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

Antibiotic hypersensitivity and adverse reactions: management and implications in clinical practice

Background

Studies have shown the discrepancy between self-reported antibiotic allergies and true allergies. Inaccurate reporting of antibiotic hypersensitivities can limit treatment options and result in use of more expensive antibiotics and contribute to resistance.

Methods

This retrospective cohort chart review obtained data on 16,515 patients after obtaining IRB approval. Patients who had an antibiotic adverse reaction were identified, recorded, and their management reviewed. 7926 patients were selected from inpatient internal medicine clinics, 8042 patients from outpatient internal medicine clinics, and 547 from orthopedic clinics.

Results

The prevalence of reported antibiotic sensitivity in our study was 9.89% (n = 1624). Reported antibiotic sensitivity was 8.88% (n = 704) in inpatient settings as compared to 11.2% (n = 902) and 5.12% (n = 28) in medicine and orthopedic outpatient settings respectively. The top five antibiotic adverse reactions reported were penicillins (42%), sulfonamides (25%), fluoroquinolones (4.3%), tetracyclines (4.2%), and macrolides (3.5%). In all settings, penicillins and sulfonamides adverse reactions were the top two reportings. 11.88% (n = 193) of patients with reported adverse reactions reported sensitivities to multiple antibiotics.

Conclusion

Our study demonstrated high prevalence of reported antibiotic sensitivity in three clinical settings. However, a significant portion of these patients may not be truly hypersensitive to these antibiotics. There is a need for increased awareness among medical professionals about the importance of detailed history taking and management of self-reported antibiotic allergies to combat unnecessary use of antibiotics.

Does systemic antibiotic prophylaxis prior to the placement of totally implantable venous access devices reduce early infection? A retrospective study of 1,485 cases at a large academic institution

BACKGROUND

To determine if ending the practice of administering prophylactic antibiotics prior to the placement of totally implantable venous access devices (TIVADs) is correlated with an increase in 30-day bloodstream infection-related TIVADs removals.

METHODS

The practice of administering prophylactic antibiotics prior to the placement of TIVADs ended in July 2013 at our institution. We compiled a list of patients who had TIVADs placed between July 2010 and July 2016 and cross-referenced this list to a list of patients who had TIVADs removed between July 2010 and August 2016 to evaluate the 30-day bloodstream infection-related TIVAD removals. Retrospective chart review of all patients was performed to collect demographic information, indication for placement, and type of antibiotic administered, if applicable.

RESULTS

Over the study period of 6 years, a total of 1,513 TIVADs were placed, of which 28 cases were excluded because of death within 30 days unrelated to TIVAD placement. Of the remaining 1,485 cases, 733 TIVADs were placed in 709 unique patients with prophylactic antibiotic treatment and 752 TIVADs were placed in 709 unique patients without treatment. A total of 8 patients were identified to have TIVADs removed within 30 days owing to infection, of which 4 patients were treated with prophylactic antibiotics. The odds of infection-related removals without prophylactic treatment compared with prophylactic treatment was 0.97 (95% confidence interval, 0.24-3.91; P = .97).

CONCLUSIONS

Ending the practice of administrating systemic antibiotic prophylaxis prior to the placement of TIVADs had no effect on the 30-day bloodstream infection-related TIVAD removals rate at our institution. We do not recommend the use of prophylactic antibiotics for the placement of TIVAD.

Anaphylaxis for Internists: Definition, Evaluation, and Management, with a Focus on Commonly Encountered Problems

Anaphylaxis is an acute systemic allergic reaction that can be life threatening. In adults, the most common causes of anaphylaxis are foods, drugs, and insect stings. This article reviews the definition, classification, evaluation, differential diagnosis, prognosis, complications, and management of anaphylaxis. Tailored for internists, the article focuses on anaphylactic medication allergies. It provides a guide to optimally evaluate and manage patients with antibiotic allergy using a simple, rapid risk stratification technique, graded antibiotic challenge (test dose), and/or allergist-guided drug desensitization. It also reviews other causes of anaphylaxis that internists are likely to encounter, and an approach to their management.

A Prospective Evaluation of Adverse Reactions to Single-Dose Intravenous Antibiotic Prophylaxis During Outpatient Hand Surgery

Background: While it is established that routine prophylactic antibiotics are not needed for all hand surgery, some cases do require it. The purpose of this study was to determine the rate of adverse reactions resulting from prophylactic antibiotic administration on patients undergoing outpatient hand and upper extremity surgical procedures. We hypothesize that the rate of complications resulting from the use of antibiotic prophylaxis is smaller than that reported in the currently referenced literature. Methods: We prospectively evaluated 570 consecutive patients undergoing outpatient upper extremity surgery. Patients were excluded if they were on antibiotics prior to surgery, were discharged on antibiotics, or if they wished to be excluded. Nineteen patients were excluded, resulting in a study cohort of 551 patients. Patients were monitored perioperatively, 2 to 3 days postoperatively, during the first postoperative visit and 1 month postoperatively for adverse reactions. The type and timing of the adverse reaction was recorded. Results: Five hundred fifty-one patients were included for evaluation and 8 patients (1.5%) developed an adverse reaction to antibiotics. Five patients (0.9%) reported a rash and 3 patients (0.5%) reported diarrhea within 3 days of surgery. There were no anaphylactic reactions or complications necessitating hospital transfer or admission in the postoperative period. Conclusion: This study represents a prospective investigation designed to determine the rate of adverse reactions to single-dose antibiotics given during outpatient hand surgery. We conclude that the use of intravenous, single-dose prophylactic antibiotic is safe in the outpatient setting for cases that require it.

Addressing the epidemic of antibiotic "allergy" over-diagnosis

OBJECTIVE

An epidemic of antibiotic allergy is occurring.

DATA SOURCES

Articles published since 2008.

STUDY SELECTIONS

Articles on antibiotic allergy and stewardship.

RESULTS

A number of overlapping factors contribute. The most important factor is antibiotic overuse. Antibiotics are commonly used in situations in which no antibiotics are indicated. Thirty percent to 50% of ambulatory antibiotic use may be inappropriate. The duration of indicated antibiotic use is often excessive, which leads to more side effects. All antibiotic use can result in adverse reactions, and a fraction of these will be dutifully recorded as an allergy in the electronic health record (EHR). Most EHRs are not well structured to accurately convey information on expected side effects that have occurred, metabolic or other contraindications, dose-related or situational toxicities, personal preferences, clinically significant immunologically mediated hypersensitivity, and other reasons a particular patient may not want or should not be given a specific drug or type of drug in the future. As populations age, their accumulated baggage of reported antibiotic allergies increase. Suspected antibiotic allergy is rarely confirmed with appropriate testing or rechallenge. Patients then receive suboptimal antibiotic therapy and experience more side effects, treatment failures, and serious antibiotic-resistant infections. Reporting an antibiotic allergy in the EHR is nominally done to improve patient safety, but unfortunately, this is often not the actual result.

