Cross-Reactivity and Tolerability of Cephalosporins in Patients with IgE-Mediated Hypersensitivity to Penicillins

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.

Quality corner: Safely using cephalosporins in almost all patients with penicillin allergies: Mini-review and suggested protocol to improve efficacy and surgical outcomes

Surgical site infections (SSI) are one of the most common gynecologic oncology postoperative complications and they have a significant deleterious impact on the healthcare system and in patients' outcomes. Cefazolin is the recommended antibiotic in women undergoing gynecologic surgical procedures that require that require prophylaxis. However, 10-20% of patients may report a penicillin allergy which can result in administration of a less effective antibiotic. This quality review evaluated the literature around this common perioperative issue and demonstrated that healthcare teams should consider the implementation of a protocol to safely use cefazolin in most patients with a penicillin allergy. Overall, literature shows this is a safe adjustment and would improve antimicrobial stewardship, decrease SSI rates, avoid acute kidney injury, and increase cost savings.

Is Penicillin Allergy a Clinical Problem? A Systematic Review of Total Joint Arthroplasty Procedures With Implications for Patient Safety and Antibiotic Stewardship

BACKGROUND

Patients undergoing total joint arthroplasty (TJA) who report penicillin allergy (PA) are frequently administered second-line antibiotics, although recent evidence suggests that this may be unnecessary and could increase infection risk. Many institutions have aimed to improve antibiotic deployment via allergy testing and screening; however, there is little standardization to this process. This review aimed to evaluate (1) antibiotic selection in patients who report PA and assess the impact of screening and testing interventions, (2) rates of allergic reactions in patients who report PA, and (3) the association between reported PA and screening or testing programs and odds of surgical site infection or periprosthetic joint infection.

METHODS

PubMed, EBSCOhost, and Google Scholar electronic databases were searched on February 4, 2023 to identify all studies published since January 1, 2000 that evaluated the impact of PA on patients undergoing TJA (PROSPERO study protocol registration: CRD42023394031). Articles were included if full-text manuscripts in English were available, and the study analyzed the impact of PA and related interventions on TJA patients. There were 11 studies evaluating 1,276,663 patients included. Interventions were compared via presentation of key findings regarding rates of clinically relevant or high-risk PA reported upon screenings or testings, cephalosporin utilizations, allergic reactions, and postoperative infections (surgical site infection and periprosthetic joint infection).

RESULTS

All 6 studies found that PA screening and testing markedly increase the use of first-line antibiotics. Testing showed low rates of true allergy (0.7 to 3%) and allergic reaction frequency for patients who have reported PA receiving cephalosporins was between 0% and 2%. Although there were mixed findings across studies, there was a trend toward second-line antibiotic prophylaxis being associated with a slightly higher rate of infection in PA patients.

CONCLUSIONS

Using PA screening and testing can promote antibiotic stewardship by safely increasing the use of first-line antibiotics in patients who have a reported PA.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Patient Adherence to Written Instructions following Complete Allergological Evaluation for Suspected Beta-Lactam Allergy: A Tertiary Hospital Study in Greece

BACKGROUND

Beta-lactam (BL) antibiotics are among the most prescribed groups of drugs worldwide and have been implicated in a variety of allergic reactions. There is a paucity of literature regarding patient adherence to prescribed instructions following comprehensive allergy assessments.

OBJECTIVE

The objective was to follow up the clinical course of BL allergy in patients who underwent thorough allergological investigation for suspected BL allergy at a tertiary hospital and ascertain patients' compliance with the provided written instructions.

MATERIALS

An observational study in patients referred for suspected BL allergy who underwent a comprehensive allergy workup (in vivo ± in vitro tests, DPT in culprit and/or alternative BL) and who subsequently received written instructions was conducted. Data on the nature of the reported drug hypersensitivity reaction, the culprit BL drug, the allergological workup, and the detailed instructions provided in a written drug allergy report were collected retrospectively. Patients' compliance with the instructions was recorded by a telephone survey using a pre-defined questionnaire.

RESULTS

Among the 212 patients meeting the inclusion criteria, 87 patients (72.4% women; mean age 50.1 years; age range 6-84 years) responded to the telephone survey and were included in this study. Surprisingly, 45 out of 87 (51.7%) patients did not adhere to the written instructions. The primary factor contributing to non-compliance was the fear of re-occurrence of a drug-induced allergic reaction (personal and/or triggered by their treating physician reluctance), accounting for 77.7% of cases. The analysis demonstrated that the initial reaction's severity and type, as well as the outcomes of skin testing, did not correlate with compliance to instructions (p > 0.05). Surprisingly enough, a drug provocation test (DPT), irrespectively of the result, emerged as a negative predictor for adherence, with only 40.6% of DPT patients complying compared to 77.8% of those who did not undergo DPT (p = 0.005; odds ratio = 0.195; 95% confidence interval: 0.058-0.655). Variables such as performing DPT with alternative or incriminated drugs or the result of the DPT (positive-negative) were not associated with patient compliance. Conversely, the type of instructions provided exhibited a noteworthy correlation with compliance. Patients who were explicitly instructed to entirely avoid all BL antibiotics demonstrated markedly higher adherence rates (83.3%) compared to those who were advised to have a partial or complete release of BLs (31.8% and 58.1%, respectively; p < 0.05). Notably, among compliant patients who received either the original culprit drug or the alternative (32 out of 87, 36.7%), no allergic reactions were reported. In contrast, among the 12 patients with written avoidance of all BLs, subsequent BL intake led to immediate reactions (Grade I and IV) in 2 patients (16.6%).

