Safely diagnosing clinically significant penicillin allergy using only penicilloyl-poly-lysine, penicillin, and oral amoxicillin

Surgical prophylaxis in pediatric orthopedic patients with penicillin allergy: a multicentered retrospective prognostic study

Up to 20% of orthopedic surgeons still avoid the use of cephalosporins in patients with penicillin allergies despite its reported safety in the adult and general surgery pediatric population. The primary objective is to determine the incidence of adverse effects and allergic reactions when using cephalosporins in pediatric orthopedic patients labeled as penicillin-allergic as compared to those without previously reported penicillin allergy. A multicenter retrospective chart review was performed across three level 1 trauma centers from January 2013 to February 2020 to identify penicillin-allergic as well as non-penicillin-allergic pediatric patients treated for orthopedic injuries. Data were collected regarding patient demographics, antibiotic administered, timing of antibiotic administration, reported drug allergy, and described allergic reaction. Postoperative or intraoperative allergic reactions to antibiotics, surgical site infections, and complications were recorded. A total of 2289 surgeries performed by four fellowship-trained surgeons were evaluated. Eighty-five patients diagnosed with penicillin allergy were identified and underwent 95 surgeries and 95 patients without previously reported penicillin allergy underwent 95 surgeries. One patient, with a documented history of anaphylaxis to cefazolin, sustained an anaphylactic reaction intraoperatively to cefazolin. There were no other reported reactions, surgical site infections, or complications. There was no statistically significant difference in rate of allergic reaction in patients with previously reported penicillin allergy treated with cefazolin and those with no previous reported reaction ( P > 0.05). Prophylaxis with cephalosporins is not associated with increased risk for allergic reaction. Cephalosporins can be safely administered to pediatric patients with penicillin allergy undergoing orthopedic intervention. Level of evidence: Level II, Multicenter Retrospective Prognostic Study.

Early testing and grade of the reaction are affecting factors of skin test positivity in β-Lactam allergies

Background: β-Lactams are the most widely used antibiotic family in the world. Nevertheless, they also stand out as the primary culprits for inducing drug hypersensitivity reactions (HSR). Methods: Between May 2018 and March 2023, patients with suspected HSRs to β-lactams, who underwent skin tests (ST), were retrospectively screened. The determinants of allergenic penicillin (DAP) tests, which include penicillin minor and major determinants, clavulanic acid, and amoxicillin, along with ampicillin, sulbactam, the identified culprit drugs, and alternative cephalosporins, which include cefuroxime, ceftriaxone prick and/or intradermal tests, were administered. The analysis focused on identifying positive ST results and determining the true HSRs rates in this patient cohort. Results: Of the 147 patients, 78.9% (n = 116) were women and the median (minimum-maximum) age was 41 years (18-71 years). Mild HSRs (grades 1-2) were observed in 72.78% (n = 107), whereas 24.4% (n = 36) had severe reactions (grades 3-4) and 2.7% (n = 4) had an unknown grade. Of the patients, 64% (n = 94) experienced HSRs within the first hour after the last dose of the identified culprit drug. The overall positivity rate for all STs was 26.5% (n = 39). ST positivity rates were notably higher in individuals who had experienced HSRs within the past 6 months (p = 0.02) and those with severe anaphylaxis (p < 0.001). Conclusion: β-Lactam ST positivity is higher, especially in those with grades 3-4 reactions and consulted a physician within the first 6 months after their HSRs.

Delabelling beta-lactam allergy

Background: Hypersensitivity to beta-lactam (BL) antibiotics is one of the most frequent reported drug allergies. In our population, it is common to find labels of BL allergy in electronic medical records (EMRs) that have not been assessed. The objective of our study was to detect patients with beta-lactam allergy labels in their EMRs and to assess how many of them are false after a correct diagnostic evaluation. Methods: A multicentre prospective study was performed with patients labelled as allergic to BLs in their EMRs in the previous 5 years. Demographical and clinical data, as well as variables regarding the BL allergy label and the characteristics of the index reaction from clinical history and EMRs, were recorded. Then, diagnostic assessments including clinical history, skin tests (STs), and drug provocation tests (DPTs) were conducted in order to confirm or exclude the diagnosis of BL allergy. Results: A total of 249 patients completed the study, of which 160 (64.3%) were women with a median age of 57 years (interquartile range [IQR], 45-68). The most frequent BL allergy labels detected were for penicillin (124), amoxicillin/clavulanic acid (61), and amoxicillin (54). Of the 204 patients who underwent STs, 20.1% were positive. DPTs were performed in 224 patients, showing good tolerance in 87.1% of cases. After the allergy diagnosis work-up, 186 patients (74.7%) were diagnosed as non-allergic to BL antibiotics. Conclusion: In our study population, the number of patients labelled as allergic to BLs in their EMRs was similar to that in previously published studies, with proportions near to 75%-80% being falsely labelled as allergic to BLs.

Preoperative survey to evaluate the patients' allergy list and its relevance to perioperative care

INTRODUCTION

Perioperative hypersensitivity and allergic reactions can result in significant morbidity and mortality. For routine anesthetic care, allergies are determined from a review of the electronic medical record supplemented by a detailed patient history. Although the electronic medical record is generally assumed to be accurate, it may be that allergies are erroneously listed or not based on sound medical practice. The purpose of the current study is to evaluate allergies listed in the electronic medical record of children presenting for surgery and determine their origin, authenticity, and impact on perioperative care.

METHODS

Eligible patients included those presenting for a surgical procedure in the main operating room, who were ≤ 21 years of age, with a drug allergy listed on the EMR. Prior to intraoperative care, an electronic survey questionnaire containing questions related to medication allergies was provided to a guardian or parent. Two anesthesiology physicians reviewed the survey responses to determine the validity of any reported allergies. A second electronic survey was given postoperatively to the attending anesthesiologist to determine whether the documented allergy impacted anesthetic care.

