Allergy to β-lactam antibiotics

Intramuscular versus Enteral Penicillin Prophylaxis to Prevent Progression of Rheumatic Heart Disease: Study protocol for a non-inferiority randomized trial (the GOALIE trial)

BACKGROUND

Rheumatic Heart Disease (RHD) persists as a major cardiovascular driver of mortality and morbidity among young people in low- and middle-income countries. Secondary antibiotic prophylaxis (SAP) with penicillin remains the cornerstone of RHD control, however, sub-optimal treatment adherence undermines most secondary prevention programs. Many of the barriers to optimal SAP adherence are specific to the intramuscular form of penicillin and may potentially be overcome by use of oral penicillin. This non-inferiority trial is comparing the efficacy of intramuscular to oral penicillin SAP to prevent progression of mild RHD at 2 years.

METHODS/DESIGN

The Intramuscular versus Enteral Penicillin Prophylaxis to Prevent Progression of Rheumatic Heart Disease (GOALIE) trial is randomizing Ugandan children aged 5-17 years identified by echocardiographic screening with mild RHD (Stage A or B as defined by 2023 World Heart Federation criteria) to Benzathine Benzyl Penicillin G (BPG arm, every-28-day intramuscular penicillin) or Phenoxymethyl Penicillin (Pen V arm, twice daily oral penicillin) for a period of 2 years. A blinded echocardiography adjudication panel of 3 RHD experts and 2 cardiologists is determining the echocardiographic stage of RHD at enrollment and will do the same at study completion by consensus review. Treatment adherence and study retention are supported through peer support groups and case management strategies. The primary outcome is the proportion of children in the Pen V arm who progress to more advanced RHD compared to those in the BPG arm. Secondary outcomes are patient-reported outcomes (treatment acceptance, satisfaction, and health related quality of life), costs, and cost-effectiveness of oral compared to intramuscular penicillin prophylaxis for RHD. A total sample size of 1004 participants will provide 90% power to demonstrate non-inferiority using a margin of 4% with allowance for 7% loss to follow-up. Participant enrollment commenced in October 2023 and final participant follow-up is expected in December 2026. The graphical abstract (Figure 1) summarizes the flow of echocardiographic screening, participant enrollment and follow-up.

DISCUSSION

The GOALIE trial is critical in global efforts to refine a pragmatic approach to secondary prevention for RHD control. GOALIE insists that the inferiority of oral penicillin be proven contemporarily and against the most important near-term clinical outcome of progression of RHD severity. This work also considers other factors that could influence the adoption of oral prophylaxis and change the calculus for acceptable efficacy including patient-reported outcomes and costs.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05693545.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Antibiotic concentrations and antibiotic resistance in aquatic environments of the WHO Western Pacific and South-East Asia regions: a systematic review and probabilistic environmental hazard assessment

BACKGROUND

Antibiotic resistance poses human health risks, and there are concerns about the effect of environmental antibiotic residues in the selection and spread of antibiotic resistance. The aim of this study was to identify antibiotic residue levels that are likely to select for resistance and relative contributions from different aquatic sources, of various aquatic environmental compartments of the WHO Western Pacific region (WPR) and the WHO South-East Asia region (SEAR), including in China and India.

METHODS

A systematic review of empirical studies that measured antibiotic concentrations in aquatic environments, published between 2006 and 2019, and a probabilistic environmental hazard assessments approach, were used to identify antibiotic concentrations that are likely to select for resistance in various aquatic environmental compartments of the WPR and SEAR, including in China and India. The assessment involved the use of measured environmental concentrations and predicted no-effect concentrations (PNECs).

FINDINGS

The systematic review found 218 relevant studies of 5230 screened from the WPR and 22 relevant studies of 2625 screened from the SEAR; some of these relevant studies were largely from China (n=168) and India (n=15). 92 antibiotics in the WPR and 45 in the SEAR were detected in various aquatic compartments. Antibiotic concentrations that most likely exceeded PNECs (0-100%) were observed in wastewater, and influents and effluents of wastewater treatment plants. Antibiotic concentrations that most likely exceeded PNECs were also observed in aquatic environmental compartments. The highest risk for the development of resistance was in tap or drinking water of the WPR and China for ciprofloxacin (62·5%). The relative contributions of potential sources of antibiotic contamination in waterways, such as hospitals, municipals, livestock, and pharmaceutical manufacturing, was determined for each antibiotic.

INTERPRETATION

The concentrations of antibiotic residues found in wastewater and wastewater treatment plants of the WPR and SEAR make them potential hotspots for the development of antibiotic resistance, which creates human health risks from environmental exposure via drinking water. These findings can help decision makers to target risk reduction measures against environmental residues of priority antibiotics in high-risk sites, and help to focus research efforts in these world regions.

FUNDING

Swedish Research Council.