CONCLUSIONS

A notable disparity in patient adherence to written instructions prohibiting or releasing beta-lactams was demonstrated. Less than half of the patients ultimately complied with the provided instructions, underscoring the need for tailored patients' education and strategies to improve adherence in the management of suspected BL allergy.

Use of single agent Cefotetan for Gustilo-Anderson type III open fracture prophylaxis

INTRODUCTION

The prophylactic intravenous antibiotic regimen for Gustilo-Anderson Type III open fractures traditionally consists of cefazolin with an aminoglycoside plus penicillin for gross contamination. Cefotetan, a second-generation cephalosporin, offers a wide spectrum of activity against both aerobes and anaerobes as well as against Gram-positive and Gram-negative bacteria. Cefotetan has not been previously established within orthopedic surgery as a prophylactic intravenous agent.

PATIENTS AND METHODS

Cefotetan monotherapeutic prophylaxis versus any other antibiotic regimen (standard/literature-supported and otherwise) was studied for patient encounters between September 2010 and December 2019 within a single Level 1 regional trauma center. Patient comorbidities, preoperative fracture characteristics, and in-hospital/operative metrics (including length of stay [LOS], number of antibiotic doses, and antibiotic costs [US$]) were included for analysis. Postoperative outcomes up to 1 year included rates of surgical site infection (SSI), deep infection necessitating return to the operating room (OR), non-union, prescribed outpatient antibiotics, hospital readmissions, and related returns to the emergency department (ED). Sensitivity analyses were also conducted to include standard/literature-supported antibiotic regimens as a nested random factor within the non-cefotetan cohort.

RESULTS

The nested variable accounting for standard/literature-supported antibiotic regimens had no significant effect in any model for any outcome (for each, P ≥ 0.302). Thus, 1-year data for 138 Type III open fractures were included, accounting for only the binary effect of cefotetan (n = 42) versus non-cefotetan cohorts. The cohorts did not differ significantly at baseline. The cefotetan cohort received fewer in-house dose/day antibiotics (P < 0.001), was less likely to receive outpatient antibiotics in the following year (P = 0.023), had decreased return to the OR (35.7% versus 54.2%, P = 0.045), and demonstrated non-union rates of 16.7% versus 28.1% (P = 0.151). When adjusted for length of stay (LOS), the dose/day total costs for antibiotics were $8.71/day more expensive for the cefotetan cohort (P = 0.002). Type III open fractures incurred overall rates of SSI reaching 16.7% in the cefotetan cohort and 14.7% for non-cefotetan (P = 0.773). Deep infections necessitating return to the OR were 9.5% and 11.6%, respectively (P = 0.719).

CONCLUSION

Cefotetan alone may provide superior antibiotic stewardship with similar infectious sequalae compared to more traditional antibiotic prophylaxis regimens for Gustilo-Anderson Type III open long bone fractures.

LEVEL OF EVIDENCE

Level III Retrospective Cohort Study.

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.

Cefazolin vs Second-line Antibiotics for Surgical Site Infection Prevention After Total Joint Arthroplasty Among Patients With a Beta-lactam Allergy

Background

Cefazolin is a first-line agent for prevention of surgical site infections (SSIs) after total joint arthroplasty. Patients labeled allergic to beta-lactam antibiotics frequently receive clindamycin or vancomycin perioperatively due to the perceived risk of a hypersensitivity reaction after exposure to cefazolin.

Methods

This single-system retrospective review included patients labeled allergic to penicillin or cephalosporin antibiotics who underwent a primary total hip and/or knee arthroplasty between January 2020 and July 2021. A detailed chart review was performed to compare the frequency of SSI within 90 days of surgery and interoperative hypersensitivity reactions (HSRs) between patients receiving cefazolin and patients receiving clindamycin and/or vancomycin.

