The High Impact of Penicillin Allergy Registration in Hospitalized Patients

Penicillin or cephalosporin antibiotic allergy label: Influence on length of stay and hospital readmission

Background

A penicillin or cephalosporin antibiotic (PCA) allergy label (PCAAL) has negative implications for both the patient and health care alike.

Objective

A retrospective study was undertaken to evaluate the influence of a PCAAL on length of stay (LOS) and hospital readmissions.

Methods

Over 4 weeks, inpatients with a PCAAL who were referred to the allergy service or opportunistically reviewed were grouped in the categories delabeled (group 1a) or advice not followed (ie, label carriage) (group 1b). Comparator groups without a PCAAL were identified, those either on a PCA (the PCA group [group 2]) or on a non-PCA (the non-PCA group [group 3]).

Results

The study population comprised 77 patients as follows: group 1a (n = 19), group 1b (n = 6), group 2 (n = 36), and group 3 (n = 16). Those in group 1a were significantly older (median age 78 years) than those in group 1b (median age 53 years [P = .013]) or group 3 (median age 59 years [P = .013]).There was a trend toward lower LOS in group 1a (10 days) than in group 1b (11.5 days [P = not significant]). Group 2 had a significantly lower LOS (6 days) than either both group 1a (10 days [P = .043]) or group 3 (15 days [P = .002]). Group 3 had the highest rate of patients readmitted within 30 days (n = 5 [71.4%]).

Conclusion

A PCAAL carries influence on both LOS and readmissions, thus identifying the prompt need for allergy review to provide specific recommendations: delabeling and transition to an appropriate antibiotic. The significantly older group of those with a PCAAL who received a PCA after delabeling (ie, a 20-year age difference) may also be a signal that more elderly and comorbid patients benefit from this intervention the most.

Surgical prophylaxis in pediatric orthopedic patients with penicillin allergy: a multicentered retrospective prognostic study

Up to 20% of orthopedic surgeons still avoid the use of cephalosporins in patients with penicillin allergies despite its reported safety in the adult and general surgery pediatric population. The primary objective is to determine the incidence of adverse effects and allergic reactions when using cephalosporins in pediatric orthopedic patients labeled as penicillin-allergic as compared to those without previously reported penicillin allergy. A multicenter retrospective chart review was performed across three level 1 trauma centers from January 2013 to February 2020 to identify penicillin-allergic as well as non-penicillin-allergic pediatric patients treated for orthopedic injuries. Data were collected regarding patient demographics, antibiotic administered, timing of antibiotic administration, reported drug allergy, and described allergic reaction. Postoperative or intraoperative allergic reactions to antibiotics, surgical site infections, and complications were recorded. A total of 2289 surgeries performed by four fellowship-trained surgeons were evaluated. Eighty-five patients diagnosed with penicillin allergy were identified and underwent 95 surgeries and 95 patients without previously reported penicillin allergy underwent 95 surgeries. One patient, with a documented history of anaphylaxis to cefazolin, sustained an anaphylactic reaction intraoperatively to cefazolin. There were no other reported reactions, surgical site infections, or complications. There was no statistically significant difference in rate of allergic reaction in patients with previously reported penicillin allergy treated with cefazolin and those with no previous reported reaction ( P > 0.05). Prophylaxis with cephalosporins is not associated with increased risk for allergic reaction. Cephalosporins can be safely administered to pediatric patients with penicillin allergy undergoing orthopedic intervention. Level of evidence: Level II, Multicenter Retrospective Prognostic Study.

Delabelling beta-lactam allergy

Background: Hypersensitivity to beta-lactam (BL) antibiotics is one of the most frequent reported drug allergies. In our population, it is common to find labels of BL allergy in electronic medical records (EMRs) that have not been assessed. The objective of our study was to detect patients with beta-lactam allergy labels in their EMRs and to assess how many of them are false after a correct diagnostic evaluation. Methods: A multicentre prospective study was performed with patients labelled as allergic to BLs in their EMRs in the previous 5 years. Demographical and clinical data, as well as variables regarding the BL allergy label and the characteristics of the index reaction from clinical history and EMRs, were recorded. Then, diagnostic assessments including clinical history, skin tests (STs), and drug provocation tests (DPTs) were conducted in order to confirm or exclude the diagnosis of BL allergy. Results: A total of 249 patients completed the study, of which 160 (64.3%) were women with a median age of 57 years (interquartile range [IQR], 45-68). The most frequent BL allergy labels detected were for penicillin (124), amoxicillin/clavulanic acid (61), and amoxicillin (54). Of the 204 patients who underwent STs, 20.1% were positive. DPTs were performed in 224 patients, showing good tolerance in 87.1% of cases. After the allergy diagnosis work-up, 186 patients (74.7%) were diagnosed as non-allergic to BL antibiotics. Conclusion: In our study population, the number of patients labelled as allergic to BLs in their EMRs was similar to that in previously published studies, with proportions near to 75%-80% being falsely labelled as allergic to BLs.

An eco-friendly liquid chromatographic analysis of the triple therapy protocol of amoxicillin, metronidazole and vonoprazan for H. Pylori eradication: application to combined dosage forms and simulated gastric fluid

Helicobacter pylori has a big sway when peptic ulcers are concerned. For its eradication, different protocols have been approved. Among which, the tripartite therapy protocol which embraces vonoprazan as potassium competitive acid blocker in combination with amoxicillin and metronidazole as antibiotics. An environmentally benign HPLC method is addressed in order to simultaneously determine amoxicillin (AMX), metronidazole (MET) and vonoprazan (VPZ) in bulk powder and combined tablet mixture. Full separation of AMX, MET and VPZ is accomplished using C8 column, and a gradient mobile phase system, composed of methanol and phosphate buffer of a pH value of 5. Fine linearity in the concentration ranges 50-600 µg mL-1 amoxicillin, 50-400 µg mL-1 metronidazole and 10-100 µg mL-1 vonoprazan was denoted by the high correlation coefficient (0.9999). The method accuracy and precision are confirmed upon analyzing AMX, MET and VPZ triple therapy not only in their synthetic mixtures and combined tablet mixtures but also in their combined tablet mixtures in simulated gastric fluid. AMX, MET and VPZ triple therapy could be routinely analyzed in QC labs, in case of being co-formulated, using the presented method. Three different assessment tools were adopted revealing the benign environmental impact of presented method.

Long-Term Outcomes Associated With β-Lactam Allergies

Importance

β-lactam (BL) allergies are the most common drug allergy worldwide, but most are reported in error. BL allergies are also well-established risk factors for adverse drug events and antibiotic-resistant infections during inpatient health care encounters, but the understanding of the long-term outcomes of patients with BL allergies remains limited.

Objective

To evaluate the long-term clinical outcomes of patients with BL allergies.

Design, Setting, and Participants

This longitudinal retrospective cohort study was conducted at a single regional health care system in western Pennsylvania. Electronic health records were analyzed for patients who had an index encounter with a diagnosis of sepsis, pneumonia, or urinary tract infection between 2007 and 2008. Patients were followed-up until death or the end of 2018. Data analysis was performed from January 2022 to January 2024.

Exposure

The presence of any BL class antibiotic in the allergy section of a patient's electronic health record, evaluated at the earliest occurring observed health care encounter.

Main Outcomes and Measures

The primary outcome was all-cause mortality, derived from the Social Security Death Index. Secondary outcomes were defined using laboratory and microbiology results and included infection with methicillin-resistant Staphylococcus aureus (MRSA), Clostridium difficile, or vancomycin-resistant Enterococcus (VRE) and severity and occurrence of acute kidney injury (AKI). Generalized estimating equations with a patient-level panel variable and time exposure offset were used to evaluate the odds of occurrence of each outcome between allergy groups.

