Full-dose challenge of moderate, severe, and unknown beta-lactam allergies in the emergency department

OBJECTIVE

This study aims to assess the outcome of challenging documented moderate, severe, or unknown beta-lactam allergies with full dose administration of a beta-lactam antibiotic in emergency department (ED) patients admitted for acute bacterial infection.

METHODS

A single-center, retrospective, descriptive study of adult patients challenged with a full dose of beta-lactam in the ED from January 2021 to December 2022 was conducted. Included patients had at least one documented moderate, severe, or unknown beta-lactam allergy in the electronic medical record (EMR) without documentation of prior tolerance. Patient demographics, prior beta-lactam antibiotic reaction, beta-lactam administered in the ED, inpatient beta-lactam continuation, adverse drug reactions, and updates to allergy profiles were collected. Descriptive statistics for data analysis were performed using SPSS Version 22.

RESULTS

Of the 184 ED encounters with full-dose beta-lactam challenges, five (2.7%) patients with documented moderate, severe, or unknown beta-lactam allergies experienced an allergic reaction after the challenge; one (0.5%) patient had an allergic reaction in the ED, and the remaining four (2.2%) occurred after admission. No anaphylactic reactions occurred. All allergic reactions were limited to mild rash or itching. Most patients (98.9%) were challenged with a cephalosporin. A beta-lactam was continued in 86.4% of cases, and the allergy profile was updated for future utilization in 73.4% of patients.

CONCLUSIONS

This study suggests that full-dose challenge of moderate, severe, or unknown beta-lactam allergies can be safely accomplished in the ED. This approach avoids unnecessary penicillin allergy skin testing and reduces utilization of suboptimal alternative antibiotic regimens.

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.

Carbene-Catalyzed Atroposelective Annulation for Quick Access to Axially Chiral Thiazine Derivatives

An N-heterocyclic carbene (NHC)-catalyzed atroposelective annulation reaction is disclosed for quick and efficient access to thiazine derivatives. A series of axially chiral thiazine derivatives bearing various substituents and substitution patterns were produced in moderate to high yields with moderate to excellent optical purities. Preliminary studies revealed that some of our products exhibit promising antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo) that causes rice bacterial blight.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcome of preoperative cefazolin use for infection prophylaxis in patients with self-reported penicillin allergy

BACKGROUND

Cephalosporins are the preferred antibiotics for prophylaxis against surgical site infections. Most studies give a rate of combined IgE and non-IgE penicillin allergy yet it is recommended that cephalosporins be avoided in patients having the former but can be used in those with the latter. Some studies use penicillin allergy while others penicillin family allergy rates. The primary goal of this study was to determine the rates of IgE and non-IgE allergy as well as cross reactions to both penicillin and the penicillin family. Secondary goals were to determine the surgical services giving preoperative cefazolin and the types of self reported reactions that patients' had to penicillin prompting their allergy status.

METHODS

All patients undergoing elective and emergency surgery at a University Health Sciences Centre were retrospectively studied. The hospital electronic medical record was used for data collection.

RESULTS

8.9% of our patients reported non-IgE reactions to penicillin with a cross reactivity rate of 0.9% with cefazolin. 4.0% of our patients reported IgE reactions to penicillin with a cross reactivity rate of 4.0% with cefazolin. 10.5% of our patients reported non-IgE reactions to the penicillin family with a cross reactivity rate of 0.8% with cefazolin. 4.3% of our patients reported IgE reactions to the penicillin family with a cross reactivity rate of 4.0% with cefazolin.

CONCLUSIONS

Our rate of combined IgE and non-IgE reactions for both penicillin and penicillin family allergy was within the range reported in the literature. Our rate of cross reactivity between cefazolin and combined IgE and non-IgE allergy both to penicillin and the penicillin family were lower than reported in the old literature but within the range of the newer literature. We found a lower rate of allergic reaction to a cephalosporin than reported in the literature. We documented a wide range of IgE and non-IgE reactions. We also demonstrated that cefazolin is frequently the preferred antibiotics for prophylaxis against surgical site infections by many surgical services and that de-labelling patients with penicillin allergy is unnecessary.

Beta-lactam allergies, surgical site infections, and prophylaxis in solid organ transplant recipients at a single center: A retrospective cohort study

BACKGROUND

Beta-lactam allergies (BLAs) are common in hospitalized patients, including transplant recipients. BLA is associated with decreased use of preferred surgical site infection (SSI) prophylaxis and increased SSIs, but this has not been studied in the transplant population.

METHODS

We reviewed adult heart, kidney, and liver transplant recipients between January 1, 2016 and December 31, 2019 to characterize reported BLA and collect SSI prophylaxis regimens at time of transplant. We compared the use of preferred SSI prophylaxis and SSI incidence based on reported BLA status. Post hoc we collected antibiotic days of therapy (DOT) (excluding pneumocystis prophylaxis) in the 30-day period posttransplant for patients without SSI. We utilized descriptive statistics for comparisons.

RESULTS

Of 691 patients included (116 heart, 400 kidney, and 175 liver transplant recipients), 118 (17%) reported BLA. Rash and hives were the two most reported BLA reactions (36% and 24%), categorized as potential T-cell mediated and IgE mediated, respectively. Preferred SSI prophylaxis was prescribed in 13 (11%) patients with BLA and 573 (92%) without BLA (p < .001). No difference could be detected in SSI incidence between BLA and non-BLA patients (4.2 vs. 4.3%, p = 1.0). Of 659 without SSI, 169 (25.6%) received antibiotics within 30 days of transplant; mean antibiotic DOT for BLA and non-BLA patients were 3.5 ± 8.0 versus 2.3 ± 5.8, p = .12.

CONCLUSION

BLA transplant recipients received nonpreferred SSI prophylaxis more frequently than non-BLA recipients, but there was no difference in 30-day SSIs between the groups. One-fourth of solid organ transplant recipients received systemic antibiotics within 30 days of transplant.

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.

Antibiotic Use in Patients With β-Lactam Allergies and Pneumonia: Impact of an Antibiotic Side Chain-Based Cross-Reactivity Chart Combined With Enhanced Allergy Assessment

BACKGROUND

β-lactam antibiotics with dissimilar R-group side chains are associated with low cross-reactivity. Despite this, patients with β-lactam allergies are often treated with non-β-lactam alternative antibiotics. An institutional β-lactam side chain-based cross-reactivity chart was developed and implemented to guide in antibiotic selection for patients with β-lactam allergies.

