De-labeling of β-lactam allergy reduces intraoperative time and optimizes choice in antibiotic prophylaxis

Examining cefazolin utilization and perioperative anaphylaxis in patients with and without a penicillin allergy label: A cross-sectional study

STUDY OBJECTIVE

To compare the occurrence of cefazolin perioperative anaphylaxis (POA) in patients with and without a penicillin allergy label (PAL) to determine whether the prevalence of cefazolin POA differs based on the presence of a PAL.

DESIGN

Cross-sectional study.

SETTING

A large U.S. healthcare system in the Baltimore-D.C. region, July 2017 to July 2020.

PATIENTS

112,817 surgical encounters across inpatient and outpatient settings in various specialties, involving 90,089 patients. Of these, 4876 (4.3%) encounters had a PAL.

INTERVENTIONS

Perioperative cefazolin administration within 4 h before surgery to 4 h after the procedure began.

MEASUREMENTS

The primary outcome was cefazolin POA in patients with and without PALs. Potential POA cases were identified based on tryptase orders or diphenhydramine administrations within the initial cefazolin administration to 6 h postoperatively. Verification included two validation steps. The first checked for hypersensitivity reaction (HSR) documentation, and the second, led by Allergy specialists, identified POA and the probable culprit. The secondary outcome looked at cefazolin use trends in patients with a PAL, stratified by setting and specialty.

MAIN RESULTS

Of 112,817 encounters, 1421 (1.3%) had possible cefazolin HSRs. Of these, 22 (1.5%) had POA, resulting in a 0.02% prevalence. Of these, 13 (59.1%) were linked to cefazolin and 9 (40.9%) attributed to other drugs. Only one cefazolin POA case had a PAL, indicating no significant difference in cefazolin POA prevalence between patients with and without PALs (p = 0.437). Perioperative cefazolin use in patients with PALs steadily increased from 2.6% to 6.0% between 2017 and 2020, specifically in academic settings.

CONCLUSIONS

The prevalence of cefazolin POA does not exhibit significant differences between patients with and without PALs, and notably, the incidence remains remarkably low. Based on these findings, it is advisable to view cefazolin as an acceptable choice for prophylaxis in patients carrying a PAL.

Perioperative anaphylaxis and the principle of primum non nocere

Perioperative anaphylaxis is a rare and unpredictable event that continues to cause patient harm. More work is needed to decrease the risk to patients through measures to limit sensitisation, optimise management and investigation, and ensure that patients are not inadvertently re-exposed to allergens. Robust epidemiological data such as that provided by the consecutive GERAP surveys over the past 30 yr have been invaluable in defining the problem, identifying emerging allergens, acting as a catalyst for change, and stimulating research.

Eliciting the barriers and enablers towards anaesthetists giving penicillin-based antibiotic prophylaxis to low-risk patients who have had their penicillin allergy label removed as part of a preoperative delabelling process

Background

Some penicillin allergy labels can be removed by non-allergy specialists by direct oral challenge, but there is reluctance amongst anaesthetists to give penicillin to these patients. We aimed to assess anaesthetist beliefs about giving penicillin to patients delabelled by direct oral challenge.

Methods

A survey, developed using the Theoretical Domains Framework, was circulated to anaesthetists within a regional research network in England. Domains were rated using 5-point Likert scales. Overall and group medians were used to dichotomize domains rated by group into 'relatively important/unimportant' and 'relative enabler/barrier'.

Results

We received 257 responses from six hospitals (response rate 49.7%). Seven domains were rated as important for all stakeholder groups and hospitals: Knowledge, Skills, Belief in Capabilities, Belief in Consequences, Memory/Attention/Decisions, Environmental Context and Resources, and Emotions. Social and Professional Role was also important to all respondents except those in one hospital. Intentions and Optimism were rated as important for some groups/hospitals and unimportant for others. All four other domains were rated as unimportant for all groups/hospitals. All domains rated as important were enablers for all groups/hospitals, with the exception of Memory/Attention/Decisions and Emotions, which were rated as discordant barriers/enablers between groups. This means they were acting as a barrier for some staff groups/hospitals and an enabler for others. Barrier domains (Reinforcement, Goals, Social Influences, Behavioural Regulation) were all rated unimportant.

Conclusions

Behavioural influences on giving penicillin prophylaxis to a delabelled patient are complex and nuanced. These findings could inform targeted interventions, both across and within hospitals and staff groups.