RESULTS

The study cohort included 250 patients, ranging in age from 5 to 14 years (median age 9 years). All of the patients had at least one allergy listed on the electronic medical record. Seventy of the 250 patients (28%) had more than one drug allergy listed for a total of 351 medication allergies. The majority of the listed allergies were related to antibiotics including 155 (44%) from the penicillin family, 26 (7%) cephalosporins, 16 (5%) sulfonamides, and 36 (10%) other antimicrobial agents. Other commonly listed allergies were 27 (8%) nonsteroidal anti-inflammatory agents and 15 (4%) opioids. The remaining 76 (22%) included a miscellaneous list of other medications. On further review of the allergies, the survey was completed for 301 medications. After physician review, 135 of 301 (45%) responses were considered consistent with IgE reactions "true allergy," 73 (24%) were deemed less relevant to IgE reactions "unlikely true allergy," and 93 (31%) were not related to IgE reactions "not an allergy." Care alterations during surgery were uncommon regardless of whether the issue was assessed as a true allergy (11%), unlikely to be a true allergy (3%), or not a true allergy (13%).

CONCLUSION

A significant portion of the documented allergies in children are not true allergies, but rather recognized adverse effects (apnea from an opioid, renal failure from an NSAIDs) or other nonallergic concerns (gastrointestinal upset such as nausea). Erroneously listed allergies may lead to unnecessary alterations in patient care during perioperative care. A careful analysis of the allergy list on the EMR should be supplemented by a thorough patient history with specific questions related to the drug allergy. Once this is accomplished, the allergy listed should be updated to avoid its erroneous impact on perioperative care.

Challenging dogmas: Intravenous versus oral beta-lactam antibiotic provocation tests

Background

Drug provocation tests (DPT) are considered the gold standard procedure to ascertain the diagnosis of beta-lactam (BL) allergy. Regarding route of administration, current recommendations prioritize oral challenges, considering them safer, and reserving the intravenous route for drugs for which this is the only formulation.

Objective

To compare in terms of tolerance and safety two protocols of BL DPT, using an oral protocol (OR-DPT) and an intravenous protocol (IV-DPT).

Methods

A descriptive, retrospective study was performed, including adult patients who underwent IV-DPT or OR-DPT for suspected immediate or delayed hypersensitivity to BL antibiotics, over a period of 4 years (between January 2018 and December 2021). Demographical data, index hypersensivity reactions' characteristics and tolerance to DPT were reviewed.

Results

A total of 1036 patients underwent DPT, mean age of 56.8 (standard deviation, SD, 17.8) years, 655 were women (63.2%). Immediate drug hypersensitivity reactions (DHR) had occurred in 564 of patients (54.4%). OR-DPT were performed in 439 (42.4%) and IV-DPT in 597 (57.6%). The frequency of reactions during DPT, regardless of the route used, was low (3.6%): only 16 (3.6%) in OR-DPT and 21 (3.5%) in IV-DPT. From IV-DPT, 16 out 21 DHR during DPT were immediate compared with 4 out of 16 in OR-DPT. Adjusted relative risk of developing a hypersensitivity reaction during IV-DPT versus OR-DPT was 1.13 (95% confidence interval (CI)0.57-2.22).

Conclusion

The results suggest that OR-DPT and IV-DPT are both safe procedures when adequately performed. However, IV-DPT protocols showed a higher rate of immediate DHR during DPT probably due to the selection of basal high-risk patients to undergo IV-DPT. In conclusion, IV-DPT may be considered as an option for challenges in drug-allergy studies, entailing a precise administration.

β-Lactam allergy delabeling is safe and saves costs in Primary Care

OBJECTIVE

To determine whether the β-lactam allergy delabeling was safe and cost-saving in Primary Care (PC) patients.

DESIGN

We have conducted a retrospective chart review of PC patients with β-lactam allergy label evaluated in our Allergy Unit between 2017 and 2022. SITE: Allergy Department. Hospital Virgen del Rocio (Sevilla).

PARTICIPANTS

A total of 391 patients labeled for β-lactam allergy in PC were studied.

MAIN MEASUREMENTS

(a) Outcome evaluation of a β-lactam allergy delabeling procedure. (b) A ratio between the total e-prescribed antibiotic cost and the number of treatment days (the experimental daily antibiotic cost or EDAC) before and after delabeling was analyzed in delabeled and truly allergic patients.

RESULTS

The results of skin testing were positive in 9.2% of the reported cases (36 of 391 patients). The reactions to oral provocation challenge (OPC) occurred in 2.14% of the patients who underwent negative skin testing to offending β-lactam (in 15 of 699 OPC). A total of 307 patients (78.5%) were delabeled; 70 (17.9%) had a β-lactam selective response and 14 (3.59%) reacted to both penicillin and cephalosporin. The EDAC before and after the procedure in delabeled patients was significantly lower (0.88 € vs 0.62 €, p<10-3), than that observed in truly allergic group (0.87 € vs. 0.76 €, p=not significant).

CONCLUSION

To delabel β-lactam allergy in Primary Care patients is safe in most patients, cost-saving in antibioticotherapy, and allows identify the main clinical β-lactam allergy phenotypes that benefit from this procedure.

Beta-lactam antibiotics administration among adult inpatients with a beta-lactam allergy label: incidence, predictors, and outcomes

Background

A beta-lactam antibiotics (BLA) allergy label is common, resulting in disadvantageous outcomes due to the usage of second-line antimicrobial agents. Noncontrolled case-series analyses report low rates of hypersensitivity reactions, following intentional/non-intentional BLA challenges among labeled inpatients. The study aims were to explore predictors and outcomes associated with hypersensitivity reactions following BLA challenge among BLA-allergic labeled inpatients.

Methods

Retrospective cohort study (2019-2020) of adult (≥18 years) inpatients (Shamir Medical Center, Israel), labeled as allergic to ≥1 BLA, who received ≥1 dose/s of BLA during their stay. Independent predictors to develop allergic reactions and the independent associations of allergic reactions with clinical outcomes were queried by logistic and Cox regressions.

Results

Of 9,670 inpatients (14,088 hospitalizations), 3,570 (37%) were labeled as allergic to ≥1 BLA. Of those, 1,171 (33%) patients received ≥1 BLA. The majority were women (67%), and the mean age was 69.3 ± 19.4 years. Only 30 patients (2.6%) developed a reaction, all mild. Independent predictors to develop an allergic reaction were documented reactions in the past, atopic background, antihistamines administration prior to the BLA challenge, and high risk for cross-reactivity, based on the BLA side chains, between the labeled and the challenged agents. Reaction upon the BLA challenge was not independently associated with any worse outcome.

