Use of cephalosporins in patients with immediate penicillin hypersensitivity: cross-reactivity revisited

Group B Streptococcus and the risk of perinatal morbidity and mortality following term labor

Streptococcus agalactiae (group B Streptococcus) colonizes the genital tract of approximately 20% of pregnant women. In the absence of intervention, approximately 1% of infants born to colonized mothers exhibit a clinical infection. This has led to implementation of screening and intervention in the form of intrapartum antibiotic prophylaxis in many countries, including the United States. However, screening has not been introduced in a substantial minority of other countries because of the absence of supportive level 1 evidence, the very large number needed to treat to prevent 1 case, and concerns about antimicrobial resistance. Optimal screening would involve rapid turnaround (to facilitate intrapartum testing) and report antibiotic sensitivity, but no such method exists. There is significant scope for a personalized medicine approach, targeting intrapartum antibiotic prophylaxis to cases at greatest risk, but the pathogen and host factors determining the risk of invasive disease are incompletely understood. Epidemiologic data have indicated the potential of prelabor invasion of the uterus by group B Streptococcus, and metagenomic analysis revealed the presence of group B Streptococcus in the placenta in approximately 5% of pregnant women at term before onset of labor and membrane rupture. However, the determinants and consequences of prelabor invasion of the uterus by group B Streptococcus remain to be established. The vast majority (98%) of invasive neonatal disease is caused by 6 serotypes, and hexavalent vaccines against these serotypes have completed phase 2 trials. However, an obstacle to phase 3 studies is conducting an adequately powered trial to demonstrate clinical effectiveness given that early-onset disease affects approximately 1 in 1000 births in the absence of vaccination.

Group B Streptococcus in Pregnancy

To decrease risk of early-onset neonatal sepsis from group B streptococcus (GBS), pregnant patients should undergo screening between 36 0/7 and 37 6/7 weeks' gestation. Patients with a positive vaginal-rectal culture, GBS bacteriuria , or history of newborn with GBS disease should receive intrapartum antibiotic prophylaxis (IAP) with an agent targeting GBS. If GBS status is unknown at time of labor, IAP should be administered in cases of preterm birth, rupture of membranes for >18 hours, or intrapartum fever. The antibiotic of choice is intravenous penicillin; alternatives should be considered in cases of penicillin allergy depending on allergy severity.

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.

Immediate and Delayed Hypersensitivity Reactions to Beta-Lactam Antibiotics

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

Impact of Beta-lactam Allergy on Treatment of Outpatient Infections

PURPOSE

The most commonly reported medication allergies in the United States involve beta-lactam antibiotics, creating an important consideration for prescribers when choosing optimal treatment of infections. Currently, few data exist on outpatient prescribing patterns in response to patients with a beta-lactam allergy. This study sought to evaluate the appropriateness of outpatient antibiotic therapy in patients with documented beta-lactam allergies within a Veterans Affairs health care system to evaluate areas of improvement in prescribing practices.

METHODS

Patients receiving outpatient oral antibiotics were prospectively identified through real-time electronic alerts from June 2017 through February 2018. Prescriptions were then reviewed retrospectively to identify appropriateness of antibiotic, drug choice, dose, and duration based on current guideline recommendations. Data were compared between patients with a listed beta-lactam allergy and patients without a beta-lactam allergy to determine the impact on prescribing patterns and outcomes. Baseline characteristics were compared by using descriptive statistics. Significant risk factors for inappropriate prescribing were identified through a multivariable analysis.

FINDINGS

The cohort included 1844 antibiotic prescriptions (documented beta-lactam allergy, 221; no beta-lactam allergy, 1623). Appropriate drug, dose, and duration for antibiotics prescribed in patients reporting a beta-lactam allergy versus nonallergic patients were 44.3% versus 53.0% (P = 0.02), 91.4% versus 86.2% (P = 0.03), and 75.1% versus 76.2% (P = 0.83), respectively. Patients with a reported beta-lactam allergy were 31% less likely to receive the correct drug for indication empirically (95% CI, 0.52-0.92) in the multivariable regression model when adjusted for fluoroquinolone use. In addition, patients reporting a beta-lactam allergy were 2.2 times (95% CI, 1.6-3.0) more likely to receive a fluoroquinolone antibiotic. Antibiotics were considered overall inappropriate based on at least one aspect of therapy in 79.6% of patients reporting a beta-lactam allergy and in 71% of nonallergic patients.

