which children could be delabeled and to evaluate the public health impact that a penicillin allergy has for children.

DATA SOURCES

Data for this review were obtained via PubMed searches and then retrieval of articles from their respective journals for further review.

STUDY SELECTIONS

Studies regarding the safety of different ways to evaluate penicillin allergy in children were identified via PubMed searches. Any study that reported different ways of testing (3-tier, direct oral challenge, 5-day oral challenges) were included. This same format was used when selecting relevant articg:les related to the costs, prescription patterns, and stewardship trends associated with a penicillin allergy label.

RESULTS

This review found that penicillin allergy testing is a safe and effective way to delabel those with reported allergy. In children with low-risk allergy symptoms, a direct oral challenge approach may be optimal. In those children with a history of high-risk allergy symptoms, a 3-tiered approach is ideal. The review also found that there is a significant cost associated with reported penicillin allergy and that there are increased negative health benefits to those children with reported allergy.

CONCLUSION

Penicillin allergy is overdiagnosed, often incorrectly, and the label is frequently first applied during childhood. Targeting children for the removal of the incorrect penicillin allergy label provides a mechanism to reduce the use of broader-spectrum and less effective antibiotics.

Preoperative penicillin allergy testing in patients undergoing cardiac surgery

BACKGROUND

Cefazolin is a first-line prophylactic antibiotic used to prevent surgical site infections (SSIs) in cardiac surgery. Patients with a history of penicillin allergy often receive less effective second-line antibiotics, which is associated with an increased SSI risk.

OBJECTIVE

To describe the impact of preoperative penicillin allergy evaluation on perioperative cefazolin use in patients undergoing cardiac surgery.

METHODS

We performed a retrospective cohort study of patients with a documented penicillin allergy who underwent cardiac surgery at the Massachusetts General Hospital from September 2015 to December 2018. We describe penicillin allergy evaluation assessment and outcomes. We evaluated the association between preoperative penicillin allergy evaluation and first-line perioperative antibiotic use using a multivariable logistic regression model.

RESULTS

Of 3802 cardiac surgical patients, 510 (13%) had a documented penicillin allergy; 165 (33%) were referred to allergy and immunology practitioners. Of 160 patients (31%) who underwent penicillin allergy evaluation (ie, penicillin skin testing and, if results were negative, an amoxicillin challenge), 154 (97%) were found not to have a penicillin allergy. Patients who underwent preoperative penicillin allergy evaluation were more likely to receive the first-line perioperative antibiotic (92% vs 38%, P < .001). After adjusting for potential confounders, patients who underwent preoperative penicillin allergy evaluation had higher odds of first-line perioperative antibiotic use (adjusted odds ratio, 26.6; 95% CI, 12.8-55.2).

CONCLUSION

Integrating penicillin allergy evaluation into routine preoperative care ensured that almost all evaluated patients undergoing cardiac surgery received first-line antibiotic prophylaxis, a critical component of SSI risk reduction. Further efforts are needed to increase access to preoperative allergy evaluation.

The challenge of de-labeling penicillin allergy

BACKGROUND

Even though 8%-25% of most populations studied globally are labeled as penicillin allergic, most diagnoses of penicillin allergy are made in childhood and relate to events that are either not allergic in nature, are low risk for immediate hypersensitivity, or are a potential true allergy that has waned over time. Penicillin allergy labels directly impact antimicrobial stewardship by leading to use of less effective and broader spectrum antimicrobials and are associated with antimicrobial resistance. They may also delay appropriate antimicrobial therapy and lead to increased risk of specific adverse healthcare outcomes. Operationalizing penicillin allergy de-labeling into a new arm of antimicrobial stewardship programs (ASPs) has become an increasing global focus.

METHODS

We performed an evidence-based narrative review of the literature of penicillin allergy label carriage, the adverse effects of penicillin allergy labels, and current approaches and barriers to penicillin allergy de-labeling. Over the period 1928-2018 in Pubmed and Medline, search terms used included "penicillin allergy" or "penicillin hypersensitivity" alone or in combination with "adverse events," "testing," "evaluation," "effects," "label," "de-labeling," "prick or epicutaneous," and "intradermal" skin testing, "oral challenge or provocation," "cross-reactivity," and "antimicrobial stewardship".

RESULTS

Penicillin allergy labels are highly prevalent, largely inaccurate and their carriage may lead to unnecessary treatment and inferior outcomes with alternative agents as well as adverse public health outcomes such as antibiotic resistance.

