Self-reported antibiotic allergy incidence and prevalence: age and sex effects

Prevalence, Characteristics and Factors Associated with Adverse Drug Reactions Among Hospitalized Patients

Objectives: This study aimed to describe the prevalence and characteristics of ADRs and to identify the factors associated with ADRs among hospitalized patients. Methodology: A descriptive cross-sectional study was conducted over a 6 month period at Teaching Hospital Karapitiya (THK), Sri Lanka. A total of 2000 patients, who were admitted consecutively for any type of treatment during the study period were enrolled. The factors associated with ADRs were evaluated using logistic regression models, using ADR occurrence as the outcome. Results: A total of 123 ADRs were found from the sample. The prevalence of ADRs among hospitalized patients was 6.2%. (95% CI 5.1-7.2). ADRs were reported in 62 males (50.4%). The median (IQR) age of ADR occurrence was 52 (35-67) years. The most prevalent type of ADR was Type A (n = 62, 50.4%) and out of the total ADRs, 74 were moderately severe reactions (60.2%). Antibiotics (n = 29, 23.5%) were the most common causative agent for ADRs, followed by anticoagulants (n = 10, 8.1%). The multivariate logistic regression model showed that the number of prescribed drugs (P = .011), ADR history (P = 0 0.01) and diabetes mellitus (P = .003) were significantly associated with the occurrence of ADRs. Age (P = .21), gender (P = .31), ethnicity (P = .14), and other concomitant illnesses (Hypertension P = .66, Ischemic Heart Disease P = .25, etc.) did not associated with the occurrence of ADRs. Conclusion: According to this study the prevalence of ADRs was significant among inward patients in the Teaching Hospital, Karapitiya. The number of prescribed drugs, ADR history and diabetes mellitus were significantly correlated with the occurrence of ADRs. The results of the study can be used to guide healthcare professionals to revise the medication list frequently and monitor the patients who are at risk for developing ADRs.

Implementation of the pharmacovigilance database in the usage of antibiotics in a tertiary care hospital: A pilot study

Background

Antimicrobial resistance (AMR) has evolved into a severe public health issue that defies all current control strategies and needs multidisciplinary, creative solutions. Antimicrobial stewardship (AMS) activities demand a set of tools and abilities that can be used by health systems. In view of the growing AMR and the difficulty for the surveillance of it in the developing country, this study was conducted to incorporate pharmacovigilance (PV) in the AMS program.

Materials and Methods

A cross-sectional pilot study was conducted to collect the PV database of antimicrobials induced adverse drug reactions (ADR) from the Adverse Drug Reactions Monitoring Center (AMC) of the institute for a period of 2 months from August 2022 to September 2022. The information from the database was analyzed to estimate the usage of antibiotics from the PV database from AMC and classified it under the Anatomical Therapeutic Chemical, to assess the rationality of the antimicrobial's usage based on "Access," "Watch," and "Reserve" (AWaRe) classification, and to assess the ADR of the antibiotics. The analysis was done by using the SPSS version 20.0 for Windows.

Results

The results showed that the prevalence of ADRs were more in adults' population with preponderance in female. The antibiotics usage was as per with World Health Organization standard and most of the antibiotics used were from the Access group of AWaRe classifications. Tetracyclines and penicillins were the most used antibiotic group of drugs. The number of patients included in the study was 70. Most of the causality assessment was "possible" (62.85%). In the study, almost 90% of the drug was withdrawn and 70% of the patients were in the recovering stage.

Conclusion

Using existing PV approaches to address usage of antibiotics and AMR issues would allow PV to progress as a field, and governments will get a stronger return on their PV investments.

Protein Haptenation and Its Role in Allergy

Humans are exposed to numerous electrophilic chemicals either as medicines, in the workplace, in nature, or through use of many common cosmetic and household products. Covalent modification of human proteins by such chemicals, or protein haptenation, is a common occurrence in cells and may result in generation of antigenic species, leading to development of hypersensitivity reactions. Ranging in severity of symptoms from local cutaneous reactions and rhinitis to potentially life-threatening anaphylaxis and severe hypersensitivity reactions such as Stephen-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), all these reactions have the same Molecular Initiating Event (MIE), i.e. haptenation. However, not all individuals who are exposed to electrophilic chemicals develop symptoms of hypersensitivity. In the present review, we examine common chemistry behind the haptenation reactions leading to formation of neoantigens. We explore simple reactions involving single molecule additions to a nucleophilic side chain of proteins and complex reactions involving multiple electrophilic centers on a single molecule or involving more than one electrophilic molecule as well as the generation of reactive molecules from the interaction with cellular detoxification mechanisms. Besides generation of antigenic species and enabling activation of the immune system, we explore additional events which result directly from the presence of electrophilic chemicals in cells, including activation of key defense mechanisms and immediate consequences of those reactions, and explore their potential effects. We discuss the factors that work in concert with haptenation leading to the development of hypersensitivity reactions and those that may act to prevent it from developing. We also review the potential harnessing of the specificity of haptenation in the design of potent covalent therapeutic inhibitors.

Antibiotic allergy prevalence and documentation quality in Massachusetts long-term care facilities: A cross-sectional survey

BACKGROUND

Antimicrobial resistance poses a significant global health challenge, particularly affecting older adults who are more susceptible to infections and their complications. Accurate diagnosis and documentation of antibiotic allergies are essential for effective antimicrobial stewardship. Despite the recognized overdiagnosis of antibiotic allergies, comprehensive studies on this subject in long-term care (LTC) settings are limited.

OBJECTIVE

To determine the point prevalence of antibiotic allergies and documentation quality in Massachusetts LTC facilities.

METHODS

We conducted a cross-sectional, 1-day point prevalence survey from July 1, 2023, to March 31, 2024, across 20 participating LTC facilities in Massachusetts in partnership with the Massachusetts Department of Public Health. The survey assessed the prevalence and documentation of antibiotic allergies among 2345 residents. Multivariable logistic regression was used to explore associations between documented penicillin allergy and demographic factors, including non-penicillin antibiotic allergies.

RESULTS

The overall point prevalence of documented antibiotic allergies was 39.1%, with the most frequently reported classes being penicillins at 23.1%, sulfonamides at 15.4%, and cephalosporins at 5.2%. Significant documentation gaps were identified, with up to 92.8% of the allergy records found to be incomplete. Factors associated with documented penicillin allergies included female sex (adjusted odds ratio [aOR], 1.50; 95% CI, 1.16-1.94), White race (aOR, 1.92; 95% CI, 1.25-2.94), having allergies to non-penicillin antibiotics (aOR, 2.89; 95% CI, 2.33-3.59), and receipt of antibiotic (aOR, 2.13; 95% CI, 1.68-2.71).

CONCLUSION

The high prevalence of documented antibiotic allergies and the notable deficiencies in their documentation underscore the urgent need for enhanced antibiotic evaluation, documentation practices, and penicillin delabeling in LTC facilities.

Analysis of Allergy and Hypersensitivity Reactions to COVID-19 Vaccines According to the EudraVigilance Database

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic presented a new challenge in modern medicine: the development of vaccines was followed by massive population vaccinations. A few reports on post-vaccination allergic reactions have made patients and medical personnel uneasy as to COVID-19 vaccines' allergic potential. Most of the studies in this area to date have been small, and some that were based on global databases skipped most of the allergic diseases and concentrated only on anaphylaxis. We aimed to analyze the incidence of serious allergic reactions based on the EudraVigilance (EV) database, regardless of the reported symptoms and allergy mechanism.