Results

A total of 1128 hip and/or knee arthroplasties from 1047 patients were included in the analysis (cefazolin n = 809, clindamycin/vancomycin n = 319). More patients in the clindamycin and/or vancomycin group had a history of cephalosporin allergy and allergic reactions with immediate symptoms. There were fewer SSIs in the cefazolin group compared with the clindamycin and/or vancomycin group (0.9% vs 3.8%; P < .001) including fewer prosthetic joint infections (0.1% vs 1.9%). The frequency of interoperative HSRs was not different between groups (cefazolin = 0.2% vs clindamycin/vancomycin = 1.3%; P = .06).

Conclusions

The use of cefazolin as a perioperative antibiotic for infection prophylaxis in total joint arthroplasty in patients labeled beta-lactam allergic is associated with decreased postoperative SSI without an increase in interoperative HSR.

Six Long-Standing Questions about Antibiotic Prophylaxis in Surgery

Surgical site infections (SSIs) are the most common adverse event occurring in surgical patients. Optimal prevention of SSIs requires the bundled integration of a variety of measures before, during, and after surgery. Surgical antibiotic prophylaxis (SAP) is an effective measure for preventing SSIs. It aims to counteract the inevitable introduction of bacteria that colonize skin or mucosa into the surgical site during the intervention. This document aims to guide surgeons in appropriate administration of SAP by addressing six key questions. The expert panel identifies a list of principles in response to these questions that every surgeon around the world should always respect in administering SAP.

Prevalence, Antibiotic Susceptibility Profile and Associated Factors of Group A Streptococcal pharyngitis Among Pediatric Patients with Acute Pharyngitis in Gondar, Northwest Ethiopia

Background

Streptococcus pyogenes (S. pyogenes) or group A streptococcus is a common cause of bacterial pharyngitis in children. Since it is difficult to distinguish between viral and bacterial pharyngitis using solely signs and symptoms, culture-based diagnosis and treatment are critical for avoiding serious complications. Therefore, this study aimed to determine the prevalence, antimicrobial susceptibility patterns, and associated factors of S. pyogenes among pediatric patients with acute pharyngitis.

Methods

A hospital-based cross-sectional study was conducted at the University of Gondar Comprehensive Specialized Hospital from April to June 2021. Standard microbiological procedures were used to collect and process throat swabs and to isolate and identify S. pyogenes. The disc diffusion method was used for antimicrobial susceptibility testing (AST).

Results

A total of 215 children with acute pharyngitis were included in this study. Of these, 23 (10.7%) were culture positive for S. pyogenes. The presence of an inflamed tonsil, tonsillar exudate, scalariform rash, and dysphagia were associated with streptococcal pharyngitis. Children aged 5 to 15 were more susceptible to streptococcal throat infection than younger children. Penicillin, vancomycin, chloramphenicol, clindamycin, and ceftriaxone were effective against 100%, 95.7%, 95.7%, 91%, and 87% of isolates, respectively. In contrast, 56.5%, 39.1%, and 30.4% of isolates showed at least reduced susceptibility to tetracycline, erythromycin, and azithromycin, respectively.

Conclusion

Streptococcus pyogenes is responsible for 10.7% of acute pharyngitis cases among pediatric patients in the study area. Although all isolates remain sensitive to penicillin, many showed reduced susceptibility to tetracycline and macrolides. Therefore, prior to antibiotic prescription, screening children with acute pharyngitis for S. pyogenes and testing the antibiotic susceptibility of isolates is recommended.

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.

CROSS-REACTIVITY TO ANTIBIOTICS: PROPOSITIONS FOR SELECTING ALTERNATIVES

OBJECTIVE

The aim: To analyze CR among antibacterials of different classes and to overcome some widespread misconceptions regarding CR between different classes of antibiotics.

PATIENTS AND METHODS

Materials and methods: The narrative review represents an assessment of the most pertinent literary sources published in English language, which dealt with the issues of cross-reactivity between individual antibiotics and different classes of these ones.

CONCLUSION

Conclusions: With a high probability of type I AR in a patient in the past, it is better to plan the treatment of patients together with an allergist / immunologist. If this probability is estimated to be low, the choice of a particular antibiotic may be based to some extent on CR data.

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

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

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

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

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

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.

The Chemical Relationship Among Beta-Lactam Antibiotics and Potential Impacts on Reactivity and Decomposition

Beta-lactam antibiotics remain one of the most commonly prescribed drug classes, but they are limited by their propensity to cause hypersensitivity reactions (e.g., from allergy to anaphylaxis) as well as by the emergence of bacteria with a myriad of resistance mechanisms such as β-lactamases. While development efforts continue to focus on overcoming resistance, there are ongoing concerns regarding cross-contamination of β-lactams during manufacturing and compounding of these drugs. Additionally, there is a need to reduce levels of drugs such as β-lactam antibiotics in waste-water to mitigate the risk of environmental exposure. To help address future development of effective remediation chemistries and processes, it is desired to better understand the structural relationship among the most common β-lactams. This study includes the creation of a class-wide structural ordering of the entire β-lactam series, including both United States Food and Drug Association (US-FDA)-approved drugs and experimental therapies. The result is a structural relational map: the “Lactamome,” which positions each substance according to architecture and chemical end-group. We utilized a novel method to compare the structural relationships of β-lactam antibiotics among the radial cladogram and describe the positioning with respect to efficacy, resistance to hydrolysis, reported hypersensitivity, and Woodward height. The resulting classification scheme may help with the development of broad-spectrum treatments that reduce the risk of occupational exposure and negative environmental impacts, assist practitioners with avoiding adverse patient reactions, and help direct future drug research.