Management of Penicillin Allergy in the Perioperative Setting

The selection of perioperative antibiotic prophylaxis is challenging in patients with a history of penicillin allergy; as such, we present a literature review exploring current best practices and the associated supporting evidence, as well as areas for future research. Guidelines recommend the use of alternative agents in patients with an IgE-mediated hypersensitivity reaction, but those alternative agents are associated with worse outcomes, including an increased risk of surgical site infection, and higher cost. More recent data suggest that the risk of cross-reactivity between penicillins and cephalosporins, particularly cefazolin, is extremely low, and that cefazolin can be used safely in most penicillin-allergic patients. Studies have therefore explored how best to implement first-line cefazolin use in patients with a penicillin allergy label. A variety of interventions, including preoperative allergy de-labeling with incorporation of penicillin skin testing, use of patient risk-stratification questionnaires, and utilization of clinician algorithms to guide antibiotic selection intraoperatively, have all been shown to significantly increase cefazolin utilization without a corresponding increase in adverse events. Further studies are needed to clarify the most effective interventions and implementation strategies, as well as to evaluate whether patients with severe delayed hypersensitivity reactions to penicillin should continue to be excluded from receipt of other beta-lactams.

Penicillin Allergy Evaluation Should Be Performed Proactively in Patients With a Penicillin Allergy Label

Penicillin allergy is the most common drug allergy in the US population. A penicillin allergy label is associated with poor patient outcomes including increased hospital length of stay, increased perioperative infections, and overall increased mortality. A penicillin allergy evaluation accurately identifies approximately 9 of 10 patients who, despite reporting a history of penicillin allergy, can receive penicillins safely. Penicillin allergy evaluations should be offered proactively to healthy patients during routine visits, including children and pregnant women, in advance of antibiotic need.

Should Penicillin Allergy Testing Be Included as Part of Preoperative Testing?

INTRODUCTION

Penicillin allergy is the most commonly reported drug allergy in the United States. Patients labeled with penicillin allergy are at risk of receiving broad-spectrum antibiotics for surgical site infection prophylaxis, which can lead to increased antibiotic resistance, higher morbidity, suboptimal antibiotic therapy, and higher medical costs. This study aimed to determine the true prevalence of penicillin allergy among surgical patients and to decrease the unnecessary use of broad-spectrum antibiotics.

METHODS

A retrospective chart review was performed of patients who underwent urogynecologic surgery in 2017. In 2018, a quality initiative was started, and all patients reporting penicillin allergies were offered antibiotic allergy testing as part of their preoperative testing.

RESULTS

In 2017, 15% of patients reported penicillin allergy and 52% of them received surgical prophylaxis with broad-spectrum antibiotics. In 2018, 463 patients underwent surgery, 55 of whom reported penicillin allergy and were offered penicillin allergy testing. 35 (64%) agreed to proceed with testing, and of those tested, 33 (94%) tested negative for penicillin allergy.

CONCLUSIONS

94% of patients with stated penicillin allergy who consented to allergy testing proved to have negative test. Penicillin allergy testing should be considered as part of preoperative management.

Computer-Assisted Clinical Diagnosis and Treatment

PURPOSE OF REVIEW

Computer-assisted diagnosis and treatment (CAD/CAT) is a rapidly growing field of medicine that uses computer technology and telehealth to aid in the diagnosis and treatment of various diseases. The purpose of this paper is to provide a review on computer-assisted diagnosis and treatment. This technology gives providers access to diagnostic tools and treatment options so that they can make more informed decisions leading to improved patient outcomes.

RECENT FINDINGS

CAD/CAT has expanded in allergy and immunology in the form of digital tools that enable remote patient monitoring such as digital inhalers, pulmonary function tests, and E-diaries. By incorporating this information into electronic medical records (EMRs), providers can use this information to make the best, evidence-based diagnosis and to recommend treatment that is likely to be most effective. A major benefit of CAD/CAT is that by analyzing large amounts of data, tailored recommendations can be made to improve patient outcomes and reduce the risk of adverse events. Machine learning can assist with medical data acquisition, feature extraction, interpretation, and decision support. It is important to note that this technology is not meant to replace human professionals. Instead, it is designed to assist healthcare professionals to better diagnose and treat patients.

Increasing cefazolin use for surgical prophylaxis in penicillin-allergy-labeled patients

Objective

Penicillin (PCN) allergy labels affect antimicrobial selection for surgical prophylaxis. We aimed to increase the percentage of cefazolin usage in patients with PCN allergy labels undergoing orthopedic surgery from 50% to 80%.