METHODS

The total number of administrated vaccine doses was extracted on 5 October 2023 from Vaccine Tracker and included all administrations since vaccinations began in the European Economic Area (EEA). Data on serious allergic reactions to COVID-19 vaccines were extracted from the EudraVigilance database with the same time point. The code names of 147 allergic symptoms or diseases were used.

RESULTS

The frequency of serious allergic reactions per 100,000 administered vaccine doses was 1.53 for Comirnaty, 2.16 for Spikevax, 88.6 for Vaxzevria, 2.11 for Janssen, 7.9 for Novavax, 13.3 for VidPrevtyn Beta, and 3.1 for Valneva. The most prevalent reported reactions were edema (0.46) and anaphylaxis (0.40). Only 6% of these reactions were delayed hypersensitivity-oriented.

CONCLUSIONS

The overall frequency of potential serious allergic reactions to COVID-19 is very rare. Therefore, COVID-19 vaccines seem to be safe for human use. The lowest frequency of allergic reaction was observed for Comirnaty and the highest for Vaxzevria.

Predicting Penicillin Allergy: A United States Multicenter Retrospective Study

BACKGROUND

Using the reaction history in logistic regression and machine learning (ML) models to predict penicillin allergy has been reported based on non-US data.

OBJECTIVE

We developed ML positive penicillin allergy testing prediction models from multisite US data.

METHODS

Retrospective data from 4 US-based hospitals were grouped into 4 datasets: enriched training (1:3 case-control matched cohort), enriched testing, nonenriched internal testing, and nonenriched external testing. ML algorithms were used for model development. We determined area under the curve (AUC) and applied the Shapley Additive exPlanations (SHAP) framework to interpret risk drivers.

RESULTS

Of 4777 patients (mean age 60 [standard deviation: 17] years; 68% women, 91% White, and 86% non-Hispanic) evaluated for penicillin allergy labels, 513 (11%) had positive penicillin allergy testing. Model input variables were frequently missing: immediate or delayed onset (71%), signs or symptoms (13%), and treatment (31%). The gradient-boosted model was the strongest model with an AUC of 0.67 (95% confidence interval [CI]: 0.57-0.77), which improved to 0.87 (95% CI: 0.73-1) when only cases with complete data were used. Top SHAP drivers for positive testing were reactions within the last year and reactions requiring medical attention; female sex and reaction of hives/urticaria were also positive drivers.

CONCLUSIONS

An ML prediction model for positive penicillin allergy skin testing using US-based retrospective data did not achieve performance strong enough for acceptance and adoption. The optimal ML prediction model for positive penicillin allergy testing was driven by time since reaction, seek medical attention, female sex, and hives/urticaria.

Ceftriaxone-Induced Hemolytic Anemia: A Rare and Fatal Reaction

Ceftriaxone, a regularly used antibiotic for broad-spectrum coverage, is a rare cause of hemolytic anemia. Patients may present with truncal pain, nausea, vomiting, and an acute drop in hemoglobin within 48 hours of administration. Prompt recognition and initiation of treatment are essential. We describe a case of a 65-year-old woman being treated for osteomyelitis who developed hemolytic anemia, disseminated intravascular coagulation, and multi-system organ failure after being de-escalated from cefepime to ceftriaxone.

Documented Penicillin Allergies on Antibiotic Selection at Pediatric Emergency Department Visits

BACKGROUND

Penicillin or amoxicillin are the recommended treatments for the most common pediatric bacterial illnesses. Allergies to penicillin are commonly reported among children but rarely true. We evaluated the impact of reported penicillin allergies on broad-spectrum antibiotic use overall and for the treatment of common respiratory infections among treat-and-release pediatric emergency department (ED) visits.

METHODS

Retrospective cohort study of pediatric patients receiving antibiotics during a treat-and-release visit at a large, pediatric ED in the northeast from 2014 to 2016. Study exposure was a reported allergy to penicillin in the electronic medical record. Study outcomes were the selection of broad-spectrum antibiotics and alternative (second-line) antibiotic therapy for the treatment of acute otitis media (AOM) and group A streptococcus (GAS) pharyngitis. We used unadjusted and adjusted generalized estimating equation models to analyze the impact of reported penicillin allergies on the selection of broad-spectrum antibiotics. We used unadjusted and adjusted logistic regression models to determine the probability of children with a documented penicillin allergy receiving alternative antibiotic treatments for AOM and GAS.

RESULTS

Among 12,987 pediatric patients, 810 (6.2%) had a documented penicillin allergy. Penicillin allergies increased the odds of children receiving a broad spectrum versus narrow spectrum antibiotic (adjusted odds ratio, 13.55; 95% confidence interval (CI), 11.34-16.18). In our adjusted logistic regression model, the probability of children with a documented penicillin allergy receiving alternative antibiotic treatment for AOM was 0.97 (95% CI, 0.94-0.99) and for GAS was 0.97 (95% CI, 0.92-0.99).

CONCLUSIONS

Antibiotic stewardship efforts in pediatric EDs may consider the delabeling of penicillin allergies particularly among children receiving antibiotics for an acute respiratory infection as a target for intervention.

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.

Changing patterns in the epidemiology of drug allergy

Drug allergy (DA) remains a complex and unaddressed problem worldwide that often deprives patients of optimal medication choices and places them at risk for life-threatening reactions. Underdiagnosis and overdiagnosis are common and due to the lack of standardized definitions and biomarkers. The true burden of DA is unknown, and recent efforts in data gathering through electronic medical records are starting to provide emerging patterns around the world. Ten percent of the general population engaged in health care claim to have a DA, and the most common label is penicillin allergy. Up to 20% of emergency room visits for anaphylaxis are due to DA and 15%-20% of hospitalized patients report DA. It is estimated that DA will increase based on the availability and use of new and targeted antibiotics, vaccines, chemotherapies, biologicals, and small molecules, which are aimed at improving patient's options and quality of life. Global and regional variations in the prevalence of diseases such as human immunodeficiency virus and mycobacterial diseases, and the drugs used to treat these infections have an impact on DA. The aim of this review is to provide an update on the global impact of DA by presenting emerging data on drug epidemiology in adult and pediatric populations.

Suppressive Antibiotic Therapy After Debridement, Antibiotics, and Implant Retention is Well-Tolerated Without Inducing Resistance: A Multicenter Study

BACKGROUND

Suppressive antibiotic therapy (SAT) after total joint arthroplasty (TJA) debridement, antibiotics, and implant retention (DAIR) maximizes reoperation-free survival. We evaluated SAT after DAIR of acutely infected primary TJA regarding: 1) adverse drug reaction (ADR)/intolerance; 2) reoperation for infection; and 3) antibiotic resistance.

METHODS

Patients who underwent total knee arthroplasty (TKA) or total hip arthroplasty (THA) DAIR for acute periprosthetic joint infection at two academic medical centers from 2015 to 2020 were identified (n = 115). Data were collected on patient demographics, infecting organisms, antibiotics, ADR/intolerances, reoperations, and antibiotic resistances. Median SAT duration was 11 months. Stepwise multivariate logistic regressions were used to identify covariates significantly associated with outcomes of interest.

RESULTS

There were 11.1 and 16.3% of TKA and THA DAIR patients, respectively, who had ADR/intolerance to SAT. Patients prescribed trimethoprim/sulfamethoxazole (P = .0014) or combination antibiotic therapy (P = .0169) after TKA DAIR had increased risk of ADR/intolerance. There was no difference in reoperation-free survival between TKA (83.3%) and THA (65.1%) DAIR (P = .5900) at mean 2.8-year follow-up. Risk of reoperation for infection was higher among TKA Staphylococcus aureus infections (P = .0004) and lower with increased SAT duration (P < .0450). The optimal duration of SAT was nearly 2 years. No cases of antibiotic resistance developed due to SAT.

