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

Evidence for overdiagnosis in noncancer conditions was assessed: a metaepidemiological study using the 'Fair Umpire' framework

OBJECTIVES

To evaluate the strength of the evidence for, and the extent of, overdiagnosis in noncancer conditions.

STUDY DESIGN AND SETTING

We systematically searched for studies investigating overdiagnosis in noncancer conditions. Using the 'Fair Umpire' framework to assess the evidence that cases diagnosed by one diagnostic strategy but not by another may be overdiagnosed, two reviewers independently identified whether a Fair Umpire-a disease-specific clinical outcome, a test result or risk factor that can determine whether an additional case does or does not have disease-was present. Disease-specific clinical outcomes provide the strongest evidence for overdiagnosis, follow-up or concurrent tests provide weaker evidence, and risk factors provide only weak evidence. Studies without a Fair Umpire provide the weakest evidence of overdiagnosis.

RESULTS

Of 132 studies, 47 (36%) did not include a Fair Umpire to adjudicate additional diagnoses. When present, the most common Umpire was a single test or risk factor (32% of studies), with disease-specific clinical outcome Umpires used in only 21% of studies. Estimates of overdiagnosis included 43-45% of screen-detected acute abdominal aneurysms, 54% of cases of acute kidney injury, and 77% of cases of oligohydramnios in pregnancy.

CONCLUSION

Much of the current evidence for overdiagnosis in noncancer conditions is weak. Application of the framework can guide development of robust studies to detect and estimate overdiagnosis in noncancer conditions, ultimately informing evidence-based policies to reduce it.

Beta-lactam comprehensive allergy management program in a community medical center

Objective

The Beta-lactam Comprehensive Allergy Management Program (CAMP) was implemented to facilitate complete beta-lactam allergy history documentation in the electronic medical record (EMR) and increase beta-lactam utilization. The study objective was to assess the rate of complete allergy histories and days of antimicrobial therapy (DOT) before versus after CAMP implementation.

Design

Quasi-experimental study with interrupted time-series analysis.

Setting

Non-teaching, urban, and community medical center within a multi-hospital health system.

Patients

Adult inpatients with a beta-lactam allergy receiving antimicrobial therapy.

Methods

The multidisciplinary CAMP team screened, interviewed, and collected allergy history details of adult inpatients with a beta-lactam allergy receiving antimicrobial therapy starting January 4, 2021. Patients were stratified as high, moderate, or low risk of IgE-mediated allergy and referred to an allergist for skin testing or drug challenge. The EMR was updated with interview details and drug challenge or skin test results. The primary endpoint was rate of complete allergy history documentation before (12/1/18-4/1/19) compared to after (1/4/21-5/1/21) program implementation. The secondary endpoint was days of inpatient beta-lactam therapy. Implementation logistics, de-labeling rate, and antimicrobial therapy changes were evaluated.

Results

The program evaluated 392 individuals, with 184 and 208 patients comprising the pre- and post-intervention groups, respectively. The post-intervention period was associated with an increase of 19.8% in complete allergy histories (0.359 PPc; R 2 0.26; p = 0.002) and 9.34 beta-lactam DOT per 1,000-days-present (1.106 PPc; R 2 0.194; p = 0.009).

Conclusion

Implementation of a comprehensive beta-lactam allergy management program was associated with higher rates of complete beta-lactam allergy history and beta-lactam use.

Drug allergy in primary care: systematic review to support quality improvement initiative of management and optimization of healthcare pathways

PURPOSE OF REVIEW

The aim of this study was to review the practice of general practitioners (GPs) in regard to the diagnosis and management of drug hypersensitivity reactions (DHRs) to identify major challenges and to facilitate the development of decision support tools to GPs confronted with DHRs patients.

RECENT FINDINGS

DHRs are still a challenge in the GPs clinical practice, which implies difficulties in clinical decisions and referral to allergy specialists.