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.

Diagnosis and Treatment of Sexually Transmitted Infections: A Review

IMPORTANCE

Approximately 1 in 5 adults in the US had a sexually transmitted infection (STI) in 2018. This review provides an update on the epidemiology, diagnosis, and treatment of gonorrhea, chlamydia, syphilis, Mycoplasma genitalium, trichomoniasis, and genital herpes.

OBSERVATIONS

From 2015 to 2019, the rates of gonorrhea, chlamydia, and syphilis increased in the US; from 1999 to 2016, while the rates of herpes simplex virus type 1 (HSV-1) and HSV-2 declined. Populations with higher rates of STIs include people younger than 25 years, sexual and gender minorities such as men and transgender women who have sex with men, and racial and ethnic minorities such as Black and Latinx people. Approximately 70% of infections with HSV and trichomoniasis and 53% to 100% of extragenital gonorrhea and chlamydia infections are asymptomatic or associated with few symptoms. STIs are associated with HIV acquisition and transmission and are the leading cause of tubal factor infertility in women. Nucleic acid amplification tests have high sensitivities (86.1%-100%) and specificities (97.1%-100%) for the diagnosis of gonorrhea, chlamydia, M genitalium, trichomoniasis, and symptomatic HSV-1 and HSV-2. Serology remains the recommended method to diagnose syphilis, typically using sequential testing to detect treponemal and nontreponemal (antiphospholipid) antibodies. Ceftriaxone, doxycycline, penicillin, moxifloxacin, and the nitroimidazoles, such as metronidazole, are effective treatments for gonorrhea, chlamydia, syphilis, M genitalium, and trichomoniasis, respectively, but antimicrobial resistance limits oral treatment options for gonorrhea and M genitalium. No cure is available for genital herpes. Effective STI prevention interventions include screening, contact tracing of sexual partners, and promoting effective barrier contraception.

CONCLUSIONS AND RELEVANCE

Approximately 1 in 5 adults in the US had an STI in 2018. Rates of gonorrhea, chlamydia, and syphilis in the US have increased, while rates of HSV-1 and HSV-2 have declined. Ceftriaxone, doxycycline, penicillin, moxifloxacin, and the nitroimidazoles are effective treatments for gonorrhea, chlamydia, syphilis, Mycoplasma genitalium, and trichomoniasis, respectively, but antimicrobial resistance limits oral therapies for gonorrhea and Mycoplasma genitalium, and no cure is available for genital herpes.

Understanding Penicillin Allergy, Cross-reactivity, and Antibiotic Selection in the Preoperative Setting

Penicillin allergies are reported by 8% to 15% of the US population, but up to 95% of these allergies do not correspond to a true allergy when tested. Recent studies have demonstrated that having a penicillin allergy label (PAL) results in a 50% increased odds of surgical site infection among patients reporting a penicillin allergy entirely attributable to the use of a beta-lactam alternative antibiotic (primarily clindamycin or vancomycin). This study provides a review of the prevalence of PAL, the cross-reactivity with cefazolin, immunogenic components of cefazolin and penicillin, and current guidelines for preoperative antibiotic selection in patients with PALs. On understanding these principles, a new set of guidelines and a risk stratification tool are proposed for assessing allergies and determining appropriate antibiotic choice, dosage, and timing in the orthopaedic preoperative setting.

A Simple Algorithmic Approach Allows the Safe Use of Cephalosporin in "Penicillin-Allergic" Patients without the Need for Allergy Testing

BACKGROUND

Patients who report a penicillin allergy are often given second-line antibiotic prophylaxis during total joint arthroplasty (TJA), with only a minority of patients undergoing additional consultations and allergy testing. In an effort to increase the use of cephalosporin prophylaxis in TJA, the present study aimed to assess the effectiveness of a simple, protocol-driven penicillin allergy screening program without the need for additional work-up.

METHODS

Following implementation of a questionnaire-based screening protocol in May 2019, all patients scheduled for primary TJA were risk-stratified into low or high-risk categories. The low-risk cohort received cefazolin, and the high-risk cohort received non-cefazolin antibiotics. Patients were monitored prospectively, and data on antibiotic usage and adverse outcomes were documented. The protocol group (n = 2,078) was propensity score matched 1:1 with a control group that included patients who underwent TJA in the same institution prior to implementation of the protocol. The primary end point was the efficacy of the protocol in reducing unnecessary use of non-cephalosporin antibiotics for prophylaxis. Secondary outcomes included the rate of surgical site infections and allergic reactions to the administered antibiotic.