CONCLUSIONS

Operationalizing penicillin allergy de-labeling as an aspect of ASP has become an increasing global focus. There is a need for validated approaches that optimally combine the use of history and ingestion challenge with or without proceeding formal skin testing to tackle penicillin allergy efficiently within complex healthcare systems. At the same time, there is great promise for penicillin allergy evaluation and de-labeling as an individual and public health strategy to reduce adverse healthcare outcomes, improve antimicrobial stewardship, and decrease healthcare costs.

Non-β-Lactam Antibiotic Hypersensitivity Reactions

OBJECTIVES

Antibiotics are among the most common prescriptions in children, and non-β-lactam antibiotics (NBLAs) account for almost half of those prescribed in Australian pediatric hospitals. Despite this, data on NBLA hypersensitivity in children are limited. This study describes reported hypersensitivity reactions to NBLAs in children and the results of allergy evaluation.

METHODS

Children with a suspected NBLA allergy who had skin testing and/or an intravenous or oral challenge test (OCT) between May 2011 and June 2018 were included. Patients were excluded if they were >18 years old or did not complete the allergy evaluation for any reason other than allergic reaction.

RESULTS

Over the 7-year study period, 141 children had 150 allergy evaluations of 15 different NBLAs. The median time from the initial reported reaction to allergy evaluation was 1.9 (range 0.1-14.9) years. Overall, 27 of the 150 (18.0%) challenge tests to NBLAs had positive results, with the rate of positive OCT results being highest for trimethoprim-sulfamethoxazole (15 of 46; 32.6%) and macrolides (8 of 77; 10.4%). Although 4 children reported initial anaphylactic reactions, no patients had severe symptoms on rechallenge or required adrenaline. Of the challenges that had positive results, the majority of children (23 of 27; 85.2%) had symptoms on repeat challenge similar to those that were initially reported.

CONCLUSIONS

Overall, 8 of 10 children with NBLA allergy could be delabeled. On average, patients waited 1.9 years to be rechallenged. Timely access to allergy evaluation to delabel these patients is needed to preserve first-line antibiotics.

Allergological Study of 565 Elderly Patients Previously Labeled as Allergic to Penicillins

Purpose

Elderly people thought to have an allergy to beta-lactams (BLs) may tolerate the drugs in subsequent exposures due to initial false labeling of allergies, the spontaneous loss of sensitivity to BLs over time or age-related decline in sensitization. As a result, they may be treated with less appropriate antibiotics, causing more side effects and entailing increased costs for health systems. The aim of this investigation was to assess whether patients in the third and fourth age with previously confirmed allergies to BLs had lost sensitization and could tolerate these antibiotics.

Patients and methods

Patients allergic to BLs were divided into group A (aged 60-79 years) and B (aged ≥80 years). Clinical history, skin testing, drug challenge tests (DCT) and evaluation of resensitization were used to classify participants as showing immediate reactions, non-immediate reactions, or tolerance. We compared clinical entities, drugs involved, and final outcome by age group.

Results

Of 1362 cases evaluated, 565 underwent an allergological study. The skin was the most common organ involved. Anaphylaxis and side chain reactions were more frequent in group A (p<0.01), as were positive DCT. Classical benzylpenicillin determinants (benzylpenicilloyl and/or minor determinant mixture) were more frequent triggers in group B (p< 0.01). Resensitization after challenge occurred in very few participants.

Conclusion

The risk for allergy to BLs decreases with age and a history of anaphylaxis by BLs is a predictor of positive results in skin tests (ST). Both immunoglobin E (IgE) and T-cell-mediated responses can disappear in elderly people, who can develop tolerance to these antibiotics. These results are of clinical relevance to patients who need to be treated with antibiotics from this family.

Penicillin Allergy Assessment and Skin Testing in the Outpatient Setting

Penicillin allergies are among of the most commonly reported allergies, yet only 10% of these patients are truly allergic. This leads to potential inadvertent negative consequences for patients and makes treatment decisions challenging for clinicians. Thus, allergy assessment and penicillin skin testing (PST) are important management strategies to reconcile and clarify labeled penicillin allergies. While PST is more common in the inpatient setting where the results will immediately impact antibiotic management, this process is becoming of increasing importance in the outpatient setting. PST in the outpatient setting allows clinicians to proactively de-label and educate patients accordingly so beta-lactam antibiotics may be appropriately prescribed when necessary for future infections. While allergists have primarily been responsible for PST in the outpatient setting, there is an increasing role for pharmacist involvement in the process. This review highlights the importance of penicillin allergy assessments, considerations for PST in the outpatient setting, education and advocacy for patients and clinicians, and the pharmacist’s role in outpatient PST.