SUMMARY

DHRs can range from mild to severe and even life-threatening. Drugs are the main cause of anaphylaxis deaths in most countries. Most DHRs are firstly seen by GPs, paediatricians or emergency doctors. However, our systematic review demonstrated difficulties in differentiating DHRs from other drug side effects. Most DHRs epidemiological data are from hospital and emergency departments, which may not reflect the real-life experience in primary care. GPs should be aware of the alert signs of DHRs: the involvement of other systems beyond the skin and/or atypical skin/ mucosal involvement, which mandated immediate referral to an emergency department. Data still stress difficulties in the recognition of DHRs clinical manifestations and highlight the need for decision aids to support their management by GPs. Structured clinical history and clinical examination are key diagnostic tools. Reasons for referring to allergy specialists based on the literature are to investigate cause, to undergo specific procedure, such as desensitization and to identify well tolerated, alternative drugs.

Cues to improve antibiotic-allergy registration: A mixed-method study

BACKGROUND

Approximately 2% of patients in primary care practice and up to 25% of hospital patients are registered as being allergic to an antibiotic. However, up to 90% of these registrations are incorrect, leading to unnecessary prescription of 2nd choice antibiotics with the attendant loss of efficacy, increased toxicity and antibiotic resistance. To improve registration, a better understanding is needed of how incorrect labels are attributed.

OBJECTIVE

To investigate the quality of antibiotic allergy registration in primary care and identify determinants to improve registration of antibiotic allergies.

DESIGN

Registration of antibiotic allergies in primary care practices were analysed for 1) completeness and 2) correctness. To identify determinants for improvement, semi-structured interviews with healthcare providers from four healthcare domains were conducted.

PARTICIPANTS

A total of 300 antibiotic allergy registrations were analysed for completeness and correctness. Thirty-four healthcare providers were interviewed.

MAIN MEASURES

A registration was defined as complete when it included a description of all symptoms, time to onset of symptoms and the duration of symptoms. It was defined as correct when the conclusion was concordant with the Salden criteria. Determinants of correct antibiotic allergy registrations were divided into facilitators or obstructers.

KEY RESULTS

Rates of completeness and correctness of registrations were 0% and 29.3%, respectively. The main perceived barriers for correct antibiotic allergy registration were insufficient knowledge, lack of priority, limitations of registration features in electronic medical records (EMR), fear of medical liability and patients interpreting side-effects as allergies.

CONCLUSIONS

The quality of antibiotic allergy registrations can be improved. Potential interventions include raising awareness of the consequences of incomplete and the importance of correct registrations, by continued education, and above all simplifying registration in an EMR by adequate ICT support.

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.

Betalactam hypersensitivity: The importance of delabelling in primary care

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

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.

Knowledge gaps of drug allergy in children: a survey of primary care doctors

INTRODUCTION

There is still lack of knowledge of drug allergy in children. Proper knowledge and management of drug hypersensitivity reactions is important to physicians.

AIM

To evaluate the approach of primary care doctors regarding drug allergy in children.

MATERIAL AND METHODS

A total of 195 primary care doctors were questioned in various parts of Lithuania from 2015 to 2016. An original questionnaire was used. The incidence of a suspected drug allergy, culprit drugs, the clinical pattern and management of the suspected drug hypersensitivity were analysed.

RESULTS

The majority of primary care doctors (74.4%) reported a suspected drug allergy. The main suspected drugs were antibiotics (95.2%) and nonsteroidal anti-inflammatory drugs (32.4%). Skin symptoms (skin rash (100%) and itching (82.1%)) were the main symptoms of the suspected drug allergy. The vast majority of doctors (93.8%) withdrew the use of a suspected drug and 68.3% of respondents prescribed an alternative drug. The fact that skin tests, blood tests and provocation tests could be used in a drug allergy workup were indicated by 43.6% of doctors. Most doctors (69.2%) knew about the opportunity to test children for drug allergy in Lithuania and 41.4% of doctors referred patients for the further drug allergy workup.

CONCLUSIONS

The majority of primary care doctors reported a suspected drug allergy in children. The most common suspected drugs were antibiotics and skin symptoms were the main symptoms. Most doctors knew about the possibility to test for the drug allergy but only less than half of them referred patients for the drug allergy workup.