CONCLUSION

Audit and feedback, to help ensure adherence to Choosing Wisely recommendations and good antibiotic stewardship practices, can help reduce inappropriate antibiotic use. Restructuring EHRs to facilitate correct drug intolerance reporting, along with active antibiotic allergy delabeling programs, can help stem this epidemic.

Allergological Study of 565 Elderly Patients Previously Labeled as Allergic to Penicillins

Purpose

Elderly people thought to have an allergy to beta-lactams (BLs) may tolerate the drugs in subsequent exposures due to initial false labeling of allergies, the spontaneous loss of sensitivity to BLs over time or age-related decline in sensitization. As a result, they may be treated with less appropriate antibiotics, causing more side effects and entailing increased costs for health systems. The aim of this investigation was to assess whether patients in the third and fourth age with previously confirmed allergies to BLs had lost sensitization and could tolerate these antibiotics.

Patients and methods

Patients allergic to BLs were divided into group A (aged 60-79 years) and B (aged ≥80 years). Clinical history, skin testing, drug challenge tests (DCT) and evaluation of resensitization were used to classify participants as showing immediate reactions, non-immediate reactions, or tolerance. We compared clinical entities, drugs involved, and final outcome by age group.

Results

Of 1362 cases evaluated, 565 underwent an allergological study. The skin was the most common organ involved. Anaphylaxis and side chain reactions were more frequent in group A (p<0.01), as were positive DCT. Classical benzylpenicillin determinants (benzylpenicilloyl and/or minor determinant mixture) were more frequent triggers in group B (p< 0.01). Resensitization after challenge occurred in very few participants.

Conclusion

The risk for allergy to BLs decreases with age and a history of anaphylaxis by BLs is a predictor of positive results in skin tests (ST). Both immunoglobin E (IgE) and T-cell-mediated responses can disappear in elderly people, who can develop tolerance to these antibiotics. These results are of clinical relevance to patients who need to be treated with antibiotics from this family.

Beta-lactam allergy in Chinese patients and factors predicting genuine allergy

Introduction

Beta-lactams (BL) are the most frequently reported drug allergy, but the vast majority of patients are found not to be genuinely allergic after evaluation. Few studies have investigated the clinical predictors of genuine BL allergy, and the prevalence in hospitalized Chinese patients is unknown.

Methods

Patients admitted to a tertiary hospital in Hong Kong (HK) were analyzed to identify the prevalence and factors associated with the presence of BL allergy labels among hospitalized Chinese patients. A combined cohort of patients having completed allergy investigation for suspected BL allergies in the United Kingdom (UK) and HK were analyzed to identify predictors of genuine allergy.

Results

The prevalence of BL allergy labels in hospitalized HK Chinese was 5%, which was associated with female gender and concomitant non-BL antibiotic allergy labels. The rate of genuine BL allergy patients referred for suspected allergies in the UK and HK cohort was only 14%. History of anaphylaxis and interval of less than a year since the index reaction were independent clinical predictors of genuine BL allergy. The negative predictive value of penicillin skin testing was 90%, confirming the need for drug provocation testing after negative skin testing. There was a high rate of confirmed piperacillin-tazobactam allergy.

Discussion

The estimated true prevalence of genuine BL allergy in hospitalized HK Chinese is around 0.5%. This high rate of BL mislabeling highlights the need for comprehensive allergy evaluation and screening. History of anaphylaxis and duration since the index reaction are important predictors of genuine allergy. Piperacillin-tazobactam allergy may pose a unique challenge in this population with a high prevalence of suspected allergies, surging antibiotic resistance, and lack of testing available.

Sulfonamide Allergies

As one of the earliest developed antimicrobial classes, sulfonamides remain important therapeutic options for the empiric and definitive treatment of various infectious diseases. In the general population, approximately 3–8% of patients are reported to experience a sulfonamide allergy. Sulfonamide allergies can result in various physical manifestations; however, rash is reported as the most frequently observed. In patients with human immunodeficiency virus (HIV), dermatologic reactions to sulfonamide antimicrobial agents occur 10 to 20 times more frequently compared to immunocompetent patients. This article describes the incidence, manifestations, and risk factors associated with sulfonamide allergies. The potential for cross-reactivity of allergies to sulfonamide antimicrobials with nonantimicrobial sulfonamide medications is also reviewed. Data suggest that substitutions at the N₁ and N₄ positions are the primary determinants of drug allergy instead of the common sulfonamide moiety. For patients with an indication for a sulfonamide antimicrobial with a listed allergy, it is important for healthcare practitioners to adequately assess the allergic reaction to determine appropriate management. Rechallenge and desensitization strategies may be appropriate for patients with delayed maculopapular eruptions, while alternative treatment options may be prudent for more severe reactions. Available data suggests a low risk of cross-allergenicity between sulfonamide antimicrobial and nonantimicrobial agents.

Perspective on current and emerging drugs in the treatment of acute and chronic toxoplasmosis

No new drugs for treatment of toxoplasmosis have been approved in over 60 years, despite the burden of toxoplasmosis on human society. The small selection of effective drugs is limited by important side effects, often limiting patient use. This perspective highlights promising late-stage drug candidates in the treatment of toxoplasmosis. Presently, drugs target the tachyzoite form of the parasite Toxoplasma gondii responsible for the acute infection but do not eradicate the tissue cyst form underlying chronic infection. Pyrimethamine - the first-line and only approved drug for treatment of toxoplasmosis in the United States - inhibits parasite DNA synthesis by inhibiting dihydrofolate reductase (DHFR). Two novel DHFR inhibitors with improved potency and selectivity for parasite DHFR over human DHFR are in clinical-stage development. One of the most advanced and promising therapeutic targets, demonstrating potential to treat both acute and chronic toxoplasmosis, is the calcium-dependent protein kinase 1 (CDPK1) which plays an essential role in the intracellular replicative cycle of the parasite, and has no direct mammalian homolog. Two CDPK1 inhibitor programs have identified potent and selective lead series, demonstrating acceptable systemic and CNS exposure, and in vivo efficacy in animal models of acute and chronic infection. Physicians need a better arsenal of parasiticidal drugs for the treatment of toxoplasmosis, particularly those active against tissue cysts.