Results

A total of 20 092 patients (mean [SD] age, 62.9 [19.7] years; 12 231 female [60.9%]), of whom 4211 (21.0%) had BL documented allergy and 15 881 (79.0%) did not, met the inclusion criteria. A total of 3513 patients (17.5%) were Black, 15 358 (76.4%) were White, and 1221 (6.0%) were another race. Using generalized estimating equations, documented BL allergies were not significantly associated with the odds of mortality (odds ratio [OR], 1.02; 95% CI, 0.96-1.09). BL allergies were associated with increased odds of MRSA infection (OR, 1.44; 95% CI, 1.36-1.53), VRE infection (OR, 1.18; 95% CI, 1.05-1.32), and the pooled rate of the 3 evaluated antibiotic-resistant infections (OR, 1.33; 95% CI, 1.30-1.36) but were not associated with C difficile infection (OR, 1.04; 95% CI, 0.94-1.16), stage 2 and 3 AKI (OR, 1.02; 95% CI, 0.96-1.10), or stage 3 AKI (OR, 1.06; 95% CI, 0.98-1.14).

Conclusions and Relevance

Documented BL allergies were not associated with the long-term odds of mortality but were associated with antibiotic-resistant infections. Health systems should emphasize accurate allergy documentation and reduce unnecessary BL avoidance.

Direct oral challenge for immediate and non-immediate beta-lactam allergy in children: A real-world multicenter study

BACKGROUND

Allergy to beta-lactam antibiotics (BLA) is frequently suspected in children, but a drug provocation test (DPT) rules it out in over 90% of cases. Direct oral DPT (DODPT), without skin or other previous tests, is increasingly been used to delabel non-immediate BLA reactions. This real-world study aimed to assess the safety and effectiveness of DODPT in children with immediate and non-immediate reactions to BLAs.

METHODS

Ambispective registry study in children (<15 years), attended between 2016 and 2023 for suspected BLA allergy in 15 hospitals in Spain that routinely perform DODPT.

RESULTS

The study included 2133 patients with generally mild reactions (anaphylaxis 0.7%). Drug provocation test with the implicated BLA was performed in 2014 patients (94.4%): 1854 underwent DODPT (86.9%, including 172 patients with immediate reactions). One hundred forty-five (7.2%) had symptoms associated with DPT, although only four reactions were severe: two episodes of anaphylaxis and two of drug-induced enterocolitis syndrome, which resolved rapidly with treatment. Of the 141 patients with mild reactions in the first DPT, a second DPT was considered in 87 and performed in 57, with 52 tolerating it without symptoms. Finally, BLA allergy was ruled out in 90.9% of the sample, confirmed in 3.4%, and remained unverified, usually due to loss to follow-up, in 5.8%.

CONCLUSIONS

Direct oral DPT is a safe, effective procedure even in immediate mild reactions to BLA. Many reactions observed in DPT are doubtful and require confirmation. Severe reactions are exceptional and amenable to treatment. Direct oral DPT can be considered for BLA allergy delabeling in pediatric primary care.

Recent findings on drug hypersensitivity in children

Drug hypersensitivity reactions (DHR) in children have a significant impact on clinical practice and public health. Both under-diagnosis (due to under-reporting) and over-diagnosis (due to the overuse of the term "allergy") are potential issues. The aim of this narrative review is to describe the most recent findings of DHR in children/adolescents and gaps regarding epidemiology, antibiotic allergy, antiepileptic hypersensitivity, vaccine allergy, and severe cutaneous adverse reactions (SCAR) in this age group.

The impact of antibiotic stewardship interventions and patient related factors on antibiotic prescribing in a vascular surgical department

PURPOSE

The development of guidelines tailored to the departments' needs and counselling during ward rounds are important antibiotic stewardship (AS) strategies. The aim was to analyse the impact of AS ward rounds and institutional guidelines as well as patient-related factors on antibiotic use in vascular surgical patients.

METHODS

A retrospective prescribing-analysis of 3 months (P1, P2) before and after implementing weekly AS ward rounds and antimicrobial treatment guidelines was performed. Choice of systemic antibiotics, days of antibiotic therapy and clinical data were obtained from electronic patient records.

RESULTS

During P2, the overall antibiotic consumption as well as the use of last-resort compounds like linezolid and fluoroquinolones decreased distinctly (overall: 47.0 days of therapy (DOT)/100 patient days (PD) vs. 35.3 DOT/100PD, linezolid: 3.7 DOT/100PD vs. 1.0 DOT/100PD, fluoroquinolones: 7.0 DOT/100PD vs. 3.2 DOT/100PD) while narrow-spectrum beta-lactams increased by 48.4%. Courses of antibiotics were de-escalated more often during P2 (30.5% vs. 12.1%, p = 0.011). Only in P2, an antibiotic therapy was initiated in patients suffering from more comorbidities (i.e. higher Charlson Comorbidity Index) more frequently. Other patient factors had no distinct impact on antibiotic prescribing.

CONCLUSION

Weekly AS ward rounds improved adherence to institutional antibiotic treatment guidelines and antibiotic prescribing in vascular surgical patients. Clear patient-related determinants affecting choice of antibiotic therapies could not be identified.

The Burden of Self-Reported Antibiotic Allergies in Health Care and How to Address It: A Systematic Review of the Evidence

BACKGROUND

Antibiotics are the first-line treatment for bacterial infections; however, overuse and inappropriate prescribing have made antibiotics less effective with increased antimicrobial resistance. Unconfirmed reported antibiotic allergy labels create a significant barrier to optimal antimicrobial stewardship in health care, with clinical and economic implications.

OBJECTIVE

A systematic review was conducted to summarize the impact of patient-reported antibiotic allergy on clinical outcomes and various strategies that have been employed to effectively assess and remove these allergy labels, improving patient care.

METHODS

The review was undertaken using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A critical appraisal was conducted on all studies and a narrative synthesis was performed to identify themes.

RESULTS

Four themes emerged: the prevalence of antibiotic allergy, impact of antibiotic allergy on antimicrobial prescribing, impact of antibiotic allergy on clinical outcomes, and delabeling strategies to improve clinical outcomes. Of the 32 studies, including 1,089,675 participants, the prevalence of reported antibiotic allergy was between 5% and 35%. Patients with a reported antibiotic allergy had poorer concordance with prescribing guidelines in 30% to 60% of cases, with a higher use of alternatives such as quinolone, tetracycline, macrolide, lincosamide, and carbapenem and lower use of beta-lactam antibiotics. Antibiotic allergy delabeling was identified as an intervention and recommendation to advance the state of the science.

CONCLUSIONS

There is substantial evidence within the literature that antibiotic allergy labels significantly impact patient clinical outcomes and a consensus that systematic assessment of reported antibiotic allergies, commonly referred to as delabeling, improves the clinical management of patients.

Characterizing Antibiotic Allergy Labels in a Large UK Hospital Population to Inform Antimicrobial Stewardship and Delabeling Assessment Strategy

BACKGROUND

Antibiotic allergy labels are important barriers to treatment and antimicrobial stewardship, but their prevalence in UK hospitals is poorly described.

OBJECTIVE

To ascertain the prevalence and characteristics of antibiotic allergy labels in a large UK hospital setting and estimate the proportion of penicillin allergy labels for which point-of-care (POC) delabeling assessment would be appropriate.

METHODS

Electronic health records data were analyzed from all patients treated at Cambridge University Hospitals NHS Foundation Trust in 2019. Validated POC delabeling risk stratification criteria were retrospectively applied to penicillin allergy labels.