Design

Quality improvement initiative.

Setting

Children's Mercy Kansas City (CMKC), a freestanding children's hospital.

Patients

Children scheduled for an orthopedic surgery (excluding spinal surgery) at CMKC who had a PCN allergy label and received a perioperative antibiotic.

Methods

No standardized process existed to identify and clarify PCN-allergic-labeled patients preoperatively. We developed a process for patient identification combined with a pharmacist phone interview for PCN allergy clarification. In plan-do-study-act (PDSA) part 1, we implemented a computer-generated patient list. In PDSA part 2, we combined automated identification with a phone interview. In PDSA part 3, we enhanced the patient list, making it timely and concise. In PDSA part 4, we included a PCN allergy clarification electronic survey to caregivers via the electronic medical record.

Results

Cefazolin use in PCN-allergic surgical patients increased from 50% to 74% following interventions. Patients who had their PCN allergy label clarified were 4 times more likely to receive cefazolin compared to those whose allergy labels were not clarified (OR, 4.21; 95% CI, 1.68-11.61; P = 0.003). Moreover, 90% of patients received cefazolin when their PCN allergy was clarified and cefazolin was recommended. When a PCN allergy label was not clarified, only 59% of patients received cefazolin.

Conclusions

Appropriate clarification and documentation of PCN allergy labels increases the use of cefazolin for surgical prophylaxis.

Beta-lactam allergy in patients: an antibiotic stewardship challenge

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Impact of Reported β-Lactam Allergy on Clinical Outcomes and Antibiotic Use Among Solid Organ Transplant Recipients

Background

Reported β-lactam allergies (BLAs) are common and frequently inaccurate, but there are limited data on the clinical implications of BLA among solid organ transplant (SOT) recipients. We examined the impact of BLA on clinical outcomes and antibiotic use among SOT recipients.

Methods

This retrospective cohort study included adult patients undergoing single-organ heart, kidney, liver, lung, or pancreas transplant at a United States academic medical center from 1 April 2017 to 31 December 2020. Demographic and clinical data were collected from the electronic health record. Multivariate median regression was performed to evaluate the association between BLA and days alive and out of the hospital in the first 180 days posttransplant (DAOH180). Multivariate logistic regression was performed to evaluate the association between BLA and antibiotic use.

Results

Among 1700 SOT recipients, 285 (16.8%) had a BLA at the time of transplant. BLA was not associated with DAOH180 (adjusted median difference, -0.8 days [95% confidence interval {CI}, -2.7 to 1.2]; P = .43). Patients with BLA were more likely to receive intravenous vancomycin (adjusted odds ratio [aOR], 1.8 [95% CI, 1.3-2.6]; P < .001), clindamycin (aOR, 9.9 [95% CI, 5.1-18.9]; P < .001), aztreonam (aOR, 19.6 [95% CI, 5.9-64.4]; P < .001), fluoroquinolones (aOR, 3.8 [95% CI, 2.8-5.0]; P < .001), or aminoglycosides (aOR, 3.9 [95% CI, 2.5-6.2]; P < .001).

Conclusions

BLA was associated with use of β-lactam alternative antibiotics but not DAOH180 among SOT recipients.

Penicillin Allergy and Perioperative Anaphylaxis

Penicillin allergy is the most commonly reported drug allergy, while perioperative anaphylaxis is overall rare. This review covers the epidemiology of both penicillin allergy and perioperative anaphylaxis both separately and taken together. Considerations regarding anaphylaxis to penicillin during pregnancy are also discussed, since penicillin is the drug of choice for Group B Streptococcus prophylaxis. The minimal cross reactivity between penicillins and cephalosporins is addressed, since the vast majority of patients with a penicillin allergy label can receive perioperative cephalosporins. The management of the patient who has experienced perioperative anaphylaxis, including the importance of allergy referral is covered. Approaches to pre-operative penicillin allergy evaluations and opportunities for education are highlighted.

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.

ANAPHYLAXIS AND PREGNANCY: A SYSTEMATIC REVIEW AND CALL FOR PUBLIC HEALTH ACTIONS

BACKGROUND

Although rare, anaphylaxis during pregnancy implies a risk to both mothers and newborns.

OBJECTIVE

This systematic review is intended to identify key issues in the diagnosis and management of this condition in order to support prevention strategies and decrease the risk of death related to anaphylaxis during pregnancy.