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.

Direct drug provocation test for the diagnosis of self-reported, mild and immediate drug hypersensitivity reaction in children and adolescents: our real-life experience

BACKGROUND

Approximately 10% of the parents report suspected drug hypersensitivity reactions to at least one drug in their children, but most of these reactions are not confirmed after an adequate diagnostic work-up. The diagnosis of drugs hypersensitivity is frequently laborious and based on anamnesis, skin tests, serum specific IgE research and drug provocation test. Nevertheless, drug provocation test is necessary to confirm or definitively exclude the diagnosis of allergy. Aims of our study were to evaluate the real incidence of drug hypersensitivity in a large pediatric population and the validity of a short diagnostic algorithm.

METHODS

One hundred nine patients with a history of self-reported, immediate and mild drug hypersensitivity reactions to β-lactam antibiotics, macrolides and non-steroidal anti-inflammatory drugs underwent drug provocation test without prior skin or blood tests. After one-year, a telephone questionnaire was conducted in order to evaluate patient's use of the tested drug and any reactions.

RESULTS

Only 7 of the 109 patients (6.4%) resulted positive to drug provocation test. No severe reactions were reported. After the challenge, 64 patients took the culprit drug again within one year and only two reported a drug reaction.

CONCLUSIONS

Drug hypersensitivity is highly overestimated. Our results prompt the opportunity to directly perform the challenge for those children with self-reported, mild and immediate drug hypersensitivity reaction.

Presumed β-Lactam Allergy and Cross-reactivity in the Operating Theater: A Practical Approach

A β-lactam allergy is the most common suspected in-hospital drug allergy. This article aims to provide a practical approach to a patient with presumed β-lactam allergy in the perioperative setting.

Supplemental Digital Content is available in the text.

An EAACI task force report: recognising the potential of the primary care physician in the diagnosis and management of drug hypersensitivity

Adverse drug reactions include drug hypersensitivity reactions (DHRs), which can be immunologically mediated (allergy) or non-immunologically mediated. The high number of DHRs that are unconfirmed and often self-reported is a frequent problem in daily clinical practice, with considerable impact on future prescription choices and patient health. It is important to distinguish between hypersensitivity and non-hypersensitivity reactions by adopting a structured diagnostic approach to confirm or discard the suspected drug, not only to avoid life-threatening reactions, but also to reduce the frequent over-diagnosis of DHRs. Primary care physicians are often the first point of contact for the sufferer of a reaction, as such they have a key role in deciding whether to discard the diagnosis or send the patient for further investigation. In this review, we highlight the importance of diagnosing DHRs, analysing in detail the role of primary care physicians. We describe the common patterns of DHRs and signs of its progression, as well as the indications and contraindications for referring the patient to an allergist. The diagnostic process is described and the possible tests are discussed, which often depend on the drug involved and the type of DHR suspected. We also describe recommendations regarding the avoidance of medication suspected to have caused the reaction and the use of alternatives.

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

BACKGROUND

Suspected penicillin allergic individuals receive suboptimal non-β-lactams for intraoperative prophylaxis which may prolong operations and have negative clinical outcomes. We therefore studied if β-lactam de-labeling optimized choice of prophylactic antibiotics and improved intraoperative time efficiency.

METHODS

A multistep approach was used. It included a risk assessment tool by an allergist, β-lactam skin testing and oral provocation. To determine the value of de-labeling, we appraised intraoperative antibiotic choices and correlated them with time to first incision.

RESULTS

A total of 194 patients were evaluated preoperatively. Four patients were diagnosed β-lactam allergic on skin testing. Of the remaining 190 skin test negative patients, 146 were β-lactam challenged. Only 5% reacted and were considered β-lactam allergic. Cefazolin became the perioperative antibiotic of choice for 77% of patients requiring antibiotic prophylaxis. Only 5 confirmed β-lactam allergic patients received intraoperative vancomycin. Patients avoiding use of vancomycin saved an average of 22 minutes in operative time. Of the 44 patients not having a β-lactam challenge, 36 received antibiotics and 18 (50%) of these were prescribed intraoperative cefazolin.