RESULTS

Recorded reactions to antibiotics were present in 11.8% of all patients (32,148 of 273,216), 16.3% of inpatients (13,874 of 85,230), and 9.7% of outpatients (18,274 of 187,986). Penicillins were the commonest reaction precipitant described (9.0% of patients; 24,646 of 273,216), followed by sulfonamides/trimethoprim (1.4%; 3869 of 273,216) and macrolides/lincosamides (1.3%; 3644 of 273,216). A total of 3.9% of inpatients had recorded reactions to >1 antibiotic class (3348 of 85,230). Cutaneous manifestations were the most commonly described reaction features (40.7% of labels; 15,821 of 38,902). Of 15,949 labels describing probable or possible penicillin "allergy" with sufficient detail to allow for the retrospective assessment of POC delabeling suitability, 1702 were deemed suitable for removal or downgrading of the label to "intolerance" without further investigation (10.7%), 11,887 were appropriate for POC assessment using an oral penicillin challenge (OPC) or OPC with prior bedside skin testing (74.5%), and 2360 were identified as unsuitable for any form of POC assessment (14.8%).

CONCLUSIONS

Antibiotic allergy labels are highly prevalent in a UK hospital setting. A large proportion of penicillin allergy labels may be suitable for POC delabeling assessment.

Delabeling of Penicillin Allergy: Room for Improvement

BACKGROUND

Penicillin allergy labels have been shown to be associated with suboptimal treatment, negative health outcomes, and increased antibiotic resistance. Many inpatients claim to have penicillin allergy, but studies show that allergy can be disproved and the label removed in up to 90% of cases.

OBJECTIVES

The purpose of the study was to investigate the proportion of patients with a penicillin allergy label in a Danish hospital and to classify patients according to the risk of having penicillin allergy in "no risk," low, and high risk.

METHODS

For 22 days, inpatients with penicillin allergy labels were interviewed, had their dispensed penicillin prescriptions examined, and were subsequently categorized into risk groups based on the risk evaluation criteria in national guidelines.

RESULTS

In total, 260 patients had a penicillin allergy label (10% of the inpatients). Out of 151 included patients, 25 were "no risk" patients (17%), who could potentially have their penicillin allergy label removed without testing. 42 were low-risk patients (28%). 10 "no risk" patients and 20 low-risk patients had been prescribed and dispensed one or more penicillins despite an allergy label.

CONCLUSION

Ten percent of inpatients have a penicillin allergy label in a Danish hospital. 17% of these could potentially have their penicillin allergy label removed without allergy testing.

Impact of Penicillin Allergy Label on Clinical Outcomes of Pneumonia in Children

BACKGROUND

Penicillin (PCN) allergy label, reported in approximately 5% of children, influences antibiotic choice and prolongs hospital stay. To our knowledge, the impact of PCN allergy label on clinical outcomes of pneumonia in children is not well characterized.

OBJECTIVES

To investigate the impact of PCN allergy label on clinical outcomes of pneumonia in children.

METHODS

In this propensity score-matched cohort study, we used the TriNetX research network, a population-based database, to compare the 30-day risk of hospitalization, need for intensive level of care, and acute respiratory failure from pneumonia between pediatric patients (aged 1-17 years) with and without a PCN allergy label after matching the 2 cohorts for demographic and medical comorbidities. Antibiotic prescription patterns were also contrasted.

RESULTS

When comparing 3793 pediatric patients with pneumonia labeled with a PCN allergy with matched children without a PCN allergy label, PCN allergy label was associated with a higher risk of hospitalization (relative risk [RR], 1.15; 95% confidence interval [CI], 1.07-1.23), acute respiratory failure (RR, 1.27; 95% CI, 1.17-1.39), and need for intensive level of care (RR, 1.46; 95% CI, 1.15-1.84). PCN allergy label resulted in overutilization of broader-spectrum antibiotics and increased complications including cutaneous drug reactions (RR, 2.43; 95% CI, 1.31-4.52) and Clostridioides difficile infection (RR, 2.25; 95% CI, 1.14-4.44).

CONCLUSION

Children with a PCN allergy label are more likely to be hospitalized, receive broader-spectrum antibiotics, and develop acute respiratory failure from pneumonia. Delabeling may offer a way to lessen morbidity from pneumonia in children.

Relationship of Reaction History to Positive Penicillin Skin Tests

BACKGROUND

Previous data suggest that up to one-third of patients classified as allergic based on positive penicillin skin tests have a vague reaction history. Direct oral challenge (DOC) has been recommended for patients with a low-risk reaction history. A variety of published models stratify reaction risk to guide the use of DOC.

OBJECTIVE

To reassess the proportion of penicillin skin test-positive patients with vague or low-risk reaction histories and evaluate the relationship between the reaction risk history and the likelihood of positive skin test results.

METHODS

We identified patients who underwent penicillin allergy evaluation over a 5-year period. We recorded drug reaction history, demographic variables, skin testing, and challenge results. Matched controls whose skin tests were negative were identified for skin test-positive patients. Drug reaction histories were assigned a risk category based on 2 previously published risk stratification models. We used logistic regression to investigate whether reaction history risk was associated with positive skin test results.

RESULTS

Penicillin skin testing was performed in 3382 patients; 207 (6.1%) were positive. Positive skin tests were more frequent in outpatients (P < .001), younger patients (P < .001), and female patients (P < .001). Percentages of each risk category in each model were similar in cases versus matched controls. The likelihood for positive skin tests increased with a high-risk reaction history in one stratification model.

CONCLUSION

Our data confirm that a substantial proportion of patients who self-report penicillin allergy and have positive skin test results have a low-risk history and imply that penicillin skin testing is associated with a poor positive predictive value.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Artificial intelligence and the potential for perioperative delabeling of penicillin allergies for neurosurgery inpatients

PURPOSE OF THE ARTICLE

Patients with penicillin allergy labels are more likely to have postoperative wound infections. When penicillin allergy labels are interrogated, a significant number of individuals do not have penicillin allergies and may be delabeled. This study was conducted to gain preliminary evidence into the potential role of artificial intelligence in assisting with perioperative penicillin adverse reaction (AR) evaluation.

MATERIAL AND METHODS

A single-centre retrospective cohort study of consecutive emergency and elective neurosurgery admissions was conducted over a two-year period. Previously derived artificial intelligence algorithms for the classification of penicillin AR were applied to the data.

RESULTS

There were 2063 individual admissions included in the study. The number of individuals with penicillin allergy labels was 124; one patient had a penicillin intolerance label. Of these labels, 22.4% were not consistent with classifications using expert criteria. When the artificial intelligence algorithm was applied to the cohort, the algorithm maintained a high level of classification performance (classification accuracy 98.1% for allergy versus intolerance classification).

CONCLUSIONS

Penicillin allergy labels are common among neurosurgery inpatients. Artificial intelligence can accurately classify penicillin AR in this cohort, and may assist in identifying patients suitable for delabeling.

A Comparison of Doxycycline and Amoxicillin Containing Quadruple Eradication Therapy for Treating Helicobacter pylori-Infected Duodenal Ulcers: A Multicenter, Opened, Randomized Controlled Trial in China

Background: Increased antibiotic resistance is one of the major factors contributing to the failure of H. pylori eradication. This study aimed to compare the efficacy and safety of doxycycline and amoxicillin, both critical components for bismuth-based quadruple therapy, for the first-line treatment of H. pylori-infected duodenal ulcers. Methods: An open, randomized case-controlled, multicenter trial was conducted in seven hospitals in China. A total of 184 eligible participants were divided into an IDFB (ilaprazole 5 mg, doxycycline 100 mg, furazolidone 100 mg, and bismuth 220 mg bid) or IAFB (ilaprazole 5 mg, amoxicillin 1000 mg, furazolidone 100 mg, and bismuth 220 mg bid) group for 14 days. Both groups were administrated with ilaprazole 5 mg qd for another 14 days. The main outcome was an H. pylori eradication rate; secondary outcomes were ulcer healing, relief of symptoms, and incidence of adverse effects. Results: The H. pylori eradication rates were 85.9% (95% CI 78.6−93.9) in the IDFB vs. 84.8% (95% CI 77.3−92.3) in the IAFB group in ITT analysis (p > 0.05), and 92.9% (95% CI 87.4−98.5) vs. and 91.8% (95% CI 85.8−97.7) in PP analysis (p > 0.05). The overall ulcer healing rates of IDFB and IAFB were 79.1% and 84.7% (p > 0.05), both effective in relieving symptoms. Only nine participants had adverse reactions in this trial (4/92 in IDFB and 5/92 in IAFB). Conclusion: A bismuth quadruple regimen containing doxycycline or amoxicillin could be an effective and safe treatment for H. pylori eradication, while doxycycline replacement is an alternative for participants with penicillin allergy.