Overview and Insights into Carbapenem Allergy

Understanding antibiotic allergies and the risk of cross-sensitivity between and within antibiotic classes can have a substantial impact on patient care. The purpose of this review article is to provide insight into carbapenem allergies, describing the overall incidence, risk factors, and in-class cross-sensitivity. A PubMed search was conducted using the following search terms: carbapenem, allergy, cross-sensitivity, incidence, imipenem/cilastatin, meropenem, ertapenem, and doripenem. Article bibliographies and relevant drug monographs were also reviewed. The overall reported incidence of carbapenem allergy is 0.3%–3.7%. Risk of cross-sensitivity between penicillins and carbapenems is less than 1% in patients with a positive penicillin skin test. Data on cross-sensitivity between cephalosporins and carbapenems are limited; however, the risk appears to also be low. No clinical studies have described cross-sensitivity between the carbapenem agents thus far. The limited data available from case reports demonstrates a lack of cross-sensitivity between the individual carbapenems, suggesting that an alternative carbapenem may cautiously be used in patients with a reported carbapenem allergy.

Cephalosporins: A Focus on Side Chains and β-Lactam Cross-Reactivity

Cephalosporins are among the most commonly prescribed antibiotic classes due to their wide clinical utility and general tolerability, with approximately 1-3% of the population reporting a cephalosporin allergy. However, clinicians may avoid the use of cephalosporins in patients with reported penicillin allergies despite the low potential for cross-reactivity. The misdiagnosis of β-lactam allergies and misunderstanding of cross-reactivity among β-lactams, including within the cephalosporin class, often leads to use of broader spectrum antibiotics with poor safety and efficacy profiles and represents a serious obstacle for antimicrobial stewardship. Risk factors for cephalosporin allergies are broad and include female sex, advanced age, and a history of another antibiotic or penicillin allergy; however, cephalosporins are readily tolerated even among individuals with true immediate-type allergies to penicillins. Cephalosporin cross-reactivity potential is related to the structural R1 side chain, and clinicians should be cognizant of R1 side chain similarities when prescribing alternate β-lactams in allergic individuals or when new cephalosporins are brought to market. Clinicians should consider the low likelihood of true cephalosporin allergy when clinically indicated. The purpose of this review is to provide an overview of the role of cephalosporins in clinical practice, and to highlight the incidence of, risk factors for, and cross-reactivity of cephalosporins with other antibiotics.

Self-reported beta-lactam intolerance: not a class effect, dangerous to patients, and rarely allergy

Introduction: About 8% of the United States population carries an unconfirmed penicillin 'allergy' in their medical record. Many physicians needlessly avoid other beta-lactam use in individuals with unconfirmed penicillin allergies. There is a significantly increased risk of developing serious antibiotic-resistant infections, and increased morbidity and mortality in those who report penicillin allergy. Areas covered: Within this study, we reviewed the relevant literature on self-reported beta-lactam allergy. We discuss how the myth of serious allergy to penicillin developed and then discuss and in detail clinically significant immunologically mediated hypersensitivity reactions. Following this discussion, we delineate the risks of not using a beta-lactam when it is the drug of choice and then discuss the epidemiology of beta-lactam-associated anaphylaxis, serious cutaneous adverse reactions, and serious systemic immunologically mediated reactions. Following these topics, we further discuss the consensus current best practices to de-label patients with reported penicillin allergy. Expert opinion: An unconfirmed allergy to penicillin offers considerable harm to patients. Many patients have low-risk allergy symptoms to penicillin who could likely tolerate the medication without having an allergic reaction. The current best practices to de-label reported penicillin allergy is the utilization of a single dose oral challenge, with 1 h of observation, in low-risk patients.

Recent developments in drug hypersensitivity in children

Introduction: Drug allergy is an important public health problem that causes 0.4-10.3% of hospital admissions in children. The epidemiology, clinical spectrum, diagnosis, and management of drug hypersensitivity reactions (DHRs) differ in pediatric and adult patients. However, the same algorithms used in adults have often been applied in the pediatric population due to a lack of evidence in the literature. Areas covered: In this review, we aimed to discuss recent developments in the area of pediatric DHRs based on the growing body of literature advancing our understanding of the epidemiology, clinical aspects, and diagnostic approaches to DHRs in children. Expert opinion: Misdiagnosis, under-diagnosis, and self-diagnosis are common problems related to drug allergies in children. Viral infections are particularly frequent in children and make diagnosis difficult. Identifying true DHR is a key step in the management of drug allergy in children. Therefore, a complete allergy work-up with standardized drug allergy tests is necessary. In order to eliminate non-standardized tests, future studies including larger numbers of children should be conducted to determine more accurate standardized tests for diagnosing DHRs in the pediatric population.

Identifying Low-Risk Beta-Lactam Allergy Patients in a UK Tertiary Centre

BACKGROUND

There are marked geographical as well as temporal differences in patient sensitization profiles to β-lactams (BL).

OBJECTIVE

To determine the utility of skin test reagents and identify a cohort of patients where skin testing can be safely omitted in a cohort of patients referred to a UK tertiary referral center.

METHODS

A retrospective study of the clinical characteristics of 1092 patients referred for BL allergy testing was analyzed using multivariate regression analysis. The effectiveness of skin test reagents was also evaluated.

RESULTS

Multivariate logistic regression identified that a history of anaphylaxis (odds ratio [OR] 10.98, P = .001) and the patients' recall of the index drug (apart from ampicillin and meropenem, OR 3.51-12.43, P < .05) were independent predictors of type I BL allergic status and a time of less than 1 year elapsed since index reaction significantly increasing the odds of a patient with a history of anaphylaxis, having a type I BL allergy (OR 38.66, P = .003). An absence of anaphylactic severity, unknown name of the index drug and a reaction occurring more than 1 year before testing, has a negative predictive value (NPV) of 98.4%, which was similar to the NPV of skin testing of 98.9% for type I BL allergy. The NPV of skin testing with benzylpenicillin + amoxicillin ± index BL was similar with (98.9%) or without (98.1%) the use of benzylpenicillin polylysine and minor determinant for type I BL allergy.

CONCLUSION

We identified a "low risk" cohort of patients where the history is of similar reliability to skin testing in predicting nonallergic status for BL allergy.

Adherence to antibiotic guidelines and reported penicillin allergy: pooled cohort data on prescribing and allergy documentation from two English National Health Service (NHS) trusts

OBJECTIVE

To investigate documentation of antimicrobial allergy and to determine prescribing adherence to local antibiotic guidelines for inpatients with and without reported penicillin allergy treated for infection in a National Health Service (NHS) context.

SETTING

Data were collected at two English hospital NHS trusts over two time-periods: June 2016 and February 2017.

DESIGN

Cohort study. Trust 1 data were sourced from prospective point prevalence surveys. Trust 2 data were extracted retrospectively from an electronic report.

PARTICIPANTS

Inpatients treated for urinary tract infection (UTI), community-acquired pneumonia (CAP), hospital-acquired pneumonia (HAP) and skin and soft tissue infection (SSTI). Data on allergy were collected, and antibiotic selection assessed for adherence to trust guidelines with differences between groups presented as adjusted ORs.