Conclusions

Despite the commonality of allergy labeling, and the commonality of BLA administration to labeled inpatients, hypersensitivity reactions were mild and rare. Interventional stewardship strategies for active BLA de-labeling among low-risk patients should be promoted, to improve patients' and institutional health and fiscal outcomes.

Diagnosis and Treatment of Perioperative Allergic Complications: A Practical Review

Background

Reported drug allergies are commonly encountered by surgeons and can lead to uncertainty in selecting an appropriate agent due to concerns of associated risks with related and cross-reactive drugs. This uncertainty can ultimately lead to increased infection rates.

Methods

A literature review was conducted in PubMed using a combination of the terms "allergy," "allergic reaction," "anaphylaxis," and "surgery," "surgical," or "operating room" for articles published within the last 10 years. Publications identified with these search terms were then filtered for review articles, sorted by "best match," and a maximum of 100 articles were manually reviewed for each combination of search terms.

Results

Search results yielded 46,484 articles, 676 of which were ultimately included for manual review, based on selection criteria. Specifically, articles selected for inclusion focused on surgical allergic reactions that were either related to mechanism of action, causative agent for the allergic reaction, timing of allergic reaction, or recommendations for appropriate management.

Conclusions

Allergic reactions can be a common occurrence in the operative room. Knowledge of likely causative agents, timing of a reaction to various agents, and appropriate management in the immediate and delayed setting can improve outcomes and safety for plastic surgery patients.

Cefazolin as the mainstay for antibiotic prophylaxis in patients with a penicillin allergy in obstetrics and gynecology

Cefazolin is the most common antibiotic used for prophylaxis in obstetrics and gynecology. Among those with a penicillin allergy, alternative antibiotics are often chosen for prophylaxis, given fears of cross-reactivity between penicillin and cefazolin. Alternative antibiotics in this setting are associated with adverse sequelae, including surgical site infection, induction of bacterial resistance, higher costs to the healthcare system, and possible Clostridium difficile infection. Given the difference in R1 side chains between penicillin and cefazolin, cefazolin use is safe and should be recommended for patients with a penicillin allergy, including those who experience Immunoglobulin E-mediated reactions such as anaphylaxis. Cefazolin should only be avoided in those who experience a history of a severe, life-threatening delayed hypersensitivity reaction manifested as severe cutaneous adverse reactions (Steven-Johnson Syndrome), hepatitis, nephritis, serum sickness, and hemolytic anemia in response to penicillin administration. In addition, >90% of those with a documented penicillin allergy do not have true allergies on skin testing. Increased referral for penicillin allergy testing should be incorporated into routine obstetric care and preoperative assessment to reduce suboptimal antibiotic prophylaxis use. More education is needed among providers surrounding penicillin allergy assessment and cross-reactivity among penicillins and cephalosporins to optimize antibiotic prophylaxis in obstetrics and gynecology.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

INTERPRETATION

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

Invasive group A streptococcal disease

We report on two children who had presented in a poor clinical state after an initial bout of cough, sore throat and fever for a few days. Both of them had multisystemic involvement with fluid-refractory septic shock requiring ionotropic support, intubation and care in the paediatric intensive care unit. Recent significant rise in scarlet fever has led to a significant increase in the number of invasive group A streptococcal infections with increased mortality in paediatric patients. Both of them had co-infection with influenza, which could have led to an increased risk of invasive group A streptococcal (iGAS) infection. After prompt treatment, including early initiation of antibiotics, they both recovered well. To our knowledge, there are no reported cases of iGAS infection from the UK in any medical journal though the fatal cases have been reported to the health statistics department by various National Health Service trusts individually.

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

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

Risk factors for allergy documentation in electronic health record: A retrospective study in a tertiary health center in Switzerland

BACKGROUND

Most hospitals use electronic health records (EHR) to warn health care professionals of drug hypersensitivity (DH) and other allergies. Indiscriminate recording of patient self-reported allergies may bloat the alert system, leading to unjustified avoidances and increases in health costs. The aim of our study was to analyze hypersensitivities documented in EHR of patients at Lausanne University Hospital (CHUV).

METHODS

We conducted a retrospective study on patients admitted at least 24 h to CHUV between 2011 and 2021. After ethical clearance, we obtained anonymized data. Because culprit allergen could be either manually recorded or selected through a list, data was harmonized using a reference allergy database before undergoing statistical analysis.

RESULTS

Of 192,444 patients, 16% had at least one allergy referenced. DH constituted 60% of all allergy alerts, mainly beta-lactam antibiotics (BLA) (30%), NSAID (11%) and iodinated contrast media (ICM) (7%). Median age at first hospitalization and hospitalization length were higher in the allergy group. Female to male ratio was 2:1 in the allergic group. Reactions were limited to the skin in half of patients, and consistent with anaphylaxis in 6%. In those deemed allergic to BLA, culprit drug was specified in 19%, 'allergy to penicillin' otherwise. It was impossible to distinguish DH based on history alone or resulting from specialized work-up.

CONCLUSIONS

Older age, longer hospital stays, and female sex increase the odds of in-patient allergy documentation. Regarding DH, BLA were referenced in 4% of inpatient records. Specific delabeling programs should be implemented to increase data reliability and patient safety.

Drug allergy in older adults: A study from the United States Drug Allergy Registry

BACKGROUND

Older adults have an increased risk of adverse drug reactions and negative effects associated with alternative antibiotic use. Although the number of antibiotic allergies reported increases with age, the characteristics and outcomes of older adults receiving drug allergy assessment are unknown.

OBJECTIVE

To assess the characteristics and outcomes of drug allergy evaluations in older adults.

METHODS

We considered patients aged above or equal to 65 years enrolled in the United States Drug Allergy Registry (USDAR), a US multisite prospective cohort (January 16, 2019 to February 28, 2022). Data were summarized using descriptive statistics.

RESULTS

Of 1678 USDAR participants from 5 sites, 406 older adults aged above or equal to 65 years (37% 65-69 years, 37% 70-74 years, 16% 75-79 years, and 10% ≥80 years) received 501 drug allergy assessments. USDAR older adults were primarily of female sex (69%), White (94%), and non-Hispanic (98%). Most USDAR older adults reported less than or equal to 1 infections per year (64%) and rated their general health as good, very good, or excellent (80%). Of 296 (59%) penicillin allergy assessments in USDAR older adults, 286 (97%) were disproved. Other drug allergy assessments included sulfonamide (n = 41, 88% disproved) and cephalosporin (n = 20, 95% disproved) antibiotics. All 41 drug allergy labels in USDAR participants aged above or equal to 80 years and all 80 penicillin allergy labels in USDAR men aged above or equal to 65 years were disproved.