Drug allergy evaluation in children with suspected mild antibiotic allergy

Background

Adverse antibiotic reactions caused by an immunological mechanism are known as allergic reactions. The percentage of reported antibiotic allergies is likely to differ from the one validated after a drug provocation test (DPT) with the culprit antibiotic. This study aimed to compare the percentage of children who were thought to be allergic to a certain antibiotic with those who have a true allergy, as confirmed by DPTs. We also validated Skin Prick Tests (SPTs) and Intradermal Tests (IDTs) by assessing their sensitivity and specificity, in diagnosing antibiotic allergies using DPT as the gold standard. Furthermore, we investigated epidemiological risk factors such as personal and family history of atopic disease and eosinophilia.

Methods

Children with a history of possible allergic reaction to an antibiotic underwent a diagnostic procedure that included: (1) Eosinophil blood count, (2) SPTs, (3) IDTs and (4) DPTs. The parameters were compared with Pearson's Chi-Square and Fisher's Exact Test. Several risk factors that were found significant in univariate analysis, such as personal and family history of atopic disease, and positive SPTs and IDTs were examined with multiple logistic regression analysis to see if they were related to a higher risk for a positive DPT.

Results

Semi-synthetic penicillin was the most common group of antibiotics thought to cause allergic reactions in this study. Overall, 123 children with a personal history of an adverse reaction to a certain antibiotic, were evaluated. In 87.8% of the cases, the symptoms had occurred several hours after administration of the culprit antibiotic. Both SPTs and IDTs had low sensitivity but high specificity. Moreover, they had a high positive predictive value (PPV). In contrast, eosinophilia was not recognized as a risk factor. Seventeen patients (13.8%) had a true antibiotic allergy, as confirmed by a positive DPT. A positive IDT was a strong predictor of a positive DPT, along with a positive personal and family history of atopy.

Conclusion

SPTs and IDTs are very reliable in confirming antibiotic allergy when found positive. A negative result of a SPT highly predicts a negative DPT. A positive IDT and a positive personal and family history of atopy were recognized as significant risk factors for antibiotic allergy.

Differences in beta-lactam and penicillin allergy: Beyond the West and focusing on Asia-Pacific

Beta-lactam (BL) antibiotic "allergy" labels are common, but often overdiagnosed. Although much research has been focused on the BL allergy and the delabelling process in the West, studies from other parts of the world remain sparse. This review outlines the contrasting global epidemiology, shifting clinical practices and disparities of BL allergy in the Asia-Pacific region compared with the West. Innovative strategies to overcome barriers in BL allergy workup are discussed and potential directions for future research and service development are also proposed.

Individualized surgical antibiotic prophylaxis – why, when, and how?

"Surgical site infections (SSI) greatly concern clinicians, as they are associated with significant morbidity and mortality, prolonged hospitalization, and costs. Antibiotic prophylaxis plays a pivotal role among the procedures that are usually employed for the prevention of surgical-related infections. This narrative review aims to cover some of the particular situations when the clinician might consider individualizing antibiotic prophylaxis for a patient. With the rising incidence of multi-drug resistant bacteria carriage among not only hospitalized or institutionalized patients but also patients from the community, there might be a tendency to use extended-spectrum antibiotics for longer periods for surgical infection prevention. However, the inappropriate use of antibiotics increases the selection pressure, thus favoring the spreading of resistant bacteria. Moreover, specific patient characteristics or pathologies might need to be considered to customize the type, dose, or length of administration of an antibiotic as surgical prophylaxis. Using prosthetic material or prolonged surgeries with large fluid shifts are other situations when individualized antibiotic prophylaxis might be thought of. Keeping in mind that it is of utmost importance that everyone adheres to the current guidelines for surgical antibiotic prophylaxis, customization of local protocols according to well-thought-out strategies might prove beneficial in SSI prevention."

Hong Kong Drug Allergy Delabelling Initiative (HK-DADI) consensus statements for penicillin allergy testing by nonallergists

Introduction

Penicillin allergy testing has been traditionally performed by allergists, but there remains a huge deficit of specialists. A multidisciplinary effort with nonallergists would be invaluable to overcome the magnitude of penicillin allergy labels via the Hong Kong Drug Allergy Delabelling Initiative (HK-DADI). These consensus statements (CSs) offer recommendations and guidance to enable nonallergists to screen for low-risk (LR) patients and perform penicillin allergy testing.

Methods

CSs were formulated by the HK-DADI Group using the Delphi method. An agreement was defined as greater than or equal to 80% consensus.

Results

A total of 26 CSs reached consensus after multiple rounds of Delphi. CSs were categorized into risk assessment, skin testing, drug provocation testing (DPT), and post-testing management. For risk assessment, the essentials of allergy history and exclusion criteria were detailed. Patients with only LR features can proceed with testing by nonallergists. Skin tests should be performed prior to DPT. Details regarding the timing, preparation, and interpretation of skin tests were elaborated. DPT remains the gold standard to diagnose genuine allergy or tolerance and should be performed when there is a low pretest probability following negative skin testing. Details of DPT preparations, dosing protocols, and interpretation were elaborated. For post-testing management, inaccurate allergy labels should be delabeled following negative DPT with proper patient counseling.

Conclusion

CSs support penicillin allergy testing by nonallergists in Hong Kong. LR cases can be managed by nonallergists at Spoke Clinics, with training and support of an allergist-led Hub.

Association of antibiotic allergy labels with hospital length of stay

BACKGROUND

Many antibiotic allergy labels (AAL) are invalid. Excluding true allergy in people with AAL ("delabeling") could improve health outcomes and decrease costs. Several studies with limited covariate adjustment have associated AAL with a prolonged hospital length of stay (LOS).

OBJECTIVE

This study determined whether AAL's association with LOS persisted after extensive adjustment for potential confounders and covariates.

METHODS

All nonpsychiatric admissions to a tertiary care teaching hospital from 2012 to 2015 were included. Generalized estimating equation methods were used to model the daily discharge likelihood as a function of AAL and other important factors (death risk score, daily discharge score, daily severity of illness score, antibiotic use, hospital day and location, weekend-holiday status, and service).

RESULTS

A total of 111,611 admissions (76,460 patients) were studied, in which 16,489 (14.8%) had recorded AAL. Patients with an AAL had a notably greater disease burden: they were older and had more comorbidities, greater health system utilization, and higher death risk. In the univariate analysis, AAL was associated with a significantly decreased daily discharge likelihood (odds ratio [OR], 0.93; [95% confidence interval, 0.90-0.95]). After adjustment for potential confounders and covariates, AAL was not associated with daily discharge likelihood (adjusted OR [aOR] without antibiotics: 1.00 [0.98-1.03]; aOR with antibiotics: 1.02 [0.99-1.04]). Similar results were also seen with penicillin AAL (aOR without antibiotics: 0.99 [0.95-1.02]; aOR with antibiotics: 1.00 [0.96-1.03]).

CONCLUSION

Antibiotic allergy label was strongly associated with a greater disease burden. After adjusting for important covariates, our analysis found no significant association between AAL and hospital LOS.

Safer prescription of drugs: impact of the PREFASEG system to aid clinical decision-making in primary care in Catalonia

BACKGROUND

In 2008, the Institut Català de la Salut (ICS, Catalan Health Institute) implemented a prescription decision support system in its electronic clinical workstation (ECW), which automatically generates online alerts for general practitioners when a possible medication-related problem (MRP) is detected. This tool is known as PREFASEG, and at the time of beginning a new treatment, it automatically assesses the suitability of the treatment for the individual patient. This analysis is based on ongoing treatments, demographic characteristics, existing pathologies, and patient biochemical variables. As a result of the assessment, therapeutic recommendations are provided. The objective of this study is to present the PREFASEG tool, analyse the main alerts that it generates, and determine the degree of alert acceptance.