CONCLUSIONS

Consider SAT after TJA DAIR due to improved reoperation-free survival and favorable safety profile. Prolonged SAT did not induce antibiotic resistance. Use trimethoprim/sulfamethoxazole with caution because of the increased likelihood of ADR/intolerance.

LEVEL OF EVIDENCE

Therapeutic Level III.

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.

Safety of Direct Drug Provocation for the Evaluation of Penicillin Allergy in Low-Risk Adults

BACKGROUND

About 10% of patients have a penicillin allergy label, but less than 5% of them are actually allergic. Unnecessary penicillin avoidance is associated with serious medical consequences. Given the growing number of these labels, it is imperative that our diagnostic strategy for penicillin allergy be as efficient as possible. The validity of traditionally used skin tests (STs) has been questioned, whereas drug provocation testing (DPT), the criterion standard, without previous ST appears very safe in most cases.

OBJECTIVE

To evaluate the safety of direct DPT without consideration for ST results and the validity of ST in the diagnosis of penicillin allergy.

METHODS

In this prospective cohort study without a control group, we recruited patients consulting an allergist for penicillin allergy. Patients underwent ST followed by DPT regardless of ST results. Patients with anaphylaxis to penicillin within the past 5 years or a severe delayed reaction were excluded, as were those with significant cardiorespiratory comorbidity.

RESULTS

None of the 1002 recruited patients had a serious reaction to DPT. Ten (1.0%) had a mild immediate reaction, of whom only 1 (0.1%) was considered likely IgE-mediated. The positive and negative predictive values of ST for an immediate reaction were 3.6% and 99.1%, respectively.

CONCLUSIONS

In a low-risk adult population reporting penicillin allergy, ST has very poor positive predictive value. Direct DPT without ST is safe and appears to be an ideal diagnostic strategy to remove penicillin allergy labels that could be implemented in first-line practice.

Antibiotic use, best practice statement adherence, and UTI rate for intradetrusor onabotulinumtoxin-A injection for overactive bladder: A multi-institutional collaboration from the SUFU Research Network (SURN)

INTRODUCTION

Onabotulinumtoxin A (BTX-A) is a well-established treatment for overactive bladder (OAB). The American Urological Association (AUA) 2008 Antibiotic Best Practice Statement (BPS) recommended trimethoprim-sulfamethoxazole or fluoroquinolone for cystoscopy with manipulation. The aim of the study was to evaluate concordance with antibiotic best practices at the time of BTX-A injection and urinary tract infection (UTI) rates based on antibiotic regimen.

METHODS

Men and women undergoing first-time BTX-A injection for idiopathic OAB with 100 units in 2016, within the SUFU Research Network (SURN) multi-institutional retrospective database were included. Patients on suppressive antibiotics were excluded. The primary outcome was concordance of periprocedural antibiotic use with the AUA 2008 BPS antimicrobials of choice for "cystoscopy with manipulation." As a secondary outcome we compared the incidence of UTI among women within 30 days after BTX-A administration. Each outcome was further stratified by procedure setting (office vs. operating room; OR).

RESULTS

Of the cohort of 216 subjects (175 women, 41 men) undergoing BTX-A, 24 different periprocedural antibiotic regimens were utilized, and 98 (45%) underwent BTX-A injections in the OR setting while 118 (55%) underwent BTX-A injection in the office. Antibiotics were given to 86% of patients in the OR versus 77% in office, and 8.3% of subjects received BPS concordant antibiotics in the OR versus 82% in office. UTI rates did not vary significantly among the 141 subjects who received antibiotics and had 30-day follow-up (8% BPS-concordant vs. 16% BPS-discordant, CI -2.4% to 19%, p = 0.13). A sensitivity analysis of UTI rates based on procedure setting (office vs. OR) did not demonstrate any difference in UTI rates (p = 0.14).

CONCLUSIONS

This retrospective multi-institutional study demonstrates that antibiotic regimens and adherence to the 2008 AUA BPS were highly variable among providers with lower rates of BPS concordant antibiotic use in the OR setting. UTI rates at 30 days following BTX-A did not vary significantly based on concordance with the BPS or procedure setting.

Identifying the most at-risk age-group and longitudinal trends of drug allergy labeling amongst 7.3 million individuals in Hong Kong

BACKGROUND

Incorrect drug 'allergy' labels remain a global public health concern. Identifying regional trends of drug allergy labeling can guide appropriate public health interventions, but longitudinal or population drug allergy studies remain scarce. We analysed the serial epidemiology of drug allergy labeling to identify specific subgroups at highest risk of drug allergy labeling for potential interventions.

METHODS

Longitudinal, population-wide drug allergy labels and clinical data from over 7,337,778 individuals in Hong Kong between 2016 and 2021 were analysed.

RESULTS

The absolute prevalence and incidence of documented drug allergy were 5.61% and 277/100,000 population, respectively. Annual incidence of new allergy labels was stable between 2016 and 2019, until a significant drop in 2020 (-16.3%) during the COVID19 pandemic. The most common allergy labels were anti-infectives (245,832 [44.5%]), non-steroidal anti-inflammatory (106,843 [19.3%]), and nervous system drugs (45,802 [8.3%]). The most common labeled culprits for the most severe immediate-type (anaphylaxis) and non-immediate-type (Stevens-Johnson syndrome) reactions were beta-lactams and nervous system drugs, respectively. For individuals at highest risk of labeling, there was significantly higher incidence of overall drug and beta-lactam allergy labeling amongst individuals aged > 40 years which contributed to the majority of newly labeled allergies (377,004, 68.2%).

CONCLUSIONS

Contrary to traditional dogma, we identified disproportionately higher incidence of drug allergy labeling amongst older individuals, rather than the paediatric age group. We advocate for more population-wide drug allergy studies to investigate this phenomenon in other cohorts as well as future preventative and delabeling efforts focusing on the adult population.

Oral amoxicillin challenges for low-risk penicillin-allergic patients at a large Veterans Affairs facility: a retrospective feasibility analysis

We retrospectively reviewed the records of 136 veterans with a penicillin allergy label during a quality improvement initiative. We identified 82 inpatients eligible for removal of penicillin allergy by oral amoxicillin challenge, including 40 out of 82 (48%) still eligible after accounting for other limiting factors.

The epidemiology of cephalosporin allergy labels in pediatric primary care

Background

Recent studies have sought to understand the epidemiology and impact of beta-lactam allergy labels on children; however, most of these studies have focused on penicillin allergy labels. Fewer studies assess cephalosporin antibiotic allergy labels in children. The objective of this study was to determine the prevalence, factors associated with, and impact of cephalosporin allergy labels in children cared for in the primary care setting.

Methods

Cephalosporin allergy labels were reviewed among children in a dual center, retrospective, birth cohort who were born between 2010 and 2020 and followed in 90 pediatric primary care practices. Antibiotic prescriptions for acute otitis media were compared in children with and without cephalosporin allergies.

Results

334,465 children comprised the birth cohort and 2,877 (0.9%) were labeled as cephalosporin allergic during the study period at a median age of 1.6 years. Third-generation cephalosporins were the most common class of cephalosporin allergy (83.0%). Cephalosporin allergy labels were more common in children with penicillin allergy labels than those without (5.8% vs. 0.6%). Other factors associated with a cephalosporin allergy label included white race, private insurance, presence of a chronic condition, and increased health care utilization. Children with third-generation cephalosporin allergy labels received more amoxicillin/clavulanate (28.8% vs. 10.2%) and macrolides (10.4% vs. 1.9%) and less amoxicillin (55.8% vs. 70.9%) for treatment of acute otitis media than non-allergic peers p < 0.001.