Penilloic acid is the chief culprit involved in non-IgE mediated, immediate penicillin-induced hypersensitivity reactions in mice

Metabolites/impurities (MIs) of penicillin are normally considered to be the main substances inducing immediate hypersensitivity reactions in penicillin treatment. Our previous research found that penicillin can cause non-allergic hypersensitivity reactions (NAHRs) by directly triggering vascular hyperpermeability and exudative inflammation. However, the chief culprits and underlying mechanisms involved in penicillin-induced NAHRs have not yet been fully elucidated. In this study, we used a combination of approaches including a mouse non-allergic hypersensitivity reaction model, UPLC-MS/MS analyses of arachidonic acid metabolites (AAMs), immunoblotting technique, and molecular docking, etc to investigate the culprits involved in penicillin-induced hypersensitivity reactions. We found penilloic acid, one of the main MIs of penicillin, could trigger NAHRs via inducing increased vascular permeability, while the other MIs did no exhibit similar effect. Penilloic acid-induced reactions were not IgE-dependent. Significantly increased arachidonic acids and cascade metabolites in lungs, and activation of RhoA/ROCK signaling pathway in the ears and lungs of mice were noticed after once administration of penilloic acid. This study revealed that penilloic acid was the chief culprit involved in penicillin-induced immediate NAHRs in mice, which mainly associated with direct stimulation of vascular hyperpermeability and exudative inflammation. The activations of AAMs and RhoA/ROCK signaling pathway played important roles in these reactions.

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

Importance

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

Objective

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

Design, Setting, and Participants

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

Exposures

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

Main Outcomes and Measures

Addition of penicillin allergy label in the electronic medical record.

Results

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

Conclusions and Relevance

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

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

DISCLAIMER

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

IL-17 stimulates neutrophils to release S100A8/A9 to promote lung epithelial cell apoptosis in Mycoplasma pneumoniae-induced pneumonia in children

Mycoplasma pneumoniae-induced pneumonia (MPP) is a common cause of community-acquired respiratory tract infections, increasing risk of morbidity and mortality, in children. However, diagnosing early-stage MPP is difficult owing to the lack of good diagnostic methods. Here, we examined the protein profile of bronchoalveolar lavage fluid (BALF) and found that S100A8/A9 was highly expressed. Enzyme-linked immunosorbent assays used to assess protein levels in serum samples indicated that S100A8/A9 concentrations were also increased in serum obtained from children with MPP, with no change in S100A8/A9 levels in children with viral or bacterial pneumonia. In vitro, S100A8/A9 treatment significantly increased apoptosis in a human alveolar basal epithelial cell line (A549 cells). Bioinformatics analyses indicated that up-regulated S100A8/A9 proteins participated in the interleukin (IL)-17 signaling pathway. The origin of the increased S100A8/A9 was investigated in A549 cells and in neutrophils obtained from children with MPP. Treatment of neutrophils, but not of A549 cells, with IL-17A released S100A8/A9 into the culture medium. In summary, we demonstrated that S100A8/A9, possibly released from neutrophils, is a new potential biomarker for the clinical diagnosis of children MPP and involved in the development of this disease through enhancing apoptosis of alveolar basal epithelial cells.

Impact of Antibiotic Allergy Labels on Patient Outcomes in a Tertiary Paediatric Hospital

OBJECTIVES

Antibiotic allergies are reported in 5 to 15% of children. This study aimed to evaluate the impact of common β-lactam antibiotic allergy labels (AALs) on hospital treatment, focussing on length of stay and appropriateness of antibiotic prescribing.

STUDY DESIGN

Retrospective cohort study over 21-months at the Royal Children's Hospital Melbourne, Australia. A subset of children with the most common β-lactam allergies, and who required admission for intravenous antibiotics over a 12-month period, was analysed for appropriateness of prescribing. Non-allergic patients were matched to evaluate associations between AALs and hospital treatment.

RESULTS

There were 98,912 children admitted over the study period, of whom 938 (1%) had at least one AAL on first admission. Of all encounters, 5145 (2.5%) were for children with AALs. The most common AALs were to amoxicillin and amoxicillin-clavulanic acid combinations (40.8%), cefalexin (14.4%) and trimethoprim-sulfamethoxazole (9.7%). For the subset, there were 66 admissions for children who required intravenous antibiotics. Documentation was adequate for 27% of AALs. Inappropriate prescribing occurred in almost half (47%). Hospital stay was longer for children with AALs (median 4.7 days; IQR 2.3 to 9.2) compared to non-allergic controls (median 3.9 days; IQR 1.9 to 6.8; P=0.02). Children with AALs were more likely to receive restricted antibiotics (aOR 3.03; 95%CI, 1.45 to 6.30; p=0.003).

CONCLUSION

This is the first study to demonstrate high rates of inappropriate prescribing in children with AALs. Children with AALs were significantly more likely to receive restricted antibiotics and had a longer length of stay compared with non-allergic controls.

Establishing Amoxicillin Allergy in Children Through Direct Graded Oral Challenge (GOC): Evaluating Risk Factors for Positive Challenges, Safety, and Risk of Cross-Reactivity to Cephalosporines

BACKGROUND

Data on the diagnostic properties of direct oral challenges without the use of skin tests in children with suspected amoxicillin allergy are sparse.

OBJECTIVE

Assess the use of direct oral challenges.

METHODS

A cohort study was conducted between March 2013 and March 2020, in Montreal and Winnipeg. All children referred with reported history of benign reactions (ie, limited to the skin with no mucosal lesions and no vesicles) to amoxicillin were recruited and a 2-step graded oral challenge (GOC) was conducted. Data were collected on demographic characteristics, clinical characteristics, and comorbidities. Eligible children were followed to assess reactions to subsequent use of amoxicillin and to assess the safety of cephalexin use in children with a positive GOC.