METHODS

This single-center, retrospective cohort study analyzed the impact of the implementation of the cross-reactivity chart for patients with pneumonia. Study time periods were defined as January 2013 to October 2014 prior to implementation of the chart (historical cohort) and January 2017 to October 2018 (intervention cohort) following implementation. The primary outcome was the incidence of β-lactam utilization between time periods. Propensity-weighted scoring and interrupted time-series analyses compared outcomes.

RESULTS

A total of 341 and 623 patient encounters were included in the historical and intervention cohorts, respectively. There was a significantly greater use of β-lactams in the intervention cohort (70.4% vs 89.3%; P < .001) and decreased use of alternative therapy (58.1% vs 36%; P < .001). There was no difference in overall allergic reactions between cohorts (2.4% vs 1.6%; P = .738) or in reactions caused by β-lactams (1.3% vs 0.9%; P = .703). Inpatient mortality increased (0% vs 6.4%; P < .001); however, no deaths were due to allergic reactions. Healthcare facility-onset Clostridioides difficile infections decreased between cohorts (1.2% vs 0.2%; P = .032).

CONCLUSIONS

Implementation of a β-lactam side chain-based cross-reactivity chart and enhanced allergy assessment was associated with increased use of β-lactams in patients with pneumonia without increasing allergic reactions.

Base-promoted Cyclization Reaction of o-Isothiocyanato Arylacetylenes and Aroylacetonitriles: Easy Access to Benzo[d][1,3]thiazines

A green and efficient synthesis of benzo[d][1,3]thiazines through base-promoted cyclization reaction of o-isothiocyanato arylacetylenes with aroylacetonitriles has been developed. This protocol displays high step economy and efficiency, and tolerates various...

Classifying cephalosporins: from generation to cross-reactivity

PURPOSE OF REVIEW

To review the most recent literature studying the classifications, immunochemistry, and crossreactivity of allergy reactions to cephalosporins.

RECENT FINDINGS

Over the last five years, research interest has focused on three areas related to cephalosporin allergy: cross-reactivity among cephalosporins and with other beta-lactams; the incidence of adverse reactions in penicillin allergy patients or in reported penicillin allergy labels; and new cephalosporins structures involved in the immunological recognition.

SUMMARY

Meta-analysis of a substantial number of studies shows that cephalosporins are safer than previously thought. Evidence supports two main conclusions in that regard. First, there is a relatively low percentage of cross-reactivity between cephalosporins and other beta-lactams with penicillins in penicillin allergy patients. Second, there is a very low incidence of allergy reactions in nonselected as well as in selected penicillin allergy patients when cephalosporins are used prior to surgical intervention.On the other hand, few structures have been discovered related to the immune mechanism of cephalosporin allergy reactions, and these are far from being ready to use in clinical practice.

Multiple drug allergy syndrome in pregnancy: Lessons for sexual health physicians

Co-existence of multiple drug allergies and pregnancy often results in vexing dilemmas for physicians. A 21-year-old pregnant woman presented with asymptomatic cervicitis with dual infection with Chlamydia trachomatis and Neisseria gonorrhoeae during her third trimester. She reported a history of generalised rash with mucous membrane involvement following use of both macrolides and penicillins. Her gonococcal infection was successfully treated with a single dose of intramuscular gentamicin and chlamydial infection with oral clindamycin and rifampicin.

Safety of direct oral provocation testing using the Amoxicillin-2-step-challenge in children with history of non-immediate reactions to amoxicillin

BACKGROUND

Previous studies have shown that direct oral provocation tests, without prior skin testing, in children having delayed onset, benign rashes to beta-lactam antibiotic is safe and effective. Although, this test is useful in confirming drug hypersensitivity reactions, there is no standard protocol recommendation of drug provocation tests. This study aimed to evaluate the safety of the direct oral provocation test, using the Amoxicillin-2-step-challenge without prior skin testing, in children with history of non-immediate reactions to amoxicillin.

METHODS

The Amoxicillin-2-step-challenge protocol was performed in children with history of non-immediate reactions to amoxicillin. This protocol is composed of 2 doses of amoxicillin, with a 30-min interval; continued for a total of 5 days. All of the patients had not undergone skin testing before the oral provocation test.

RESULTS

This study included 54 children, having a median age of 6.6 years, with 70.4% being male. Amoxicillin and amoxicillin-clavulanic acid were reported as the culprit drug in 75.9% and 24.1%, respectively. The index reactions were maculopapular (MP) rash in 79.6% and delayed urticarial rash/angioedema in 20.4%. Five patients (9.3%) had a reaction during the provocation test, all of these patients had delayed urticaria and were treated with oral antihistamine. However, 1 patient developed a fever alongside an MP rash. Laboratory investigation for this patient showed increased atypical lymphocytes and liver enzymes elevation.

CONCLUSIONS

Direct oral provocation tests, using the Amoxicillin-2-step-challenge, without prior skin testing, revealed good, immediate safety for the diagnosis of amoxicillin hypersensitivity in children with history of non-immediate reactions to amoxicillin.

Impact of an Antibiotic Side-Chain-Based Cross-reactivity Chart Combined With Enhanced Allergy Assessment Processes for Surgical Prophylaxis Antimicrobials in Patients With β-Lactam Allergies

BACKGROUND

β-Lactam antibiotics are first-line therapy for perioperative prophylaxis; however, patient-reported allergies often lead to increased prescribing of alternative antibiotics that may increase the incidence of surgical site infections. The R-group side chain of the β-lactam ring is responsible for allergic cross-reactivity and experts recommend the use of β-lactams that are structurally dissimilar.

METHODS

An internally developed, antibiotic side-chain-based cross-reactivity chart was developed and implemented alongside enhanced allergy assessment processes. This single-center, quasi-experimental study analyzed antibiotic prescribing in all adult patients with a documented β-lactam allergy undergoing an inpatient surgical procedure between quartile (Q) 1 (2012)-Q3 (2014) (historical group) and Q3 (2016)-Q3 (2018) (intervention group). Propensity-weighted scoring analyses compared categorical and continuous outcomes. Interrupted time-series analysis further analyzed key outcomes.