CONCLUSION

Using this three step process, almost all of those claiming penicillin allergy were de-labeled. In most patients that were drug challenged, β-lactam antibiotics became the perioperative drug of choice. In cases where oral challenge was not used in the assessment only 50% were given a β-lactam. The reduced use of vancomycin minimized delays in initiation of incision time, thus improving operative efficiency. Ultimately, randomized controlled studies are required to objectively determine the effectiveness of this approach.

The impact of penicillin allergy labels on antibiotic and health care use in primary care: a retrospective cohort study

BACKGROUND

Suspected penicillin allergy (Pen-A) is often not verified by diagnostic testing. In third line penicillin allergy labels were associated with prescription of broad spectrum antibiotics, hospital stay duration and readmission.

OBJECTIVE

Assess the impact of Pen-A labels on antibiotic and health care use in primary care.

METHODS

A retrospective cohort study was conducted in primary care in the Utrecht area, the Netherlands. All patients registered with a penicillin allergy on 31 December 2013 were selected from the General Practitioner Network database. Each patient with a Pen-A label was matched for age, gender, follow-up period with three patients without Pen-A label. Risk (OR) of receiving a reserve and second choice antibiotic, number and type of antibiotics prescribed during follow-up and number of GP contacts were compared between the two cohorts.

RESULTS

Of 196,440 patients, 1254 patients (0.6%) with a Pen-A label were identified and matched with 3756 patients without Pen-A label. Pen-A labels resulted in higher risk of receiving ≥1 antibiotic prescription per year (OR 2.56, 95% CI 2.05-3.20), ≥1 s choice antibiotic prescription per year (OR 2.21 95% CI 1.11-4.40), and ≥4 GP contacts per year (OR 1.71 95% CI 1.46-2.00). The chance of receiving tetracyclins (OR 2.24, 95% CI 1.29-3.89), macrolides/lincosamides/streptogamins (OR 8.69, 95% CI 4.26-17.73) and quinolones (OR 2.59, 95% CI 1.22-5.48) was higher in Pen-A patients.

CONCLUSIONS

In primary health care Pen-A labels are associated with increased antibiotic use, including second choice antibiotics, and more health care use.

The High Impact of Penicillin Allergy Registration in Hospitalized Patients

BACKGROUND

Suspected penicillin allergy (Pen-A) is often not verified or excluded by diagnostic testing.

OBJECTIVE

To assess the prevalence and impact of Pen-A registration in a Dutch University Medical Center.

METHODS

In a prospective matched cohort study, all admitted patients (July 2013-July 2014) who underwent a pharmacotherapeutic interview were selected. Patients with a registered Pen-A were matched on age, sex, and department of admission with up to 3 patients without a registered Pen-A. Relative risks (RRs) of receiving a reserve antibiotic, death during hospitalization, and rehospitalization were compared in the 2 cohorts. The number and type of antibiotics prescribed during admission and duration of hospitalization were compared.

RESULTS

Of 17,959 patients, 1010 (5.6%) patients (66.7% women; median age, 55 years) had a Pen-A registration. These patients had a higher risk of receiving reserve antibiotics (RR, 1.38; 95% CI, 1.22-1.56) and of being rehospitalized within 12 weeks (RR, 1.28; 95% CI, 1.10-1.49). A significantly larger proportion of Pen-A registered patients received reserve antibiotics such as tetracyclines (1.8% vs 0.8%), macrolides/lincosamides/streptogramins (12.5% vs 4.9%), and quinolones (7.9% vs 4.3%) or received 2 or more types of antibiotics during hospitalization (21.7% vs 16.9%).

CONCLUSIONS

Prevalence of Pen-A registration in hospitalized patients is high, has high impact on antibiotic prescribing, and is associated with a higher risk of readmission. Verification of the Pen-A in hospitalized patients might restrict the use of reserve antibiotics and improve patient outcome.