RESULTS

Among 1914 children recruited, 1811 (94.6%) tolerated the GOC, 42 (2.2%) developed mild immediate reactions, and 61 (3.2%) developed mild nonimmediate reactions. Among 265 participants who had a negative GOC and reused amoxicillin, 226 (85.3%) reported tolerance and 39 (14.7%) had mild cutaneous reactions. Chronic urticaria (adjusted odds ratio [aOR], 1.16; 95% CI, 1.09-1.23) and an index reaction occurring within 5 minutes of exposure (aOR, 1.09; 95% CI, 1.04-1.14) were associated with immediate reactions during the GOC. Symptoms lasting longer than 7 days (aOR, 1.05; 95% CI, 1.02-1.09) and parental drug hypersensitivity (aOR, 1.04; 95% CI, 1.03-1.06) were associated with nonimmediate reactions. Among those reacting to the GOC, 12.5% reacted with mild cutaneous reactions to cephalexin challenge.

CONCLUSIONS

Direct GOCs are an accurate and safe confirmatory to establish true hypersensitivity among children reporting benign reactions to amoxicillin.

Frequency of severe reactions following penicillin drug provocation tests: A Bayesian meta-analysis

BACKGROUND

Patients with a penicillin allergy label tend to have worse clinical outcomes and increased healthcare use. Drug provocation tests (DPT) are the gold-standard in the diagnostic workup of penicillin allergy, but safety concerns may hinder their performance. We aimed to assess the frequency of severe reactions following a DPT in patients with reported allergy to penicillins or other β-lactams.

METHODS

We performed a systematic review, searching MEDLINE, Scopus, and Web of Science. We included primary studies assessing participants with a penicillin allergy label who underwent a DPT. We performed a Bayesian meta-analysis to estimate the pooled frequency of severe reactions to penicillin DPTs. Sources of heterogeneity were explored by subgroup and metaregression analyses.

RESULTS

We included 112 primary studies which included a total of 26,595 participants. The pooled frequency of severe reactions was estimated at 0.06% (95% credible interval [95% CrI] = 0.01%-0.13%; I2  = 57.9%). Most severe reactions (80/93; 86.0%) consisted of anaphylaxis. Compared to studies where the index reaction was immediate, we observed a lower frequency of severe reactions for studies assessing non-immediate index reactions (OR = 0.05; 95% CrI = 0-0.31). Patients reporting anaphylaxis as their index reaction were found to be at increased risk of developing severe reactions (OR = 13.5; 95% CrI = 7.7-21.5; I2  = 0.3%). Performance of direct DPTs in low-risk patients or testing with the suspected culprit drug were not associated with clinically relevant increased risk of severe reactions.

CONCLUSIONS

In patients with a penicillin allergy label, severe reactions resulting from DPTs are rare. Therefore, except for patients with potentially life-threatening index reactions or patients with positive skin tests-who were mostly not assessed in this analysis -, the safety of DPTs supports their performance in the diagnostic assessment of penicillin allergy.

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.

Brazilian Protocol for Sexually Transmitted Infections 2020: acquired syphilis

The Clinical Protocol and Therapeutic Guidelines for Comprehensive Care of People with Sexually Transmitted Infections, published by the Brazilian Ministry of Health in 2020, includes updates concerning acquired syphilis. The document comprises rapid test use, safety and efficacy of benzathine benzylpenicillin, case follow-up, neurosyphilis clinical and laboratory management, approaching sex partners, assistance and monitoring of diagnosed pregnant women, and syphilis and HIV co-infection specificities, as well as a case notification summary. Health managers and professionals must be continuously trained so as to integrate care and surveillance, to strengthen actions for efficient control of syphilis, to broaden the search for sex partners, and to expand access of most vulnerable populations to health services. Most people with syphilis are asymptomatic; this contributes to the maintenance of the transmission chain. Without adequate treatment of pregnant women with syphilis, severe consequences can occur, such as miscarriage, prematurity, low birth weight, natimortality, and congenital syphilis.

Taking a Rational Approach to a Reported Antibiotic Allergy

Up to 10% of hospitalized patients have an antibiotic allergy label in their medical file, most frequently concerning penicillins. However, the vast majority of reported allergies to antibiotics does not represent a "true" allergy but are due to drug intolerance, idiosyncratic reactions or symptoms of the concurrent infectious disease. Since antibiotic allergy labels result in deviation from first-choice antimicrobial therapy, tackling the issue of incorrect antibiotic allergy labelling, already at young age, is a core element of antibiotic stewardship. In this article, we describe the structured approach to the patient with a presumed antibiotic allergy with emphasis on key elements of allergy-specific history taking and the limited risk of cross-allergic reactions between beta-lactam subclasses.

[Brazilian Protocol for Sexually Transmitted Infections 2020: acquired syphilis]

The Clinical Protocol and Therapeutic Guidelines for Comprehensive Care for People with Sexually Transmitted Infections, published by the Ministry of Health of Brazil in 2020, includes the update on acquired syphilis. The document comprises rapid tests use, safety and efficacy of the administration of benzathine benzylpenicillin, follow-up of cases, clinical and laboratory management of neurosyphilis, approach to sexual partnerships, assistance and monitoring of diagnosed pregnant women, and specificities of syphilis and HIV co-infection, as well as a summary of the notification of cases. It is necessary to train health managers and professionals on a continuous basis, with a view to integrating care and surveillance, strengthening effective syphilis control actions, increasing the search for sexual partnerships, and expanding the access of the most vulnerable populations to health services.

Comparison between the prophylactic effects of amoxicillin 24 and 48 hours pre-operatively on surgical site infections in Japanese patients with impacted mandibular third molars: A prospective cohort study

INTRODUCTION

According to the guidelines, the dosage for mandibular wisdom tooth extraction (MWTE) varies within the administration period. There is a 24-fold difference between the minimum and maximum doses. If an appropriate antimicrobial can be administered without increasing incidence of surgical site infection (SSI), it may lead to a global action plan on antimicrobial resistance (AMR). Therefore, we prospectively surveyed incidence of SSI post-operatively and use of oral antibiotics (OA) for MWTE.