RESULTS

A total of 1119 and 1089 patients were included in the historical and intervention cohorts, respectively. There was a significant difference in patients receiving a β-lactam alternative antibiotic between cohorts (84.9% vs 15.1%; P < .001). There was a decrease in 30-day readmissions in the intervention cohort (7.9% vs 6.3%; P = .035); however, there was no difference in the incidence of SSIs in patients readmitted (14.8% vs 13%; P = .765). No significant differences were observed in allergic reactions (0.5% vs 0.3%; P = .323), surgical site infections, in-hospital and 30-day mortality, healthcare facility-onset Clostridiodes difficile infection, acute kidney injury, or hospital costs.

CONCLUSIONS

Implementation of an antibiotic cross-reactivity chart combined with enhanced allergy assessment processes significantly improved the prescribing of β-lactam antibiotics for surgical prophylaxis.

Comparison of immediate hypersensitivity reactions to preoperative antibiotics in patients labeled as penicillin allergic

BACKGROUND

Cefazolin is routinely recommended as the first-line agent for surgical antibiotic prophylaxis because it prevents more surgical site infections than second-line antibiotics. Clinicians often avoid administering cefazolin to patients who are labeled as penicillin allergic due to concerns of cross-reactivity. The aim of this study was to compare the incidence of hypersensitivity reactions between cefazolin and the second-line antibiotics vancomycin and clindamycin.

METHODS

This retrospective study included patients who were labeled as penicillin allergic and received either cefazolin, clindamycin, or vancomycin as preoperative antibiotics. The primary outcome was intraoperative hypersensitivity reactions.

RESULTS

A total of 734 surgical procedures in 690 patients were included. Fifteen immediate hypersensitivity reactions were identified. Probable hypersensitivity reactions occurred in 3 (0.9%) patients in the cefazolin group, 4 (1.4%) in the clindamycin group, and 1 (1.1%) in the vancomycin group. Seven of 8 patients reported allergies to additional medications beyond penicillin. There were seven cases of possible hypersensitivity reactions, 3 (0.9%) in the cefazolin group, 1 (1.1%) in the vancomycin group, and 3 (1.0%) in the clindamycin group.

CONCLUSION

Our data suggest that perioperative hypersensitivity reactions are uncommon in patients labeled as penicillin allergic. The frequency of immediate hypersensitivity reactions was not different between patients receiving cefazolin, clindamycin, or vancomycin. Avoiding cefazolin in patients labeled as penicillin allergic may not be warranted.

Assessment of the Frequency of Dual Allergy to Penicillins and Cefazolin: A Systematic Review and Meta-analysis

Importance

Cefazolin is the preoperative antibiotic of choice because it is safer and more efficacious than second-line alternatives. Surgical patients labeled as having penicillin allergy are less likely to prophylactically receive cefazolin and more likely to receive clindamycin or vancomycin, which results in higher rates of surgical site infections.

Objective

To examine the incidence of dual allergy to cefazolin and natural penicillins.

Data Sources

MEDLINE/PubMed, Web of Science, and Embase were searched without language restrictions for relevant articles published from database inception until July 31, 2020.

Study Selection

In this systematic review and meta-analysis, a search of MEDLINE/PubMed, Web of Science, and Embase was performed for articles published from database inception to July 31, 2020, for studies that included patients who had index allergies to a natural penicillin and were tested for tolerability to cefazolin or that included patients who had index allergies to cefazolin and were tested for tolerability to a natural penicillin. A total of 3228 studies were identified and 2911 were screened for inclusion.

Data Extraction and Synthesis

Data were independently extracted by 2 authors. Bayesian meta-analysis was used to estimate the frequency of allergic reactions.

Main Outcomes and Measures

Dual allergy to cefazolin and a natural penicillin.

Results

Seventy-seven unique studies met the eligibility criteria, yielding 6147 patients. Cefazolin allergy was identified in 44 participants with a history of penicillin allergy, resulting in a dual allergy meta-analytical frequency of 0.7% (95% credible interval [CrI], 0.1%-1.7%; I2 = 74.9%). Such frequency was lower for participants with unconfirmed (0.6%; 95% CrI, 0.1%-1.3%; I2 = 54.3%) than for those with confirmed penicillin allergy (3.0%; 95% CrI, 0.01%-17.0%; I2 = 88.2%). Thirteen studies exclusively assessed surgical patients (n = 3884), among whom 0.7% (95% CrI, 0%-3.3%; I2 = 85.5%) had confirmed allergy to cefazolin. Low heterogeneity was observed for studies of patients with unconfirmed penicillin allergy who had been exposed to perioperative cefazolin (0.1%; 95% CrI, 0.1%-0.3%; I2 = 13.1%). Penicillin allergy was confirmed in 16 participants with a history of cefazolin allergy, resulting in a meta-analytical frequency of 3.7% (95% CrI, 0.03%-13.3%; I2 = 64.4%). The frequency of penicillin allergy was 4.4% (95% CrI, 0%-23.0%; I2 = 75%) for the 8 studies that exclusively assessed surgical patients allergic to cefazolin.

Conclusions and Relevance

These findings suggest that most patients with a penicillin allergy history may safely receive cefazolin. The exception is patients with confirmed penicillin allergy in whom additional care is warranted.

Evaluation of Clinical Properties and Diagnostic Test Results of Cephalosporin Allergy in Children

INTRODUCTION

Beta-lactams (BLs) are one of the most frequent causes of drug hypersensitivity reactions (HRs), and cephalosporins are a widely used subclass of BLs, especially in children. The aim of this study was to evaluate the clinical features and diagnostic test results of pediatric patients evaluated for suspected cephalosporin allergy.

METHODS

This study included patients who presented to our pediatric allergy clinic with a history of reactions attributed to cephalosporins between January 1, 2011, and December 31, 2019, and whose diagnostic tests were completed for the diagnosis.

RESULTS

This study included 120 pediatric patients and 69 (57.5%) of them were girls. The median age was 38.63 (interquartile range 10.5-85.7) months. Reactions occurring within 1 h of drug intake were reported in 33 patients (27.5%). Reactions were maculopapular rash in 55 (45.8%) patients, urticaria and/or angioedema in 49 (40.8%), anaphylaxis in 11 (9.2%), severe cutaneous drug reaction in 4 (3.3%), and fixed drug reaction in 1 patient (0.83%). The most frequently suspected agent was cefixime in 41 patients (34.2%). In total, 30 (25%) patients were diagnosed as having cephalosporin hypersensitivity. Confirmation of HRs was also significantly more frequent among patients who were older (p: 0.000), who had taken the drug parenterally (p: 0.000) and with immediate reactions (p: 0.000).