METHODS

We searched MEDLINE, Cochrane, Lilacs, Scielo and Science Direct databases for manuscripts concerning terms "anaphylaxis during pregnancy" without language restrictions. We screened studies, extracted data, and assessed risk of bias independently in duplicate.

RESULTS

We selected 12 articles. Frequency of anaphylaxis during pregnancy is estimated between 1.5 to 3.8 per 100 000 maternities. Only one study provided anaphylaxis mortality data in pregnant women, and the rate of anaphylaxis-related maternal mortality is estimated at 0.05 per 100 000 live births. No standard definition of anaphylaxis severity has been utilized. Forty-nine percent to 74% of anaphylaxis cases were described during caesarean sections. Beta-lactam antibiotics (58%), latex (25%) and anaesthetic agents (17%) were the main culprits. In 17% of papers, causative agents were proven by allergy testing. Seventy two percent of articles proposed the same management and treatment for a clinical episode of anaphylaxis during pregnancy as in non-pregnant patients, and, use of epinephrine in the patient's care during anaphylaxis in pregnancy.

CONCLUSION

Few studies address anaphylaxis during pregnancy, and the majority have been produced by non-allergy specialists. Collaboration between different specialists involved in the care of pregnant women should be established in order to support preventive strategies and reduce avoidable deaths.

Optimizing preoperative antibiotics in patients with β-lactam allergies: A role for pharmacy

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

Patients with a reported β-lactam allergy (BLA) are often given alternative perioperative antibiotic prophylaxis, increasing risk of surgical site infections (SSIs), acute kidney injury (AKI), and Clostridioides difficile infection (CDI). The purpose of this study was to implement and evaluate a pharmacist-led BLA clarification interview service in the preoperative setting.

Methods

A pharmacist performed BLA clarification telephone interviews before elective procedures from November 2018 to March 2019. On the basis of allergy history and a decision algorithm, first-line preoperative antibiotics, alternative antibiotics, or allergy testing referral was recommended. The pharmacist intervention (PI) group was compared to a standard of care (SOC) group who underwent surgery from November 2017 to March 2018.

Results

Eighty-seven patients were included, with 50 (57%) and 37 (43%) in the SOC and PI groups, respectively. The most common surgeries included orthopedic surgery in 41 patients (47%) and neurosurgery in 17 patients (20%). In the PI group, all BLA labels were updated after interview. Twenty-three patients were referred for allergy testing, 12 of the 23 (52%) completed BLA testing, and penicillin allergies were removed for 9 of the 12 patients. Overall, 28 of the 37 (76%) pharmacy antibiotic recommendations were accepted. Cefazolin use significantly increased from 28% to 65% after the intervention (P = 0.001). SSI occurred in 5 (10%) patients in the SOC group and no patients in the PI group (P = 0.051). All of these SSIs were associated with alternative antibiotics. Incidence of AKI and CDI was similar between the groups. No allergic reactions occurred in either group.

Conclusion

Implementation of a pharmacy-driven BLA reconciliation significantly increased β-lactam preoperative use without negative safety outcomes.

Betalactam hypersensitivity: The importance of delabelling in primary care

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Safety and efficacy of de-labelling penicillin allergy in adults using direct oral challenge: a systematic review

Background

Approximately 10% of people have an unverified penicillin allergy, with multiple personal and public health consequences.

Objectives

To assess the efficacy and safety of direct oral challenge, without prior skin testing, in this population.

Methods

MEDLINE, EMBASE, CINAHL, the Cochrane Library and Google Scholar were searched from inception to 28 June 2020 (updated November 2020) to find published and unpublished studies that reported direct oral challenge for the purpose of removal of penicillin allergy labels. Population weighted mean was used to calculate the proportion of patients who developed an immediate or delayed reaction to direct oral challenge across the studies.

Results

Thirteen studies were included in the review, with a sample size of 1202 (range 7–328). Studies included inpatient and outpatient cohorts assessed as low risk for true allergy. In pooled analysis of all 13 studies there were 41/1202 (3.41%) mild immediate or delayed reactions to direct oral challenge. The population-weighted mean incidence of immediate or delayed reaction to an oral challenge across studies was also 3.41% (95% CI: 2.38%–4.43%). There were no reports of serious adverse reactions, 96.5% of patients could be de-labelled and many were subsequently successfully treated with penicillin.