Conclusions

One in 100 children is labeled as cephalosporin allergic, and these children receive different antibiotics for the treatment of acute otitis media compared to non-allergic peers.

Trimethoprim-sulfamethoxazole prophylaxis during treatment of granulomatosis with polyangiitis with rituximab in the United States of America: a retrospective cohort study

BACKGROUND

Antibiotic prophylaxis is recommended during ANCA-associated vasculitis (AAV) induction. We aimed to describe the frequency, persistence, and factors associated with trimethoprim-sulfamethoxazole (TMP-SMX) use in an adult population sample with granulomatosis with polyangiitis (GPA) treated with rituximab (RTX).

METHODS

We identified adults with GPA treated with RTX within the Merative™ Marketscan® Research Databases (2011-2020). TMP-SMX prophylaxis was defined as a [Formula: see text] 28-day prescription dispensed within a month of starting RTX. We estimated TMP-SMX persistence, allowing prescription refill gaps of 30 days. Multivariable logistic regression and Cox proportional hazards regression assessed the factors associated with baseline TMP-SMX use and persistence, respectively. Covariates included age, sex, calendar year, insurance type, immunosuppressant use, hospitalization, and co-morbidities.

RESULTS

Among 1877 RTX-treated GPA patients, the mean age was 50.9, and 54% were female. A minority (n = 426, 23%) received TMP-SMX with a median persistence of 141 (IQR 83-248) days. In multivariable analyses, prophylaxis was associated with prednisone use in the month prior to RTX ([Formula: see text] 20 mg/day vs none, OR 3.96; 95% CI 3.0-5.2; 1-19 mg/day vs none, OR 2.63; 95% CI 1.8-3.8), and methotrexate use (OR 1.48, 95% CI 1.04-2.1), intensive care (OR 1.95; 95% CI 1.4-2.7), and non-intensive care hospitalization (OR 1.56; 95% CI 1.2-2.1) in the 6 months prior to RTX. Female sex (OR 0.63; 95% CI 0.5-0.8) was negatively associated with TMP-SMX use.

CONCLUSIONS

TMP-SMX was dispensed to a minority of RTX-treated GPA patients, more often to those on glucocorticoids and with recent hospitalization. Further research is needed to determine the optimal use and duration of TMP-SMX prophylaxis following RTX in AAV.

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.

Diagnostic Evaluation of Hypersensitivity Reactions to Antibiotics in a Large Cohort of Mastocytosis Patients

BACKGROUND

Anaphylactic reactions are a well-known feature of mastocytosis, particularly in relation to hymenoptera venom stings. Although data on the frequency of drug hypersensitivity reactions is limited in mastocytosis, it is hypothesized that these patients may be predisposed to hypersensitivity reactions to certain drugs, including antibiotics. Nevertheless, this issue has not been systematically investigated. Thus, we investigate the prevalence and clinical features of hypersensitivity reactions to antibiotics (HRA) in mastocytosis.

METHODS

A 15-year retrospective study was conducted among 239 (≥18 years old) consecutive mastocytosis patients who were investigated in our center. All patients underwent a thorough allergy work-up, where self-reported reactions were individually evaluated by an allergist.

RESULTS

Overall, 34 patients (14.2%) were deemed to have HRA. Most patients reacted with cutaneous symptoms (74%), and anaphylaxis was rare, confirmed only in two of 34 patients (0.8%). Beta-lactams were the most common elicitors (63%). There were no differences in age, gender, atopic status and tryptase levels between mastocytosis patients with and without antibiotic hypersensitivity.

CONCLUSIONS

The present study indicates a similar prevalence of HRA in mastocytosis compared to those of the general population. Moreover, antibiotics appear to be rare elicitors of anaphylaxis in these patients. Hence, our results suggest that mastocytosis patients without a history of HRA may be treated with these drugs without special precautions.

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

Background

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

Methods

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

Results

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

Conclusions

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

Penicillin allergy delabeling: Opportunities for implementation and dissemination

Although existing as a safety measure to prevent iatrogenic harm, unconfirmed penicillin allergy labels have a negative impact on personal and public health. One downstream effect of unconfirmed penicillin allergy is the continued emergence and transmission of resistant bacteria and their associated health care costs. Recognizing the consequences of inaccurate penicillin allergy labels, professional and public health organizations have started promoting the adoption of proactive penicillin allergy evaluations, with the ultimate goal of removing the penicillin allergy label when the allergy is disproved, also known as penicillin allergy "delabeling." A penicillin allergy evaluation includes a comprehensive allergy history often followed by drug challenge, sometimes with preceding skin testing. Currently, penicillin allergy delabeling is largely carried out by allergy specialists in outpatient settings. Penicillin allergy delabeling is performed on inpatients, albeit rarely, often at the time of need, as a point-of-care procedure. Access to penicillin allergy evaluation services is limited. Recent studies demonstrate the feasibility of expanding penicillin allergy evaluations and delabeling to internists, pediatricians, emergency medicine physicians, infectious diseases specialists, and clinical pharmacists. However, reducing the impact of mislabeled penicillin allergy will require comprehensive efforts and new investments. In this review, we summarize the current practices of penicillin allergy delabeling and discuss expansion opportunities for penicillin allergy delabeling as quality improvement.

A Novel Informatics Tool to Detect Periprocedural Antibiotic Allergy Adverse Events for Near Real-time Surveillance to Support Audit and Feedback

Importance

Standardized processes for identifying when allergic-type reactions occur and linking reactions to drug exposures are limited.

Objective

To develop an informatics tool to improve detection of antibiotic allergic-type events.

Design, Setting, and Participants

This retrospective cohort study was conducted from October 1, 2015, to September 30, 2019, with data analyzed between July 1, 2021, and January 31, 2022. The study was conducted across Veteran Affairs hospitals among patients who underwent cardiovascular implantable electronic device (CIED) procedures and received periprocedural antibiotic prophylaxis. The cohort was split into training and test cohorts, and cases were manually reviewed to determine presence of allergic-type reaction and its severity. Variables potentially indicative of allergic-type reactions were selected a priori and included allergies entered in the Veteran Affair's Allergy Reaction Tracking (ART) system (either historical [reported] or observed), allergy diagnosis codes, medications administered to treat allergic reactions, and text searches of clinical notes for keywords and phrases indicative of a potential allergic-type reaction. A model to detect allergic-type reaction events was iteratively developed on the training cohort and then applied to the test cohort. Algorithm test characteristics were assessed.

Exposure

Preprocedural and postprocedural prophylactic antibiotic administration.

Main Outcomes and Measures

Antibiotic allergic-type reactions.

Results

The cohort of 36 344 patients included 34 703 CIED procedures with antibiotic exposures (mean [SD] age, 72 [10] years; 34 008 [98%] male patients); median duration of postprocedural prophylaxis was 4 days (IQR, 2-7 days; maximum, 45 days). The final algorithm included 7 variables: entries in the Veteran Affair's hospitals ART, either historic (odds ratio [OR], 42.37; 95% CI, 11.33-158.43) or observed (OR, 175.10; 95% CI, 44.84-683.76); PheCodes for "symptoms affecting skin" (OR, 8.49; 95% CI, 1.90-37.82), "urticaria" (OR, 7.01; 95% CI, 1.76-27.89), and "allergy or adverse event to an antibiotic" (OR, 11.84, 95% CI, 2.88-48.69); keyword detection in clinical notes (OR, 3.21; 95% CI, 1.27-8.08); and antihistamine administration alone or in combination (OR, 6.51; 95% CI, 1.90-22.30). In the final model, antibiotic allergic-type reactions were identified with an estimated probability of 30% or more; positive predictive value was 61% (95% CI, 45%-76%); and sensitivity was 87% (95% CI, 70%-96%).