METHODS

A cross-sectional descriptive study was carried out to analyse the generation of MRP-related alerts detected by PREFASEG during 2016, 2017, and 2018 in primary care (PC) in Catalonia. The number of MRP alerts generated, the drugs involved, and the acceptance/rejection of the alerts were analysed. An alert was considered "accepted" when the medication that generated the alert was not prescribed, thereby following the recommendation given by the tool. The MRP alerts studied were therapeutic duplications, safety alerts issued by the Spanish Medicines Agency, and drugs not recommended for use in geriatrics. The prescriptions issued by 6411 ICS PC physicians who use the ECW and provide their services to 5.8 million Catalans through 288 PC teams were analysed.

RESULTS

During the 3 years examined, 67.2 million new prescriptions were analysed, for which PREFASEG generated 4,379,866 alerts (1 for every 15 new treatments). A total of 1,222,159 alerts (28%) were accepted. Pharmacological interactions and therapeutic duplications were the most detected alerts, representing 40 and 30% of the total alerts, respectively. The main pharmacological groups involved in the safety alerts were nonsteroidal anti-inflammatory drugs and renin-angiotensin system inhibitors.

CONCLUSIONS

During the period analysed, 28% of the prescriptions wherein a toxicity-related PREFASEG alert was generated led to treatment modification, thereby helping to prevent the generation of potential safety MRPs. However, the tool should be further improved to increase alert acceptance and thereby improve patient safety.

Direct Challenges for the Evaluation of Beta-Lactam Allergy: Evidence and Conditions for Not Performing Skin Testing

In the western world, up to 10% of the general population and more than 15% of hospitalized patients report penicillin allergy. After a comprehensive evaluation, more than 95% of patients who report a penicillin allergy can subsequently tolerate this antibiotic. Traditionally, the most widely accepted protocol to evaluate beta-lactam (BL) allergy consisted of skin testing (ST) followed by a drug provocation test (DPT) in ST-negative patients. DPT is the gold standard for proving or excluding BL allergy and is considered the final and definitive step in the evaluation. Recently, studies have been published that support the use of direct DPTs without preceding ST for both pediatric and adult patients who report a low-risk historical reaction to BLs. However, these studies use various risk-stratification criteria to determine eligibility for a direct DPT. A standardized protocol for DPT is also lacking. In this review, we assess the current literature and evidence for performing direct DPT in the pediatric and adult populations. On the basis of this evidence, we also present risk-based algorithms for the evaluation of BL allergy in pediatric and adult populations based on a description of the historical reaction.

Burden of antibiotic allergy labels in Australian aged care residents: Findings from a national point-prevalence survey

OBJECTIVE

To determine the prevalence of antibiotic allergy labels (AALs) in Australian aged care residents and to describe the impact of labels on antibiotic prescribing practices.

DESIGN

Point-prevalence survey.

SETTING

Australian residential aged care facilities.

PARTICIPANTS

We surveyed 1,489 residents in 407 aged care facilities.

METHODS

Standardized data were collected on a single day between June 1 and August 31, 2018, for residents prescribed an antibiotic. An AAL was reported if it was documented in the resident's health record. Resident-level data were used to calculate overall prevalence, and antibiotic-level data were used to report relative frequency of AALs for individual antibiotics and classes.

RESULTS

Among 1,489 residents, 356 (24%) had 1 or more documented AALs. The AALs for penicillin (28.3%), amoxicillin or amoxicillin/clavulanic acid (10.5%), cefalexin (7.2%), and trimethoprim (7.0%) were most commonly reported. The presence of an AAL was associated with significantly less prescribing of penicillins (OR, 0.43; 95% CI, 0.31-0.62; P < .001) and significantly more prescribing of lincosamides (OR, 4.81; P < .001), macrolides (OR, 2.03; P = .007), and tetracyclines (OR, 1.54; P = .033). Of residents with AALs, 7 residents (1.9%) were prescribed an antibiotic that was listed on the allergy section of their health record.

CONCLUSIONS

A high prevalence of AALs was observed among residents of Australian aged care facilities, comparable to the prevalence of AALs in high-risk hospitalized patients. Significant increases in prescribing of lincosamide, macrolide, and tetracycline agents poses a potential risk to aged populations, and future studies must evaluate the benefits of AAL delabelling programs tailored for aged care settings.

Role of clinical history in beta-lactam hypersensitivity

PURPOSE OF REVIEW

Understand how the clinical history has been used to risk stratify patients reporting a beta-lactam allergy, both in clinical care pathways and predictive models.

RECENT FINDINGS

Drug allergy clinical care pathways have emerged as a safe and effective method of stratifying patients with a reported beta-lactam allergy into risk categories, with 'low-risk' patients able to proceed straight to direct challenges or test doses. These methods have streamlined antibiotic stewardship policies and penicillin allergy de-labeling. However, how to define 'low-risk' has been subject to much debate. New research has developed predictive models that utilize the clinical history to assess a patient's true risk of beta-lactam allergy.

SUMMARY

The clinical history has long been an essential part of drug allergy evaluation and has proven invaluable within the past decade in the development of drug allergy clinical pathways. Evidence-based predictive models that use the clinical history to assess a patient's true risk of beta-lactam allergy offer tremendous promise, but differ in crucial areas such as the populations they study, the predictor variables they use, and the ultimate accuracy they attain. These models highlight key aspects of the drug allergy history and pave the way for future large-scale research.

Beta-lactam allergy labeling in intensive care units: An observational, retrospective study

ABSTRACT

This retrospective study aimed to describe the association between the "β-lactam allergy" labeling (BLAL) and the outcomes of a cohort of intensive care unit (ICU) patients.Retrospective cohort study.Seven ICU of the Aix Marseille University Hospitals from Marseille in France.We collected the uses of the label "β-lactam allergy" in the electronic medical files of patients aged 18 years or more who required more than 48 hours in the ICU with mechanical ventilation and/or vasopressors admitted to 7 ICUs of a single institution.We retrospectively compared the patients with this labeling (BLAL group) with those without this labeling (control group).The primary outcome was the duration of ICU stay. Among the 7146 patients included in the analysis, 440 and 6706 patients were classified in the BLAL group and the control group, respectively. The prevalence of BLAL was 6.2%. In univariate and multivariate analyses, BLAL was weakly or not associated with the duration of ICU and hospital stays (respectively, 6 [3-14] vs 6 [3-14] days, standardized beta -0.09, P = .046; and 18 [10-29] vs 15 [8-28] days, standardized beta -0.09, P = .344). In multivariate analysis, the ICU and 28-day mortality rates were both lower in the BLAL group than in the control group (aOR 0.79 95% CI [0.64-0.98] P = .032 and 0.79 [0.63-0.99] P = .042). Antibiotic use differed between the 2 groups, but the outcomes were similar in the subgroups of septic patients in the BLAL group and the control group.In our cohort, the labeling of a β-lactam allergy was not associated with prolonged ICU and hospital stays. An association was found between the labeling of a β-lactam allergy and lower ICU and 28-day mortality rates.Trial registration: Retrospectively registered.

Implementing a new antibiotic allergy protocol in clinical practice: well-trusted but not used

Background

Suboptimal antibiotic prescriptions in patients with an antibiotic allergy label lead to increased incidence of adverse events and antimicrobial resistance (AMR). An antibiotic allergy protocol was developed in a Dutch academic hospital guiding optimal and safe antibiotic use in potentially penicillin-allergic patients. Informed by previous studies of implementation processes in clinical care, we studied the implementation of this protocol.