CONCLUSION

Older adults represented a quarter of USDAR participants but were neither racially nor ethnically diverse and were generally healthy without considerable antibiotic need. Most older adults presented for antibiotic allergy assessments, the vast majority of which were disproved. Drug allergy assessments may be underutilized in the older adults who are most vulnerable to the harms of unconfirmed antibiotic allergy labels.

Beta-lactam comprehensive allergy management program in a community medical center

Objective

The Beta-lactam Comprehensive Allergy Management Program (CAMP) was implemented to facilitate complete beta-lactam allergy history documentation in the electronic medical record (EMR) and increase beta-lactam utilization. The study objective was to assess the rate of complete allergy histories and days of antimicrobial therapy (DOT) before versus after CAMP implementation.

Design

Quasi-experimental study with interrupted time-series analysis.

Setting

Non-teaching, urban, and community medical center within a multi-hospital health system.

Patients

Adult inpatients with a beta-lactam allergy receiving antimicrobial therapy.

Methods

The multidisciplinary CAMP team screened, interviewed, and collected allergy history details of adult inpatients with a beta-lactam allergy receiving antimicrobial therapy starting January 4, 2021. Patients were stratified as high, moderate, or low risk of IgE-mediated allergy and referred to an allergist for skin testing or drug challenge. The EMR was updated with interview details and drug challenge or skin test results. The primary endpoint was rate of complete allergy history documentation before (12/1/18-4/1/19) compared to after (1/4/21-5/1/21) program implementation. The secondary endpoint was days of inpatient beta-lactam therapy. Implementation logistics, de-labeling rate, and antimicrobial therapy changes were evaluated.

Results

The program evaluated 392 individuals, with 184 and 208 patients comprising the pre- and post-intervention groups, respectively. The post-intervention period was associated with an increase of 19.8% in complete allergy histories (0.359 PPc; R 2 0.26; p = 0.002) and 9.34 beta-lactam DOT per 1,000-days-present (1.106 PPc; R 2 0.194; p = 0.009).

Conclusion

Implementation of a comprehensive beta-lactam allergy management program was associated with higher rates of complete beta-lactam allergy history and beta-lactam use.

Challenges and opportunities related to penicillin allergy in the Veterans Health Administration: a narrative review

The presence of a penicillin allergy label in a patient's medical chart is associated with negative clinical and economic outcomes. Given that less than 10% of reported reactions are truly immunoglobulin E-mediated, removal of unverified penicillin allergy labels is a public health priority and an area of ongoing implementation research. The Veterans Health Administration (VHA) is the largest integrated healthcare system in the United States, with almost 9 million veterans currently enrolled. However, studies analyzing the impact of the penicillin allergy label in this population are limited to single facilities and largely focus on short-term outcomes of allergy documentation correction, usage of β-lactams, and avoidance of antibiotic-related side effects. Broader, national VHA studies focusing on health outcomes and costs are lacking. As with non-VHA facilities, penicillin allergy evaluations are limited owing to the absence of formal allergy/immunology services at most VHA facilities. Pharmacy-driven screening and referral for clinic-based penicillin skin testing is a promising and frequently discussed modality in the literature, but its scalability within the VHA is not yet proven. Broader, evidence-based strategies that can be adapted to the available resources of individual VHA facilities, including those without on-site access to allergy providers, are needed.

Diagnosis and selection of alternative antibiotics in beta-lactams hypersensitivity reactions: Current recommendations and challenges

Beta-lactam (BLM) antibiotics, including amino-penicillin and cephalosporins, are typically the first-choice treatment for bacterial infections. However, adverse reactions to these antibiotics are frequently reported, causing non-allergist physicians to select alternative broad-spectrum antibiotics that can have harmful consequences. Patients with unclear histories of hypersensitivity reactions to BLMs should undergo an allergy workup to establish a firm diagnosis, particularly when different drugs are prescribed simultaneously. However, finding the safest, most precise, and cost-effective methods for confirming BLMs hypersensitivity and selecting the most appropriate alternative BLM is uncertain, particularly in severe delayed reactions. This review aims to provide data and recommendations on the availability and validity of skin tests (STs), drug provocation test (DPT) protocols, based on the latest published literature and guideline. To make the process more practical, we focused on cross-reactivity between BLMs and diagnostic tests. There are two main novel aspects of this document: 1) For T-cell-mediated reactions, patient stratification into high, moderate, and low-risk groups based on the mortality and morbidity of adverse drug reactions. 2) For IgE-mediated reactions, stratification of individuals with isolated limited urticarial without anaphylaxis in a low-risk group and removal of the extensive limitation.

Drug Hypersensitivity Reactions

Drug hypersensitivity reactions are a diverse group of reactions mediated by the immune system after exposure to a drug. The Gell and Coombs classification divides immunologic DHRs into 4 major pathophysiologic categories based on immunologic mechanism. Anaphylaxis is a Type I hypersensitivity reaction that requires immediate recognition and treatment. Severe cutaneous adverse reactions (SCARs) are a group of dermatologic diseases that result from a Type IV hypersensitivity process and include drug reaction with eosinophilia and systemic symptom (DRESS) syndrome, Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP). Other types of reactions are slow to develop and do not always require rapid treatment. Emergency physicians should have a good understanding of these various types of drug hypersensitivity reactions and how to approach the patient regarding evaluation and treatment.

The state and consideration for skin test of β-lactam antibiotics in pediatrics

β-lactam antibiotics are the most frequently used drugs and the most common drugs that cause allergic reactions in pediatrics. The occurrence of some allergic reactions can be predicted by skin testing, especially severe adverse reactions such as anaphylactic shock. Thus, penicillin and cephalosporin skin tests are widely used to predict allergic reactions before medication in pediatrics. However, false-positive results from skin tests were more often encountered in pediatrics than in adults. In fact, many children labeled as allergic to β-lactam are not allergic to the antibiotic, leading to the use of alternative antibiotics, which are less effective and more toxic, and the increase of antibiotic resistance. There has been controversy over whether β-lactam antibiotics should be tested for skin allergies before application in children. Based on the great controversy in the implementation of β-lactam antibiotic skin tests, especially the controversial cephalosporin skin tests in pediatrics, the mechanism and reasons of anaphylaxis to β-lactam antibiotics, the significance of β-lactam antibiotic skin tests, the current state of β-lactam antibiotic skin tests at home and abroad, and the problems of domestic and international skin tests were analyzed to determine a unified standard of β-lactam antibiotic skin tests in pediatrics to prevent and decrease adverse drug reactions, avoid waste of drugs, and a large amount of manpower and material resource consumption.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

[allergy to penicillin - no beta-lactam antibiotics?]