RESULTS

A total of 1497 patients were included, with 2645 antibiotics orders. Patients were treated for CAP (n=495; 33.1%), UTI (407; 27.2%), HAP (330; 22%) and SSTI (265; 17.7%). There were 240 (16%) patients with penicillin allergy. Penicillin allergy was recorded as allergy (n=52; 21.7%), side effect (27; 11.3%) and no documentation (161; 67.1%). Overall, 2184 (82.6%) antibiotic orders were guideline-adherent. Adherence was greatest for those labelled penicillin allergy (453 of 517; 87.6%) versus no allergy (1731 of 2128; 81.3%) (OR 0.52 (95% CI 0.37 to 0.73) p<0.001). Guideline-adherence for CAP was higher if penicillin allergy (151 of 163; 92.6%) versus no allergy (582 of 810; 71.9%) (OR 0.20 (95% CI 0.10 to 0.37) p<0.001). There was no difference in adherence between those with and without penicillin allergy for UTI, HAP or SSTI treatment.

CONCLUSIONS

A relatively high proportion of patients had a penicillin allergy and two thirds of these had no description of their allergy, which has important implications for patient safety. Patients with penicillin allergy treated for CAP, received more guideline adherent antibiotics than those without allergy. Future studies investigating the clinical impact of penicillin allergy should include data on adherence to antibiotic guidelines.

Pediatric drug hypersensitivity: which diagnostic tests?

Along with the anamnesis and clinical evaluation, diagnostic tests are one of the mainstream key points in the evaluation and management of drug hypersensitivity reactions (DHR). A wide knowledge gap, both in diagnosis and management of pediatric DHR, must be filled.  Only a few published studies evaluated sensitivity and specificity of skin and in vitro tests in children. However, selected case series show that diagnostic work-up for adults could be useful, with some limitations, in pediatric age. Indeed, despite improvement in in vivo and in vitro diagnosis, drug provocation test remains the gold standard in pediatric age, too. Unmet needs in children include multi-centric studies on incidence of DHR, utility and feasibility of in vivo and in vitro diagnostic tests and specifically dedicated guidelines for the diagnosis and management of DHR in children.

Evaluation and Management of Penicillin Allergy: A Review

IMPORTANCE

β-Lactam antibiotics are among the safest and most effective antibiotics. Many patients report allergies to these drugs that limit their use, resulting in the use of broad-spectrum antibiotics that increase the risk for antimicrobial resistance and adverse events.

OBSERVATIONS

Approximately 10% of the US population has reported allergies to the β-lactam agent penicillin, with higher rates reported by older and hospitalized patients. Although many patients report that they are allergic to penicillin, clinically significant IgE-mediated or T lymphocyte-mediated penicillin hypersensitivity is uncommon (<5%). Currently, the rate of IgE-mediated penicillin allergies is decreasing, potentially due to a decreased use of parenteral penicillins, and because severe anaphylactic reactions to oral amoxicillin are rare. IgE-mediated penicillin allergy wanes over time, with 80% of patients becoming tolerant after a decade. Cross-reactivity between penicillin and cephalosporin drugs occurs in about 2% of cases, less than the 8% reported previously. Some patients have a medical history that suggests they are at a low risk for developing an allergic reaction to penicillin. Low-risk histories include patients having isolated nonallergic symptoms, such as gastrointestinal symptoms, or patients solely with a family history of a penicillin allergy, symptoms of pruritus without rash, or remote (>10 years) unknown reactions without features suggestive of an IgE-mediated reaction. A moderate-risk history includes urticaria or other pruritic rashes and reactions with features of IgE-mediated reactions. A high-risk history includes patients who have had anaphylaxis, positive penicillin skin testing, recurrent penicillin reactions, or hypersensitivities to multiple β-lactam antibiotics. The goals of antimicrobial stewardship are undermined when reported allergy to penicillin leads to the use of broad-spectrum antibiotics that increase the risk for antimicrobial resistance, including increased risk of methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus. Broad-spectrum antimicrobial agents also increase the risk of developing Clostridium difficile (also known as Clostridioides difficile) infection. Direct amoxicillin challenge is appropriate for patients with low-risk allergy histories. Moderate-risk patients can be evaluated with penicillin skin testing, which carries a negative predictive value that exceeds 95% and approaches 100% when combined with amoxicillin challenge. Clinicians performing penicillin allergy evaluation need to identify what methods are supported by their available resources.

CONCLUSIONS AND RELEVANCE

Many patients report they are allergic to penicillin but few have clinically significant reactions. Evaluation of penicillin allergy before deciding not to use penicillin or other β-lactam antibiotics is an important tool for antimicrobial stewardship.

Antibiotic allergy

Antibiotics are the commonest cause of life-threatening immune-mediated drug reactions that are considered off-target, including anaphylaxis, and organ-specific and severe cutaneous adverse reactions. However, many antibiotic reactions documented as allergies were unknown or not remembered by the patient, cutaneous reactions unrelated to drug hypersensitivity, drug-infection interactions, or drug intolerances. Although such reactions pose negligible risk to patients, they currently represent a global threat to public health. Antibiotic allergy labels result in displacement of first-line therapies for antibiotic prophylaxis and treatment. A penicillin allergy label, in particular, is associated with increased use of broad-spectrum and non-β-lactam antibiotics, which results in increased adverse events and antibiotic resistance. Most patients labelled as allergic to penicillins are not allergic when appropriately stratified for risk, tested, and re-challenged. Given the public health importance of penicillin allergy, this Review provides a global update on antibiotic allergy epidemiology, classification, mechanisms, and management.

Prevalence of self-reported drug hypersensitivity reactions among Lithuanian children and adults

INTRODUCTION AND OBJECTIVES

Drug hypersensitivity reactions (DHRs) are the adverse effects of drugs that, when taken at doses generally tolerated by normal subjects, clinically resemble allergy. We aimed to assess the prevalence of self-reported DHRs among Lithuanian children and adults and to identify possible risk factors.

MATERIALS AND METHODS

A cross-sectional survey of a population visiting their general practitioners in Vilnius and Kaunas regions of Lithuania was performed. Thirty-five questions on drug allergy symptoms, in addition, food, pollen allergy and family history were included.

RESULTS

3222 (60.0%) children and 2148 (40.0%) adults were included in the study. 7.9% of children and 13.8% of adults reported a DHR for at least one drug (p<0.001). 69.8% of children and 47.3% of adults, who indicated DHRs, had skin symptoms. Rate of anaphylaxis was similar in both groups (about 10%). 4.5% of children and 7.3% of adults had DHRs induced by antibiotics and this was the most implicated group of drugs. Significant self-reported risk factors for DHRs were family history of DHRs (OR=6.007, 95%CI 4.756-7.587), pollen allergy (OR=2.0, 95%CI 1.573-2.544), food allergy (OR=1.92, 95%CI 1.505-2.448), female gender (OR=1.439, 95%CI 1.187-1.744) and age (OR=1.017 in favour of adults, 95%CI 1.013-1.021).