METHODS

Subjects were patients who underwent MWTE in our dental outpatient clinic from May 2019 to April 2020. Two groups were formed depending on type of administration period they received: 24 h and 48 h after surgery. The following information was collected: (1) patient factors (age, gender, body mass index, presence/absence of preoperative medication, diagnosis, impacted wisdom tooth status; (2) surgical factors (operative time, presence/absence of closure, presence/absence of hemostat, doctor career, type and frequency of painkiller); (3) relationship between administration period of OA and SSI occurrence; and (4) details of SSI.

RESULTS

Three hundred forty subjects were analyzed, all of which used amoxicillin. There were 106 cases in 24 h group and 234 cases in 48 h group. The total incidence of SSI was 1.1% (4/340 cases), with 0.9% (1/106 cases) in 24 h group and 1.3% (3/234 cases) in 48 h group; there was no difference between the two groups.

CONCLUSION

Our study suggests that amoxicillin (250 mg/dose every 8 h x 3 doses beginning 1 h before surgery) might be sufficient in preventing SSI in Japanese dental patients without SSI risk factors.

Knowledge, Attitude, and Practice on Antibiotics and Its Resistance: A Two-Phase Mixed-Methods Online Study among Pakistani Community Pharmacists to Promote Rational Antibiotic Use

Antibiotic resistance (ABR) is an emerging global threat to public health. Substantial evidence has indicated that community pharmacists (CPs) can play a critical role in managing the ever-increasing threat of antibiotic resistance. This study aimed to determine the knowledge, attitude, and practices of CPs (n = 180) towards antibiotics and antibiotic resistance as well as to improve the rational use of antibiotics. A two-phase mixed-methods (quantitative and qualitative) online study was conducted in Pakistan from August 2019 to March 2020 by using validated questionnaires and semi-structured interview data. Different statistical methods were used to tabulate the quantitative data, whereas inductive thematic analysis was conducted to categorize themes from the qualitative data and to draw conclusions. Approximately 64.4% of the CPs were male (mean: 29–33 years old). Overall, CPs had good knowledge of and were familiar with multidrug-resistant organisms and their roles in ABR (65.6%, median = 1, and IQR = 1), although their knowledge was poor in differentiating some antibiotic groups with their respective ABR patterns (31.1%, median = 1, and IQR = 1). Most CPs have a positive attitude towards antibiotics, with most (90.0%) identifying ABR as a critical issue in public health (median = 1 and IQR = 0). Overall, CPs’ practices towards antibiotics were somewhat acceptable, where they leaned towards educating patients about the rational use of antibiotics (52.8%, median = 1, and IQR = 1). The two main themes discovered (antibiotics and counseling of patients) were related to self-medication, while educational intervention is the main subtheme. ABR is multifactorial, with subthemes related to budget, time constraints, incompetent staff, the absence of CPs, the lack of training, and the enforcement of laws and regulations being the needs of the hour in Pakistan. Effective antibiotic stewardship programs, patient education, and awareness campaigns about antibiotics and ABR along with training of the CPs are important factors that have to be addressed in a timely manner.

First pediatric electronic algorithm to stratify risk of penicillin allergy

Beta-lactam allergy is reported in 5–10% of children in North America, but up to 94–97% of patients are deemed not allergic after allergist assessment. The utility of standardized skin testing for penicillin allergy in the pediatric population has been recently questioned. Oral drug challenges when appropriate, are preferred over skin testing, and can definitively rule out immediate, IgE-mediated drug allergy. To our knowledge, this is the only pediatric study to assess the reliability of a penicillin allergy stratification tool using a paper and electronic clinical algorithm. By using an electronic algorithm, we identified 61 patients (of 95 deemed not allergic by gold standard allergist decision) as low risk for penicillin allergy, with no false negatives and without the need for allergist assessment or skin testing. In this study, we demonstrate that an electronic algorithm can be used by various pediatric clinicians when evaluating possible penicillin allergy to reliably identify low risk patients. We identified the electronic algorithm was superior to the paper version, capturing an even higher percentage of low risk patients than the paper version. By developing an electronic algorithm to accurately assess penicillin allergy risk based on appropriate history, without the need for diagnostic testing or allergist assessment, we can empower non-allergist health care professionals to safely de-label low risk pediatric patients and assist in alleviating subspecialty wait times for penicillin allergy assessment.

Perioperative Severe Anaphylaxis to Paracetamol in a Child

The data on perioperative anaphylaxis (PA) in children is limited and usually reported with neuromuscular blocking agents and antibiotics. However we present a first pediatric case who developed PA with paracetamol unlike the literature.