Drug allergies are frequently reported by patients undergoing pre-anesthesia evaluation, potentially resulting in a suboptimal treatment with alternative substances. While about 10% of patients report to be allergic to penicillin, less than 1% have a true IgE-mediated allergy. Multiple factors contribute to this large prevalence, such as misinterpretations of common gastrointestinal side effects as “allergic”, a history of penicillin treatment for infectious mononucleosis resulting in skin rashes, uncritical acceptance of the diagnosis by medical staff or neglect to the fact that most patients will lose their sensitivity after 10 years. In addition to this, cephalosporins are regularly withheld from patients with penicillin allergy due to an unwarranted fear of cross-reactivity. Therefore, a correct identification of those in which penicillins or cephalosporins are truly contraindicated is paramount to avoid an unnecessary use of antibiotics with a less favorable spectrum.

Management of the Pregnant Patient with Beta-Lactam Allergy

PURPOSE OF REVIEW

We review the literature and discuss the logistics of testing pregnant patients for penicillin allergy.

RECENT FINDINGS

As in the general population, pregnant patients commonly report a penicillin allergy, but most patients are able to tolerate penicillin. Avoidance of beta-lactams in pregnancy is associated with increased morbidity: longer hospitalizations, more frequent infections, and more complications. Penicillin allergy testing is safe in pregnant patients, and obstetricians are eager for allergists to offer this procedure to their patients. As allergists, we can improve our patients' health outcomes by offering penicillin allergy testing in our practices. The protocols for testing both with and without skin testing in pregnant patients have been studied, and future studies will continue to clarify the safety and efficacy of penicillin allergy delabeling in pregnant patients.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The Evolution of Our Understanding of Penicillin Allergy: 1942-2022

This article reviews our evolving understanding of penicillin hypersensitivity at the 80th anniversary of penicillin's clinical introduction. Penicillin breakdown products covalently bond to serum proteins, leading to classic drug hypersensitivity. Penicillin remains the most frequently reported drug "allergy." Adverse reactions were presumed, in retrospect incorrectly, to implicate a risk for anaphylaxis, and therefore skin testing for IgE became the focus. Skin test positivity may wane over time. This insight has led to the radical conclusion that penicillin hypersensitivity may not be "forever." Atopic background, other drug allergies, family history, gender, and race are apparently not risk factors for penicillin hypersensitivity. Confirmed penicillin hypersensitivity has declined since the 1960s, potentially due to "cleaner" penicillin products and lower dose oral, instead of parenteral, use. Avoiding penicillins, without evaluation, caused unanticipated problems that have been appreciated only recently including longer hospital stays, increased cost of care, suboptimal outcomes from serious infections, and greater toxicities and costs with alternative antibiotics. There are personal and public health advantages with broadly implemented penicillin allergy delabeling based on a reaction history-based risk assessment. Limited skin testing followed by an oral challenge, if negative, for higher-risk histories, and direct oral challenges in lower-risk individuals are currently the reference standard tests to confirm current tolerance.

Preoperative allergy testing for patients reporting penicillin and cephalosporin allergies is economically justified in preventing infection after total shoulder arthroplasty

BACKGROUND

The use of alternative antibiotics to cefazolin has been associated with increased risk of infection after shoulder arthroplasty. Routine preoperative allergy testing in patients reporting penicillin and cephalosporin allergies increases the number able to receive cefazolin and may reduce the occurrence of infection after shoulder arthroplasty, but the financial viability of this practice is unclear. We used break-even modeling to determine the economic viability of routine preoperative allergy testing for infection prevention in total shoulder arthroplasty patients reporting penicillin and cephalosporin allergies.

METHODS

Allergy testing cost ($248.24), infection rates after shoulder arthroplasty following use of noncefazolin antibiotics (3.09%), and infection-related care costs ($55,243) were derived from the literature. A break-even equation using these variables was developed to determine the absolute risk reduction (ARR) in the infection rate that would economically justify the routine implementation of preoperative allergy testing. The number needed to treat was calculated from the ARR.

RESULTS

Preoperative allergy testing is considered economically justified if it prevents at least 1 infection out of 223 shoulder arthroplasties (ARR = 0.45%). These protocols remained economically viable at varying allergy testing costs, initial infection rates, and infection-related care costs.

CONCLUSIONS

Routine preoperative penicillin allergy testing is an economically justified infection prevention strategy among patients reporting penicillin and cephalosporin allergies in the setting of elective shoulder arthroplasty. Widespread implementation of this practice may considerably reduce the economic and societal burden associated with prosthetic infections.

Drug reintroduction testing and beta-lactam hypersensitivity in children: Protocols and results, a 12-year experience

Introduction: Oral provocation test (OPT) to beta-lactam antibiotics (BL) is a gold standard in allergology investigation. We aimed to demonstrate the contribution of OPT in BL hypersensitivity (HS) indicated as a first step in diagnosis. Methods: We conducted a retrospective study from 2007 to 2019, in a single Tunisian tertiary care academic center. It concerned children with presumed non-severe allergic manifestations to BL, with a reaction that has occurred at least 6 months before the OPT. Results: We identified 35 children for inclusion. After the first OPT, a second OPT with a different BL was performed in case of a positive result of the first one. In 12 cases (34.2%), the OPT elicited a reaction. In eight cases the allergy was to penicillin and in two cases to cephalosporins (cefixim). Cross-reactivity was noted in two cases. Conclusion: An OPT to BL indicated in the first instance in non-severe reaction in children will allow a rapid diagnosis in case of suspicion of HS to BL.

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

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

Use of clindamycin as an alternative antibiotic prophylaxis

BACKGROUND

Clindamycin serves as an alternative surgical prophylactic antibiotic in patients with penicillin (PCN) or cephalosporin allergy labels. In the previous reports, the use of clindamycin was associated with higher incidences of surgical site infections (SSIs). We aimed to determine the characteristics of PCN or cephalosporin allergic reactions to stratify patient's risk and indicate subsequent management; leading to de-labeling of PCN or cephalosporin allergy.

