Assessing the Diagnostic Properties of a Graded Oral Provocation Challenge for the Diagnosis of Immediate and Nonimmediate Reactions to Amoxicillin in Children

Patient Perceptions of Penicillin Allergy Testing in a Public Health System

BACKGROUND

Documented penicillin allergies are associated with increased morbidity, increased hospital stay, and an increase in resistant infections. Penicillin allergy evaluations using a direct oral challenge with or without skin testing has been recommended as a delabeling strategy for patients with penicillin reaction histories. Barriers for achieving equitable access, however, exist. Understanding patient perceptions regarding their penicillin allergy across diverse populations is crucial to mitigate potential obstacles to penicillin allergy testing (PAT) and the use of penicillin-like antibiotics after delabeling.

OBJECTIVE

The objective of this study was to gather perceptions of patients delabeled of their penicillin allergy after testing through a PAT program.

METHODS

Patients who underwent PAT and had a subsequent allergy removal due to a negative result were interviewed using closed and open-ended questions.

RESULTS

A total of 100 patient interviews were completed. Awareness of the risks associated with unnecessary penicillin avoidance and PAT was low. Initial concerns regarding PAT were common but were frequently alleviated with targeted education. Most patients undergoing testing reported a positive experience and would recommend PAT to others. A minority of patients continued to have discordant perceptions regarding their penicillin allergy label with mistrust in the negative result being a critical theme identified.

CONCLUSIONS

Future interventions increasing the awareness of penicillin allergy labels and the risks and benefits of PAT in the general population are needed and must consider health literacy levels, languages, and cultural contexts. Measures to offer PAT within a clinical setting that has built high levels of patient trust will likely achieve the greatest long-term success.

Safe Penicillin Allergy Delabeling in Primary Care: A Systematic Review and Meta-Analysis

BACKGROUND

Ten percent of the population is labeled as allergic to penicillin(s), when in fact 90% of these labels are inappropriate. Recent studies have shown that inpatient delabeling by a direct drug challenge (dDC) is safe in low-risk patients. However, there is a need for outpatient and nonallergist delabeling.

OBJECTIVE

To assess the safety of delabeling low-risk adults by means of dDC in primary care.

METHODS

We searched the MEDLINE, Embase, and Cochrane Library databases from inception to March 15, 2022 (updated June 5, 2023) for studies performing dDC in adults in primary care or other outpatient settings. Two researchers independently screened studies for eligibility. The data extraction and critical appraisal were performed by 1 reviewer, and we pooled the results in a meta-analysis.

RESULTS

Of 2138 results, 12 studies (1070 participants) were eligible for inclusion. Three studies evaluated delabeling in primary care and 9 studies in an outpatient hospital setting. There were no critical adverse events during dDC. No reaction occurred in 97.13% of the 1070 patients, who previously labeled as penicillin-allergic, and were safely delabeled. Ten patients (<1%) developed an immediate reaction: 3 had self-limiting reactions and 7 needed antihistaminics, steroids, epinephrine, and/or salbutamol.

CONCLUSIONS

No serious allergic reactions are observed during direct amoxicillin challenge in adults in an outpatient setting. However, with the exception of 1 recent report, these studies are of low to moderate quality. Nonspecialist delabeling is promising, but further research is required on correct risk stratification and safety assessment in large cohort studies evaluating dDC in primary care.

Comparing Skin and Serum Testing to Direct Challenge Outcomes in Children With β-Lactam Allergies

BACKGROUND

There is a scarcity of prospective studies investigating the relative roles of skin prick and intradermal testing, serum specific IgE, and extended oral challenges in diagnosing children with reported β-lactam allergies.

OBJECTIVE

To determine the sensitivity and specificity of skin testing and serum specific IgE in children with β-lactam allergies, with immediate and nonimmediate historic reactions.

METHODS

Four hundred children with parent-reported β-lactam allergies were recruited into an open-label prospective study. Detailed allergy histories were collected. Those with medically observed and documented histories of anaphylaxis, requiring epinephrine, or severe cutaneous adverse reactions were excluded. In total, 380 children underwent all testing modalities and a direct provocation test. Each child was followed up for a minimum of 3 years.