Conclusions and Relevance

In this retrospective cohort study of patients receiving periprocedural antibiotic prophylaxis, an algorithm with a high sensitivity to detect incident antibiotic allergic-type reactions that can be used to provide clinician feedback about antibiotic harms from unnecessarily prolonged antibiotic exposures was developed.

[Drug allergy: Fundamental aspects in diagnosis and treatment.]

BACKGROUND

Any substance used as a treatment for any disease can produce harmful or unpleasant events called adverse drug reactions (ADRs). They are due to inherent biological effects of the drug and are caused by immunological and non-immunological mechanisms.

OBJECTIVES

To describe the immunological mechanisms of hypersensitivity reactions (HSR) to drugs, their epidemiology, risk factors, classification, clinical manifestations, diagnosis, treatment, and prognosis.

METHODS

A review of the most current literature in English and Spanish was carried out, in the main databases, related to the HSR of various drug groups.

RESULTS

This study describes the terms used to define ADRs and HSRs, their classification and clinical manifestations, current diagnostic tools, treatment algorithms and prognosis of the most frequently used medications and with the highest prevalence of reported adverse events.

CONCLUSION

ADRs are a challenging entity, with a complex pathophysiology that has not been fully understood. Its approach requires a careful consideration since not all drugs have validated tests for their diagnosis nor a specific treatment. When indicating the use of any drug, the severity of the disease, the availability of other treatments and the potential risks of developing future adverse events should always be taken into consideration.

Dose optimization in surgical prophylaxis: sub-inhibitory dosing of vancomycin increases rates of biofilm formation and the rates of surgical site infection

Antibiotic stewardship is viewed as having great public health benefit with limited direct benefit to the patient at the time of administration. The objective of our study was to determine if inappropriate administration of antibiotics could create conditions that would increase the rates of surgical infection. We hypothesized that sub-MIC levels of vancomycin would increase Staphylococcus aureus growth, biofilm formation, and rates of infection. S. aureus MRSA and MSSA strains were used for all experiments. Bacteria were grown planktonically and monitored using spectrophotometry. Quantitative agar culture was used to measure planktonic and biofilm bacterial burden. A mouse abscess model was used to confirm phenotypes in vivo. In the planktonic growth assay, increases in bacterial burden at ¼ MIC vancomycin were observed in USA300 JE2 by 72 h. Similar findings were observed with ½ MIC in Newman and SH1000. For biofilm formation, USA300 JE2 at ¼ and ½ MIC vancomycin increased biofilm formation by approximately 1.3- and 2.3-fold respectively at 72 h as compared to untreated controls. Similar findings were observed with Newman and SH1000 with a 2.4-fold increase in biofilm formation at ½ MIC vancomycin. In a mouse abscess model, there was a 1.2-fold increase with sub-MIC vancomycin at 3 days post infection. Our study showed that Sub-optimal vancomycin dosing promoted S. aureus planktonic growth and biofilm formation, phenotypic measures of bacterial virulence. This phenotype induced by sub-MIC levels of vancomycin was also observed to increase rates of infection and pathogenesis in our mouse model. Risks of exposure to sub-MIC concentrations with vancomycin in surgical procedures are greater as there is decreased bioavailability in tissue in comparison to other antibiotics. This highlights the importance of proper antibiotic selection, stewardship, and dosing for both surgical prophylaxis and treatment of infection.

Impact of Penicillin Allergy Labels on Children Treated for Outpatient Respiratory Infections

BACKGROUND

Penicillin allergy is the most common antibiotic allergy, yet most children labeled as allergic tolerate penicillin. The impact of inaccurate penicillin allergy labels (PALs) on pediatric outpatients is unknown. The objective of this study was to compare outcomes between children with and without a PAL after treatment for outpatient respiratory tract infections (RTI).

METHODS

A retrospective, longitudinal birth cohort study was performed in children who received care in 90 pediatric primary care practices in Philadelphia and Houston metropolitan areas. Prescribing and clinical outcomes of children with a PAL at the time of an RTI were compared to non-allergic children, adjusting for potential confounders.

RESULTS

Antibiotics were prescribed for 663,473 non-recurrent RTIs among 200,977 children. Children with a PAL (5% of cohort) were more likely than non-allergic children to receive broad-spectrum antibiotics (adjusted relative risk (aRR) 3.24, 95% CI 3.22-3.26) and second-line antibiotics (aRR 4.87, 95% CI 4.83, 4.89). Compared to non-allergic children receiving first-line antibiotics, children with a PAL were more likely to return with adverse drug events (aRR 1.28, 95% CI 1.18-1.39). There was no difference in treatment failure between groups (aRR 0.95, 95% CI 0.90-1.00).

CONCLUSIONS

PALs lead to higher rates of broad-spectrum and second-line antibiotic prescribing in children treated for RTIs in primary care and contribute to unnecessary healthcare utilization through increased adverse events. Given the frequency of PALs, efforts to prevent inappropriate penicillin allergy labeling and promote de-labeling of existing inaccurate allergy labels may improve care of children treated for common bacterial infections.

Trends in antibiotic prescribing in Dutch general practice and determinants of nonprudent antibiotic prescriptions

BACKGROUND

Antibiotic resistance is mainly driven by (incorrect) use of antibiotics. Most antibiotics are prescribed in family medicine. Therefore, regularly monitoring of antibiotic prescriptions and evaluation of their (non-) prudent use in primary care is warranted.

OBJECTIVES

The aim of this study was to determine time trends in antibiotic prescriptions by Dutch family physicians (FPs) and to identify determinants of nonprudent antibiotic prescriptions by Dutch FPs.

METHODS

Retrospective study among 27 Dutch general practices from the Research Network Family Medicine Maastricht, from 2015 to 2019.

RESULTS

In total 801,767 patient years were analysed. Antibiotic prescriptions mainly increased in patients aged 65+ while prescriptions mainly decreased in patients below 65 years. Nonprudent antibiotic prescriptions decreased from 2015 to 2019 with the highest percentage of decline found in skin infections (66.9% [2015] to 53.9% [2019]). Overall, higher likelihood of nonprudent antibiotic prescriptions was found among men (odds ratio [OR] 4.11, 95% confidence interval [CI]: 3.91-4.33), patients aged 80+ (OR 1.44, 95% CI: 1.03-2.01; reference category ≤17 years), patients with comedication (OR 1.24, 95% CI: 1.17-1.31), and patients in urban general practices (OR 1.47, 95% CI: 1.38-1.56).

CONCLUSIONS

Antibiotic prescriptions increased over time in the elderly aged categories. Although an overall decrease in nonprudent antibiotic prescriptions was established from 2015 to 2019, percentages of nonprudent prescriptions remained high for skin infections and respiratory tract infections. Additionally, men, elderly aged patients (80+), patients with comedication and patients in urban general practices were more likely to receive nonprudent antibiotic prescriptions. Our results will help FPs to prioritize optimalization of antibiotic prescriptions in family medicine.

The Evolution of Our Understanding of Penicillin Allergy: 1942-2022

This article reviews our evolving understanding of penicillin hypersensitivity at the 80th anniversary of penicillin's clinical introduction. Penicillin breakdown products covalently bond to serum proteins, leading to classic drug hypersensitivity. Penicillin remains the most frequently reported drug "allergy." Adverse reactions were presumed, in retrospect incorrectly, to implicate a risk for anaphylaxis, and therefore skin testing for IgE became the focus. Skin test positivity may wane over time. This insight has led to the radical conclusion that penicillin hypersensitivity may not be "forever." Atopic background, other drug allergies, family history, gender, and race are apparently not risk factors for penicillin hypersensitivity. Confirmed penicillin hypersensitivity has declined since the 1960s, potentially due to "cleaner" penicillin products and lower dose oral, instead of parenteral, use. Avoiding penicillins, without evaluation, caused unanticipated problems that have been appreciated only recently including longer hospital stays, increased cost of care, suboptimal outcomes from serious infections, and greater toxicities and costs with alternative antibiotics. There are personal and public health advantages with broadly implemented penicillin allergy delabeling based on a reaction history-based risk assessment. Limited skin testing followed by an oral challenge, if negative, for higher-risk histories, and direct oral challenges in lower-risk individuals are currently the reference standard tests to confirm current tolerance.