RESULTS

A total of 357 patients (17.2%) reported a penicillin allergy in the protocol group compared with 310 patients (14.9%) with a recorded allergy in the control group (p = 0.052). The number of patients who received non-cephalosporin antibiotics was significantly lower in the protocol group (5.7% compared with 15.2% in the control group; p < 0.001), whereas there was no difference in the rate of total allergic reactions (0.8% compared with 0.7%, respectively; p = 0.857). Of the 239 low-risk patients (66.9%) in the protocol group, only 3 (1.3%) experienced a mild cutaneous reaction following cefazolin administration. There were no differences in the rates of superficial wound, deep periprosthetic, or Clostridioides difficile infections between the protocol and control groups.

CONCLUSIONS

A simple screening protocol allowed two-thirds of patients with a self-reported allergy to receive cefazolin without the need for additional consultations or testing. We believe this protocol can be safely implemented to increase the rate of cefazolin usage without a corresponding increase in the number of allergic reactions.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Immediate and Delayed Hypersensitivity Reactions to Beta-Lactam Antibiotics

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

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.

Urticaria: The 1-1-1 Criterion for Optimized Risk Atratification in β-Lactam Allergy Delabeling

BACKGROUND

A spurious label of β-lactam allergy compromises antibiotic stewardship. Delabeling protocols based on direct challenges (ie, not preceded by allergy tests) can be applied in low-risk patients.

OBJECTIVE

This study aims at determining the significance of the characteristics of urticaria in the risk stratification for delabeling.

METHODS

The characteristics of urticarial eruptions that had occurred during therapeutic courses with a β-lactam, namely the time interval between the exposure and onset, the dose (first or subsequent) after which urticaria appeared, and the duration of the eruption, were correlated to the results of a systematic allergy workup (skin tests, specific IgE measurements, and challenges). Data from 410 patients enrolled in 3 allergy centers (Rome and Troina, Italy, and Antwerp, Belgium) were analyzed. A multivariable logistic regression was performed, which included appearance within 1 hour after the first dose and regression within 1 day: a model that can be summarized as the "1-1-1" urticaria criterion.

RESULTS

An urticarial eruption that had appeared within 1 hour after the first dose and had regressed within 1 day was more frequently reported in the group with a positive allergy workup, with odds ratios of 17 (95% confidence interval [CI]: 9-31), 11 (95% CI: 6-20), and 48 (95% CI: 14-157), respectively (P < .005). The 1-1-1 criterion displayed a sensitivity and specificity of 85%, and a negative predictive value and a positive predictive value of 80% and 90%, respectively.

CONCLUSION

Patients with urticaria meeting the 1-1-1 criterion should be considered at high risk and referred for an allergy workup with skin testing and specific IgE measurement before challenging.

β-lactam exposure outcome among patients with a documented allergy to penicillins post-implementation of a new electronic medical record system and alerting rules

BACKGROUND

Recent studies suggest that type I hypersensitivity cross-reactivity between β-lactam antibiotics is due to side chain similarity and not the common β-lactam ring. As a result, the prescriber-alerting rules of an electronic medical record (EMR) system were adjusted to only flag prescribers when prescribing penicillins or β-lactams with similar side chains (viz, cephalexin, cefadroxil, and cefoxitin) to patients with a documented allergy to penicillins. This study was conducted to assess and confirm the safety of the adjusted alerting rules; the primary outcome was the prevalence of anaphylaxis on β-lactam re-exposure.

METHODS

Retrospective chart review was conducted for patients who, under the reformed alerting rules, received a β-lactam antibiotic post-documentation of an allergy to penicillins in their EMR from April 2018 to July 2019 at a 268-bed community hospital. Given the volume of eligible patients, a 25% sample was randomly selected for review from initiation of the β-lactam antibiotic up to 30 days post-exposure to determine the prevalence of anaphylaxis.

RESULTS

Of the 325 charts reviewed, 300 patients (92.3%) received a β-lactam antibiotic with a different side chain than penicillins (not alerted on prescribing). Chart review of these 300 patients confirmed no reports of anaphylaxis secondary to β-lactam exposure (0%), and two patients developed non-anaphylactic delayed reactions (rash).

CONCLUSIONS

There were no reports of immediate life-threatening anaphylaxis under the reformed alerting rules, despite 25 patients (7.7%) receiving an alerted drug, such as piperacillin-tazobactam. The reformed alerting rules better reflect current literature and reduce the risk of prescriber-alerting fatigue without compromising patient safety. The occurrence of delayed reactions reinforced the need to monitor for these reactions on β-lactam antibiotic prescribing.

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.