Conclusions

Direct oral challenge is safe and effective for de-labelling patients assessed as low risk for true allergy. Non-specialist clinicians competent in using an assessment algorithm can offer evaluation of penicillin allergy labels using direct oral challenge in appropriate patients. These measures will facilitate optimal infection treatment for patients, support antimicrobial stewardship, and minimize antimicrobial resistance.

Is Patient-reported Penicillin Allergy Independently Associated with Increased Risk of Prosthetic Joint Infection After Total Joint Arthroplasty of the Hip, Knee, and Shoulder?

BACKGROUND

Patients with a patient-reported penicillin allergy may be at greater risk for postoperative prosthetic joint infection (PJI) after total joint arthroplasty of the hip, knee, or shoulder. The increased risk of PJI in these patients has been attributed to these patients receiving a less-effective perioperative antibiotic. However, prior reports did not fully address the clinical characteristics of these unique patients, who may inherently be at greater risk of having a PJI, which may confound prior findings.

QUESTIONS/PURPOSES

After controlling for risk factors for PJI such as BMI, anxiety, depression, and other comorbidities, we asked: Are patients with a patient-reported penicillin allergy more likely to have a PJI after THA, TKA, or total shoulder arthroplasty than patients without such a reported allergy?

METHODS

We queried patient records from 2010 to 2017 from a nationwide administrative claims database of 122 million patients to adequately power an investigation comparing the 1-year incidence of PJI after TKA, total shoulder arthroplasty, and THA in patients with patient-reported penicillin allergy versus patients without a patient-reported penicillin allergy. Operative treatments for deep joint infection, identified by Current Procedural Terminology and ICD-9 and ICD-10 codes were used as a surrogate for PJI. Clinical characteristics such as age, sex, BMI, length of stay, and Charlson comorbidity index and specific comorbidities including alcohol abuse, anemia, anxiety, cardiac disease, diabetes, immunocompromised status, rheumatoid arthritis, depression, liver disease, chronic kidney disease, tobacco use, and peripheral vascular disease were queried for each study group. The odds of PJI within 1 year of THA, TKA, or total shoulder arthroplasty were compared using multiple logistic regression after adjusting for potential confounders.

RESULTS

After adjusting for potential confounding factors such as BMI, anxiety, depression and other comorbidities, we found that patient-reported penicillin allergy was independently associated with an increased odds of PJI after TKA (odds ratio 1.3 [95% confidence interval 1.1 to 1.4]; p < 0.01) and total shoulder arthroplasty (OR 3.9 [95% CI 2.7 to 5.4]; p < 0.01). However, patient-reported penicillin allergy was not independently associated with an increased odds of PJI after THA (OR 1.1 [95% CI 0.9 to 1.3]; p = 0.36) after controlling for the same risk factors.

CONCLUSIONS

In this study, we found that patients with patient-reported penicillin allergy were at an increased risk for PJI after TKA and total shoulder arthroplasty, which we suspect-but cannot prove-is likely a function of those patients receiving a second-line antibiotic for presurgical prophylaxis. Since prior research has found that many patients listed in medical records as having a penicillin allergy are in fact not allergic to penicillin, we suggest that surgeons consider preoperative allergy testing, such as using an intraoperative test dose, to aid in choosing the most appropriate antibiotic choice before knee or shoulder arthroplasty and to amend patient medical records based on testing results. Future studies should determine whether this additional diagnostic maneuver is cost-effective.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Update on perioperative hypersensitivity reactions: joint document from the Brazilian Society of Anesthesiology (SBA) and Brazilian Association of Allergy and Immunology (ASBAI) - Part II: etiology and diagnosis

This second joint document, written by experts from the Brazilian Association of Allergy and Immunology (ASBAI) and Brazilian Society of Anesthesiology (SBA) concerned with perioperative anaphylaxis, aims to review the pathophysiological reaction mechanisms, triggering agents (in adults and children), and the approach for diagnosis during and after an episode of anaphylaxis. As anaphylaxis assessment is extensive, the identification of medications, antiseptics and other substances used at each setting, the comprehensive data documentation, and the use of standardized nomenclature are key points for obtaining more consistent epidemiological information on perioperative anaphylaxis.

GRAded oral challenge for Drug allergy Evaluation-Delabelling described through families' voices

BACKGROUND

Children are often diagnosed with an antibiotic allergy, with little investigation to confirm whether it is a true allergy. Recent studies support the use of oral challenges to confirm antibiotic allergy. Yet, little is known about families' perceptions of these challenges, or experiences of living with a misdiagnosis, often for many years.