Skin testing as a biomarker in drug allergy

Despite the significant negative impact drug allergies can have on patient care, the diagnosis is largely based on clinical history, and there are limited diagnostic tests that can be done at the time of a reaction. Biomarkers are needed to improve the diagnosis and the identification of the culprit medication. Skin testing is the most useful biomarker for immediate- and delayed-type reactions available, but it is limited by its low sensitivity. To improve its accuracy and reproducibility, a standardized procedure must be used. For immediate-type reactions, penicillin skin testing is the most widely studied, and it can be used in patients with history of anaphylaxis or recent immunoglobulin E-mediated reaction or for whom there is a significant risk if a reaction were to occur, such as pregnancy. Skin testing is also important in allergy to platinum agents allowing for continued first-line therapy. For delayed-type reactions, patch testing and delayed intradermal testing, used in conjunction with clinical history, can help to improve identification of the culprit medication depending on the type of reaction. Other biomarkers including in vitro testing for specific immunoglobulin E, basophil activation test, lymphocyte transformation test, ELISpot, and genetic factors that increase the likelihood of reaction are under investigation, and they may be most helpful when used in combination with the clinical history and skin testing results.

Assessing the prevalence and characteristics of self-reported penicillin allergy in Saudi Arabian population: A nationwide cross-sectional study

Introduction

Being allergic to penicillin can lead to the overuse of broad-spectrum antibiotics, contributing to the growing problem of multidrug resistance. Knowing the exact allergy history is essential as some circumstances may allow reinitiating penicillin. This study focused on assessing the prevalence and characteristics of self-reported penicillin allergy in the Saudi Arabian population.

Methods

We conducted a nationwide cross-sectional study via an electronic self-administered questionnaire directed toward the Saudi Arabian general adult population. Variables about respondent demographics as well as type and characteristics of the allergy were collected.

Results

One hundred ninety-three out of 2022 participants who completed the survey (9.5%) reported allergy to penicillin, with the most reported reaction being anaphylaxis in 89 participants (46.1%), non-anaphylaxis reported by 69 participants (35.8%). Twenty-two participants (11.4%) were identified as not having a true allergy due to reporting a tolerability issue or a non-penicillin-type agent. About 38% reported that the allergy occurred more than ten years ago.

Conclusion

This is the first study to report the prevalence and characteristics of self-reported penicillin allergy in Saudi Arabia. The data from this study provides valuable information to consider starting in-hospital penicillin de-labeling programs and providing evidence for healthcare providers to consider re-challenging certain qualified patients.

Allergy Electronic Health Record Documentation: A 2022 Work Group Report of the AAAAI Adverse Reactions to Drugs, Biologicals, and Latex Committee

The allergy section of the electronic health record (EHR) is ideally reviewed and updated by health care workers during routine outpatient visits, emergency room visits, inpatient hospitalizations, and surgical procedures. This EHR section has the potential to help proactively and comprehensively avoid exposures to drugs, contact irritants, foods, and other agents for which, based on an individual's medical history and/or genetics, there is increased risk for adverse outcomes with future exposures. Because clinical decisions are made and clinical decision support is triggered based on allergy details from the EHR, the allergy module needs to provide meaningful, accurate, timely, and comprehensive allergy information. Although the allergy section of the EHR must meet these requirements to guide appropriate clinical decisions and treatment plans, current EHR allergy modules have not achieved this standard. We urge EHR vendors to collaborate with allergists to optimize and modernize allergy documentation. A work group within the Adverse Reactions to Drugs, Biologicals, and Latex Committee of the American Academy of Allergy, Asthma & Immunology was formed to create recommendations for allergy documentation in the EHR. Whereas it is recognized that the term "allergy" is often used incorrectly because most adverse drug reactions (ADRs) are not true immune-mediated hypersensitivity reactions, "allergy" in this article includes allergies and hypersensitivities as well as side effects and intolerances. Our primary objective is to provide guidance for the current state of allergy documentation in the EHR. This guidance includes clarification of the definition of specific ADR types, reconciliation of confirmed ADRs, and removal of disproved or erroneous ADRs. This document includes a proposal for the creation, education, and implementation of a drug allergy labeling system that may allow for more accurate EHR documentation for improved patient safety.

Feasibility of trimethoprim/sulfamethoxazole desensitization therapy in hematological diseases

The effectiveness and safety of trimethoprim/sulfamethoxazole (TMP/SMX) desensitization therapy is insufficiently evaluated in hematological diseases. From 2002 to 2019, we retrospectively analyzed 112 patients with hematological diseases who underwent desensitization therapy after TMP/SMX prophylaxis withdrawal due to adverse events. They orally started TMP/SMX at 0.4 mg/2 mg, which was then increased daily to 80 mg/400 mg for 5 or 9 days. Eighty-eight patients (79%) had complete desensitization, and the major reason for failure was rash seen in 21 cases (19%). The cause of desensitization and reasons for failure matched in 22 cases (92%). Pneumocystis pneumonia was not observed throughout the study. In the failure group, the number of eosinophils and alanine aminotransferase (ALT) levels were significantly increased after desensitization. In particular in the failure group, the slight increase in eosinophils was seen through the beginning to halfway during desensitization (36/μL (0-900/μL) and 48/μL (0-2560/μL), respectively, p = 0.025). These data show that TMP/SMX desensitization therapy is effective and safe in hematological diseases. The recurrence of adverse events could help predict desensitization success.

Penicillin allergy SHACK: Survey of hospital and community knowledge

AIM

Penicillin allergy accounts for the majority of all reported adverse drug reactions in adults and children. Foregoing first-line antibiotic therapy due to penicillin allergy label is associated with an increased prevalence of infections by resistant organisms and longer hospitalisation. Clinician awareness of allergy assessment, referral indications, management of allergy and anaphylaxis is therefore vital but globally lacking. We aim to assess the knowledge of penicillin allergy, assessment and management in Western Australian health professionals.

METHODS

An anonymous survey was distributed to pharmacists, nurses and physicians within Western Australian paediatric and adult Hospitals, Community and General Practice.

RESULTS

In total, 487/611 were completed and included in the statistical analysis. Only 62% (301/487) of respondents routinely assessed for patient medication allergies. Of those who assessed allergy, 9% (28/301) of respondents met the Australian standards for allergy assessment. Only 22% (106/487) of participants correctly cited all indications for management with adrenaline in anaphylaxis to antibiotics and 67% (197/292) of physicians rarely or never referred to an allergy service. Paediatric clinicians had an increased understanding of allergy assessment and anaphylaxis management. Recent penicillin allergy education within a 5-year period led to significant improvements in allergy knowledge.

CONCLUSION

Overall, knowledge, assessment and management of penicillin allergies among practitioners in Western Australia are currently inadequate in adults and paediatric clinicians to provide safe and effective clinical care. The implementation of a targeted education program for WA health professionals is urgently required and is expected to improve clinician knowledge and aid standardised penicillin assessment (de-labelling) practices.