Methods

Medical professionals in the Departments of Surgery, Internal Medicine, and Pulmonary Care were interviewed. Additionally, focus groups were conducted in Internal Medicine and Pulmonary Care to validate the outcomes of the interviews.

Results

Dissemination of the protocol via the regular online hospital-wide guidance system did not have a significant impact on the knowledge about or use of the protocol. If healthcare professionals found the protocol, they thought it was valuable and expressed trust in the expertise embodied in it. However, its use in practice was rather minimal. Interviewees doubted the accuracy of the patient’s histories about their previous adverse drug reactions, and/or the information in their medical records and concluded that adherence to the expert guideline was needlessly risky. They felt the acute allergic reaction risk for a patient outweighed the risk of suboptimal therapy or future AMR.

Conclusions

For successful implementation and dissemination of the protocol, the accessibility of the protocol, the information about the actual risks of following the protocol and the registration of allergic history should be improved. However, whether this actually results in improvement also depends on changes in the hospital culture and organization.

Penicillin Allergy Testing Is Cost-Saving: An Economic Evaluation Study

BACKGROUND

Having a penicillin allergy label is associated with the use of less appropriate and more expensive antibiotics and increased healthcare utilization. Penicillin allergy testing results in delabeling most allergy claimants and may be cost-saving. This study aimed to project whether penicillin allergy testing in patients reporting a penicillin allergy is cost-saving.

METHODS

In this economic evaluation study, we built decision models to project the economic impact of 2 strategies for a patient with a penicillin allergy label: (1) perform diagnostic testing (drug challenges, with or without skin tests); and (2) do not perform diagnostic testing. The health service perspective was adopted, considering costs with penicillin allergy tests, and with hospital bed-days/outpatient visits, antibiotic use, and diagnostic testing. Twenty-four base case decision models were built, accounting for differences in the diagnostic workup, setting (inpatient vs outpatient) and geographic region. Uncertainty was explored via probabilistic sensitivity analyses.

RESULTS

Penicillin allergy testing was cost-saving in all decision models built. For models assessing the performance of both skin tests and drug challenges, allergy testing resulted in average savings (in United States [US] dollars) of $657 for inpatients (US: $1444; Europe: $489) and $2746 for outpatients (US: $256; Europe: $6045). 75% of simulations obtained through probabilistic sensitivity analysis identified testing as the less costly option.

CONCLUSIONS

Penicillin allergy testing was projected to be cost-saving across different scenarios. These results are devised to inform guidelines, supporting the adoption of policies promoting widespread testing of patients with a penicillin allergy label.

Allergy to penicillin and betalactam antibiotics

Betalactams are the most frequent cause of hypersensitivity reactions to drugs mediated by a specific immune mechanism. Immediate reactions occur within 1 to 6 hours after betalactam administration, and are generally IgE-mediated. They clinically translate into urticaria, angioedema and anaphylaxis. Non-immediate or delayed reactions occur after 1 hour of administration. These are the most common reactions and are usually mediated by T cells. The most frequent type is the maculopapular or morbilliform exanthematous eruption. Most individuals who report allergies to penicillin and betalactams can tolerate this group of antibiotics. To make diagnosis, a detailed medical history is essential to verify whether it was an immediate or non-immediate reaction. Thereafter, in vivo and/or in vitro tests for investigation may be performed. The challenging test is considered the gold standard method for diagnosis of betalactam hypersensitivity. The first approach when suspecting a reaction to betalactam is to discontinue exposure to the drug, and the only specific treatment is desensitization, which has very precise indications. The misdiagnosis of penicillin allergy affects the health system, since the "penicillin allergy" label is associated with increased bacterial resistance, higher rate of therapeutic failure, prolonged hospitalizations, readmissions, and increased costs. Thus, it is essential to develop strategies to assist the prescription of antibiotics in patients identified with a label of "betalactam allergy" at hospitals, and to enhance education of patients and their caregivers, as well as of non-specialist physicians.

Assessing Use of a Standardized Allergy History Questionnaire for Patients with Reported Allergy to Penicillin

BACKGROUND

Inappropriate allergy labelling is associated with significant clinical and pharmacoeconomic implications. Detailed antimicrobial allergy assessments represent a key component of antimicrobial stewardship and aid in identifying true type I (immediate hypersensitivity) reactions. The allergy history form currently used at the University Hospital of Northern British Columbia (UHNBC), in Prince George, relies on the assessor's ability to ask appropriate prompting questions to obtain a thorough history, but it may not be sufficient to accurately identify true allergies.

OBJECTIVE

To compare a standardized allergy history questionnaire and the current allergy history form in terms of the quality and quantity of documentation gathered.

METHODS

This prospective observational study involved patients who were admitted to medical and surgical services at UHNBC from November 2018 to January 2019 with a penicillin-class allergy reported on their electronic medical record (EMR). A list of patients with EMR-reported allergies was generated by the hospital's health information software system, and these patients were interviewed using the standardized allergy history questionnaire.

RESULTS

A total of 48 patients were assessed during the study period. Nineteen (40%) of the patients had an inappropriate allergy label on their EMR. Only 36 (75%) had an allergic reaction described on their EMR. Furthermore, only 36 (75%) of the 48 patients had the same allergy recorded on the EMR and on the allergy history form contained in their paper chart, of whom 22 had a documented reaction. The mean time to complete the standardized allergy history questionnaire was 2 minutes.

CONCLUSIONS

At the study institution, documentation of allergy histories was often incomplete. Detailed allergy assessments are the first step in identifying true immunoglobulin E-mediated hypersensitivity reactions. Utilization of a standardized allergy history questionnaire is feasible and may serve to improve documentation and overall antimicrobial stewardship.

Viral Infections and Cutaneous Drug-Related Eruptions

In the general population, up to 10% of children treated by antibiotics have cutaneous adverse drug reaction, but allergy is confirmed in less than 20% of patients. Most of the non-allergic reactions are probably due to virus, such as enterovirus acute infection or Ebstein-Barr Virus (EBV) acute infection or reactivation. Especially in children, viruses have the propensity to induce skin lesions (maculopapular rash, urticaria) due to their skin infiltration or immunologic response. In drug-related skin eruptions, a virus can participate by activating an immune predisposition. The culprit antibiotic is then the trigger for reacting. Even in severe drug-induced reactions, such as Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome, viruses take part in immune phenomena, especially herpes viruses. Understanding the mechanisms of both virus- and drug-induced skin reaction is important to develop our clinical reflection and give an adaptive care to the patient. Our aim is to review current knowledge on the different aspects and potential roles of viruses in the different type of drug hypersensitivity reactions (DHR). Although major advances have been made those past year, further studies are needed for a better understanding of the link between viruses and DHR, to improve management of those patients.

Prevalence of Antibiotic Allergy Labels in a Tertiary Referral Center in Belgium

BACKGROUND

Antibiotic (AB) allergies are among the most frequently occurring adverse drug reactions. In US literature, AB allergy labels (AAL) are reported in 10% to 15% of patients' charts; however, large-scale European analyses are scarce.

OBJECTIVES

To retrospectively assess the prevalence of AAL in a tertiary referral hospital in Belgium between 2010 and 2018.

METHODS

Patients who consulted and/or were hospitalized during the study period, who had been labeled with an AB allergy, were selected for further analysis.

RESULTS

Of 1,009,598 unique patients (outpatients, n = 736,469; inpatients, n = 273,129), 28,147 patients (3%) were registered with 1 or more AAL, being 1% of outpatients (n = 9562) and 7% of inpatients (n = 18,585). Women were more likely to carry an AAL (68%) compared with men (32%, P < .001). In patients with an AAL, 9% had multiple labels and 5% had labels for multiple AB classes. Most frequently, beta-lactams were involved (84% of AAL), followed by quinolones (7%) and sulfonamides and macrolides (both 3%). Moreover, 88% of the reactions were self-reported, mostly being an unspecified rash (53%), whereas only 3% were considered confirmed AAL.