METHODS

We conducted a prospective cohort study of patients receiving clindamycin as surgical antibiotic prophylaxis from September 2021 to March 2022. Data were collected from electronic medical records; included demographic data, antibiotic allergy labels, allergic reaction, and allergy testing.

RESULTS

Clindamycin was administered in 445 patients who underwent 451 operations. Among these patients, 53.0% (n = 236) were female with a median age of 15 years (range; 0.5-57.0 years). PCN and cephalosporin allergies were labelled in 83.8% (n = 373) and 25.6% (n = 114) patients, respectively; 11.4% (n = 51) of patients were allergic to both classes of the antibiotics. There were 191 (51.2%) and 73 (64.0%) possible hypersensitivity reactions (HSRs) in PCN and cephalosporin groups, respectively. The most common reactions were rash (PCN: n = 99, 26.5%; cephalosporin: n = 35, 30.7%), and hives (PCN: n = 71, 19.0%; cephalosporin: n = 24, 21.1%). Severe reactions included angioedema (PCN: n = 7, 1.9%; cephalosporin: n = 5, 4.4%), anaphylaxis (PCN: n = 8, 2.1%; cephalosporin: n = 7, 6.1%), bronchospasm (cephalosporin: n = 1, 0.9%), airway involvement (PCN: n = 1, 0.3%; cephalosporin: n = 1, 0.9%), serum sickness (PCN: n = 1, 0.3%), blisters (PCN: n = 1, 0.3%), and drug reaction with eosinophilia and systemic symptoms (DRESS) (PCN: n = 1, 0.3%). Low-risk history of allergy included gastrointestinal side effects (PCN: n = 9, 2.4%; cephalosporin: n = 3, 2.7%), positive family history (PCN: n = 7, 1.9%; cephalosporin: n = 1, 0.9%), and remote history of allergy (PCN: n = 2, 0.5%). There were 201 (53.9%) and 53 (46.5%) unknown reactions in PCN and cephalosporin groups, respectively. In the overall cohort, 3 patients (0.7%) were skin tested for drug allergy (PCN: n = 2, 0.5%; cephalosporin: n = 2, 1.8%).

CONCLUSION

Clindamycin was largely administered in patients with non-severe HSRs, low-risk history or unknown reactions to PCN or cephalosporin, whom cefazolin could have been administered safely. Obtaining a detailed history of antibiotic allergy, allergy testing and/or direct oral challenge can de-label unsubstantiated PCN or cephalosporin allergy and ultimately reduce the incidence of SSIs by optimizing the rate of more effective antibiotic administration.

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.

Negative impact of penicillin allergy labels on antibiotic use in hospitalized patients in Chinese Mainland

Background

Penicillin allergy labels have gained increasing global attention. However, to date, there are no data on the influence of penicillin allergy labels on patients in Chinese mainland.

Methods

This retrospective study reviewed the electronic health record (EHR) of hospitalized patients between June 1, 2018 and May 31, 2019. Patients with a penicillin allergy record were included in the allergy group. Every allergy patient was matched with 4 control patients by using propensity score-based matching to make sure the following were balanced: age, sex, date of admission, and the main diagnosis. We estimated the prevalence of penicillin allergy labels and compared the antibiotic prescription patterns and other clinical outcomes between the 2 groups.

Results

A total of 5691 patients and 22 585 patients were included in the allergy group and control group, respectively. The prevalence of penicillin allergy labels among the hospitalized patients in this study was 4.00%. Compared to the control group, significantly fewer patients in the allergy group were prescribed penicillins and most cephalosporins, while a larger proportion of allergy patients received clindamycin (10.02% vs 5.41%, p < 0.001) and some higher-class antibiotics, such as monobactams (1.81% vs 0.54%, p < 0.001), carbapenems (5.80% vs 4.98%, p = 0.014), macrolides (0.60% vs 0.25%, p < 0.001), and quinolones (17.62% vs 12.40%, p < 0.001). Allergy patients also had longer hospital stays and a greater need to consult infection specialists.

Conclusion

The prevalence of penicillin allergy labels was 4.00% in Chinese hospitalized patients. Penicillin allergy labels could cause irrational antibiotic prescribing, prolonged hospital stays, and greater consultation needs.

Amoxicillin hypersensitivity: patient outcomes in a seven-year retrospective study

BACKGROUND

The beta-lactam antibiotic amoxicillin and the beta-lactamase inhibitor clavulanic acid in combination with amoxicillin are known to both cause immediate and non-immediate type hypersensitivity.

OBJECTIVE

To characterize a large cohort of patients with a history of amoxicillin or amoxicillin-clavulanic acid hypersensitivity.

METHODS

Retrospective analysis of demographics, presentation, investigation, and management of 331 patients presenting to one allergy center with a history of hypersensitivity to amoxicillin or amoxicillin-clavulanic acid.

RESULTS

Hypersensitivity was confirmed in 37/221 (17%) patients who took amoxicillin and 47/110 (43%) patients who took amoxicillin-clavulanic acid as the index drug. In immediate hypersensitivity, skin testing confirmed the diagnosis in 66/139 (47%) patients. Penicillin cross-reactivity was observed in 16/36 (44%). 13/16 (81%) cross-reactive patients reacted to amoxicillin-clavulanic acid as the index drug. All skin test negative patients (73/139) underwent drug provocation. The negative predictive value of skin tests was 89%. In non-immediate hypersensitivity, delayed intradermal tests confirmed diagnosis in 12/170 (7%). 8/12 (67%) skin test positive patients presented with DRESS. All skin test negative patients (158/170) underwent drug provocation. The negative predictive value of skin tests was 95%. Penicillin cross-reactivity was observed in 3/12 (25%). Ten patients were diagnosed with hypersensitivity to clavulanic acid.

CONCLUSION

The negative predictive value of skin tests in both immediate and non-immediate hypersensitivity reactions is excellent and excludes severe allergy. Non-immediate hypersensitivity is rare. Confirmed hypersensitivity is more likely if amoxicillin-clavulanic acid is the index drug. Cross-reactivity was more common in patients presenting with immediate hypersensitivity, most commonly involving benzylpenicillin. A minority of patients were allergic to clavulanic acid.