CONCLUSIONS

The prevalence of self-reported DHRs in Lithuania is higher among adults than children. Drug-induced skin reactions were the predominant symptom in both groups. Besides female gender and age, a positive family history of DHR and presence of pollen or food allergy may be associated with DHR.

Cephalosporin Allergy: Current Understanding and Future Challenges

Cephalosporins are commonly used antibiotics both in hospitalized patients and in outpatients. Hypersensitivity reactions to cephalosporins are becoming increasingly common with a wide range of immunopathologic mechanisms. Cephalosporins are one of the leading causes for perioperative anaphylaxis and severe cutaneous adverse reactions. Patients allergic to cephalosporins tend to tolerate cephalosporins with disparate R1 side chains but may react to other beta-lactams with common R1 side chains. Skin testing for cephalosporins has not been well validated but appears to have a good negative predictive value for cephalosporins with disparate R1 side chains. In vitro tests including basophil activation tests have lower sensitivity when compared with skin testing. Rapid drug desensitization procedures are safe and effective and have been used successfully for immediate and some nonimmediate cephalosporin reactions. Many gaps in knowledge still exist regarding cephalosporin hypersensitivity.

Drug-Induced Anaphylaxis Documented in Electronic Health Records

BACKGROUND

Although drugs represent a common cause of anaphylaxis, few large studies of drug-induced anaphylaxis have been performed.

OBJECTIVE

To describe the epidemiology and validity of reported drug-induced anaphylaxis in the electronic health records (EHRs) of a large United States health care system.

METHODS

Using EHR drug allergy data from 1995 to 2013, we determined the population prevalence of anaphylaxis including anaphylaxis prevalence over time, and the most commonly implicated drugs/drug classes reported to cause anaphylaxis. Patient risk factors for drug-induced anaphylaxis were assessed using a logistic regression model. Serum tryptase and allergist visits were used to assess the validity and follow-up of EHR-reported anaphylaxis.

RESULTS

Among 1,756,481 patients, 19,836 (1.1%) reported drug-induced anaphylaxis; penicillins (45.9 per 10,000), sulfonamide antibiotics (15.1 per 10,000), and nonsteroidal anti-inflammatory drugs (NSAIDs) (13.0 per 10,000) were most commonly implicated. Patients with white race (odds ratio [OR] 2.38, 95% CI 2.27-2.49), female sex (OR 2.20, 95% CI 2.13-2.28), systemic mastocytosis (OR 4.60, 95% CI 2.66-7.94), Sjögren's syndrome (OR 1.94, 95% CI 1.47-2.56), and asthma (OR 1.50, 95% CI 1.43-1.59) had an increased odds of drug-induced anaphylaxis. Serum tryptase was performed in 135 (<1%) anaphylaxis cases and 1,587 patients (8.0%) saw an allergist for follow-up.

CONCLUSIONS

EHR-reported anaphylaxis occurred in approximately 1% of patients, most commonly from penicillins, sulfonamide antibiotics, and NSAIDs. Females, whites, and patients with mastocytosis, Sjögren's syndrome, and asthma had increased odds of reporting drug-induced anaphylaxis. The low observed frequency of tryptase testing and specialist evaluation emphasize the importance of educating providers on anaphylaxis management.

Variability in Antibiotic Prescribing for Upper Respiratory Illnesses by Provider Specialty

OBJECTIVE

To evaluate variation in antibiotic prescribing between pediatric and nonpediatric providers for common upper respiratory illnesses.

STUDY DESIGN

Patient encounters for children aged <18 years from a regional health care system were identified. Electronic medical records from 2011 to 2016 were extracted for diagnoses of upper respiratory infection, pharyngitis, acute otitis media, and sinusitis. Encounters with competing medical diagnoses, recent hospitalization, and antibiotic prescriptions within 30 days were excluded. Adherence to antibiotic guidelines was assessed by provider training (pediatric, nonpediatric physicians, and advance practice providers). Additional factors assessed were calendar year, and patient's age, sex, insurance status, and number of sick visits in the prior year.

RESULTS

Across 6 years, 141 361 visits were examined: 43 914 for upper respiratory infection, 43 701 for pharyngitis, 43 925 for acute otitis media, and 9821 for sinusitis. Pediatricians were more likely than Advanced practice providers (APP) and nonpediatric providers to have guideline-concordant prescribing for pharyngitis (pediatricians, 66.7% [95% CI, 54.5-77.0]; nonpediatricians, 49.1% [95% CI, 36.3-62.0], APPs, 52.2% [95% CI, 39.4-64.7]; P < .0001) and sinusitis (pediatricians, 70.8% [95% CI, 53.8-83.4], nonpediatricians, 63.3% [95% CI, 46.8-77.2], APPs, 62.1% [95% CI, 45.1-76.5]; P = .48) and to withhold antibiotics for upper respiratory infection than APPs and nonpediatric providers (pediatricians, 86.6% [95% CI, 81.2-90.6], nonpediatricians, 80.8% [95% CI, 73.0-86.8], APPs, 76.8% [95% CI, 68.4-83.5]; P < .0001). Pediatricians were less likely to prescribe antibiotics for pharyngitis without a positive test for group A Streptococcus than APPs and nonpediatric providers (pediatricians, 15.1% [95% CI, 10.4-21.6], nonpediatricians, 29.4% [95% CI, 20.8-39.6], APPs, 27.2% [95% CI, 19.3-36.9]; P < .0001). First-line antibiotic prescribing for acute otitis media did not differ between provider specialties. A trend toward more guideline-concordant prescribing was seen for pharyngitis and sinusitis over the study period.

CONCLUSIONS

Pediatricians were more likely to adhere to guidelines for management of pediatric acute respiratory infections. Pediatric antibiotic stewardship efforts should also target nonpediatricians.

Drug Hypersensitivity Reactions Documented in Electronic Health Records within a Large Health System

BACKGROUND

Hypersensitivity reactions (HSRs) are immunologic responses to drugs. Identification of HSRs documented in the electronic health record (EHR) is important for patient safety.

OBJECTIVE

To examine HSR epidemiology using longitudinal EHR data from a large United States health care system.

METHODS

Patient demographic information and drug allergy data were obtained from the Partners Enterprise-wide Allergy Repository for 2 large tertiary care hospitals from 2000 to 2013. Drug-induced HSRs were categorized into immediate and delayed HSRs based on typical phenotypes. Causative drugs and drug groups were assessed. The prevalence of HSRs was determined, and sex and racial differences were analyzed.