CONCLUSION

With an overall prevalence of 3%, the burden of AAL is less in our Western European center compared with US reports. However, this prevalence most likely still represents an overestimation of genuine AB allergic patients because most labels lack confirmation and/or specifications. Our work indicates that knowledge of the local epidemiology of AAL is necessary to estimate the impact of better allergy labeling and delabeling strategies.

High-cost, high-need patients: the impact of reported penicillin allergy

OBJECTIVES

More than 90% of patients who report a penicillin allergy have the allergy disproved when tested. Unnecessary use of alternative (non-beta-lactam) antibiotics can result in more treatment failures and adverse reactions. We described the prevalence and impact of a reported penicillin allergy in high-cost, high-need (HCHN) patients.

STUDY DESIGN

Retrospective cohort.

METHODS

We identified HCHN patients in a care management program of an urban academic medical center (January 1, 2014, to December 31, 2016). We used multivariable logistic regression models to determine the association between a reported penicillin allergy and antibiotic use. We used multivariable Poisson regression models to determine the association between a reported penicillin allergy, with or without multiple drug intolerance syndrome (MDIS; ≥3 reported drug allergies), and healthcare resource utilization (HRU).

RESULTS

Of 1870 HCHN patients, 383 (20%) reported penicillin allergy, 835 (45%) had MDIS, and 290 (16%) had both. HCHN patients reporting penicillin allergy had an increased odds of beta-lactam alternative antibiotic use (adjusted odds ratio, 3.84; 95% CI, 2.17-6.80). HRU was significantly higher for patients reporting a penicillin allergy alone (adjusted relative risk [aRR], 1.13; 95% CI, 1.03-1.25) and with concurrent MDIS (aRR, 1.20; 95% CI, 1.08-1.34).

CONCLUSIONS

HCHN patients had a high burden of reported drug allergy. A reported penicillin allergy conferred a 4-fold increased odds of beta-lactam alternative antibiotic use. Reporting penicillin allergy, with and without MDIS, was associated with significantly more HRU. HCHN care management programs should consider systematic drug allergy evaluations to optimize antibiotic use in these fragile patients.

Drug hypersensitivity in children: a retrospective analysis of 101 pharmacovigilance reports

Our objective was to describe and discuss management of recent cases of drug hypersensitivity in children reported in a pharmacovigilance center. Two pediatric allergy units conducted a collaborative retrospective analysis of 101 adverse drug reactions reported to a regional pharmacovigilance center between January 2016 and July 2019. Time lapse between hypersensitivity reaction onset and allergy consultation varied from 1 month to 12 years. Sixty-two patients (61.4%) presented with immediate reactions, 11 (10.9%) with non-immediate reactions, and 28 (27.7%) had reactions impossible to classify through medical interview. Overall, 92 children (91%) were explored for simultaneously administered drugs. All 113 prick tests were negative, and 2 were uncertain. Among 108 intradermal tests, 2 were positive to penicillin and to an iodinated contrast medium, 105 were negative, and 1 was uncertain. Overall, 129 drug provocation tests were proposed. Nine provocation tests among 80 were positive (11.25%): 6 to penicillin, 1 to sulfonamide antibiotics, and 2 to non-steroidal anti-inflammatory drugs; the remaining 71 were negative. No severe reaction was observed during these tests. Finally, drug allergy was only retained in 11 reported cases (10.9%).Conclusion: These pharmacovigilance reports show the difficulty in defining drug allergy in children only by anamnesis, and that explorations, particularly provocation tests, should take place at a reasonable time lapse after drug hypersensitivity reaction onset. What is Known: • True drug allergy is rarely observed in children. • Absence of full workup leads to falsely labeling children as "allergic." What is New: • Short time lapse between hypersensitivity onset and consultation improves classification of pediatric allergy. • Timely allergy consultations are essential, and tests are useful to confirm or exclude pediatric allergy.

Impact of Beta-Lactam Allergies on Selection of Antimicrobials in an Inpatient Setting Among Veteran Population

Purpose

Beta-lactam antibiotics are among the most common and widely used antibiotics. However, reported allergy to this class of antibiotics is also common, leading to the use of alternative broad-spectrum antibiotics by healthcare providers. This has led to the emergence of various negative health outcomes. The purpose of the study is to investigate the impact of using alternative antibiotics secondary to a beta-lactam allergy among U.S. veterans who have otherwise multiple comorbidities.

Methods

This retrospective observational analysis was conducted over a 5-year period (January 1, 2011 to December 31, 2016) at the Memphis Veterans Affairs Medical Center (VAMC). Admitted patients with a documented beta-lactam allergy were categorized to preferred or non-preferred status based on initial antibiotic therapy antibiotic, allergy history, published guidelines, and local antibiogram. Preferred therapy was defined as the optimal antibiotic treatment for a given indication based on patient allergy history, published Infectious Disease Society of America guidelines, and local antibiogram of Memphis VAMC. The therapy was classified as “non-preferred” if it did not satisfy the preferred therapy criteria. Non-preferred treatments were further assessed for appropriateness based on indication and patient-specific factors. Chi-square and Fisher’s exact tests were conducted to find a difference in rates of negative sequelae among patients receiving preferred vs. non-preferred treatments and appropriate vs. inappropriate treatments.

Findings

Of the 1806 admissions identified, data were collected on 95 unique patients with 147 different antibiotic regimens. There were 68 (52%) preferred treatment regimens and 64 (48%) non-preferred treatment regimens. Of the 64 non-preferred treatments, 43 (67%) were inappropriate. There was a statistically significant decrease in the number of adverse drug events and in the combined negative sequelae outcome among patients receiving preferred therapy vs. non-preferred therapy (2 vs. 12; P &lt; .01 and 11 vs. 23; P &lt; .01, respectively).

Implications

The receipt of non-preferred antibiotic therapy among veterans with a recorded beta-lactam allergy may be associated with an increased risk of developing negative outcomes. Among military personnel, removing unnecessary beta-lactam allergies would improve readiness with optimal antibiotic choices and avoidance of unnecessary risks, expediting return to full duty.

Impact of a structured interview on beta-lactam reaction documentation quality

Incomplete documentation of β-lactam reactions often leads to inappropriate antibiotic prescribing. The objective of this study was to evaluate the impact of a structured interview on the quality of β-lactam reaction documentation. After 203 interviews, documentation of the core components of a β-lactam reaction improved (48% vs 1%; P < .001).

Investigating the impact of a β-lactam allergy label on preoperative antibiotic prophylaxis administration

OBJECTIVE

Surgical site infection (SSI) is a common postprocedure complication that may be prevented by adhering to established recommendations, including administration of preoperative antibiotic prophylaxis. Patients with a β-lactam allergy (BLA) label have an increased risk of SSI. We sought to evaluate the appropriateness of preoperative antibiotic prophylaxis in patients labeled with a BLA compared those without a BLA.

METHODS

This was a single-center, retrospective, matched cohort study of adult patients who underwent a clean or clean-contaminated knee replacement, abdominal hysterectomy, colorectal surgery, or coronary artery bypass graft (CABG). Patients with a BLA label were matched to patients without a BLA label based on procedure, age, and body mass index (BMI). The primary end point was the rate of appropriate preoperative antibiotic prophylaxis, including antibiotic selection and timing prior to incision.

RESULTS

In total, 260 patients were included. Knee replacement (38%) was the most common procedure, followed by abdominal hysterectomy (25%), colorectal surgery (18%), and CABG (18%). Appropriate preoperative antibiotic prophylaxis was higher among patients without a BLA (76% vs 37%; P < .001). Among patients with a mild-to-moderate reaction or intolerance, 29 (53%) received antibiotics that would have been appropriate only if the patient had had a severe BLA. Patients with a BLA were more likely to have had an antibiotic omitted from the prophylactic regimen (44% vs 4%; P < .001).