CONCLUSION

Cephalosporin allergy has been confirmed in approximately one-fourth of the patients evaluated for suspected cephalosporin allergy. Confirmation of HRs was significantly more common among patients who were older, had immediate reactions, and had taken the drug parenterally.

Skin testing and drug challenge in the evaluation of drug hypersensitivity reactions

Immediate hypersensitivity to drugs is characterized by symptoms such as hives, swelling, and wheezing. To prevent a negative impact on care, assessment by an allergist is important. Evaluation requires a clear clinical history, but it is often lacking or vague, which makes a diagnosis difficult. Allergists instead can use skin testing and drug challenge to evaluate drug hypersensitivity reactions, which help the patient and provider understand the causative drug(s) and, more importantly, enables the use of the exonerated drug(s). Although penicillin skin testing is standardized, well described, and widely used, skin testing for most other drugs requires the use of a nonirritating skin testing concentration that can have a low negative predictive value. Drug challenges are the criterion standard for confirming tolerance. The allergist must obtain an in-depth clinical history and then follow with skin testing and/or drug challenges when indicated to determine which drugs can be de-labelled and which should be avoided. In this review, we focused on the evaluation of drug hypersensitivity reactions to antibiotics, perioperative agents, biologics, and chemotherapeutics.

A Practical Guide for Managing Antibiotic Allergies in the Emergency Department

Up to 30% of patients report at least one antibiotic allergy, but oftentimes these antibiotic allergies are misdiagnosed. In fact, of the 10% of patients reporting penicillin allergies, 90%-98% are not truly allergic. In an era of increasing antibiotic resistance coupled with a limited number of new antibiotics, evaluating antibiotic allergies is critical in providing optimal patient care. Differentiating adverse drug reactions from antibiotic allergies may seem like a daunting task for clinicians and providers, especially in the emergency department, where decisions are made quickly. However, a systemic approach, including medical record review coupled with patient and/or family interview, is vital in managing patients with antibiotic allergies. Inappropriate, alternative antibiotics are frequently chosen due to patient allergies, and data suggest higher rates of broad-spectrum antibiotic use, antibiotic resistance, and poor outcomes as a result. Herein, we review antibiotic selection in patients reporting antibiotic allergies in the emergency department.

Antimicrobial Desensitization: A Review of Published Protocols

Antimicrobial desensitization represents a last-line option for patients with no alternative therapies, where the benefits of this intensive process must outweigh the potential harm from drug exposure. The goal of antimicrobial desensitization procedures is to establish a temporary state of tolerance to drugs that may otherwise cause hypersensitivity reactions. While no universal antimicrobial desensitization protocols exist, this review critically analyzes previously published desensitization protocols. The purpose of this review is to provide a greater insight for clinicians and institutions to ensure desensitization procedures are efficacious while minimizing potential for patient harm. With an increasing rate of antimicrobial resistance and the critical need to preserve antimicrobial agents, desensitization may represent another option in our antimicrobial stewardship toolkit.

Cephalosporins: A Focus on Side Chains and β-Lactam Cross-Reactivity

Cephalosporins are among the most commonly prescribed antibiotic classes due to their wide clinical utility and general tolerability, with approximately 1-3% of the population reporting a cephalosporin allergy. However, clinicians may avoid the use of cephalosporins in patients with reported penicillin allergies despite the low potential for cross-reactivity. The misdiagnosis of β-lactam allergies and misunderstanding of cross-reactivity among β-lactams, including within the cephalosporin class, often leads to use of broader spectrum antibiotics with poor safety and efficacy profiles and represents a serious obstacle for antimicrobial stewardship. Risk factors for cephalosporin allergies are broad and include female sex, advanced age, and a history of another antibiotic or penicillin allergy; however, cephalosporins are readily tolerated even among individuals with true immediate-type allergies to penicillins. Cephalosporin cross-reactivity potential is related to the structural R1 side chain, and clinicians should be cognizant of R1 side chain similarities when prescribing alternate β-lactams in allergic individuals or when new cephalosporins are brought to market. Clinicians should consider the low likelihood of true cephalosporin allergy when clinically indicated. The purpose of this review is to provide an overview of the role of cephalosporins in clinical practice, and to highlight the incidence of, risk factors for, and cross-reactivity of cephalosporins with other antibiotics.

The Basics of Penicillin Allergy: What A Clinician Should Know

Antimicrobials in the penicillin class are first line treatments for several infectious diseases in the pediatric and adult population today. In the United States, patients commonly report having a penicillin allergy, with penicillin being the most frequent beta-lactam allergy. However, very few patients experience a clinically significant immune-mediated allergic reaction to penicillin. If a true penicillin allergy exists, cross-reactivity to other beta-lactam antimicrobials may occur. Mislabeling patients with penicillin allergy can lead to a higher utilization of second line antimicrobial agents, potentially increasing costs and resistance due to a larger spectrum of activity. Pharmacists play an essential role in inquiring about patient specific reactions to presumed medication allergies and developing a further assessment plan, if needed, to determine if the medication allergy is real.

Strategies for Clarifying Penicillin Allergies When Skin Testing Is Not an Option

Patients with reported penicillin allergies have been proven to experience negative health consequences, such as increased cost, suboptimal antimicrobial therapy, and adverse reactions. Though skin testing has been proposed as a method to clarify penicillin allergies, many institutions may lack the resources to perform skin testing on a wide scale. This literature review describes the current literature surrounding the use of penicillin allergy interviews when skin testing is not an option. Specifically, the review highlights the steps in carrying out a successful antibiotic allergy patient interview, summarizes the clinical evidence surrounding antibiotic allergy clarifications, and addresses key advantages and disadvantages of clarifying antibiotic allergies without the availability of skin testing.

Pharmacy-Led β-Lactam Allergy Interview (BLAI) Reduces Duration of Fluoroquinolones Within a Community Hospital

BACKGROUND

Patients with reported β-lactam allergies often receive broad-spectrum antimicrobials and have been shown to experience a variety of negative health consequences, such as increased mortality, costs, readmission, and adverse reactions. Current literature focuses on β-lactam allergy skin testing but lacks evidence on β-lactam allergy interviews (BLAI) when skin testing is unavailable.