Antibiotic Prescribing Patterns and Guideline Concordance for Uncomplicated Urinary Tract Infections Among Adult Women in the US Military Health System

IMPORTANCE

Urinary tract infections (UTIs) are one of the most commonly diagnosed infections, and prior studies have reported discordance in antibiotic treatment with the Infectious Diseases Society of America (IDSA) guidelines.

OBJECTIVE

To assess IDSA guideline concordance rates for women with uncomplicated UTIs treated with antibiotics, and compare concordance rates between different specialty field.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cross-sectional study of health care claims data from the US Military Health System Data Repository, which contains comprehensive health care encounter and claims data for all military beneficiaries. Participants were adult women between the ages of 18 to 50 years with uncomplicated UTIs from October 1, 2017, to September 30, 2019. Data extraction and analysis were performed in 2022. Patients with diagnosis of UTI in the preceding 6 months, current pregnancy, history of pyelonephritis, history of diabetes, history of organ transplant, history of human immunodeficiency virus, immunosuppression, renal insufficiency, urinary tract abnormalities, or history of urologic procedures were excluded.

EXPOSURES

Antibiotic treatment for uncomplicated UTIs. Only antibiotics received within 1 day after the diagnosis were analyzed. The IDSA recommends the following antibiotics as first-line therapy: nitrofurantoin, trimethoprim-sulfamethoxazole, fosfomycin, pivmecillinam.

MAIN OUTCOMES AND MEASURES

The IDSA guideline concordance rates were calculated as the number of patients receiving first-line antibiotic therapy divided by the total number of cases for uncomplicated UTIs.

RESULTS

A total of 46 793 adult women (67.3% [31 475 of 46 793] aged 18-34 years; 38.2% [31 475 of 46 793] of White race) were diagnosed with uncomplicated UTIs with 91.0% receiving guideline-concordant antibiotic treatment. In comparison with obstetrics and gynecology, IDSA guideline-concordant treatment was more likely in internal medicine (adjusted odds ratio [aOR], 2.87; 95% CI, 2.73-3.03), family medicine (aOR, 1.81; 95% CI, 1.76-1.87), surgery (aOR, 1.51; 95% CI, 1.36-1.67), and emergency medicine (aOR, 1.36; 95% CI, 1.32-1.39) and less likely in urology (aOR, 0.40; 95% CI, 0.38-0.43). Compared with direct military care, private sector care had lower concordance rates (aOR, 0.63; 95% CI, 0.62-0.64).

CONCLUSIONS AND RELEVANCE

In this cross-sectional study of antibiotic treatments for uncomplicated UTIs in a universally insured population, the IDSA guideline-concordance rate was high at 91.0% with higher rates in direct military care compared with private sector care. There were higher rates in general medical specialties, surgery, and emergency medicine and lower rates in urology and obstetrics and gynecology. These results further enhance the literature on current antibiotic prescribing practices for uncomplicated UTIs in adult women.

Association of Sociodemographic Factors With Reported Penicillin Allergy in Pediatric Inpatients

OBJECTIVES

Characterize the association of sociodemographic factors with reported penicillin allergy in pediatric inpatients.

METHODS

We conducted a retrospective cohort study of pediatric inpatients admitted to general pediatric units at an academic medical center with reported penicillin allergy and reaction history. Sociodemographic factors evaluated were gender, age, race, ethnicity, language, and insurance payer. We conducted univariable and multivariable logistic regression models to evaluate associations between demographic variables and penicillin allergy.

RESULTS

Of 3890 pediatric inpatients, 299 (7.7%) had a reported penicillin allergy. The majority of documented reaction histories were hives, rash, or unknown. In univariable analysis, odds of penicillin allergy were lower in patients who identify as Black and who prefer a language other than English, and higher in patients of non-Hispanic/Latino ethnicity, those with private insurance, and with increasing age. In multivariable logistic regression, only Black race (adjusted odds ratio 0.42, 95% confidence interval CI 0.30-0.59) and young age were significantly associated with lower odds of penicillin allergy.

CONCLUSIONS

After adjustment for covariates, Black race was associated with lower odds of reported penicillin allergy in hospitalized children. Penicillin allergy reporting may be an indicator of racial differences in the prescribing of antimicrobial agents, patient-clinician communication, and access to health care.

Heterogeneity of Drug Allergies and Reaction Lists in Two U.S. Healthcare Systems' Electronic Health Records

BACKGROUND

Healthcare institutions have their own "picklist" for clinicians to document adverse drug reactions (ADRs) into the electronic health record (EHR) allergy list. Whether the lack of a nationally standardized picklist impacts clinician data entries is unknown.

OBJECTIVES

To assess the impact of defined reaction picklists on clinical documentation and, therefore, downstream analytics and clinical research using these data at two institutions.

METHODS

Adverse drug reaction data were obtained from the EHRs of patients who visited the emergency department or outpatient clinics at Brigham and Women's Hospital (BWH) and University of Colorado Hospital (UCH) from 2013-2018. Reported drug class ADR prevalences were calculated. We investigated the reactions on each picklist and compared the top 40 reactions at each institution, as well as the top 10 reactions within each drug class.

RESULTS

Of 2,160,116 patients, 640,444 (30%) had 928,973 active drug allergies. The most commonly reported drug class allergens were similar between BWH and UCH. BWH's picklist had 48 reactions, UCH's had 160 reactions; 29 reactions were shared by both picklists. While the top four reactions overall (rash, GI upset/nausea/vomiting, hives, itching) were identical between sites, reactions by drug class exhibited greater documentation diversity. For example, while the summed prevalence of swelling-related reactions to ACE inhibitors was comparable across sites, swelling was represented by two terms ("swelling", "angioedema") at BWH but 11 terms at UCH (e.g., "swelling", "edema", by body locality).

CONCLUSIONS

The availability and granularity of reaction picklists impacts ADR documentation in the EHR by healthcare providers; picklists may partially explain variations in reported ADRs across healthcare systems.

Safety of Cefazolin Test Dose in Patients with Penicillin Allergy Just Prior Cardiac Device Implantation: A Single Center Experience

Background

Cephalosporins are the cornerstone of cardiac device infection prophylaxis. Owing to fears of cross-reactivity, penicillin-allergic patients are exposed to potentially more-toxic drugs, with decreased efficacy. We evaluated the safety of a cefazolin test dose (CTD) in self-reported penicillin-allergic patients.

Methods

In this single-centre study, we evaluated consecutive patients with chart documentation of penicillin allergy undergoing cardiac device implantation, over a 2-year period. A CTD was performed if no cephalosporin allergy or severe anaphylactic reaction to penicillin had been documented. Patients were given 2 doses of 100 mg IV cefazolin, and if no allergic reaction occurred after 5 minutes, the full dose (1800 mg) was administered in the electrophysiology laboratory just before the implantation procedure.

Results

A total of 2200 patients were included. The frequency of reported penicillin allergy was 9.3% (n = 204). In 80% of cases, the type of allergic reaction was not reported in medical notes or was unknown by the patient. A CTD was performed in 67.6% of patients with a penicillin allergy (n = 138). A total of 5 adverse events occurred (3.6% of patients [95% confidence interval, 1.1%-6.1%]) — 4 skin rashes and 1 tongue edema. These 5 patients became asymptomatic after antihistaminic and corticosteroid IV treatment. Even if the test dose was negative, 79% of patients also were administered vancomycin before the procedure, as it requires a 1-hour infusion prior to the CTD in the implantation procedure room.

Conclusion

A CTD in most penicillin-allergic patients appears to be safe and allows its use per recommended guidelines.