CONCLUSION

Patients with a BLA were more likely to receive inappropriate preoperative antibiotic prophylaxis, attributed to misinterpretation of BLA labels and antibiotic omissions. Optimizing antibiotic prophylaxis among patients with BLAs remains an area of opportunity to prevent SSIs.

The impact of antibiotic allergy labels on antibiotic exposure, clinical outcomes, and healthcare costs: A systematic review

OBJECTIVE

A growing body of evidence suggests that antibiotic allergy labels as documented in medical records are a risk factor for poor clinical outcomes. In this systematic review, we aimed to determine how antibiotic allergy labels influence 3 domains: antibiotic use and exposure, clinical outcomes, and healthcare-related costs.

DESIGN

We performed a systematic review to identify studies reporting outcomes in patients with antibiotic allergy labels compared to nonallergic counterparts. The search included PubMed, EMBASE, Cochrane CENTRAL, EBSCO, Cochrane Database of Abstracts of Reviews of Effects and Web of Science. Two reviewers independently screened studies for inclusion and abstracted data. Studies were graded using the Newcastle-Ottawa quality assessment scale. Study outcomes included antibiotic use, clinical outcomes, and economic outcomes.

RESULTS

In total, 41 studies met our criteria for inclusion. These studies varied in medical specialty, patient population, healthcare delivery system, and design, but most were conducted among adults age >18 years (85%) in the inpatient setting (82.5%). Among 34 studies examining antibiotic exposure, 32 (94%) found that patients with antibiotic allergy labels received more broad-spectrum antibiotics. Moreover, 31 studies examined clinical outcomes such as length of hospitalization, ICU admission, hospital readmission, multidrug-resistant or opportunistic infection, or mortality, and 27 (87%) found that allergy-labeled patients had at least 1 negative outcome. Of 9 studies examining healthcare costs, 7 (78%) found that allergy-labeled patients incurred significantly higher drug or hospital-related costs.

CONCLUSIONS

Antibiotic allergy labels have negative effects on antibiotic use, clinical outcomes, and economic outcomes in a variety of clinical settings and populations.

The democratization of de-labeling: a review of direct oral challenge in adults with low-risk penicillin allergy

INTRODUCTION

Penicillin antibiotic allergy labels (AALs) are common and lead to significant negative health and health system outcomes. Direct oral challenge offers a rapid and cost-effective way of removing inaccurate AALs and improving outcomes.

AREAS COVERED

A narrative review (Medline, May 2020) of direct oral challenge in low-risk penicillin allergy in adults is described, and the evidence for the safety and efficacy of this approach in inpatients, outpatients, and special patient groups is presented.

EXPERT OPINION

Whilst the current literature demonstrates the safety and efficacy of direct oral challenge in de-labeling low-risk penicillin allergy in adults, novel approaches are needed to improve access to antibiotic allergy assessment and address the growing global need.

Inappropriate Antibiotic Allergy Documentation in Health Records: A Qualitative Study on Family Physicians' and Pharmacists' Experiences

PURPOSE

It is hypothesized that 90% of antibiotic allergies documented in patients' health records are not actual, potentially life threatening, type I allergies mediated by IgE. This distinction is important because such documentation increases antibiotic resistance, as more second-choice and broad-spectrum antibiotics are then used. Evidence is lacking regarding causes of this inappropriate documentation. To develop interventions aimed at improving documentation, we explored experiences of family physicians and pharmacists in this area.

METHODS

We conducted a qualitative study among family physicians and pharmacists using focus group discussions, based on purposeful sampling and a naturalistic approach. Discussions were audio-recorded, transcribed verbatim, and analyzed in duplicate by means of constant comparative technique.

RESULTS

We conducted 4 focus group discussions among 34 family physicians and 10 pharmacists, from which 3 main themes emerged: (1) magnitude and awareness of the problem of inappropriate antibiotic allergy documentation, (2) origin of the problem, and (3) approaches for addressing the problem. Participants noted that the magnitude of contamination of medical files with inappropriate documentation leads to skepticism about current documentation. Major hindering factors are electronic health record systems and electronic communication. In addition, family physicians and pharmacists believed they had insufficient knowledge about antibiotic allergies and called for tools to rectify inappropriate allergy documentation and facilitate proper documentation going forward.

CONCLUSIONS

Family physicians and pharmacists perceive that few documented antibiotic allergies are in fact correct. Electronic health record barriers and communication barriers, as well as a lack of knowledge and facilitating tools, are main causes for numerous inappropriately documented antibiotic allergies and therefore targets for improving documentation in the future.

The diagnosis of hypersensitivity to antibiotics is rarely confirmed by allergy work-up in cystic fibrosis patients

Cystic fibrosis (CF) patients receive many antibiotic treatments for recurrent respiratory infections and frequently report antibiotic hypersensitivity reactions (HSRs). In this retrospective study, medical records of CF patients were reviewed to clarify the clinical features, the culprit antibiotics, and the prevalence of antibiotic HSRs in the CF population. From 601 CF patients, 95 suspected antibiotic HSRs occurred in 60 patients (prevalence of 10.0%). β-Lactams were the most common inducers, but cotrimoxazole was also frequently involved. Seventy-six of 95 suspected HSRs were assessed by allergy workup including skin tests (43/76 reactions) and/or drug reintroduction as a full course of the culprit antibiotic (73 of 76 reactions). From the 43 suspected HSRs that were skin-tested, only three had positive skin tests and were not subjected to drug readministration. All the other 73 suspected HSRs received a full course of the culprit antibiotic: HSR symptoms recurred in 10 of 73 cases and therefore were considered as confirmed antibiotic HSRs; for the remaining 63 suspected HSRs that did not relapse after drug readministration, the diagnosis of antibiotic HSRs was excluded. In summary, 13 of 76 suspected HSRs were confirmed as antibiotic HSRs. The prevalence of suspected and confirmed antibiotic HSRs in CF patients appears similar to that reported in the general population. Of note, most of the antibiotic suspected HSRs are not confirmed after allergology workup. A complete allergy workup appears therefore crucial to make a correct diagnosis and to avoid unnecessary contraindication of major antibiotics.

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.

The Impact of Reported Beta-Lactam Allergy in Hospitalized Patients With Hematologic Malignancies Requiring Antibiotics

Background

Patients hospitalized with hematologic malignancy are particularly vulnerable to infection. The impact of reported beta-lactam (BL) allergy in this population remains unknown.

Methods

This was a retrospective cohort study of adult inpatients with hematologic malignancy admitted at 2 tertiary care hospitals from 2010 through 2015. The primary outcome was hospital length of stay (LOS) after administration of the first antibiotic. Secondary outcomes included readmission, mortality, complications, hospital charges, and antibiotic usage. Our goal was to define the impact of BL-only allergy (BLOA) label on clinical outcomes compared to those with no BL allergy (NBLA) in hematologic malignancy inpatients who required systemic antibiotics.

Results

In our cohort (n = 4671), 38.3% had leukemia, 4.9% had Hodgkin lymphoma, 36.1% had non-Hodgkin lymphoma, and 20.7% had multiple myeloma. Among patients, 35.1% reported antibiotic allergy, and 14.1% (n = 660) had BLOA (including 9.3% with penicillin-only allergy and 3.3% cephalosporin-only allergy). Patients with BLOA had longer median LOS compared to patients with NBLA (11.3 vs 7.6 days, P < .001), which remained significant after multivariable adjustment. Patients with BLOA also had significantly worse outcomes in terms of mortality rate at 30 days (7.6% vs 5.3%, P = .017) and 180 days (15.8% vs 12.2%, P = .013), 30-day readmission rate, Clostridium difficile rate, hospital charges ($223 046 vs $173 256, P < .001), antibiotic classes used, and antibiotic duration.

Conclusions

In hospitalized patients with hematologic malignancy, patients with reported BL allergy had worse clinical outcomes and higher healthcare cost than those without BL allergy label.

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.