Evaluating Penicillin Allergies Without Skin Testing

PURPOSE OF REVIEW

An unconfirmed penicillin allergy is known to confer significant risk to patients. Only a small minority of patients labeled with penicillin allergy will be confirmed to be hypersensitive with the current reference standard test, an oral amoxicillin therapeutic dose challenge. Skin testing has been recommended prior to oral challenges to reduce the risk of severe acute challenge reactions. The rate of severe acute anaphylactic reactions with oral amoxicillin is currently extremely low. Unfortunately, penicillin skin testing, as commonly performed, has a high rate of false positive results.

RECENT FINDINGS

Encouraging skin testing in all individuals with an unconfirmed penicillin allergy, prior to a confirmatory oral challenge, would be technically difficult, make testing all individuals with an unconfirmed penicillin allergy very unlikely, and ultimately increase the risk to patients because of suboptimal antibiotic use. Most patients, who are appropriate candidates for a direct oral amoxicillin challenge, to confirm current penicillin tolerance, can be safely identified by their clinical histories. Higher risk individuals, those with a history of anaphylaxis or other acute onset potentially IgE-mediated reaction such as hives within 6 h of the first dose of the last course of a penicillin, may benefit from properly performed puncture and intradermal skin testing, using commercially available penicilloyl-polylysine, prior to an oral challenge, if skin test negative. Direct oral amoxicillin challenges in low-risk individuals are well accepted by patients and a safe and effective part of penicillin allergy delabeling.

Patient and Primary Care Physician Perceptions of Penicillin Allergy Testing and Subsequent Use of Penicillin-Containing Antibiotics: A Qualitative Study

BACKGROUND

Removal of an inaccurate penicillin allergy record following testing allows patients to access first-line treatment for infections, and reduce the use of broad-spectrum antibiotics, which contribute to antibiotic resistance. However, it is seldom undertaken.

OBJECTIVES

To identify clinicians' working in primary care and patients' views on barriers and enablers for penicillin allergy testing and subsequent antibiotic use.

METHODS

Fifty interviews with patients and clinicians, including 31 patients with a record of penicillin allergy, 16 with experience of testing, and 19 clinicians. Interviews were analyzed thematically.

RESULTS

Patients were often unaware of the benefits of penicillin allergy testing and only those patients who had experienced negative consequences of having a penicillin allergy label were motivated to get tested. Clinicians were reluctant to change patient records on the basis of their clinical judgment alone but had limited experience of referring patients with suspected penicillin allergy and were often uncertain about referral criteria and what the testing involved. Clinicians felt that allergy testing could be beneficial and patients who had attended testing reported benefits of the test. Clinicians expressed uncertainty related to whose responsibility it was to make sure that the patient understood allergy test results.

CONCLUSIONS

Clinicians would benefit from information about penicillin allergy testing to be able to use these services appropriately, and to discuss referral with patients. Patients might be more motivated to seek testing if they were more informed regarding its benefits. Good communication between primary and secondary care would facilitate the updating of medical records, and promote better patient education.

Patient and Prescriber Views of Penicillin Allergy Testing and Subsequent Antibiotic Use: A Rapid Review

About 10% of U.K. patients believe that they are allergic to penicillin and have a "penicillin allergy label" in their primary care health record. However, around 90% of these patients may be mislabelled. Removing incorrect penicillin allergy labels can help to reduce unnecessary broad-spectrum antibiotic use. A rapid review was undertaken of papers exploring patient and/or clinician views and experiences of penicillin allergy testing (PAT) services and the influences on antibiotic prescribing behaviour in the context of penicillin allergy. We reviewed English-language publications published up to November 2017. Limited evidence on patients' experiences of PAT highlighted advantages to testing as well as a number of concerns. Clinicians reported uncertainty about referral criteria for PAT. Following PAT and a negative result, a number of clinicians and patients remained reluctant to prescribe and consume penicillins. This appeared to reflect a lack of confidence in the test result and fear of subsequent reactions to penicillins. The findings suggest lack of awareness and knowledge of PAT services by both clinicians and patients. In order to ensure correct penicillin allergy diagnosis, clinicians and patients need to be supported to use PAT services and equipped with the skills to use penicillins appropriately following a negative allergy test result.