IMPLICATIONS

Antibiotic therapy in patients with a documented beta-lactam allergy was less likely to be appropriate overall, suggesting an area of improvement for prescribing habits. Future interventions should focus on prescriber education regarding first-line and alternative treatments for patients with beta-lactam allergies to ensure that optimal treatment is being provided.

Antimicrobial stewardship intervention: optimizing antibiotic treatment in hospitalized patients with reported antibiotic allergy

BACKGROUND

Reported antibiotic allergy in hospitalized patients seems to be related to more adverse events, the use of reserve antibiotics and longer hospitalization. Most patients reporting an antibiotic allergy can be de-labelled; as such, an antimicrobial stewardship intervention was set up.

AIM

To determine the impact of reported antibiotic allergy on the antibiotic treatment of hospitalized patients, and prevent unnecessary deviation from the preferred antibiotic treatment by a proactive antimicrobial stewardship intervention.

METHODS

Hospitalized patients reporting an antibiotic allergy were included in an intervention study at a teaching hospital in the Netherlands between March and May 2019. Physicians received training and were provided with a recommendation in the electronic medical record in case the preferred antibiotic treatment was unnecessarily avoided due to the allergy label and the patient was eligible for a drug challenge.

FINDINGS

In total, 492 patients reporting an antibiotic allergy were identified, accounting for 558 hospital admissions. In 93 cases, the antibiotic allergy label interfered with the preferred antibiotic treatment. Sixty-eight of these patients were eligible for a drug challenge, and 42 patients were challenged. In 40 (95%) of these patients, no allergic reaction was observed, and the preferred antibiotic treatment was given. Two (5%) patients developed a non-severe skin reaction after a drug challenge and continued an alternative antibiotic regimen.

CONCLUSION

This antimicrobial stewardship intervention can be used to provide patients with reported antibiotic allergy labels with the preferred antibiotic treatment, and to de-label them after uneventful re-exposure to the antibiotic agent.

Endocarditis and bacterial brain abscess in a young woman with a single atrium, patent ductus arteriosus, and Eisenmenger syndrome: A case report

RATIONALE

A single atrium is a rare congenital heart disease (CHD) involving zero atrial septal traces and preserved intact ventricular septum and atrioventricular valves, requiring careful surgical intervention. However, developing to Eisenmenger syndrome (ES) makes the surgery complicated. Based on bidirectional cardiac shunting, vegetation easily develops in case of bacterial infection.

PATIENT CONCERN AND DIAGNOSES

We reported a 35-year-old woman with a single atrium, patent ductus arteriosus, pulmonary hypertension, and ES who developed infective endocarditis on her left ventricular outflow tract and complicated cerebral abscess and who underwent challenged medical treatment.

INTERVENTION

Infection was successfully controlled after 4-time change in antibiotics over 4 months. However, surgery is complicated for her.

OUTCOMES

The patient presented a relatively good outcome during follow-up for >6 months.

LESSONS

This case report suggests that patients with complex CHD should accept surgery therapy earlier before developing ES. It is imperative to avoid invasive interventions to prevent infectious endocarditis.

Prevention of Group B Streptococcal Early-Onset Disease in Newborns: ACOG Committee Opinion, Number 782