RESULTS

Among 2.7 million patients, 377,474 (13.8%) reported drug-induced HSRs, of whom 70.3% were female and 77.5% were white. A total of 580,456 HSRs were reported, of which 53.1% were immediate reaction phenotypes. Common immediate HSRs included hives (48.8%), itching (15.0%), and angioedema (14.1%). Delayed HSR phenotypes (46.9%) were largely rash (99.0%). Penicillins were associated with the most immediate (33.0%) and delayed (39.0%) HSRs. Although most HSRs were more prevalent in females and white patients, notable differences were identified for certain rare HSRs including acute interstitial nephritis, which appeared more commonly in males (0.02% vs 0.01%, P < .001). Asian patients had more fixed drug eruptions (0.007% vs 0.002%, P = .021) and severe cutaneous adverse reactions (0.05% vs 0.04%, P < .001).

CONCLUSIONS

Drug HSRs were reported in 13.8% of patients. Almost one-half of reported immediate HSR phenotypes were hives, and almost all reported delayed HSR phenotypes were rash. HSRs largely affected female and white patients, but differences were identified for specific rare HSRs.

Drug allergy in children and adults: Is it the double X chromosome?

OBJECTIVE

This article reviews the latest science and epidemiologic studies related to drug allergy in children and adults to explore possible mechanisms related to female propensity for drug allergy.

DATA SOURCES

PubMed literature review, focusing primarily on the last 5 years.

STUDY SELECTIONS

Articles reviewing the science behind female predisposition to atopic and asthmatic conditions and epidemiologic studies reviewing drug allergy and drug-induced anaphylaxis.

RESULTS

Despite adult female predilection for atopic conditions, few laboratory studies explore sex-specific mechanisms in atopic/allergic diseases, and most are focused on autoimmunity and asthma. Drug allergy is more frequently reported in adult females compared with adult males. Adult females are also more likely to have drug-induced anaphylaxis (DIA), although no clear sex predominance has been reported in fatal or severe DIA. Studies in children suggest the reverse picture, with prepubertal males more likely to have drug allergy and DIA than prepubertal girls.

CONCLUSION

Possible explanations for female predisposition for drug allergy are multifactorial and include disproportionate utilization of health care with more exposure to antibiotics or medications, genetic factors related to the X chromosome, epigenetic changes, and discrepant hormonal interactions with immune cells.

Multiple drug intolerance syndrome and multiple drug allergy syndrome: Epidemiology and associations with anxiety and depression

BACKGROUND

The epidemiology of multiple drug intolerance syndrome (MDIS) and multiple drug allergy syndrome (MDAS) is poorly characterized. We used electronic health record (EHR) data to describe prevalences of MDIS and MDAS and to examine associations with anxiety and depression.

METHODS

Patients with ≥3 outpatient encounters at Partners HealthCare System from 2008 to 2015 were included. Patients with MDIS had intolerances to ≥3 drug classes, and patients with MDAS had hypersensitivities to ≥2 drug classes. Psychiatric conditions and comorbidities were defined from the EHR and used in multivariable logistic regression models to assess the relation between anxiety/depression and MDIS/MDAS.

RESULTS

Of 746 888 patients, 47 634 (6.4%) had MDIS and 8615 (1.2%) had MDAS; 3171 (0.4%) had both. Anxiety (adjusted odds ratio [aOR] 1.72 [1.65, 1.80]), depression (aOR 1.46 [1.41, 1.52]), and both anxiety and depression (aOR 1.97 [1.86, 2.08]) were associated with increased odds of MDIS. Depression was associated with increased odds of MDAS (aOR 1.41 [1.28, 1.56]), but there were no clear associations with anxiety (aOR 1.13 [0.99, 1.30]) nor both depression and anxiety (aOR 1.13 [0.92, 1.38]).

CONCLUSION

While 6% of patients had MDIS, only 1% had MDAS. MDIS was associated with both anxiety and depression; patients with both anxiety and depression had an almost twofold increased odds of MDIS. MDAS was associated with a 40% increased odds of depression, but there was no significant association with anxiety. Psychological assessments may be useful in the evaluation and treatment of patients with MDIS and MDAS; physiologic causes for MDAS warrant further investigation.

Sulfonamide Drug Allergy

PURPOSE OF REVIEW

We sought to review past and current literature on sulfonamide drug allergy and distill it in a practical manner to assist the clinician, specifically focusing on cross-reactivity and desensitization.

RECENT FINDINGS

There do not appear to be consistent genetic markers to reliably predict features of or the presence hypersensitivity reactions. Recent evidence continues to alleviate early concerns cross-reactivity between sulfonamide antibiotics and non-antibiotics. Sulfonamide drug allergy is frequently encountered by the practicing clinician. For sulfonamide antibiotics, delayed rash is the most common clinical manifestation. There is no current evidence to support avoidance of all non-antibiotic sulfonamides in those with a reported allergy to sulfonamide antibiotics, although certain scenarios require caution. Available evidence supports the cautious reintroduction of sulfonamide antibiotics via desensitization, which is usually well tolerated and should be considered in those with strong indications for trimethoprim-sulfamethoxazole and a reported sulfonamide allergy.

Health Conditions in an Adult Population in Sierra Leone: Data Reported From the Sierra Leone Trial to Introduce a Vaccine Against Ebola (STRIVE)

Clinical Trials Registration

ClinicalTrials.gov [NCT02378753] and Pan African Clinical Trials Registry [PACTR201502001037220].

Antibiotic Allergy in Pediatrics

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

Safety of Outpatient Parenteral Antimicrobial Therapy in Children

BACKGROUND AND OBJECTIVE

Outpatient parenteral antimicrobial therapy (OPAT) provides numerous benefits but may pose unique risks in children. We aimed to determine rates of OPAT antimicrobial- and intravenous access-related complications and their associations with specific antimicrobials and type of intravenous access in pediatric patients.

METHODS

Observational cohort study of patients receiving OPAT from August 2008 to May 2015 cared for by the Infectious Diseases service at a tertiary children's hospital. Primary outcome was antimicrobial discontinuation (AD) because of OPAT-associated complications. Secondary outcomes were unplanned outpatient healthcare visits and readmissions from OPAT-associated complications.

RESULTS

Seven hundred and seven intravenous antimicrobials were prescribed in 540 cases. Nondevice-associated musculoskeletal infection was the most common diagnosis (39%). Ceftriaxone (30%), cefazolin (27%) and vancomycin (22%) were the most commonly used antimicrobials. Complications led to AD, ≥1 unplanned outpatient healthcare visit and ≥1 readmission in 23%, 30% and 17% of cases, respectively. Compared with use of ceftriaxone, use of oxacillin was associated with a significantly higher risk of AD because of any antimicrobial-related complication [hazard ratio (HR), 3.3; 95% confidence interval (CI): 1.2-9.7) and because of hepatic transaminitis (HR, 32.8; 95% CI: 4.02-268.2). Subjects treated with intravenous clindamycin (HR, 2.6; 95% CI: 1.1-5.8) and with a peripherally inserted central catheter (HR, 2.6; 95% CI: 1.04-6.3) were more likely to have unplanned outpatient visits.