RESULTS

True allergy in children was uncommon; 8.3% reacted to the direct provocation challenge or the 5-day extended oral provocation challenge. Children reporting cephalosporin allergy or a reaction within 1 year were more likely to react to direct provocation testing. The sensitivity, specificity, and positive predictive value of skin testing were 12.5%, 98.8%, and 20.0% for direct challenge outcomes, 4.76%, 99.0%, and 25.0% for extended challenge outcomes, and 6.9%, 99.0%, and 40.0% for both challenges combined, respectively. Follow-up investigations revealed that 5.7% of children had a mild repeat reaction and 2.7% continued to avoid the culprit despite successful delabeling. The relabeling rate for children readmitted to hospital was 15%, with the relabeing being unfounded.

CONCLUSIONS

Genuine β-lactam allergies were rare, with over 90% of children effectively delabeled. Skin and serum specific IgE testing did not aid the diagnosis of β-lactam antibiotic allergy in children, regardless of medical history. Extended oral challenges proved valuable in confirming allergies and boosted parental confidence.

Penicillin allergy de-labeling: Adaptation of risk stratification tool for patients and families

Penicillin allergy is reported in 10% of the population; however, over 90% of patients are deemed non-allergic upon allergist assessment. The goal of this quality improvement project is to validate a patient-driven assessment tool to safely identify patients at low risk of penicillin allergy and de-label them. Pediatric patients and pregnant women referred to the institution's allergy clinics for penicillin allergy assessment were invited to use the patient tool to complete a self-assessment, resulting in the assignment of a risk category. The risk stratification determined using the patient tool was compared against the allergist's assessment. The patient tool demonstrated agreement with the allergist assessment in 57/84 (67.9%, 95% CI [56.7%,77.4%]) assessments, intra-class correlation (ICC) = 0.618, p < 0.001. In 22/84 (26.2%) assessments, the patient tool determined a higher risk category, primarily due to differences in patients' perceived timing and description of symptoms. Only 5/84 (6.0%) patients were placed in a lower risk category by the patient tool compared to the allergist assessment. The patient tool demonstrates good validity in determining penicillin allergy risk, offering potential as a method of empowering patients to advocate in their care. Iterative changes to the patient tool will be applied to increase agreement.

Risk factors for drug hypersensitivity reactions in children

Drug hypersensitivity reactions are common in children. Risk factors predisposing to IgE-mediated drug allergies and delayed drug reactions are a matter of debate. Gender, age, previous reactions to the same drug or to another drug, reduced drug metabolism, chronic diseases, polypharmacy, drug doses are linked with the onset of hypersensitivity reactions in some children. Novel advances in genetic polymorphisms can rapidly change the approach to the prevention of reactions since gene testing can be a useful screening test for severe cutaneous adverse reactions. Viral infections may act as cofactors in susceptible individuals. Polypharmacy, high doses, repeated doses and parental route of administration are also risk factors. Clinicians should take into account risk factors to allow the risk-benefit balance to be maintained.

Penicillin Allergy: Mechanisms, Diagnosis, and Management

Allergy to penicillin can occur via any of the 4 types of Gel-Coombs hypersensitivity reactions, producing distinct clinical histories and physical examination findings. Treatments include penicillin discontinuation, and depending on the type of reaction, epinephrine, antihistamines, and/or glucocorticoids. Most beta-lactams may be safely used in penicillin-allergic patients, with the possible exception of first-generation and second-generation cephalosporins. Penicillin testing includes skin testing, patch testing, and graded challenge. The selection of the type of testing depends on the clinical setting, equipment availability, and type of hypersensitivity reaction. Desensitization may be used in some cases where treatment with penicillins is essential.

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

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

Preoperative survey to evaluate the patients' allergy list and its relevance to perioperative care

INTRODUCTION

Perioperative hypersensitivity and allergic reactions can result in significant morbidity and mortality. For routine anesthetic care, allergies are determined from a review of the electronic medical record supplemented by a detailed patient history. Although the electronic medical record is generally assumed to be accurate, it may be that allergies are erroneously listed or not based on sound medical practice. The purpose of the current study is to evaluate allergies listed in the electronic medical record of children presenting for surgery and determine their origin, authenticity, and impact on perioperative care.