Group B streptococcus (GBS) is the leading cause of newborn infection. The primary risk factor for neonatal GBS early-onset disease (EOD) is maternal colonization of the genitourinary and gastrointestinal tracts. Approximately 50% of women who are colonized with GBS will transmit the bacteria to their newborns. Vertical transmission usually occurs during labor or after rupture of membranes. In the absence of intrapartum antibiotic prophylaxis, 1-2% of those newborns will develop GBS EOD. Other risk factors include gestational age of less than 37 weeks, very low birth weight, prolonged rupture of membranes, intraamniotic infection, young maternal age, and maternal black race. The key obstetric measures necessary for effective prevention of GBS EOD continue to include universal prenatal screening by vaginal-rectal culture, correct specimen collection and processing, appropriate implementation of intrapartum antibiotic prophylaxis, and coordination with pediatric care providers. The American College of Obstetricians and Gynecologists now recommends performing universal GBS screening between 36 0/7 and 37 6/7 weeks of gestation. All women whose vaginal-rectal cultures at 36 0/7-37 6/7 weeks of gestation are positive for GBS should receive appropriate intrapartum antibiotic prophylaxis unless a prelabor cesarean birth is performed in the setting of intact membranes. Although a shorter duration of recommended intrapartum antibiotics is less effective than 4 or more hours of prophylaxis, 2 hours of antibiotic exposure has been shown to reduce GBS vaginal colony counts and decrease the frequency of a clinical neonatal sepsis diagnosis. Obstetric interventions, when necessary, should not be delayed solely to provide 4 hours of antibiotic administration before birth. This Committee Opinion, including , , and , updates and replaces the obstetric components of the CDC 2010 guidelines, "Prevention of Perinatal Group B Streptococcal Disease: Revised Guidelines From CDC, 2010."

The pathogenic microbial flora and its antibiotic susceptibility pattern in odontogenic infections

Suppurative head and neck infections of odontogenic origin are the most frequent type of head and neck infections. According to the literature, 7-10% of all antibiotics are currently prescribed for their treatment. Since penicillin was invented, the overall antibiotic sensitivity and resistance pattern of the isolated pathogenic microflora has continuously changed. The response of microorganisms to antibiotics and the development of resistance to their action is a purely evolutive process characterized by genetic mutations, acquisition of genetic material or alteration of gene expression and metabolic adaptations. All this makes challenging and difficult the correct choice of empirical antibiotic treatment for head and neck space infections even today. The aim of this paper was to evaluate the literature and to evidence the most frequent locations of odontogenic head and neck infections, the dominant pathogenic microbial flora, the genetic mutations and metabolic changes necessary for bacteria in order to aquire antibiotic resistance and as well its susceptibility and resistance to common antibiotics. We also aimed to highlight the possible changes in bacterial resistance to antibiotics over time, and to assess whether or not there is a need for fundamental changes in the empirical antibiotic treatment of these infections and show which these would be.

Suspected Reaction with Cephalosporin May Be a Predictive Factor for β-Lactam Allergy in Children

BACKGROUND

Most children diagnosed with β-lactam allergy based only on history are not truly allergic, and mislabeling leads to use of less effective and more costly alternative broader-spectrum antibiotics, significantly increasing drug resistance.

OBJECTIVE

To determine the frequency and risk factors of confirmed allergy in patients with β-lactam allergy reported by parents or their doctors and evaluate cross-reactivity between β-lactams in children with confirmed allergy.

METHOD

Sixty-seven children with suspected β-lactam allergy were evaluated via history, sIgE measurements, skin tests, and drug provocation tests over a period of 5 years.

RESULTS

β-Lactam allergy was confirmed in 10 (14.9%) patients. Six patients had a positive intradermal test result to one or more of the penicillin skin test materials or ceftriaxone, 4 patients with negative skin test results had positive test results with suspected drugs. Age, gender, time interval between evaluation and the initial reaction, personal history of atopy, parental history of drug allergy, reaction type, and multiple drug allergy history were not significantly different between allergic and tolerant patients. For culprit drugs, there was a significant different between the 2 groups; the rate of confirmed diagnosis was significantly higher for cephalosporins such as ceftriaxone, cefuroxime, and cefprozil (p = 0.03). Three patients with allergy to penicillin tolerated cefuroxime; in 4 patients with selective allergy to ceftriaxone tolerated cephalosporins with a dissimilar side chain (cefadroxil, cefuroxime, cefaclor, and cefdinir).

CONCLUSION

Our study indicates that most patients with a suspected β-lactam allergy tolerated this drug. An appropriate diagnostic allergy workup may prevent the use of less effective and more expensive alternatives.

Cross-reactivity in β-Lactam Allergy

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

Skin testing and drug challenge outcomes in antibiotic-allergic patients with immediate-type hypersensitivity

BACKGROUND

The evaluation of antibiotic immediate-type hypersensitivity is intricate because of nonstandardized skin testing and challenge method variability.

OBJECTIVE

To determine the safety outcomes and risk factors for antibiotic challenge reactions in patients reporting a history of antibiotic immediate-type hypersensitivity.