CONCLUSIONS

Use of oxacillin during OPAT was associated with higher rate of AD. Patients treated with clindamycin and those with a peripherally inserted central catheter had higher rates of unplanned outpatient visits. Providers should strongly consider alternative treatment options when possible.

Trimethoprim+Sulfamethoxazole Reduces Rates of Melioidosis in High-Risk Hemodialysis Patients

INTRODUCTION

Melioidosis causes sepsis and death in the Top End of Northern Australia during the monsoonal wet season. Dialysis-dependent adults suffer higher melioidosis rates compared to low rates among renal transplant patients who routinely receive trimethoprim+sulfamethoxazole prophylaxis.

METHODS

We performed a prospective interventional study to determine the efficacy and safety of daily trimethoprim+sulfamethoxazole prophylaxis in hemodialysis patients during the wet season, from 1 November 2014 to 30 April 2015. Hemodialysis (for ≥ 3 months) patients ≥ 18 years of age were offered treatment. A total of 269 patients on hemodialysis were eligible. Eight of the 269 patients (3%) were excluded from the analysis for being on melioidosis treatment. In all, 169 of 261 patients (64.8%) received the prophylaxis, and 92 of 261 patients (35.2%) did not, because of allergy history (n = 10), remoteness and logistical reasons (n = 60), poor dialysis attendance (n = 11), and refusal (n = 11). We monitored for clinical side effects 3 times weekly and neutropenia, thrombocytopenia, and liver function monthly throughout treatment and for 2 months posttreatment.

RESULTS

In all, 169 of 261 patients (64.8%) received the prophylaxis. There was no age (years) difference by group (prophylaxis vs. nonprophylaxis, 54.7 [11.3] vs. 54.3 [11.2] [P = 0.751]). Sixteen of 261 patients (6%) had melioidosis. The event frequency was 0% (0/169, prophylaxis, vs. 17.4% [16/92, nonprophylaxis], P < 0.001). Higher thrombocytopenia and neutropenia rates were noted in the prophylaxis group. These did not warrant treatment stoppage. There was no difference in liver function. Three patients (1.8%) withdrew from the treatment because of side effects.

CONCLUSION

Daily dosing was effective and safe. Posthemodialysis dosing in the subsequent seasons was effective and safer. We recommend this approach in melioidosis-prevalent regions.

Antibiotic-Related Adverse Drug Reactions at a Tertiary Care Hospital in South Korea

Background

Adverse drug reactions (ADRs) are any unwanted/uncomfortable effects from medication resulting in physical, mental, and functional injuries. Antibiotics account for up to 40.9% of ADRs and are associated with several serious outcomes. However, few reports on ADRs have evaluated only antimicrobial agents. In this study, we investigated antibiotic-related ADRs at a tertiary care hospital in South Korea.

Methods

This is a retrospective cohort study that evaluated ADRs to antibiotics that were reported at a 2400-bed tertiary care hospital in 2015. ADRs reported by physicians, pharmacists, and nurses were reviewed. Clinical information reported ADRs, type of antibiotic, causality assessment, and complications were evaluated.

Results

1,277 (62.8%) patients were considered antibiotic-related ADRs based on the World Health Organization-Uppsala Monitoring Center criteria (certain, 2.2%; probable, 35.7%; and possible, 62.1%). Totally, 44 (3.4%) patients experienced serious ADRs. Penicillin and quinolones were the most common drugs reported to induce ADRs (both 16.0%), followed by third-generation cephalosporins (14.9%). The most frequently experienced side effects were skin manifestations (45.1%) followed by gastrointestinal disorders (32.6%).

Conclusion

Penicillin and quinolones are the most common causative antibiotics for ADRs and skin manifestations were the most frequently experienced symptom.

Asthma, Family History of Drug Allergy, and Age Predict Amoxicillin Allergy in Children

BACKGROUND

Suspected adverse reactions to amoxicillin are common, but there are no known factors that can predict amoxicillin allergy in children. In addition, methods used for the diagnosis of amoxicillin allergy are not standardized and their role in diagnosis is not clear.

OBJECTIVE

To identify predictive factors and to assess the role of skin test in the diagnosis of amoxicillin allergy in children.

METHODS

Children with a history of immediate (excluding anaphylaxis) or nonimmediate reactions to amoxicillin were tested by skin prick test, followed by oral graded challenge with amoxicillin. Clinical characteristics of the reaction before and after the challenge were recorded, and data of personal and relatives' drug allergies and atopy were collected for statistical analysis.

RESULTS

Skin prick tests followed by an oral graded challenge with amoxicillin were performed on 133 children. The skin test result was not of clinical value because it was negative in all children. Three children (2%) had an immediate reaction and 7 children (5%) had a nonimmediate reaction. Asthma (odds ratio [OR], 0.12; 95% CI, 0.017-0.869; P = .03), family history of drug allergy (OR, 0.12; 95% CI, 0.026-0.613; P = .01), older age at reaction (OR, 0.837; 95% CI, 0.699-1; P = .05), and angioedema (OR, 0.22; 95% CI, 0.043-1.12; marginally significant at P = .069) were associated with reduced chance to pass the oral challenge.

CONCLUSIONS

Skin prick test did not contribute to the diagnosis of amoxicillin allergy. The presence of asthma, family history of drug allergy, and older age at reaction can be used as predictive factors for true amoxicillin allergy in children.

Impact of Allergy and Resistance on Antibiotic Selection for Recurrent Urinary Tract Infections in Older Women

OBJECTIVES

To review the impact of antibiotic allergy and resistance in older women with recurrent urinary tract infections (RUTIs) as determinants for a suitable oral antibiotic treatment choice.

METHODS

A prospectively maintained database of women 65 years old and older with documented RUTIs (≥3 UTI/y) and trigonitis on cystoscopy was reviewed. Demographic data, known drug allergies, renal function, antibiotic susceptibility of most recent urine culture, allergy, or resistance to trimethoprim-sulfamethoxazole (TMP-SMX), fluoroquinolones, and nitrofurantoin were obtained.

RESULTS

From 2006 to 2014, 86 women with RUTIs met study criteria. Mean age was 77.9 ± 7.8, with 94% being Caucasian. An estimated glomerular filtration rate >30 mL/min was noted in 94%. The percentage of women allergic, resistant, or both allergic and resistant to TMP-SMX was 33%, 29%, and 15%, to fluoroquinolones was 14%, 34%, and 8.1%, or nitrofurantoin was 16%, 14%, and 5%, respectively. Twenty-eight percent (24 of 86) of women who were allergic and/or resistant to TMP-SMX and fluoroquinolones were sensitive to nitrofurantoin. Twenty percent (17 of 86) were allergic and/or resistant to all 3 antibiotics. Women who were allergic or resistant to TMP-SMX had a significantly higher number of other antibiotic resistances compared with women sensitive to TMP-SMX (4.9 ± 3.6 vs 2.1 ± 2.3; P < .0001). Similarly, women with fluoroquinolone allergy or resistance had significantly more antibiotic resistances than those who were fluoroquinolone sensitive (5.8 ± 3.5 vs 2.3 ± 2.5; P < .0001).