Cephalosporins' Cross-Reactivity and the High Degree of Required Knowledge. Case Report and Review of the Literature

Antibiotic cross-reactivity represents a phenomenon of considerable interest as well as antibiotic resistance. Immediate reactions to cephalosporins are reported in the literature with a prevalence of only 1%-3% of the population, while anaphylactic reactions are rarely described (approximately 0.0001%-0.1%) as well as fatalities. Allergic reaction to cephalosporins may occur because of sensitization to unique cephalosporin haptens or to determinants shared with penicillins. Cross-reactivity between cephalosporins represents, in fact, a well-known threatening event involving cephalosporins with similar or identical R1- or R2-side chains. The present report describes the case of a 79-year-old man who suddenly died after intramuscular administration of ceftriaxone. Serum dosage of mast cell tryptase from a femoral blood sample at 3 and 24 hours detected values of 87.7μg/L and 93.5μg/L, respectively (cut-off value 44.3 μg/L); the serum-specific IgE for penicillins, amoxicillin, cephaclor and also for the most common allergens were also determined. A complete post-mortem examination was performed, including gross, histological and immunohistochemical examination, with an anti-tryptase antibody. The cause of death was identified as anaphylactic shock: past administrations of cefepime sensitized the subject to cephalosporins and a fatal cross-reactivity of ceftriaxone with cefepime occurred due to the identical seven-position side chain structure in both molecules. The reported case offers food for thought regarding the study of cross-reactivity and the need to clarify the predictability and preventability of the phenomenon in fatal events.

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.

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.

Protocols for drug allergy desensitization in children

Introduction: When a drug hypersensitivity reaction is proven, desensitization protocols allow the reintroduction of the molecule in patients for whom such therapy is essential. Through drug desensitization (DDS), a temporary immune tolerance is maintained for the single course of a specific therapy. In pediatrics, indications for such a procedure include children with chronic diseases, severe infectious diseases and/or malignancies, who have a proven drug hypersensitivity.Areas covered: We ran a search on PubMed and Web of Science for papers on DDS and on DDS in children. Most protocols and recommendations on DDS focus on adults and have been adapted for children. The best candidates for desensitization are children with a history of immediate, IgE-mediated drug allergy, but this therapy may be applied also in nonallergic hypersensitivities and in non-immediate reactions. Most protocols in literature focus on antibiotics, especially beta-lactams, on chemotherapeutic agents, and on monoclonal antibodies.Expert opinion: Pediatric allergists should cooperate with specialists in infectious diseases and onco-hematology to provide DDS to children in need. Standardized protocols and international guidelines are still needed to optimize such treatment and to implement it in clinical daily practice.

Quinolone Allergy

Quinolones are the second most common antibiotic class associated with drug-induced allergic reactions, but data on quinolone allergy are scarce. This review article discusses the available evidence on quinolone allergy, including prevalence, risk factors, diagnosis, clinical manifestations, cross-reactivity, and management of allergic reactions. Although the incidence of quinolone allergy is still lower than beta-lactams, it has been increasingly reported in recent decades, most likely from its expanded use and the introduction of moxifloxacin. Thorough patient history remains essential in the evaluation of quinolone allergy. Many diagnostic tools have been investigated, but skin tests can yield false-positive results and in vitro tests have not been validated. The drug provocation test is considered the test of choice to confirm a quinolone allergy but is not without risk. Evidence regarding cross-reactivity among the quinolones is limited and conflicting. Quinolone allergy can be manifested either as an immediate or delayed reaction, but is not uniform across the class, with moxifloxacin posing the highest risk of anaphylaxis. Quinolone should be discontinued when an allergic reaction occurs and avoided in future scenarios, but desensitization may be warranted if no alternatives are available.

Severe adverse events following benzathine penicillin G injection for rheumatic heart disease prophylaxis: cardiac compromise more likely than anaphylaxis

Objective

Secondary prophylaxis through long-term antibiotic administration is essential to prevent the progression of acute rheumatic fever to rheumatic heart disease (RHD). Benzathine penicillin G (BPG) has been shown to be the most efficacious antibiotic for this purpose; however, adverse events associated with BPG administration have been anecdotally reported. This study therefore aimed to collate case reports of adverse events associated with BPG administration for RHD prophylaxis.

Study design

A literature review was used to explore reported adverse reactions to BPG and inform development of a case report questionnaire. This questionnaire was circulated through professional networks to solicit retrospective reports of adverse events from treating physicians. Returned surveys were tabulated and thematically analysed. Reactions were assessed using the Brighton Collaboration case definition to identity potential anaphylaxis.

Results

We obtained 10 case reports from various locations, with patients ranging in age from early-teens to adults. All patients had clinical or echocardiogram-obtained evidence of valvular disease. The majority of patients (80%) had received BPG prior to the event with no previous adverse reaction. In eight cases, the reaction was fatal; in one case resuscitation was successful and in one case treatment was not required. Only three cases met Level 1 Brighton criteria consistent with anaphylaxis.

Conclusion

These results indicate that anaphylaxis is not a major cause of adverse reactions to BPG. An alternative mechanism for sudden death following BPG administration in people with severe RHD is proposed.

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

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

Cross-Reactivity to Cephalosporins and Carbapenems in Penicillin-Allergic Patients: Two Systematic Reviews and Meta-Analyses

BACKGROUND

There is no recent systematic review on the risk of cross-reactivity to cephalosporins and carbapenems in penicillin-allergic patients despite many new studies on the subject. All past reviews have several limitations such as not including any patient with a T-cell-mediated penicillin allergy.

OBJECTIVES

To determine the risk of cross-reactivity to cephalosporins and carbapenems in patients with a proven IgE- or T-cell-mediated penicillin allergy. To measure the association between R1 side chain similarity on cephalosporins and penicillins and the risk of cross-reactivity.

METHODS

MEDLINE and EMBASE were searched from January 1980 to March 2019. Studies had to include at least 10 penicillin-allergic subjects whose allergy had been confirmed by a positive skin test (ST) or drug provocation test (DPT) result. Cross-reactivity had to be assessed to at least 1 cephalosporin or carbapenem through ST or DPT. Both random-effects and fixed-effect models were used to combine data. A bioinformatic model was used to quantify the similarity between R1 side chains.