Antibiotic Allergy in Pediatrics

The overlabeling of pediatric antibiotic allergy represents a huge burden in society. Given that up to 10% of the US population is labeled as penicillin allergic, it can be estimated that at least 5 million children in this country are labeled with penicillin allergy. We now understand that most of the cutaneous symptoms that are interpreted as drug allergy are likely viral induced or due to a drug-virus interaction, and they usually do not represent a long-lasting, drug-specific, adaptive immune response to the antibiotic that a child received. Because most antibiotic allergy labels acquired in childhood are carried into adulthood, the overlabeling of antibiotic allergy is a liability that leads to unnecessary long-term health care risks, costs, and antibiotic resistance. Fortunately, awareness of this growing burden is increasing and leading to more emphasis on antibiotic allergy delabeling strategies in the adult population. There is growing literature that is used to support the safe and efficacious use of tools such as skin testing and drug challenge to evaluate and manage children with antibiotic allergy labels. In addition, there is an increasing understanding of antibiotic reactivity within classes and side-chain reactions. In summary, a better overall understanding of the current tools available for the diagnosis and management of adverse drug reactions is likely to change how pediatric primary care providers evaluate and treat patients with such diagnoses and prevent the unnecessary avoidance of antibiotics, particularly penicillins.

The 3 Cs of Antibiotic Allergy-Classification, Cross-Reactivity, and Collaboration

Antibiotic allergy labeling is highly prevalent and negatively impacts patient outcomes and antibiotic appropriateness. Reducing the prevalence and burden of antibiotic allergies requires the engagement of key stakeholders such as allergists, immunologists, pharmacists, and infectious diseases physicians. To help address this burden of antibiotic allergy overlabeling, we review 3 key antibiotic allergy domains: (1) antibiotic allergy classification, (2) antibiotic cross-reactivity, and (3) multidisciplinary collaboration. We review the available evidence and research gaps of currently used adverse drug reaction classification systems, antibiotic allergy cross-reactivity, and current and future models of antibiotic allergy care.

Diagnostic challenges, the evaluation of antibiotic allergy

PURPOSE OF REVIEW

Antibiotic allergy is commonly reported and often challenging to evaluate. This review highlights recent developments in our understanding of antibiotic allergy, primarily surrounding evaluation, and diagnosis of antibiotic allergy. We provide historical context to establish a framework, lending relevance to the latest studies.

RECENT FINDINGS

Clinicians have typically employed skin testing as a first step in the diagnosis of drug allergy, reserving drug provocation challenge, the gold standard for diagnosis, for those with negative skin tests. Although skin tests have a good negative predictive value, the positive predictive value has never been established. An increasing amount of research is demonstrating that drug provocation challenge is well tolerated as the initial evaluation in patients with non-life-threatening reactions to antibiotics. This research also calls into question the value of skin testing in these patients.

SUMMARY

Skin testing has long been used as the initial investigation in the diagnosis of drug allergy. New research supports that this may not be necessary in all patients, particularly those with non-life-threatening reactions. Further research into the validity of skin testing is required, along with the development of new diagnostic tests for antibiotic allergy.

The Effect of Penicillin Allergy Testing on Future Health Care Utilization: A Matched Cohort Study

BACKGROUND

The effect that penicillin allergy testing has on future health care utilization is uncertain.

OBJECTIVE

Determine whether penicillin allergy testing affects future overall health care utilization as measured by outpatient department (OPD) visits, emergency department (ED) visits, and hospital days.

METHODS

Potential cases and control subjects were penicillin allergic Kaiser Permanente Southern California members who had at least 2 visits between 2010 and 2012 and at least 1 year of continuous health plan coverage before their index visit.

RESULTS

It was possible to match 308 (73.2%) of the potential cases to 1251 unique controls, on the basis of age, sex, weighted Charlson comorbidity index, drug class allergies, OPD visits, ED visits, and hospital days during the years before their index visit. Cases and controls were then followed for an average of 3.6 and 4.0 years, respectively. Based on results analyzed using a generalized linear mixed model, cases were estimated to have 0.09 fewer OPD visits (P < .001), 0.13 fewer ED visits (P = .29), and 0.55 fewer hospital days (P < .001) per health plan coverage year during follow-up compared with controls. Cases were exposed to more penicillins and first- and second-generation cephalosporins and less clindamycin and macrolides.

CONCLUSIONS

Penicillin allergy testing, primarily done in the setting of an outpatient Allergy consultation, was associated with significantly less health care utilization during 3.6+ years of follow-up and greater use of narrow-spectrum antibiotics. Penicillin allergy testing has a favorable cost-benefit ratio for the incremental cost of testing versus future health care utilization and improves antibiotic stewardship.

Improving Antimicrobial Stewardship by Antibiotic Allergy Delabeling: Evaluation of Knowledge, Attitude, and Practices Throughout the Emerging Infections Network

Antibiotic allergy testing (AAT) practices of Emerging Infections Network infectious disease physicians were surveyed. Although AAT was perceived to be necessary for removal of inappropriate or unnecessary allergy labels, there was limited access to any form of testing. In this study, we discuss current antibiotic allergy knowledge gaps and the development of AAT practices within antimicrobial stewardship programs, which will potentially improve antimicrobial prescribing.