OBJECTIVE

To describe how families with a child previously labelled as "antibiotic allergic," but who has subsequently been delabelled, perceive the experience of misdiagnosis and subsequent delabelling.

METHODS

We performed semi-structured interviews with parents whose children had recently completed a graded oral challenge for antibiotic allergy. Interview transcripts were analysed concurrently, but independently, by two investigators, using content analysis.

RESULTS

A total of 15 parents (14 individual interviews; 1 mother-father dyad) participated. Children were, on average, 5.04 ± 4.5 years and were first diagnosed in infancy (mean age: 1.82 ± 1.48 years) subsequent to a rash (14/14; 100%), and commonly at a walk-in clinic (6/14; 42.9%). We identified four themes: (1) A red, raised rash results in a quick diagnosis despite a lack of testing, (2) sensitive care allays concerns, (3) delabelling brings relief, but also mystery and calls for proper diagnoses, and (4) quick diagnoses are reckless, but manageable through downward comparisons.

CONCLUSION AND CLINICAL RELEVANCE

These findings underscore the importance of a careful physical examination and clinical history of the patient, but also an ongoing dialogue to support families, both of which would ideally begin at the time of initial investigation.

Accuracy of penicillin allergy diagnostic tests: A systematic review and meta-analysis

BACKGROUND

Having a penicillin allergy label associates with a higher risk for antibiotic resistance and increased health care use.

OBJECTIVE

We sought to assess the accuracy of skin tests and specific IgE quantification in the diagnostic evaluation of patients reporting a penicillin/β-lactam allergy.

METHODS

We performed a systematic review and diagnostic accuracy meta-analysis, searching on MEDLINE, Scopus, and Web of Science. We included studies conducted in patients reporting a penicillin allergy and in whom skin tests and/or specific IgE quantification were performed and compared with drug challenge results. We quantitatively assessed the accuracy of diagnostic tests with bivariate random-effects meta-analyses. Meta-regression and subgroup analyses were performed to explore causes of heterogeneity. Studies' quality was evaluated using QUADAS-2 criteria.

RESULTS

We included 105 primary studies, assessing 31,761 participants. Twenty-seven studies were assessed by bivariate meta-analysis. Skin tests had a summary sensitivity of 30.7% (95% CI, 18.9%-45.9%) and a specificity of 96.8% (95% CI, 94.2%-98.3%), with a partial area under the summary receiver-operating characteristic curve of 0.686 (I² = 38.2%). Similar results were observed for subanalyses restricted to patients reporting nonimmediate maculopapular exanthema or urticaria/angioedema. Specific IgE had a summary sensitivity of 19.3% (95% CI, 12.0%-29.4%) and a specificity of 97.4% (95% CI, 95.2%-98.6%), with a partial area under the summary receiver-operating characteristic curve of 0.420 (I² = 8.5%). Projected predictive values mainly reflect the low frequency of true penicillin allergy.

CONCLUSIONS

Skin tests and specific IgE quantification appear to have low sensitivity and high specificity. Because current evidence is insufficient for assessing the role of these tests in stratifying patients for delabeling, we identified key requirements needed for future studies.

The challenge of de-labeling penicillin allergy

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Self-reported beta-lactam allergy and the risk of surgical site infection: A retrospective cohort study

OBJECTIVE

To assess whether a self-reported β-lactam allergy is associated with an increased risk of surgical site infection (SSI) across a broad range of procedures and to determine whether this association is mediated by the receipt of an alternate antibiotic to cefazolin.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Surgical procedures sampled by an institutional National Surgical Quality Improvement Program database over an 18-month period (January 2017 to June 2018) from 7 surgical specialties.

SETTING

Tertiary-care academic hospital.

RESULTS

Of the 3,589 surgical procedures included in the study, 369 (10.3%) were performed in patients with a reported β-lactam allergy. Those with a reported β-lactam allergy were significantly less likely to receive cefazolin (38.8% vs 95.5%) or metronidazole (20.3% vs 26.1%) and were more likely to receive clindamycin (52.0% vs 0.2%), gentamicin (3.5% vs 0%), or vancomycin (2.2% vs 0.1%) than those without allergy. An SSI occurred in 154 of 3,220 procedures (4.8%) in patients without reported allergy and 27 of 369 (7.3%) with reported allergy. In the multivariable regression model, a reported β-lactam allergy was associated with a statistically significant increase in SSI risk (adjusted odds ratio [aOR], 1.61; 95% confidence interval [CI], 1.04-2.51; P = .03). This effect was completely mediated by receipt of an alternate antibiotic to cefazolin (indirect effect aOR, 1.68; 95% CI, 1.17-2.34; P = .005).