RESULTS

Twenty-one observational studies on cephalosporin cross-reactivity involving 1269 penicillin-allergic patients showed that the risk of cross-reactivity varied with the degree of similarity between R1 side chains: 16.45% (95% CI, 11.07-23.75) for aminocephalosporins, which share an identical side chain with a penicillin (similarity score = 1), 5.60% (95% CI, 3.46-8.95) for a few cephalosporins with an intermediate similarity score (range, 0.563-0.714), and 2.11% (95% CI, 0.98-4.46) for all those with low similarity scores (below 0.4), irrespective of cephalosporin generation. The higher risk associated with aminocephalosporins was observed whether penicillin allergy was IgE- or T-cell-mediated. Eleven observational studies on carbapenem cross-reactivity involving 1127 penicillin-allergic patients showed that the risk of cross-reactivity to any carbapenem was 0.87% (95% CI, 0.32-2.32).

CONCLUSIONS

Although it remains possible that these meta-analyses overestimated the risk of cross-reactivity, clinicians should consider the increased risk of cross-reactivity associated with aminocephalosporins, and to a lesser extent with intermediate-similarity-score cephalosporins, compared with the very low risk associated with low-similarity-score cephalosporins and all carbapenems when using beta-lactams in patients with a suspected or proven penicillin allergy.

Antibiotic Allergy in Pediatrics

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

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

BACKGROUND

Studies performed since 1990 on samples of at least 30 subjects with a documented IgE-mediated hypersensitivity to penicillins have found a rate of positive responses to allergy tests with cephalosporins ranging from 0% to 27%.

OBJECTIVE

We sought to assess the cross-reactivity with cephalosporins and evaluate the possibility of using cephalosporins in penicillin-allergic subjects.

METHODS

We conducted a prospective study of 252 consecutive subjects who had suffered 319 immediate reactions (mostly anaphylaxis) to penicillins and had positive skin tests to at least 1 penicillin reagent. All patients underwent serum specific IgE assays for cefaclor, as well as skin tests with 3 aminocephalosporins (cephalexin, cefaclor, and cefadroxil), cefamandole, cefuroxime, ceftazidime, ceftriaxone, cefotaxime, and cefepime. Patients with negative results for the last 5 cephalosporins were challenged with cefuroxime axetil and ceftriaxone; those with negative results for aminocephalosporins were also challenged with cefaclor and cefadroxil.

RESULTS

Ninety-nine participants (39.3%) had positive allergy tests for cephalosporins. Specifically, 95 (37.7%) were positive to aminocephalosporins and/or cefamandole, which share similar or identical side chains with penicillins. All 244 subjects who underwent challenges with cefuroxime axetil and ceftriaxone tolerated them. Of the 170 patients who underwent aminocephalosporin challenges, 3 reacted to cefaclor and 4 to cefadroxil.

CONCLUSIONS

Cross-reactivity between penicillins and cephalosporins seems to be mainly related to side chain similarity or identity. Subjects with an IgE-mediated hypersensitivity to penicillins could be treated with cephalosporins such as cefuroxime and ceftriaxone that have side-chain determinants different from those of penicillins and are negative in pretreatment skin testing.

Evaluation and Management of Penicillin Allergy

Penicillin allergy is the most commonly reported drug allergy in the United States. Although penicillin allergy is widely reported, 80% to 90% of individuals with self-reported penicillin allergy are actually able to tolerate penicillins after undergoing evaluation for penicillin allergy. Because most patients with self-reported penicillin allergy will have subsequent negative allergy testing results and tolerate penicillins, they may be unnecessarily exposed to broader-spectrum antibiotics. Use of such antibiotics leads to increased risks of developing antibiotic-resistant microorganisms and incur higher health care utilization costs. In this article, we provide an overview of penicillin allergy and its clinical manifestations as well as an approach for the evaluation and management of penicillin allergy.

Management of Children with Hypersensitivity to Antibiotics and Monoclonal Antibodies

Proper management of drug allergy in children is based on a thorough history, in vitro testing (if available), in vivo testing, and drug challenge. This approach has been well developed with beta-lactam drugs but not with non-beta-lactam drugs and monoclonal antibodies. Children commonly develop rashes during an antibiotic course, which can lead to misdiagnosis of drug allergy. Clinical reactions to monoclonal antibodies vary and are managed depending on the type. A better knowledge of drug reactions that can occur in antibiotic allergy and monoclonal allergy can aid a provider in better management of their drug-allergic pediatric patients.

Antibiotic prophylaxis in cataract surgery in the setting of penicillin allergy: A decision-making algorithm

Cataract surgery is the most commonly performed surgical procedure in many developed countries. Postoperative endophthalmitis is a rare complication with potentially devastating visual outcomes. Currently, there is no global consensus regarding antibiotic prophylaxis in cataract surgery despite growing evidence of the benefits of prophylactic intracameral cefuroxime at the conclusion of surgery. The decision about which antibiotic regimen to use is further complicated in patients reporting penicillin allergy. Historic statistics suggesting crossreactivity of penicillins and cephalosporins have persisted into modern surgery. It is important for ophthalmologists to consider all available antibiotic options and have an up-to-date knowledge of antibiotic crossreactivity when faced with the dilemma of choosing appropriate antibiotic prophylaxis for patients undergoing cataract surgery with a history of penicillin allergy. Each option carries risks, and the choice may have medicolegal implications in the event of an adverse outcome. We assess the options for antibiotic prophylaxis in cataract surgery in the setting of penicillin allergy and provide an algorithm to assist decision-making for individual patients.