Middle-East OBGYN Graduate Education (MOGGE) Foundation practice guidelines: prevention of group B Streptococcus infection in pregnancy and in newborn. Practice guideline no. 02-O-20

Rectovaginal colonization with group B streptococcus (GBS) is commonly encountered in pregnancy. GBS is the most common cause of early onset neonatal sepsis, which is associated with 12% case-fatality rate. Although screening protocols and prophylactic treatment are readily available worldwide, practice in low-resource countries is challenged by lack of awareness and limited implementation of these protocols. In addition, antibiotic susceptibility pattern may vary globally owing to different regulations of antibiotic prescription or prevalence of certain bacterial serotypes. This guideline appraises current evidence on screening and management of GBS colonization in pregnancy particularly in low-resource settings.

Induction of penicillin tolerance during pregnancy: Allergological opinion on the recommendation of the current AWMF Guidelines on Diagnosis and Treatment of Syphilis (AWMF Registry No. 059-002)

Not available.

β-Lactam Allergy and Cross-Reactivity: A Clinician's Guide to Selecting an Alternative Antibiotic

β-Lactams which include penicillins, cephalosporins, carbapenems, and monobactams are the most common antibiotic classes reported to cause allergic reactions to drugs. This review is mainly about published studies assessing the cross-reactivity among β-lactams in penicillin- or cephalosporin-allergic subjects by carrying out diagnostic tests with alternative β-lactams and, if appropriate, graded challenges. Several studies demonstrated that cross-reactivity connected with the β-lactam ring, causing positive responses to allergy tests with all β-lactams, is infrequent in subjects with an IgE-mediated allergy and anecdotal in those with a T-cell-mediated allergy. Identities or similarities of β-lactam side-chain structures are mainly responsible for cross-reactivity among these antibiotics. For example, in aminopenicillin-allergic subjects, cross-reactivity with aminocephalosporins could possibly be over 30%. On the other hand, in a few prospective studies of penicillin-allergic individuals, less than 1% of cases show a cross-reactivity between penicillins and both aztreonam and carbapenems. Particular patterns of allergy-test positivity observed in some studies that assessed cross-reactivity among β-lactams seem to indicate that prior exposures may be responsible for coexisting sensitivities. Therefore, pre-treatment skin tests with the related β-lactams are suggested before administering them via graded challenges to β-lactam-allergic patients who need alternative β-lactams.

Penicillin and cephalosporin cross-reactivity: role of side chain and synthetic cefadroxil epitopes

BACKGROUND

Analysis of cross-reactivity is necessary for prescribing safe cephalosporins for penicillin allergic patients. Amoxicillin (AX) is the betalactam most often involved in immediate hypersensitivity reactions (IHRs), and cefadroxil (CX) the most likely cephalosporin to cross-react with AX, since they share the same R1 side chain, unlike cefuroxime (CO), with a structurally different R1. We aimed to analyse cross-reactivity with CX and CO in patients with confirmed IHRs to AX, including sIgE recognition to AX, CX, CO, and novel synthetic determinants of CX.

METHODS

Fifty-four patients with confirmed IHRs to AX based on skin test (ST) and/or drug provocation test (DPT) were included. Serum sIgE to AX and benzylpenicillin was determined by Radioallergosorbent test (RAST). Two potential determinants of CX, involving intact or modified R1 structure, with open betalactam ring, were synthesised and sIgE evaluated by RAST inhibition assay.

RESULTS

Tolerance to CX (Group A) was observed in 64.8% cases and cross-reactivity in 35.2% cases (Group B). Cross-reactivity with CO was only found in 1.8% cases from Group B. ST to CX showed a negative predictive value of 94.6%. RAST inhibition assays showed higher recognition to CX as well as to both synthetic determinants (66% of positive cases) in Group B.

CONCLUSIONS

Cross-reactivity with CX in AX allergic patients is 35%, being ST not enough for prediction. R1, although critical for recognition, is not the unique factor. The synthetic determinants of CX, 1-(HOPhG-Ser-Bu) and 2-(pyrazinone) are promising tools for determining in vitro cross-reactivity to CX in AX allergic patients.

Outcomes of Infectious Endophthalmitis in Patients with Systemic Antibiotic Allergies to Penicillins, Cephalosporins, or Vancomycin

PURPOSE

The mainstay empiric treatments of bacterial endophthalmitis are intravitreal vancomycin and ceftazidime. In the United States, up to 10% of the general population has a reported penicillin (PCN) allergy. Despite low cross-reactivity between PCN and later-generation cephalosporins, some providers alter the intravitreal antibiotic choice for endophthalmitis because of concern for allergic reactions. We evaluated the management strategies of infectious endophthalmitis in the setting of self-reported systemic antibiotic allergies and the association with adverse reactions after standard intravitreal antibiotic administration.

DESIGN

Single-center, retrospective cohort study.