OBJECTIVE

This study aimed to test the impact of a pharmacy-led BLAI on duration of fluoroquinolones at a community hospital.

METHODS

A quasi-experimental design with a prospective cohort design and historical control group was used to assess patients with reported penicillin (PCN) allergies in a community hospital. The primary outcome was duration of fluoroquinolones before and after implementation of BLAI. Secondary outcomes included length of stay (LOS), percentage of patients switched to a β-lactam antibiotic, percentage of antimicrobial stewardship recommendations made/accepted, and discrepancies between allergy in medical record and interview-reported allergy. Nonparametric continuous data and medians were evaluated by Mann-Whitney U.

RESULTS

A total of 80 patients were included in the study (43 in the control group and 37 in the prospective group). Fluoroquinolone duration was reduced after the implementation of BLAI (3.7 vs 2.7 days, P = 0.027). In all, 49% of patients in the prospective group were switched to a β-lactam antibiotic after BLAI, with no allergic reactions, adverse effects, or impact on LOS. Conclusion and Relevance: BLAI resulted in a significant reduction in fluoroquinolone duration in patients with PCN allergies and may represent a safe and effective option for institutions lacking skin-testing capabilities.

Controversies in Drug Allergy: Drug Allergy Pathways

Drug allergy pathways are standardized approaches for patients reporting prior drug allergies with the aim of quality improvement and promotion of antibiotic stewardship. At the International Drug Allergy Symposium during the 2018 American Academy of Allergy, Asthma, and Immunology/World Allergy Organization Joint Congress in Orlando, Florida, drug allergy pathways were discussed from international perspectives with a focus on beta-lactam allergy pathways and pragmatic approaches for acute care hospitals. In this expert consensus document, we review current pathways, and detail important considerations in devising, implementing, and evaluating beta-lactam allergy pathways for hospitalized patients. We describe the key patient and institutional factors that must be considered in risk stratification, the central feature of pathway design. We detail shared obstacles to widespread beta-lactam allergy pathway implementation and identify potential solutions to address these challenges.

Systematic review of professional liability when prescribing β-lactams for patients with a known penicillin allergy

OBJECTIVE

To describe medical negligence and malpractice cases in which a patient with a known penicillin allergy received a β-lactam and experienced an adverse reaction related to the β-lactam.

DATA SOURCES

Lexis-Nexus, Westlaw, and Google Scholar were searched.

STUDY SELECTIONS

Medical negligence and malpractice cases were eligible for inclusion if they met the following criteria: the plaintiff had a known penicillin allergy, received a β-lactam, and experienced an adverse event. All United States federal and state cases were eligible.

RESULTS

Twenty-seven unique cases met the inclusion criteria. Eighteen cases involved the receipt of a penicillin-based antibiotic; of these cases with a known legal outcome, the plaintiff (patient or representative) prevailed or settled in 3 cases and defendants (providers) prevailed in 7 cases. Seven cases involved the receipt of a cephalosporin; of these cases with a known legal outcome, the plaintiff settled with physicians before trial in 1 case and defendants prevailed in 3 cases. Two cases involved the receipt of a carbapenem. Defendants prevailed in one case and the legal outcome of the other case is unknown. In cases in which the defense successfully moved for summary judgment, judges cited a lack of scientific evidence demonstrating a cephalosporin or carbapenem was contraindicated for a patient with a penicillin allergy.

CONCLUSION

The cases with published legal outcomes found limited professional liability for clinicians who prescribed cephalosporins or carbapenems to a patient with a known penicillin allergy. These results may decrease the litigation fears of practitioners and risk managers within health care systems.

Addressing Inpatient Beta-Lactam Allergies: A Multihospital Implementation

Addressing inaccurate penicillin allergies is encouraged as part of antibiotic stewardship in the inpatient setting. However, implementing interventions targeted at the 10% to 15% of inpatients reporting a previous penicillin allergy can pose substantial logistic challenges. We implemented a computerized guideline for patients with reported beta-lactam allergy at 5 hospitals within a single health care system in the Boston area. In this article, we describe our implementation roadmap, including both successes achieved and challenges faced. We explain key implementation steps, including assembling a team, stakeholder engagement, developing or selecting an approach, spreading the change, establishing measures, and measuring impact. The objective was to detail the lessons learned while empowering others to be part of this important, multidisciplinary work to improve the care of patients with reported beta-lactam allergies.

Death following ceftazidime-induced Kounis syndrome

Kounis syndrome, also known as allergic myocardial infarction or allergic angina syndrome, coincides with chest pain and allergic reactions. It involves the activation of interrelated inflammatory cells following allergic, anaphylactic or anaphylactoid insults. We report a case of Kounis syndrome complicated by an injection of ceftazidime. A 52-year-old man developed shortness of breath and hypotension, leading to immediate unconsciousness, after a ceftazidime injection. Despite intensive care management, he showed no improvement and died approximately 19 h after ceftazidime administration. Autopsy showed massive laryngeal oedema, mucous plugging and collapsed lungs. An ImmunoCAP tryptase assay showed the tryptase level in an autopsy sample to be 118 µg/L (normal < 11.4 µg/L). Microscopy of the myocardium showed cellular infiltration preceding myocardial necrosis. These findings support the pathophysiological theory of Kounis syndrome, with cellular infiltration proposed as the cause of myocardial injury rather than an effect related to the healing process.

Confronting the Challenge of Beta-Lactam Allergies: A Quasi-Experimental Study Assessing Impact of Pharmacy-Led Interventions

OBJECTIVE

To improve allergy history documentation and increase the use of beta-lactams when appropriate in patients with a reported beta-lactam allergy.

METHODS

This pre-post study was conducted at a 167-bed tertiary care community hospital and evaluated multidisciplinary interventions on allergy documentation and antibiotic selection. Interventions included education, creation of local practice guidelines, and modified practices for pharmacists and pharmacy technicians. Inpatients with a reported beta-lactam allergy receiving at least 1 antibiotic for >24 hours were included; first admissions were assessed. Primary outcomes were documentation of reaction type and percentage of patients receiving non-beta-lactam therapy. Secondary outcomes included documentation of previously tolerated beta-lactams, modification of non-beta-lactam therapy, discharge antibiotics, and adverse reactions.