Management of Beta-Lactam Antibiotics Allergy: A Real-Life Study

Beta-lactam allergy is a common problem in everyday medical practice and is recognized as a major public health issue. Carrying this label frequently leads to the avoidance of all beta-lactam antibiotics, favoring the use of other less preferred classes of antibiotics, that are more expensive and associated with more side effects and increased antimicrobial resistance. Therefore, delabeling a beta-lactam allergy is part of antimicrobial stewardship programs. Herein, we retrospectively examined the clinical records of 576 patients who were referred to our center for a label of allergy to beta-lactam antibiotics and were systematically investigated following a standardized algorithm. Our main aim was to evaluate the frequency of confirmed immediate- and delayed-type allergy to commonly prescribed subclasses of beta-lactam antibiotics (penicillin and cephalosporin), as well as the negative predictive value (NPV) and the sensitivity of skin tests. Our secondary aims were to examine the safety of beta-lactam skin testing and drug challenge. We identified that 260 patients reported a history of immediate reactions, 131 of delayed reactions, and 114 of unknown timing or mechanism of reactions. Following assessment and testing, 86 (18.3%) patients had a confirmed allergy to any beta-lactam antibiotics; 63 (13.4%) with an immediate- and 23 (4.9%) with a delayed-type reaction. Most frequently identified confirmed allergy was to penicillins (65 patients), followed by cephalosporins (21 patients). When immediate-type reactions were examined, NPV of skin tests were 96.3% and 100% for penicillins and cephalosporins, respectively. When delayed reactions were considered, NPV were 91.9 and 87.5% for penicillins and cephalosporins, respectively. Evaluation of the safety of skin tests according to the standardized procedure showed that systemic allergic reactions occurred in only 0.7% of skin tests and in 3.1% of drug challenges. Overall, our data indicate that only 18.3% of patients with a beta-lactam allergy label have a confirmed allergy and non-allergic patients can be safely delabeled through allergic workup based on skin tests and drug challenge. This approach supports the policy of saving second-line antibiotics through a standardized allergy workup.

Factors Associated With Penicillin Allergy Labels in Electronic Health Records of Children in 2 Large US Pediatric Primary Care Networks

Importance

Penicillin allergy labels influence clinical decision-making, yet most children who are labeled do not have type 1 hypersensitivity allergic reactions and instead have a history of predictable adverse reactions or unspecified illness symptoms while receiving penicillin for viral infections. Studies describing penicillin allergy labeling in the pediatric outpatient setting are lacking.

Objective

To describe the epidemiology and factors associated with penicillin allergy labels across 2 large US pediatric primary care networks.

Design, Setting, and Participants

This retrospective, longitudinal birth cohort study was conducted in 90 primary care pediatric practices serving a diverse population of children across Houston, Texas, Austin, Texas, Philadelphia, Pennsylvania, and parts of New Jersey. Participants were children born between January 2010 and June 2020 who had a health care visit in the first 14 days of life and at least 2 additional visits in the first year of life at one of 90 primary care pediatric practices. Censoring criteria were additionally applied to exclude data from children no longer seeking health care in the 90 clinics over time. Statistical analysis was performed from February to May 2021.

Exposures

Basic patient demographics, health care utilization, penicillin exposure, and primary clinic location.

Main Outcomes and Measures

Addition of penicillin allergy label in the electronic medical record.

Results

Among 334 465 children in the birth cohort, 164 173 (49.1%) were female; 72 831 (21.8%) were Hispanic, 59 598 (17.8%) were non-Hispanic Black, and 148 534 (44.4%) were non-Hispanic White; the median (IQR) age at censoring was 3.8 (1.7-6.6) years; 18 015 (5.4%) were labeled as penicillin allergic, but the prevalence of penicillin allergy labeling ranged from 0.9% to 10.2% across practices. Children were labeled at a median (IQR) age of 1.3 (0.9-2.3) years. Non-Hispanic White children were more likely to be labeled compared with non-Hispanic Black children after controlling for potential confounders (adjusted odds ratio, 1.7 [95% CI, 1.6-1.8]). There were 6797 allergic children (37.7%) labeled after receiving 1 penicillin prescription and 1423 (7.9%) labeled after receiving 0 penicillin prescriptions.

Conclusions and Relevance

In this cohort study of more than 330 000 children, penicillin allergy labeling was common and varied widely across practices. Children were labeled early in life, and almost half were labeled after receiving 1 or 0 penicillin prescriptions. These findings raise questions regarding the validity of penicillin allergy labels. Future work exploring the fidelity of and outcomes associated with penicillin allergy-labeling in children is warranted.

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

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

Female sex as a risk factor for penicillin drug allergy in the inpatient setting

Background: Penicillin is the most common reported drug allergy. Previous literature suggests that there is increased prevalence of penicillin drug allergy in female patients in the outpatient setting. However, this is poorly described in the inpatient setting. Objective: This study was performed to determine whether female sex is an independent risk factor for penicillin allergy in the inpatient setting. Methods: A retrospective review of electronic medical records (January 1, 2001-December 31, 2017) was performed for patients with a history of penicillin allergy who underwent penicillin skin testing (PST). Each chart review included the age at initial skin testing, sex, medications, and medical co-morbidities. The study was approved by the institutional review board. Results: 30,883 patients underwent PST with 29,354 and 1,529 occurring in the outpatient and inpatient setting respectively. 170 patients tested positive with a ≥ 5x5 wheal. Of the 170 positive patients, 122 were female (72%) and 48 were male (28%). 15 patients tested positive in the inpatient setting. Of the 1506 adult patients tested in the inpatient setting, 809 were female and 697 were male. 12 females (92.3%) and 1 one male (7.7%) tested positive with a ≥ 5x5 wheal (OR-10.5; 95% CI-1.4-80.8; p-value=0.02). 23 pediatric patients were tested in the inpatient setting. Two pediatric male patients were positive and no female pediatric patients tested positive (OR-1.7; 95% CI-0.5-5.9; p-value=0.5). Conclusion: In the inpatient setting, adult females are 10 times more likely to have a positive PST compared to males. Female sex may be a potential risk factor for objective penicillin drug allergy in the inpatient setting.