PARTICIPANTS

All patients with endophthalmitis between 2005 and 2019 and documented PCN, PCN-analog, cephalosporin, or vancomycin allergy who received intravitreal antibiotics on the basis of International Classification of Diseases 9th and 10th Revisions, and Current Procedural Terminology codes.

METHODS

Retrospective chart review.

MAIN OUTCOME MEASURES

Any allergic reaction after intravitreal injection, additional surgical interventions required for treatment, and visual function at last recorded visit.

RESULTS

Of the 65 patients included in this cohort, the most common causes of endophthalmitis were postcataract extraction surgery (n = 23, 35.4%) and postintravitreal injection (n = 11, 16.9%). All patients (65/65) received intravitreal vancomycin, and 81.5% (53/65) received intravitreal ceftazidime. Of the 53 patients who received intravitreal ceftazidime, 46 (86.8%) had allergies to PCNs alone, 5 (9.4%) had a cephalosporin allergy alone, and 2 (3.8%) had reported allergies to both PCN and cephalosporin antibiotics. Two patients (3.1%) with a documented vancomycin allergy received intravitreal vancomycin without complication. No patients exhibited any systemic or local allergic reactions or complications after intravitreal injection.

CONCLUSIONS

There were no documented allergic reactions in this cohort of patients with systemic antibiotic allergies who were treated for infectious endophthalmitis. Our findings are consistent with previous reports of a low allergic cross-reactivity between PCN and later-generation cephalosporins. Ophthalmologists should use evidence-based practices and a careful informed consent process when choosing intravitreal antibiotics for patients with specific antibiotic allergies. In the routine patient with suspected bacterial endophthalmitis, PCN allergy may not be an absolute contraindication to intravitreal cephalosporin use.

Practical guide for evaluation and management of beta-lactam allergy: position statement from the Canadian Society of Allergy and Clinical Immunology

The vast majority of individuals labelled as allergic are not deemed truly allergic upon appropriate assessment by an allergist. A label of beta-lactam allergy carries important risks for individual and public health. This article provides an overview of beta-lactam allergy, implications of erroneous beta-lactam allergy labels and the impact that can be provided by structured allergy assessment. We provide recommendations on how to stratify risk of beta-lactam allergy, beta lactam challenge protocols as well as management of patients at high risk of beta-lactam allergy.

Testing Strategies and Predictors for Evaluating Immediate and Delayed Reactions to Cephalosporins

BACKGROUND

Although 1% to 2% of the general population carries a cephalosporin allergy label (CAL), we lack validated testing strategies and predictors of true allergy.

OBJECTIVE

To identify cross-reactivity patterns and predictors of skin test positive (STP) in geographically disparate patients with a CAL.

METHODS

A total of 780 adult patients labeled with a CAL or penicillin allergy label (PAL) with unknown tolerance of cephalosporins identified from the Austin Hospital (Melbourne, Australia) (n = 410) and Vanderbilt University Medical Center (Nashville, TN) (n = 370) between 2014 and 2018 underwent a standardized skin testing.

RESULTS

Of 328 patients with a CAL, 29 (8.8%) tested STP to ≥1 cephalosporin(s). There were no cefazolin or ceftriaxone STP, 0 of 452 (0%), in patients with a PAL only. Of 328 patients with a CAL, 16 (4.8%) were ampicillin STP. Eleven of 16 of these patients had an initial allergy label to cephalexin. Twenty of 29 cephalosporin STP patients demonstrated tolerance to a cephalosporin with a different R1 side chain, and 8 of 14 ampicillin STP patients demonstrated tolerance to ≥1 non-amino R1 group cephalosporin. Eleven of 13 patients STP to cefazolin were skin and ingestion challenge negative to all other penicillins and cephalosporins predicted by its distinct R1/R2 groups. Seven of 15 ceftriaxone STP patients demonstrated cross-reactivity with R1-similar cephalosporins. Time since the original reaction predicted STP testing to both penicillins, adjusted odds ratio (aOR) per year 0.93 (95% confidence interval [CI]: 0.90, 0.97), and cephalosporins, aOR per year 0.71 (95% CI: 0.56, 0.90).

CONCLUSIONS

Cephalosporin cross-reactivity is based on shared R1 groupings. Increasing time since the original reaction and the presence of a PAL with unknown cephalosporin tolerance predict a lower likelihood of cephalosporin STP.

Endogenous Endophthalmitis Caused by Isolated Listeria Monocytogenes Infection

PURPOSE

The purpose of this report is to present an extremely rare case of endogenous Listeria monocytogenes endophthalmitis.

METHODS

A 72-year-old woman was diagnosed with endogenous endophthalmitis. Listeria monocytogenes was identified by culture of aqueous humor. Multiple investigations could not reveal any source of infection. An overview of other published cases is presented and a standardized treatment protocol is suggested.