RESULTS

A total of 179 patients were included, 91 preintervention and 88 postintervention. No significant differences were observed between the before versus after groups in the percentage of patients with documentation of reaction type (90.1% vs 89.8%, P = .940) or the overall percentage of patients receiving non-beta-lactams (86.8% vs 84.1%, P = .605). However, significantly more patients in the after phase had documentation of previously tolerated beta-lactams (8.8% vs 28.4%, P = .001), and among patients receiving a non-beta-lactam, a greater percentage was subsequently switched to a beta-lactam (11.4% vs 25.7%, P = .022). One allergic reaction was documented during the study, which occurred in the before phase.

CONCLUSION

Multidisciplinary education and local guideline implementation led by pharmacists may improve allergy documentation and antibiotic selection in patients with reported beta-lactam allergies.

Cross-reactivity in β-Lactam Allergy

β-Lactam drugs (penicillins, amoxicillin, and cephalosporins) account for 42.6% of all severe drug-induced anaphylaxis. In this review, we focus on clinically significant immunologic cross-reactivity in patients with confirmed penicillin allergy to cephalosporins, and the structural involvement of the R₁ and R₂ chemical side chains of the cephalosporins causing IgE-mediated cross-reactivity with penicillin and other cephalosporins. Skin tests predict IgE-mediated reactions and showed cross-reactivity between penicillins and early generation cephalosporins that shared side chains, but confirmatory challenge data are lacking. Later-generation cephalosporins, which have distinct side chains, do not have any skin test cross-reactivity with penicillin/amoxicillin. There is debate as to the involvement of R₂ side chains as the antigenic determinants that cause IgE-mediated hypersensitivity with various cephalosporins. Avoidance of cephalosporins, when they are the drug of choice in a penicillin-allergic individual, results in significant morbidity that outweighs the low risk of anaphylaxis. We conclude that there is ample evidence to allow the safe use of cephalosporins in patients with isolated confirmed penicillin or amoxicillin allergy.

Feasibility, Benefits, and Limitations of a Penicillin Allergy Skin Testing Service

OBJECTIVE

To critically examine the feasibility, benefits, and limitations of an inpatient penicillin skin testing service and how pharmacists can be utilized.

DATA SOURCES

A PubMed search was performed from July 2016 through September 2016 using the following search terms: penicillin skin testing, penicillin allergy, β-lactam allergy. Additional references were identified from a review of literature citations.

STUDY SELECTION AND DATA EXTRACTION

All English-language studies assessing the use of penicillin skin testing as well as management and clinical outcomes of patients with a β-lactam allergy were evaluated.

DATA SYNTHESIS

The prevalence of people self-identifying as penicillin allergic ranges from 10% to 20% in the United States. Being improperly labeled as penicillin allergic is associated with higher health care costs, worse clinical outcomes, and an increased prevalence of multidrug-resistant infections. Penicillin skin testing can be a tool used to clarify penicillin allergies and has been demonstrated to be a successful addition to antimicrobial stewardship programs in multiple health care settings. Prior to implementing a penicillin skin testing service, institutions will need to perform a feasibility analysis of who will supply labor and accept the financial burden as well as identify if the positive benefits of a penicillin skin testing service overcome the limitations of this diagnostic test.

CONCLUSION

We conclude that institutions with high percentages of patients receiving non-β-lactams because of penicillin allergy labels would likely benefit the most from a penicillin skin testing service.

Impact of a pharmacist-driven beta-lactam allergy interview on inpatient antimicrobial therapy: A pilot project

OBJECTIVES

To determine the impact of a pharmacist-driven beta-lactam allergy interview on antimicrobial therapy.

SETTING

Tertiary care academic medical center.

PRACTICE SETTING

Clarification of beta-lactam allergy may expand treatment options for patients and potentially improve outcomes, reduce toxicity, and reduce costs.

PRACTICE INNOVATION

At our institution, a pilot service using a pharmacy resident and infectious diseases clinical pharmacist was implemented to clarify beta-lactam allergy information and, where appropriate, recommend a change to the patient's antibiotic therapy.

EVALUATION

Adult patients with a documented beta-lactam allergy who had received non-penicillin antibiotics and who had undergone a beta-lactam allergy interview were identified via pharmacy intervention data. A pharmacist interviewed these patients with the use of an internally developed allergy questionnaire. Recommendations for beta-lactam therapy were made to the patient's primary medical team based on the results of the allergy interview and factors including infection type and culture results. The primary objectives were to determine the percentage of patients successfully switched to beta-lactam therapy as a result of the drug allergy interview, to identify allergy discrepancies between the electronic medical record (EMR) and pharmacist's interview, and to quantify the acceptance rate of the pharmacist's antimicrobial recommendations after drug allergy clarification.

RESULTS

Thirty-two patients were interviewed, and 24 were candidates for a beta-lactam recommendation. As a result of the interview, 21 patients (65.6%) were successfully switched from a non-penicillin antibiotic to a cephalosporin, carbapenem, or penicillin. A discrepancy between the EMR-reported allergy and history obtained on interview was identified in 11 patients (34.4%). Medical providers accepted 87.5% of pharmacists' antimicrobial recommendations.

CONCLUSION

A pharmacist-driven beta-lactam allergy interview was effective in switching eligible patients to beta-lactam therapy and identifying discrepancies between EMR-documented allergies and confirmed allergies. Antimicrobial recommendations were well received by medical providers with a high acceptance rate.

Allergic Reactions in Hospitalized Patients With a Self-Reported Penicillin Allergy Who Receive a Cephalosporin or Meropenem

Background:

Cefepime and meropenem are used frequently in hospitalized patients for broad-spectrum empiric coverage, however, practitioners are often reluctant to prescribe these antibiotics for patients with a self-reported nonsevere, nontype I allergic reaction to penicillin.

Methods:

Retrospective review of electronic medical records of adults with a self-reported allergy to penicillin who received at least 1 dose of cefepime, ceftriaxone, cefoxitin, cephalexin, or meropenem to assess incidence and type of allergic reactions.

Results:

Of 175 patients included, 10 (6%) patients experienced an allergic reaction. The incidence for individual study drugs were cefepime 6% (6 of 96), meropenem 5% (3 of 56), cefoxitin 8% (1 of 13), ceftriaxone 0% (0 of 69), and cephalexin 0% (0 of 8). The majority of patients experienced a rash with or without pruritus and fever. Patients with a concomitant “sulfa” allergy (odds ratio [OR] 5.4, 95% confidence interval [CI] 1.4-21, P = .02) or ≥3 other drug allergies (OR 6.4, 95% CI 1.3-32, P = .025) were more likely to have an allergic reaction.