METHODS

A 5-year retrospective review of patients evaluated for immediate-type antibiotic allergy was conducted. Data analyzed included patient demographics, index reaction details, and outcomes of skin testing and challenges, classified as single-step or multistep.

RESULTS

Antibiotic hypersensitivity history was identified in 211 patients: 78% to penicillins, 10% to fluoroquinolones, 7.6% to cephalosporins, and 3.8% to carbapenems. In total, 179 patients completed the challenges (median age 67 years, range 50-76 years, 56% women), and compared with nonchallenged patients, they reported nonanaphylactic (P < .001) and remote index (P = .003) reactions. Sixteen patients (8.9%) experienced challenge reactions (5 of 28 for single-step challenge, 11 of 151 for multistep challenge), and 11 of these patients had negative skin testing results before the challenge. Challenge-reactive patients were significantly younger (P = .007), more often women (P = .036), and had additional reported antibiotic allergies (P = .005). No correlation was detected between the reported index and observed challenge reaction severities (κ = -0.05, 95% confidence interval -0.34 to 0.24). Anaphylactic rates were similar during single-step and multistep challenges (3.6% vs 3.3%).

CONCLUSION

In the present population, younger women with multiple reported antibiotic allergies were at greatest risk for challenge reactions. Negative skin testing results did not exclude reactions, and index severity was not predictive of challenge outcome. The multistep and full-dose methods demonstrated a comparable reaction risk for anaphylaxis.

Correlation analysis of gene polymorphisms and β-lactam allergy

A total of 64 patients with β-lactam allergy and 30 control subjects were enrolled in a case-control study. This study is aimed to analyze the relationship between β-lactam allergy and 10 single nucleotide polymorphisms (SNPs) in interleukin-10 (IL-10), IL-13, IL-4Rα, high-affinity immunoglobulin E-receptor β chain (FcεRIβ), interferon γ receptor 2 (IFNGR2), and CYP3A4, and within the Han Chinese population of Northwest China. Genotyping for the SNPs was conducted using the Sequenom MassARRAY(®) platform. SPSS 17.0 was employed to analyze the statistical data and SHEsis was used to perform the haplotype reconstruction and analyze linkage disequilibrium of SNPs of IL-10 and IL-13. The results showed that the genotype distribution of CYP3A4 rs2242480/CT differed significantly between case and control groups of males (P=0.022; odds ratio (OR)=0.167, 95% confidence interval (CI): 0.032-0.867). Further analysis showed that CCA, CCG, and TAA haplotypes of IL-10 had no significant correlation in patients with β-lactam allergy. The correlation between CCT and CAC haplotypes of IL-13 and β-lactam allergy needs to be further studied. The analysis did not reveal any differences in the distribution of others gene polymorphisms between cases and controls.

Deficits in allergy knowledge among physicians at academic medical centers

BACKGROUND

Allergic conditions have high prevalence in the general population. Misconceptions regarding the diagnosis and management of allergic disease among physicians can lead to suboptimal clinical care.

OBJECTIVE

To determine the extent of allergy-related knowledge deficits among physicians.

METHODS

Pediatric and internal medicine resident and attending physicians from 2 separate academic medical centers were asked to answer an anonymous electronic survey. Survey questions addressed 7 different allergy content areas.

RESULTS

Four hundred eight physicians completed surveys (23.9% response rate). Respondents had few correct answers (mean ± SD 1.91 ± 1.43). Pediatric respondents had a larger number of correct answers compared with medicine-trained physicians (P < .001). No individual answered every survey question correctly, and 50 respondents (12.3%) had no correct answer. Three hundred seventy-eight respondents (92.6%) were unable to provide correct answers for at least 50% of survey questions. Level of residency training and prior rotation through an allergy and immunology elective correlated with a larger number of correct responses (P < .01). Only 1 survey question had an overall correct response rate higher than 50% (n = 261, 64%). Correct response rate was lower than 30% for 7 of the 9 possible questions.

CONCLUSION

There are significant knowledge deficits in many areas of allergy-related content among pediatric and internal medicine physicians and across all levels of training and specialty. Given the prevalence of allergic conditions, the potential implications of a negative impact on clinical care are staggering.