RESULTS

Treatment consisted of topical therapy with antibiotics, corticosteroids, cycloplegics, and intraocular pressure-lowering agents, four intravitreal injections of vancomycin, an anterior chamber washout, intravenous amoxicillin, and eventually a pars plana vitrectomy. The inflammation subsided and the patient was discharged with a best-corrected visual acuity of 20/40.

CONCLUSION

Our study emphasizes the importance of adequate microbiological testing and initiating appropriate treatment early in the management of endogenous endophthalmitis.

Towards a more precise diagnosis of hypersensitivity to beta-lactams - an EAACI position paper

A recent survey of the European Academy of Allergy and Clinical Immunology (EAACI) Drug Allergy Interest Group (DAIG) on how European allergy specialists deal with beta-lactam (BL) hypersensitivity demonstrated a significant heterogeneity in current practice, suggesting the need to review and update existing EAACI guidelines in order to make the diagnostic procedures as safe and accurate, but also as cost-effective, as possible. For this purpose, a bibliographic search on large studies regarding BL hypersensitivity diagnosis was performed by an EAACI task force, which reviewed and evaluated the literature data using the GRADE system for quality of evidence and strength of recommendation. The updated guidelines provide a risk stratification in BL hypersensitivity according to index reaction(s), as well as an algorithmic approach, based on cross-reactivity studies, in patients with a suspicion of BL hypersensitivity and an immediate need for antibiotic therapy, when referral to an allergist is not feasible. Furthermore, the update addresses availability and concentrations of skin test (ST) reagents, ST and drug provocation test (DPT) protocols, and diagnostic algorithms and administration of alternative BL in allergic subjects. Specifically, distinct diagnostic algorithms are suggested depending on risk stratification of the patient into high and low risk based on the morphology and chronology of the reaction, immediate (ie, occurring within 1-6 hours after the last administered dose) or nonimmediate (ie, occurring more than 1 hour after the initial drug administration), and the reaction severity. Regarding the allergy workup, the main novelty of this document is the fact that in some low-risk nonimmediate reactions ST are not mandatory, especially in children. For DPT, further studies are necessary to provide data supporting the standardization of protocols, especially of those regarding nonimmediate reactions, for which there is currently no consensus.

Multiple drug allergies: Recommendations for perioperative management

Life-threatening hypersensitivity reactions are more likely to occur in patients with a history of allergy, atopy, or asthma. Hence, in a patient who presented with a history of multiple drug allergies (MDA), an allergological assessment should be performed prior to surgical procedure. Drug allergies, being one of the causes of catastrophic events occurring in the perioperative period, are of major concern to anesthesiologists. Neuromuscular blocking agents are regularly used during anesthesia and are one of the most common causes of perioperative anaphylaxis. They are estimated to be responsible for 50%-70% of perioperative hypersensitivity reactions. Antibiotics and latex represent the next two groups of drug allergy. Allergic reactions to propofol are rare with an incidence of 1:60,000 exposures. Although intraoperative drug anaphylaxis is rare, it contributes to 4.3% of deaths occurring during general anesthesia. These recommendations discuss pathophysiology of MDA, preoperative evaluation, and anesthesia considerations as well as the prevention and management of allergic reactions in anesthetized patients with a history of MDA.

Tolerability of Cefazolin and Ceftibuten in Patients with IgE-Mediated Aminopenicillin Allergy

BACKGROUND

Side-chain similarities or identities constitute the predominant factor for cross-reactivity between penicillins and cephalosporins, whereas differences in the side-chain structure seem to account for the absence of such cross-reactivity.

OBJECTIVE

We sought to assess the cross-reactivity between penicillins and 2 cephalosporins (ie, cefazolin and ceftibuten) that have side chains different from those of penicillins, as well as to evaluate the possibility of using these cephalosporins in penicillin-allergic subjects.

METHODS

We conducted a prospective study of 131 consecutive subjects who had suffered 170 immediate reactions (mostly anaphylaxis) to penicillins and had positive skin test results to at least 1 penicillin reagent. All patients underwent skin tests with cefazolin and ceftibuten. Patients with negative results were challenged with them.

RESULTS

One participant had positive skin test results to cefazolin and ceftibuten, as well as to all other reagents tested, including aztreonam and carbapenems. All 129 subjects who underwent challenges with cefazolin and ceftibuten tolerated them. One subject refused cephalosporin challenges.

CONCLUSIONS

Subjects with an IgE-mediated hypersensitivity to penicillins could be treated with cephalosporins such as cefazolin and ceftibuten, which are among the cephalosporins that have side-chain determinants different from those of penicillins. Nevertheless, in patients with such hypersensitivity who need these alternative β-lactams, pretreatment skin tests are advisable because of the possibility of coexisting sensitivities or, much less frequently, of a sensitivity to an antigenic determinant of the common β-lactam ring.