Conclusions:

In one of the largest retrospective reviews of hospitalized patients who received full dose therapy with cefepime, ceftriaxone, and meropenem, the incidence of allergic reactions was low and reactions were mild. Cefepime, ceftriaxone, and meropenem can be considered for use in patients with a self-reported nontype I penicillin allergy.

Impact of a clinical guideline for prescribing antibiotics to inpatients reporting penicillin or cephalosporin allergy

BACKGROUND

Self-reported penicillin allergy infrequently reflects an inability to tolerate penicillins. Inpatients reporting penicillin allergy receive alternative antibiotics that might be broader spectrum, more toxic, or less effective.

OBJECTIVE

To develop and assess a clinical guideline for the general inpatient provider that directs taking a history and prescribing antibiotics for patients with penicillin or cephalosporin allergy.

METHODS

A guideline was implemented to assist providers with assessing allergy history and prescribing antibiotics for patients with reported penicillin or cephalosporin allergy. The guideline used a standard 2-step graded challenge or test dose. A quasi-experimental study was performed to assess safety, feasibility, and impact on antibiotic use by comparing treatment 21 months before guideline implementation with 12 months after guideline implementation.

RESULTS

Significantly more test doses to β-lactam antibiotics were performed monthly after vs before guideline implementation (median 14.5, interquartile range 13-16.25, vs 2, interquartile range 1-3.25, P < .001). Seven adverse drug reactions occurred during guideline-driven test doses, with no significant difference in rate (3.9% vs 6.1%, P = .44) or severity (P > .5) between periods. Guideline-driven test doses decreased alternative antimicrobial therapy after the test dose, including vancomycin (68.3% vs 37.2%, P < .001), aztreonam (11.5% vs 0.5%, P < .001), aminoglycosides (6.0% vs 1.1%, P = .004), and fluoro quinolones (15.3% vs 3.3%, P < .001).

CONCLUSION

The implementation of an inpatient antibiotic prescribing guideline for patients with penicillin or cephalosporin allergy was associated with an almost 7-fold increase in the number of test doses to β-lactams without increased adverse drug reactions. Patients assessed with guideline-driven test doses were observed to have significantly decreased alternative antibiotic exposure.

Penicillin allergy and surgical prophylaxis: Cephalosporin cross-reactivity risk in a pediatric tertiary care center

BACKGROUND

First generation cephalosporins are commonly used as antibiotic prophylaxis prior to surgery. Patients labeled as penicillin-allergic are often precluded from receiving cephalosporins because of an allergic cross-reactivity. The aims of this study were to evaluate the clinical practice for surgical prophylaxis at Nationwide Children's Hospital and to determine the incidence of adverse effects and allergic reactions when using cephalosporins in patients labeled as penicillin-allergic.

METHODS

A retrospective chart review was performed to identify patients who were allergic to penicillin, penicillin antibiotic family, who required surgical treatment for an existing medical condition, and received an antibiotic to prevent surgical site infection.

RESULTS

Five hundred thirteen penicillin-allergic patients were identified, encompassing 624 surgical cases. Cephalosporins were administered in 153 cases (24.5%) with cefazolin used 83% of the time. Only one documented case of nonanaphylactic reaction was reported. Clindamycin was the most common cephalosporin substitute (n=387), and the reported adverse reaction rate was 1.5%. No cases of anaphylaxis were documented.

CONCLUSIONS

Our data suggest that the administration of cephalosporins for surgical prophylaxis following induction of anesthesia in a patient with a known or reported penicillin-allergy appears appropriate and results in a lower adverse event rate that when clindamycin is administered.

Characterization of a potential β-lactamase inhibitory metabolite from a marine Streptomyces sp. PM49 active against multidrug-resistant pathogens

Actinobacteria is a prolific producer of complex natural products; we isolated a potential marine Streptomyces sp. PM49 strain from Bay of Bengal coastal area of India. The strain PM49 exhibited highly efficient antibacterial properties on multidrug-resistant pathogens with a zone of inhibition of 14-17 mm. SSF was adopted for the production of the secondary metabolites from PM49 with ISP2; utilizing agricultural wastes for compound extraction was also attempted. Bioactive fraction of Rf value 0.69 resolved using chloroform and ethyl acetate (1:1, v/v) was obtained and subjected to further analysis. Based on UV, IR, ESI-MS, and (1)H and (13)C NMR spectral analysis, it was revealed that the compound is closely similar to cyslabdan with a molecular mass of 467.66 corresponding to the molecular formula C25H41NO5S. ESBL and MBL production was screened in the hospital test isolates of Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, and Staphylococcus aureus. PCR amplification in the phenotypically positive strains was positive for bla IMP, bla SHV, bla CTX-M, and mec genes. The β-lactamase enzyme from tested strains had cephalosporinase activity with a 31-kDa protein and isolated compound from the strain possessing β-lactamase inhibitory potential. MIC of the active fraction was 16-32 μg/ml on ATCC strains; the ceftazidime and meropenem sensitive and resistant test strains showed MIC of 64-256 μg/ml. The Streptomyces sp. PM49 aerial mycelium was rectiflexibile; the 16S rRNA showed 99 % identity with Streptomyces rochei and submitted at Genbank with accession no JX904061.1.

Beta-Lactam Hypersensitivity and Cross-Reactivity

Penicillin is the most frequently reported cause of drug allergy, and cross-reactivity of penicillins with other beta-lactam antibiotics is an area of debate. This review evaluates the available data on immunoglobulin E-mediated penicillin hypersensitivity and cross-reactivity with cephalosporin, carbapenem, and monobactam antibiotics. A MEDLINE search was conducted from 1950 to October 2013, and selected references from review articles were also evaluated. There is a wide variety in reported incidences of cross-reactivity between penicillins and cephalosporins or carbapenems, with early retrospective studies suggesting up to 41.7% and 47.4% cross-reactivity, respectively. Conversely, the use of monobactam antibiotics is frequently employed in the case of a penicillin allergy, as prescribers believe that there is no cross-reactivity between the 2 drug classes. More recent prospective studies suggest that the rates of cross-reactivity with cephalosporins and carbapenems are <5% and <1%, respectively. Similarities in penicillin and cephalosporin side chains may play a role in cross-reactivity between these classes. Cross-reactivity with monobactams is essentially negligible; however, there are some clinical data to support an interaction between ceftazidime and aztreonam, due to the similarity of their side chains. The data reviewed suggest that avoidance of other beta-lactams in patients with type 1 hypersensitivity to penicillins should be reconsidered.