The Use of Electronic Health Records to Study Drug-Induced Hypersensitivity Reactions from 2000 to 2021

Electronic health records (EHRs) have revolutionized the field of drug hypersensitivity reaction (DHR) research. In this systematic review, we assessed 140 articles from 2000-2021, classifying them under six themes: observational studies (n=61), clinical documentation (n=27), case management (n=22), clinical decision support (CDS) (n=18), case identification (n=9), and genetic studies (n=3). EHRs provide convenient access to millions of medical records, facilitating epidemiological studies of DHRs. Though the goal of CDS is to promote safe drug prescribing, allergy alerts must be designed and used in a way that supports this effort. Ultimately, accurate allergy documentation is essential for DHR prevention.

Female sex as a risk factor for penicillin drug allergy in the inpatient setting

Background: Penicillin is the most common reported drug allergy. Previous literature suggests that there is increased prevalence of penicillin drug allergy in female patients in the outpatient setting. However, this is poorly described in the inpatient setting. Objective: This study was performed to determine whether female sex is an independent risk factor for penicillin allergy in the inpatient setting. Methods: A retrospective review of electronic medical records (January 1, 2001-December 31, 2017) was performed for patients with a history of penicillin allergy who underwent penicillin skin testing (PST). Each chart review included the age at initial skin testing, sex, medications, and medical co-morbidities. The study was approved by the institutional review board. Results: 30,883 patients underwent PST with 29,354 and 1,529 occurring in the outpatient and inpatient setting respectively. 170 patients tested positive with a ≥ 5x5 wheal. Of the 170 positive patients, 122 were female (72%) and 48 were male (28%). 15 patients tested positive in the inpatient setting. Of the 1506 adult patients tested in the inpatient setting, 809 were female and 697 were male. 12 females (92.3%) and 1 one male (7.7%) tested positive with a ≥ 5x5 wheal (OR-10.5; 95% CI-1.4-80.8; p-value=0.02). 23 pediatric patients were tested in the inpatient setting. Two pediatric male patients were positive and no female pediatric patients tested positive (OR-1.7; 95% CI-0.5-5.9; p-value=0.5). Conclusion: In the inpatient setting, adult females are 10 times more likely to have a positive PST compared to males. Female sex may be a potential risk factor for objective penicillin drug allergy in the inpatient setting.

The controversy of drug hypersensitivity in patients with cystic fibrosis and review of the literature

BACKGROUND

Cystic fibrosis (CF) is reported to be a risk factor for drug hypersensitivity. However, there are conflicting data about true prevalence of drug hypersensitivity in children with CF.

METHODS

The suspicious drug hypersensitivity reactions (DHRs) of children with CF were enquired by the European Network for Drug Allergy (ENDA) questionnaire, and skin tests and/or drug provocation tests were performed according to the established guidelines.

RESULTS

Two hundred and nineteen children (48.9% boys; median [IQR] age, 8.4 years [4.8-12.4 years]) with cystic fibrosis were included in the study, among which 22 patients with 24 suspected DHRs were evaluated. Most of the suspected DHRs were of non-immediate (n = 16, 66.6%) type, and the offending drugs were amoxicillin-clavulanic acid (n = 7), macrolides (n = 4), trimethoprim-sulfamethoxazole (TMP/SMX) (n = 2), piperacillin-tazobactam (n = 1), pancrelipase (n = 1), and ursodeoxycholic acid (n = 1). Eight (33.3%) of the DHRs were classified as immediate (ceftriaxone [n = 2], ceftazidime [n = 2], meropenem [n = 1], AmBisome [n = 2], and vancomycin [n = 1]). The main clinical presentations were maculopapular eruption (41.6%) and urticaria (37.5%), accompanied by angioedema (8.3%), flushing (12.5%), and vomiting (8.3%). Nine skin tests (with beta-lactam protocol in 6 patients) and 24 DPTs were performed, and none of the skin tests revealed a positive result; however, 2 DPTs with TMP/SMX were positive.

CONCLUSION

Actual drug hypersensitivity was demonstrated in 2 of 219 patients (0.9%) with non-beta-lactam antibiotics. These results conflict with previous researches that showed higher drug hypersensitivity rates but are consistent with some recent studies. Allergological diagnostic workup is mandatory in patients with cystic fibrosis in case of a suspicious DHR.

Experience of the first 1127 COVID-19 Vaccine Allergy Safety patients in Hong Kong - Clinical outcomes, barriers to vaccination, and urgency for reform

INTRODUCTION

Hong Kong has had a low incidence of COVID-19 vaccine related anaphylaxis, partly due to its Vaccine Allergy Safety (VAS) guidelines for screening those at higher risk of COVID-19 vaccine-associated allergic reactions. We characterize the initial experience of the VAS clinics, as well as the impact of unnecessary referrals to the vaccination program.

METHODS

All patients attending the VAS Clinics of the public and private health services between February and June 2021 were reviewed.

RESULTS

Out of 1127 patients assessed at VAS clinics, 1102 (97.8%) patients were recommended for vaccination. Out of those contacted, more than 80% (450/558) received vaccination successfully; the remaining had not yet booked their vaccinations. The majority (87.5%) of patients not recommended was due to potential excipient allergies. Males were significantly more likely to be recommended (OR = 5.822, 95% CI = 1.361-24.903, p = 0.007), but no other features were associated with recommendation for vaccination. Almost half (45.1%) of public service referrals were rejected due to insufficient information or incorrect indications for referral. The majority of cases (56.2%) of patients referred for suspected "anaphylaxis" did not fulfil diagnostic criteria.

DISCUSSION

COVID-19 vaccination is very safe and 98% of high-risk patients were recommended for vaccination. Barriers to VAS include a high proportion of inappropriate referrals, inaccurate diagnoses of anaphylaxis and inability to diagnose excipient allergies. Our data validates that a prior history of COVID-vaccine unrelated anaphylaxis should be removed as a precaution for vaccination. Closer collaborations between primary care and allergy specialists and changes in pharmaceutical legislation should be made a priority to promote vaccination uptake.

Antibiotic Use in Patients With β-Lactam Allergies and Pneumonia: Impact of an Antibiotic Side Chain-Based Cross-Reactivity Chart Combined With Enhanced Allergy Assessment

BACKGROUND

β-lactam antibiotics with dissimilar R-group side chains are associated with low cross-reactivity. Despite this, patients with β-lactam allergies are often treated with non-β-lactam alternative antibiotics. An institutional β-lactam side chain-based cross-reactivity chart was developed and implemented to guide in antibiotic selection for patients with β-lactam allergies.

METHODS

This single-center, retrospective cohort study analyzed the impact of the implementation of the cross-reactivity chart for patients with pneumonia. Study time periods were defined as January 2013 to October 2014 prior to implementation of the chart (historical cohort) and January 2017 to October 2018 (intervention cohort) following implementation. The primary outcome was the incidence of β-lactam utilization between time periods. Propensity-weighted scoring and interrupted time-series analyses compared outcomes.

RESULTS

A total of 341 and 623 patient encounters were included in the historical and intervention cohorts, respectively. There was a significantly greater use of β-lactams in the intervention cohort (70.4% vs 89.3%; P < .001) and decreased use of alternative therapy (58.1% vs 36%; P < .001). There was no difference in overall allergic reactions between cohorts (2.4% vs 1.6%; P = .738) or in reactions caused by β-lactams (1.3% vs 0.9%; P = .703). Inpatient mortality increased (0% vs 6.4%; P < .001); however, no deaths were due to allergic reactions. Healthcare facility-onset Clostridioides difficile infections decreased between cohorts (1.2% vs 0.2%; P = .032).

CONCLUSIONS

Implementation of a β-lactam side chain-based cross-reactivity chart and enhanced allergy assessment was associated with increased use of β-lactams in patients with pneumonia without increasing allergic reactions.