The utility of the basophil activation test in the diagnosis of immediate amoxicillin or amoxicillin-clavulanate hypersensitivity in children and adults

Background

The basophil activation test (BAT), has been proposed as a possible assay for the diagnosis of immediate-type allergy to beta-lactams (BLs).

The aim of this study was to assess the utility of BAT in the diagnosis of amoxicillin (AMX) or AMX-clavulanate (AMX-C) IgE-mediated hypersensitivity in children and adults.

Material and methods

Eighteen children and 21 adults, with clinical history of immediate reactions to AMX or AMX-C, were referred to Anna Meyer Children’s Hospital and San Giovanni di Dio Hospital, respectively. They underwent in vivo tests (skin prick test and intradermal test). Moreover, BAT with AMX or AMX-C was performed within 6 months from the reaction.

Results

In the pediatric group, the concordance between the skin tests (ST) and BAT results was 83.3%. Upon comparing the symptom grades and ST results to the BAT results, we found that the reaction severity and ST positivity did not correlate with BAT results in children.

In the adult group, the concordance between the ST and BAT results was 61.9%. Upon comparing patients with severe reactions and patients with mild reactions in terms of BAT results, we found a BAT sensitivity of 38.5% and a specificity of 100%. When comparing the symptom grades to the BAT results, we found that no patients with mild symptoms had a positive BAT result, whereas 38.5% of patients with severe symptoms had a positive BAT result.

Conclusions

BAT does not seem to be a useful tool to increase the sensitivity of an allergy work-up to diagnose immediate hypersensitivity to AMX or AMX-C.

Usage, residue, and human health risk of antibiotics in Chinese aquaculture: A review

Aquaculture is a booming industry in the world and China is the largest producer and exporter of aquatic products. To prevent and treat diseases occurred in aquaculture, antibiotics are widely applied. However, the information of antibiotics used in Chinese aquaculture is still limited. Based on peer-reviewed papers, documents, reports, and even farmer surveys, this review summarized antibiotics used in Chinese aquaculture. In 2014, more than 47.4 million tonnes of farmed aquatic products were produced in mainland China. The outputs in the east and south parts of China can reach as much as 600 times higher than those in the northwest areas, which is clearly separated by the "Hu Line" - a line that marks a striking difference in the distribution of population. A total of 20 antibiotics belonging to eight categories have been reported for use, mainly via oral administration. However, only 13 antibiotics have been authorized for application in Chinese aquaculture and 12 antibiotics used are not authorized. Totally, 234 cases on antibiotic residues in Chinese aquatic products were recorded, including 24 fish species, eight crustacean species, and four mollusk species. Thirty-two antibiotics have been detected in aquatic products; quinolones and sulfonamides were the dominated residual chemicals. For specific compound, ciprofloxacin, norfloxacin, and sulfisoxazole have the highest concentrations. Except for a few cases, all residual concentrations were lower than the maximum residue limits. Through the consumption of aquatic products tainted by antibiotics, humans may acquire adverse drug reactions or antibiotic-resistant bacteria. However, the risk of antimicrobial resistance in human body, when exposed to antibiotics at sub-inhibitory concentrations, has not been exhaustively considered in the risk assessment. In addition, a national comprehensive investigation on the amount of antibiotics used in Chinese aquaculture is still needed in future studies.

Involvement of Histamine and RhoA/ROCK in Penicillin Immediate Hypersensitivity Reactions

The mechanism of penicillin immediate hypersensitivity reactions has not been completely elucidated. These reactions are generally considered to be mediated by IgE, but penicillin-specific IgE could not be detected in most cases. This study demonstrated that penicillin was able to cause vascular hyperpermeability in a mouse model mimicking clinical symptoms of penicillin immediate hypersensitivity reactions. The first exposure to penicillin also induced immediate edema and exudative reactions in ears and lungs of mice in a dose-dependent manner. Vasodilation was noted in microvessels in ears. These reactions were unlikely to be immune-mediated reactions, because no penicillin-specific IgE was produced. Furthermore, penicillin treatment directly elicited rapid histamine release. Penicillin also led to F-actin reorganization in human umbilical vein endothelial cells and increased the permeability of the endothelial monolayer. Activation of the RhoA/ROCK signaling pathway was observed in ears and lungs of mice and in endothelial cells after treatment with penicillin. Both an anti-histamine agent and a ROCK inhibitor attenuated penicillin immediate hypersensitivity reactions in mice. This study presents a novel mechanism of penicillin immediate hypersensitivity reactions and suggests a potential preventive approach against these reactions.

[Spanish Society of Pediatric Infectious Diseases, Spanish Society of Paediatric Clinical Immunology and Allergy, Spanish Association of Paediatric Primary Care, and the Spanish Society of Extra-hospital Paediatrics and Primary Health Care consensus document on antibiotic treatment in penicillin or amoxicillin allergy]

The suspected allergy to beta-lactam antibiotics, especially penicillin and amoxicillin, is the most frequent reason for consultation in Child Allergy Units. In this consensus document, the clinical and diagnostic criteria of allergic reactions are described, as well as alternative antibiotic treatment for the most common infections diagnosed in paediatrics for patients with known or suspected allergy.