CONCLUSION

Because of allergy and/or antibiotic resistance, several first-line antibiotics are not available for many older women with RUTIs. In nearly a third of women, nitrofurantoin was the only viable alternative.

The 3 Cs of Antibiotic Allergy-Classification, Cross-Reactivity, and Collaboration

Antibiotic allergy labeling is highly prevalent and negatively impacts patient outcomes and antibiotic appropriateness. Reducing the prevalence and burden of antibiotic allergies requires the engagement of key stakeholders such as allergists, immunologists, pharmacists, and infectious diseases physicians. To help address this burden of antibiotic allergy overlabeling, we review 3 key antibiotic allergy domains: (1) antibiotic allergy classification, (2) antibiotic cross-reactivity, and (3) multidisciplinary collaboration. We review the available evidence and research gaps of currently used adverse drug reaction classification systems, antibiotic allergy cross-reactivity, and current and future models of antibiotic allergy care.

Unique manifestations and risk factors of Jarisch-Herxheimer reaction during treatment of child congenital syphilis

OBJECTIVES

The objective of this retrospective study was to summarise the clinical manifestations of, and to analyse the incidence and risk factors of, Jarisch-Herxheimer reaction (JHR) during the treatment of children with symptomatic congenital syphilis.

METHODS

Clinical data of 60 children with clinically and laboratory diagnosed congenital syphilis, hospitalised in Beijing Ditan Hospital between January 2010 and November 2015, were collected and analysed.

RESULTS

A total of 11 patients with congenital syphilis (11/60, 18.3%) developed JHR. JHR occurred in 1-6 hour after the first dose of penicillin. Common clinical manifestations included fever (11/11, 100%), irritability (11/11, 100%), rapid pulse and breathing (11/11, 100%), exacerbation of existing rash (5/11, 45.6%) and chills (3/11, 27.3%). Of the 11 patients who developed JHR, 9 patients (9/11, 81.8%) had bone syphilis, 10 (10/11, 90.9%) had more than three organs affected by syphilis and 10 (10/11, 90.9%) had a high plasma concentration of rapid plasma reagin (RPR) (≥1:256); these percentages were significantly higher than in patients who had not developed JHR (p<0.05), suggesting that the occurrence of JHR was related to bone syphilis, having more than three organs affected by syphilis and a high plasma concentration of RPR.

CONCLUSIONS

Clinicians should be familiar with the risk factors for this reaction and its common clinical manifestations.

Penicillin and Beta-Lactam Hypersensitivity

Ten percent of patients report penicillin allergy, but more than 90% of these individuals can tolerate penicillins. Skin testing remains the optimal method for evaluation of possible IgE-mediated penicillin allergy and is recommended by professional societies, as the harms for alternative antibiotics include antimicrobial resistance, prolonged hospitalizations, readmissions, and increased costs. Removal of penicillin allergy leads to decreased utilization of broad-spectrum antibiotics, such as fluoroquinolones and vancomycin. There is minimal allergic cross-reactivity between penicillins and cephalosporins. IgE-mediated allergy to cephalosporins is usually side-chain specific and may warrant graded challenge with cephalosporins containing dissimilar R1 or R2 group side chains.

Clinical outcomes following inpatient penicillin allergy testing: A systematic review and meta-analysis

BACKGROUND

A documented penicillin allergy is associated with increased morbidity including length of hospital stay and an increased incidence of resistant infections attributed to use of broader-spectrum antibiotics. The aim of the systematic review was to identify whether inpatient penicillin allergy testing affected clinical outcomes during hospitalization.

METHODS

We performed an electronic search of Ovid MEDLINE/PubMed, Embase, Web of Science, Scopus, and the Cochrane Library over the past 20 years. Inpatients having a documented penicillin allergy that underwent penicillin allergy testing were included.

RESULTS

Twenty-four studies met eligibility criteria. Study sample size was between 24 and 252 patients in exclusively inpatient cohorts. Penicillin skin testing (PST) with or without oral amoxicillin challenge was the main intervention described (18 studies). The population-weighted mean for a negative PST was 95.1% [CI 93.8-96.1]. Inpatient penicillin allergy testing led to a change in antibiotic selection that was greater in the intensive care unit (77.97% [CI 72.0-83.1] vs 54.73% [CI 51.2-58.2], P<.01). An increased prescription of penicillin (range 9.9%-49%) and cephalosporin (range 10.7%-48%) antibiotics was reported. Vancomycin and fluoroquinolone use was decreased. Inpatient penicillin allergy testing was associated with decreased healthcare cost in four studies.

CONCLUSIONS

Inpatient penicillin allergy testing is safe and effective in ruling out penicillin allergy. The rate of negative tests is comparable to outpatient and perioperative data. Patients with a documented penicillin allergy who require penicillin should be tested during hospitalization given its benefit for individual patient outcomes and antibiotic stewardship.

Frequency of self-reported drug allergy: A systematic review and meta-analysis with meta-regression

BACKGROUND

Patients reporting drug allergy are treated with second-line therapies, with possible negative clinical and health consequences.

OBJECTIVE

To assess the prevalence of self-reported drug allergy.

METHODS

We performed a systematic review of observational studies assessing the prevalence of self-reported drug allergy. We searched 4 electronic databases. From selected studies, we extracted data on self-reported drug allergy prevalence, study design, participants' demographic characteristics, reported clinical manifestations, and suspected culprit drugs. We performed a random-effects meta-analysis followed by a meta-regression.

RESULTS

Fifty-three studies were included in the systematic review, assessing a total of 126,306 participants, of whom 8.3% (range across studies 0.7-38.5%) self-reported drug allergy. Cutaneous manifestations were reported by 68.2% of participants, and anaphylactic or systemic reactions were reported by 10.8%. Antibiotics, nonsteroidal anti-inflammatory drugs, and anesthetics were the most frequently reported culprit drug classes. The frequency of self-reported drug allergy was higher in female (11.4%) than in male (7.2%) patients, adults (10.0%) than in children (5.1%), and in studies in the medical setting (15.9% in inpatients, 11.4% in outpatients) than in the general population (5.9%). The meta-analysis rendered a pooled prevalence of 7.9% (95% confidence interval 6.4-9.6), and the meta-regression identified study region, participants' age group, and study setting as factors associated with significant heterogeneity. Confirmation tests (including skin, in vitro, and drug provocation tests) were performed in only 3 studies.

CONCLUSION

The prevalence of self-reported drug allergy is highly variable and is higher in female patients, adults, and inpatients. To overcome this variability, further studies using confirmation tests are needed.

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.