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

DISCLAIMER

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Drug Allergy Delabeling Programs: Recent Strategies and Targeted Populations

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

Case: Unexpected development of severe penicillin allergy and review of literature

A 54-year-old man developed a severe anaphylactic penicillin allergy after 16 years and 5 standard erysipelas treatments by intravenous benzylpenicillin and/or oral phenoxymethylpenicillin without any symptoms of allergy. It is recommended to analyze specific IgE antibodies for phenoxymethylpenicillin, benzylpenicillin, amoxicillin, and cefaclor to select an appropriate antibiotic.

The impact of pharmacist intervention on prophylactic antibiotics use in orthopedic surgery at a hospital in China

This study aimed to assess the impact of the pharmacist-led intervention on perioperative antibiotic prophylaxis by standardizing the cephalosporin intradermal skin test in the orthopedic department.A pre-and postintervention study was conducted among patients in the Orthopedics Department at the Beijing Chao-Yang Hospital in China. Use of intradermal skin test, perioperative antibacterial prophylaxis, and cost of care were compared between the preintervention population (admitted from 6/1/2018 to 8/31/2018) and postintervention population (admitted from 1/1/2019 to 3/31/2019). Logistic regression and generalized linear regression were used to assess the intervention impact.425 patients from the preintervention period and 448 patients from the postintervention period were included in the study. After the implementation of the pharmacist intervention program, there was a decrease in the utilization of intradermal skin tests, from 95.8% to 16.5% (P < .001). Patients were more likely to have cephalosporin as prophylactic antimicrobials (OR = 5.28, P < .001) after the implementation. The cost of antimicrobials was significantly reduced by $150.21 (P < .001) for each patient.Pharmacist-involved intervention can reduce the utilization of cephalosporins skin tests and decrease the prescription of unnecessary high-cost antimicrobials.

The effects of beta-lactam allergy relabeling on antibiotic prescribing practices

BACKGROUND

Beta-lactam antibiotic allergy labels are highly prevalent but rarely indicate an allergic intolerance. These patient-reported allergies lead to broad-spectrum antibiotic use, conferred resistance, increased expense, and adverse effects.

OBJECTIVE

To implement and assess the impact of a history-based clinical guideline that directs antibiotic management and beta-lactam allergy relabeling for patients reporting beta-lactam allergies.

METHODS

Patients with beta-lactam allergy labels were identified by our trained multidisciplinary team in diverse clinical settings. This quality improvement project was conducted to evaluate the safety and impact of the guideline on antibiotic use by comparing prescribing practices before and after guideline implementation.

RESULTS

A total of 79 patients with beta-lactam allergies were identified (penicillins-90%, cephalosporins-10%). After guideline implementation, outcomes of allergy relabeling included the following: (1) complete removal, indicating an unlikely true allergy (27%); (2) updated to detail successfully tolerated beta-lactam courses (48%); or (3) no change made to current label (25%). Beta-lactam antibiotic courses before and after guideline implementation compared with total antibiotic courses: allergy removed (44% vs 70%; P < .001), allergy updated (32% vs 68%; P < .001), and no change (27% vs 41%; P = .08). Compared with before guideline implementation, beta-lactam antibiotics were 3 times more likely to be prescribed after allergy assessment (odds ratio, 3.22; 95% confidence interval, 2.4-4.3; P < .05).

CONCLUSION

The implementation of the beta-lactam allergy clinical guideline resulted in most patients' allergy labels being removed or advantageously updated. These allergy label changes correlated with a substantial increase in the percentage of beta-lactam antibiotics prescribed. After guideline implementation, beta-lactam antibiotics had a 3-fold increased odds of being prescribed independent of allergy label outcome.

Perioperative Anaphylaxis

Perioperative anaphylaxis is a potentially life-threatening and under-recognized event most commonly caused by antibiotics, neuromuscular blocking agents, dyes, latex, and disinfectants. This review provides updates in the epidemiology and pathogenesis of perioperative anaphylaxis, discusses culprit agents, and highlights the tenets of management including a comprehensive allergy evaluation.

Anaphylaxis to Drugs, Biological Agents, and Vaccines

Anaphylaxis is a multi-system syndrome resulting from the release of mediators from mast cells and basophils. Drugs are common causes. Anaphylaxis to certain drugs, vaccines, and biological agents present clinical challenges, and merit referral to a board-certified allergist/immunologist for further evaluation and management.

Antibiotic Treatment, Mechanisms for Failure, and Adjunctive Therapies for Infections by Group A Streptococcus

Group A Streptococcus (GAS; Streptococcus pyogenes) is a nearly ubiquitous human pathogen responsible for a significant global disease burden. No vaccine exists, so antibiotics are essential for effective treatment. Despite a lower incidence of antimicrobial resistance than many pathogens, GAS is still a top 10 cause of death due to infections worldwide. The morbidity and mortality are primarily a consequence of the immune sequelae and invasive infections that are difficult to treat with antibiotics. GAS has remained susceptible to penicillin and other β-lactams, despite their widespread use for 80 years. However, the failure of treatment for invasive infections with penicillin has been consistently reported since the introduction of antibiotics, and strains with reduced susceptibility to β-lactams have emerged. Furthermore, isolates responsible for outbreaks of severe infections are increasingly resistant to other antibiotics of choice, such as clindamycin and macrolides. This review focuses on the challenges in the treatment of GAS infection, the mechanisms that contribute to antibiotic failure, and adjunctive therapeutics. Further understanding of these processes will be necessary for improving the treatment of high-risk GAS infections and surveillance for non-susceptible or resistant isolates. These insights will also help guide treatments against other leading pathogens for which conventional antibiotic strategies are increasingly failing.

Drug Hypersensitivity Reactions

Drug hypersensitivity reactions are a diverse group of reactions mediated by the immune system after exposure to a drug. The Gell and Coombs classification divides immunologic DHRs into 4 major pathophysiologic categories based on immunologic mechanism. Anaphylaxis is a Type I hypersensitivity reaction that requires immediate recognition and treatment. Severe cutaneous adverse reactions (SCARs) are a group of dermatologic diseases that result from a Type IV hypersensitivity process and include drug reaction with eosinophilia and systemic symptom (DRESS) syndrome, Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP). Other types of reactions are slow to develop and do not always require rapid treatment. Emergency physicians should have a good understanding of these various types of drug hypersensitivity reactions and how to approach the patient regarding evaluation and treatment.