A retrospective comparison of false negative skin test rates in penicillin allergy, using pencilloyl-poly-lysine and minor determinants or Penicillin G, followed by open challenge

Background

A history of penicillin allergy in patients is common, but only 10–15 % are truly allergic. While the gold standard for diagnosing penicillin allergy is challenge, it is not recommended that this be done without first carrying out diagnostic skin testing. This is carried out with the major determinant benzylpenicilloyl (PPL) and the minor determinant mixture (MDM), consisting of penilloate, penicilloate and Penicillin G. However, since availability of the MDM is limited, Penicillin G alone has been used.

Methods

A retrospective chart review was carried out on patients tested for penicillin allergy in the Clinical Immunology and Allergy Clinic at the Health Sciences Centre, Winnipeg, Canada between 2005 and 2013. A total of 521 patients charts were reviewed, of whom 240 had skin testing, ImmunoCap^® for IgE to Penicillin G and V and had oral challenges with penicillin, amoxicillin or cloxacillin.

Results

17/240 (7.5 %) were skin test positive, 8 to PPL, 4 to MDM and 5 to Penicillin G. One was also positive on ImmunoCap^® testing. Three patients had negative skin tests but weakly positive ImmunoCap^®. 222 patients with negative skin tests and serological tests were challenged. Of these, 12 patients reacted to challenge. Three of the challenges were equivocal. Of the nine patients with definite positive challenges, three were tested with Penicillin G and six with MDM. Therefore the false negative rates for testing were 2.3 % with PPL and Penicillin G and 6.97 % for PPL and MDM. The difference was not significant (p = 0.0856).

Conclusions

In this group of patients with a history of penicillin allergy tested with the major determinant of benzyl penicillin and either MDM or Penicillin G, there was no difference in the rate of false negative testing, based on oral penicillin challenges. Therefore, Penicillin G can be safely used as an alternative to MDM in diagnosing penicillin allergy.

Selective immediate responders to amoxicillin and clavulanic acid tolerate penicillin derivative administration after confirming the diagnosis

BACKGROUND

An increasing number of patients show immediate selective hypersensitivity reactions to clavulanic acid (CLV) and amoxicillin (AX), probably due to their increased prescription. The maintenance of this response should be established.

OBJECTIVE

To assess that the immediate hypersensitivity selective response to AX or to CLV is maintained after repeated administration of penicillin G (PG)/penicillin V (PV) and AX.

METHODS

Patients with proven immediate hypersensitivity to AX (Group A) or CLV (Group B) were included. Diagnosis was performed using skin tests with major and minor determinants of PG (PPL/MDM), AX and CLV and by drug provocation test (DPT) if required. Selectivity was established by confirming tolerance to PG/PV (Group A) and to PG/PV and AX (Group B). The maintenance of the selective response was verified by repeating DPT, 15 days after the initial investigation, with the same procedure.

RESULTS

Of 51 patients, 78% belonged to Group A and 22% to Group B. Most had anaphylaxis. In Group A, 72% were skin test positive; 28% required DPT. In Group B, 63% were skin test positive; 37% required DPT. Only two AX-selective cases developed positive responses after re-provocation with PG/PV. No cases selective for CLV developed a positive response to PG, PV or AX.

DISCUSSION

The selective response to AX appears consistent, and a response to penicillin determinants only develops in a minority of cases. For the case of CLV, the selective response appears not to be modified by exposure to penicillin determinants, meaning that patients with CLV allergy can take penicillin derivatives safely.

Diagnosis of allergy against beta-lactams in primary care: prevalence and diagnostic criteria

BACKGROUND

Secondary care studies showed that a recorded allergy to beta-lactams could not be confirmed by valid allergy testing in >85% of cases. In daily practice, recorded beta-lactam allergies probably cause prescription of secondary choice antibiotics. This overrating of beta-lactam allergy hampers appropriate use of narrow spectrum antibiotic and generates unnecessary cost and bacterial resistance.

OBJECTIVE

To assess registration and over diagnosis of allergies against beta-lactams in Dutch primary care.

METHODS

A retrospective cohort study in 8288 primary care subjects was performed. Patients with recorded allergy were identified through International Classification for Primary Care coding. Signs and symptoms of the recorded allergic reaction and patient's characteristics were extracted from patient's files and patients were sent a questionnaire. The probability of allergy was based on a composite reference standard that was scored by two authors independently.

RESULTS

One hundred sixty-three subjects had a recorded allergy (2.0%). In 51.5% of cases, no characteristics of the recorded allergic reaction were reported in patients' medical files. Based on our composite reference standard, allergy was excluded in 19 subjects (11.7%). Risk factors for allergy registration were female gender, age <4 years, and the comorbidities-asthma, allergies and skin disorders.

CONCLUSIONS

The prevalence of recorded allergy against beta-lactam antibiotics in a large Dutch primary care centre was 2%. Due to lack of registration of accompanying signs and symptoms of the recorded allergy, this diagnosis is uncertain in most patients. Better documentation and classification by a screening algorithm of future possible allergic reactions to beta-lactams are needed in primary care.

Beta-Lactam Hypersensitivity and Cross-Reactivity

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

Antibiotic allergy

Although allergy to β-lactam and non-β-lactam antibiotics is commonly claimed, true allergy to these drugs is often absent. Reactions to antibiotics can be classified according to the interval between the last administration of the drug and the onset of symptoms, but except for immediate reactions occurring within an hour of exposure, which are almost always either IgE-mediated or due to direct stimulation of mast cells, reactions occurring later than 1 hour probably have multiple mechanisms, including being IgE-mediated or involving cell-mediated reactions. The latter are likely caused by drug-specific T lymphocytes. The diagnosis of antibiotic allergy can be difficult.