Comprehensive identification of single nucleotide polymorphisms associated with beta-lactam resistance within pneumococcal mosaic genes

Traditional genetic association studies are very difficult in bacteria, as the generally limited recombination leads to large linked haplotype blocks, confounding the identification of causative variants. Beta-lactam antibiotic resistance in Streptococcus pneumoniae arises readily as the bacteria can quickly incorporate DNA fragments encompassing variants that make the transformed strains resistant. However, the causative mutations themselves are embedded within larger recombined blocks, and previous studies have only analysed a limited number of isolates, leading to the description of “mosaic genes” as being responsible for resistance. By comparing a large number of genomes of beta-lactam susceptible and non-susceptible strains, the high frequency of recombination should break up these haplotype blocks and allow the use of genetic association approaches to identify individual causative variants. Here, we performed a genome-wide association study to identify single nucleotide polymorphisms (SNPs) and indels that could confer beta-lactam non-susceptibility using 3,085 Thai and 616 USA pneumococcal isolates as independent datasets for the variant discovery. The large sample sizes allowed us to narrow the source of beta-lactam non-susceptibility from long recombinant fragments down to much smaller loci comprised of discrete or linked SNPs. While some loci appear to be universal resistance determinants, contributing equally to non-susceptibility for at least two classes of beta-lactam antibiotics, some play a larger role in resistance to particular antibiotics. All of the identified loci have a highly non-uniform distribution in the populations. They are enriched not only in vaccine-targeted, but also non-vaccine-targeted lineages, which may raise clinical concerns. Identification of single nucleotide polymorphisms underlying resistance will be essential for future use of genome sequencing to predict antibiotic sensitivity in clinical microbiology.

Streptococcus pneumoniae is carried asymptomatically in the nasopharyngeal tract. However, it is capable of causing multiple diseases, including pneumonia, bacteraemia and meningitis, which are common causes of morbidity and mortality in young children. Antibiotic treatment has become more difficult, especially that involving the group of beta-lactam antibiotics where resistance has developed rapidly. The organism is known to be highly recombinogenic, and this allows variants conferring beta-lactam resistance to be readily introduced into the genome. Identification of the specific genetic determinants of beta-lactam resistance is essential to understand both the mechanism of resistance and the spread of resistant variants in the pneumococcal population. Here, we performed a genome-wide association study on 3,701 isolates collected from two different locations and identified candidate variants that may explain beta-lactam resistance as well as discriminating potential genetic hitchhiking variants from potential causative variants. We report 51 loci, containing 301 SNPs, that are associated with beta-lactam non-susceptibility. 71 out of 301 polymorphic changes result in amino acid alterations, 28 of which have been reported previously. Understanding the determinants of resistance at the single nucleotide level will be important for the future use of sequence data to predict resistance in the clinical setting.

Anaphylaxis avoidance and management: educating patients and their caregivers

Anaphylaxis is an increasingly prevalent problem in westernized countries. Therefore, it is of utmost importance that the increasing numbers of patients at risk for anaphylaxis receive proper education on the etiology and risk factors as well as appropriate treatment of anaphylaxis with epinephrine. The physician’s role is crucial in order to educate the patients and care takers on effective measures to prevent anaphylaxis and empower them to take charge of early recognition and proper management of an anaphylactic reaction to prevent poor outcomes. This review summarizes the clinical presentation, triggers, avoidance, and management of anaphylaxis.

Acute rhinosinusitis in children

Acute rhinosinusitis in children is a common disorder that is characterized by some or all of the following symptoms: fever, rhinorrhea, nasal congestion, cough, postnasal drainage, and facial pain/headache. It often starts as an upper respiratory tract infection that is complicated by a bacterial infection in which the symptoms worsen, persist, or are particularly severe. The accurate diagnosis of acute rhinosinusitis is challenging because of the overlap of symptoms with other common diseases, heavy reliance on subjective reporting of symptoms by the parents, and difficulties related to the physical examination of the child. Antibiotics are the mainstay of treatment. There is no strong evidence for the use of ancillary therapy. Orbital and intracranial complications may occur and are best treated early and aggressively. This article reviews the diagnosis, pathophysiology, bacteriology, treatment, and complications of acute rhinosinusitis in children.

Effect of a drug allergy educational program and antibiotic prescribing guideline on inpatient clinical providers' antibiotic prescribing knowledge

BACKGROUND

Inpatient providers have varying levels of knowledge in managing patients with drug and/or penicillin (PCN) allergy.

OBJECTIVES

Our objectives were (1) to survey inpatient providers to ascertain their baseline drug allergy knowledge and preparedness in caring for patients with PCN allergy, and (2) to assess the impact of an educational program paired with the implementation of a hospital-based clinical guideline.

METHODS

We electronically surveyed 521 inpatient providers at a tertiary care medical center at baseline and again 6 weeks after an educational initiative paired with clinical guideline implementation. The guideline informed providers on drug allergy history taking and antibiotic prescribing for inpatients with PCN or cephalosporin allergy.

RESULTS

Of 323 unique responders, 42% (95% CI, 37-48%) reported no prior education in drug allergy. When considering those who responded to both surveys (n = 213), we observed a significant increase in knowledge about PCN skin testing (35% vs 54%; P < .001) and loss of PCN allergy over time (54% vs 80%; P < .0001). Among those who reported attending an educational session (n = 62), preparedness to determine if an allergy was severe significantly improved (77% vs 92%; P = .03). Other areas, including understanding absolute contraindications to receiving a drug again and PCN cross-reactivity with other antimicrobials, did not improve significantly.

CONCLUSIONS

Inpatient providers have drug allergy knowledge deficits but are interested in tools to help them care for inpatients with drug allergies. Our educational initiative and hospital guideline implementation were associated with increased PCN allergy knowledge in several crucial areas. To improve care of inpatients with drug allergy, more research is needed to evaluate hospital policies and sustainable educational tools.