CONCLUSIONS

Self-reported β-lactam allergy was associated with an increased SSI risk mediated through receipt of alternate antibiotic prophylaxis. Safely increasing use of cefazolin prophylaxis in patients with reported β-lactam allergy can potentially lower the risk of SSIs.

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

Purpose

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

Patients and methods

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

Results

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

Conclusion

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

β-Lactam vs Non-β-Lactam Antibiotics and Surgical Site Infection in Colectomy Patients

BACKGROUND

Surgical site infections (SSIs) represent a significant preventable source of morbidity, mortality, and cost. Prophylactic antibiotics have been shown to decrease SSI rates, and β-lactam antibiotics are recommended by national guidelines. It is currently unclear whether recommended β-lactam and recommended non-β-lactam antibiotic regimens are equivalent with respect to SSI risk reduction in colectomy patients.

STUDY DESIGN

We conducted a retrospective cohort study of SSI rates between prophylactic intravenously administered recommended β-lactam and non-β-lactam in colectomy patients (25 CPT codes) collected by the Michigan Surgical Quality Collaborative from January 2013 to February 2018. Surgical site infection rates were compared as a dichotomous variable (no SSI vs SSI). Mixed-effects regression was used to compare the association between receiving a β-lactam or non-β-lactam antibiotic and likelihood of having an SSI.

RESULTS

Of 9,949 patients, 9,411 (94.6%) received β-lactam antibiotics and 538 (5.4%) received non-β-lactam antibiotics. Overall, there were 622 (6.3%) patients with SSIs. Of the patients receiving β-lactam antibiotics, SSIs developed in 571 (6.1%) compared with 51 (9.5%) patients in the non-β-lactam group. After applying mixed-effects logistic regression, prophylactic treatment with a non-β-lactam regimen was associated with significantly higher odds of surgical site infection (odds ratio 1.65; 95% CI 1.20 to 2.26; p < 0.01).

CONCLUSIONS

Colectomy patients receiving β-lactam antibiotics had a lower likelihood of SSI compared with those receiving non-β-lactam antibiotics, even when antibiotics were compliant with national recommendations. Our findings suggest that surgeons should prescribe β-lactam antibiotics for prophylaxis whenever possible, reserving alternatives for those rare patients with true allergies or clinical indications for non-β-lactam antibiotic prophylaxis.

Penicillin allergy de-labelling ahead of elective surgery: feasibility and barriers

BACKGROUND

Around 10-15% of the in-patient population carry unsubstantiated 'penicillin allergy' labels, the majority incorrect when tested. These labels are associated with harm from use of broad-spectrum non-penicillin antibiotics. Current testing guidelines incorporate both skin and challenge tests; this is prohibitively expensive and time-consuming to deliver on a large scale. We aimed to establish the feasibility of a rapid access de-labelling pathway for surgical patients, using direct oral challenge.

METHODS

'Penicillin allergic' patients, recruited from a surgical pre-assessment clinic, were risk-stratified using a screening questionnaire. Patients at low risk of true, immunoglobulin E (IgE)-mediated allergy were offered direct oral challenge using incremental amoxicillin to a total dose of 500 mg. A 3-day course was completed at home. De-labelled patients were followed up to determine antibiotic use in surgery, and attitudes towards de-labelling were explored.

RESULTS

Of 219 patients screened, 74 were eligible for inclusion and offered testing. We subsequently tested 56 patients; 55 were de-labelled. None had a serious reaction to the supervised challenge, or thereafter. On follow-up, 17 of 19 patients received appropriate antimicrobial prophylaxis during surgery. Only three of 33 de-labelled patients would have been happy for the label to be removed without prior specialist testing.

CONCLUSION

Rapid access de-labelling, using direct oral challenge in appropriately risk-stratified patients, can be incorporated into the existing surgical care pathway. This provides immediate and potential long-term benefit for patients. Interest in testing is high among patients, and clinicians appear to follow clinic recommendations. Patients are unlikely to accept removal of their allergy label on the basis of history alone.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: AN17/92982.