METHODS

Eligible patients included those presenting for a surgical procedure in the main operating room, who were ≤ 21 years of age, with a drug allergy listed on the EMR. Prior to intraoperative care, an electronic survey questionnaire containing questions related to medication allergies was provided to a guardian or parent. Two anesthesiology physicians reviewed the survey responses to determine the validity of any reported allergies. A second electronic survey was given postoperatively to the attending anesthesiologist to determine whether the documented allergy impacted anesthetic care.

RESULTS

The study cohort included 250 patients, ranging in age from 5 to 14 years (median age 9 years). All of the patients had at least one allergy listed on the electronic medical record. Seventy of the 250 patients (28%) had more than one drug allergy listed for a total of 351 medication allergies. The majority of the listed allergies were related to antibiotics including 155 (44%) from the penicillin family, 26 (7%) cephalosporins, 16 (5%) sulfonamides, and 36 (10%) other antimicrobial agents. Other commonly listed allergies were 27 (8%) nonsteroidal anti-inflammatory agents and 15 (4%) opioids. The remaining 76 (22%) included a miscellaneous list of other medications. On further review of the allergies, the survey was completed for 301 medications. After physician review, 135 of 301 (45%) responses were considered consistent with IgE reactions "true allergy," 73 (24%) were deemed less relevant to IgE reactions "unlikely true allergy," and 93 (31%) were not related to IgE reactions "not an allergy." Care alterations during surgery were uncommon regardless of whether the issue was assessed as a true allergy (11%), unlikely to be a true allergy (3%), or not a true allergy (13%).

CONCLUSION

A significant portion of the documented allergies in children are not true allergies, but rather recognized adverse effects (apnea from an opioid, renal failure from an NSAIDs) or other nonallergic concerns (gastrointestinal upset such as nausea). Erroneously listed allergies may lead to unnecessary alterations in patient care during perioperative care. A careful analysis of the allergy list on the EMR should be supplemented by a thorough patient history with specific questions related to the drug allergy. Once this is accomplished, the allergy listed should be updated to avoid its erroneous impact on perioperative care.

Drug Allergy Mimics

When approaching a case of apparent drug allergy, the consulting clinician should consider a broad differential diagnosis. This article presents a series of cases that could be commonly referred to an allergist for assessment as "drug allergy," however, a real diagnosis exists that mandates a different diagnostic and treatment strategy, including a case of inducible laryngeal obstruction, multiple drug intolerance syndrome, viral rash, seizure due to metastatic malignancy, and hemophagocytic lymphohistiocytosis initially diagnosed as drug reaction and eosinophilia with systemic symptoms. The initial misdiagnoses of these patients delayed or interfered with their medical care, emphasizing the importance of accurate diagnoses for the benefit of our patients.

How to Define and Manage Low-Risk Drug Allergy Labels

Risk stratification in drug allergy implies that specific risk categories (eg, low, moderate, and high) classify historical drug hypersensitivity reactions. These risk categories can be based on reaction phenotypic characteristics, the timing of the reaction and evaluation, the required reaction management, and individual characteristics. Although a multitude of frameworks have been described in the literature, particularly for penicillin allergy labels, there has yet to be a global consensus, and approaches continue to vary between allergy centers. Immune-mediated drug allergies can sometimes be confirmed using skin testing, but a negative drug challenge is required to demonstrate tolerance and remove the allergy from the electronic health record ("delabel" the allergy). Even for quintessential IgE-mediated drug allergy, penicillin allergy, recent data reveal that a direct oral challenge, without prior skin testing, is an appropriate diagnostic strategy in those who are considered low-risk. Drug allergy pathogenesis and clinical manifestations may vary depending on the culprit drug, and as such, the optimal approach should be based on risk stratification that considers individual patient and reaction characteristics, the likely hypersensitivity reaction phenotype, the drug class, and the patient's clinical needs. This article will describe low-risk drug allergy labels, focusing on β-lactam and sulfonamide antibiotics, nonsteroidal anti-inflammatory drugs, iodinated contrast media, and common chemotherapeutics. This review will also address practical management approaches using currently available risk stratification and clinical decision tools.

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.

Beta-Lactam Allergy De-labeling in a Pediatric Hospital

OBJECTIVE

To assess the ability to de-label pediatric patients of their beta-lactam allergy by using a newly implemented institutional protocol and to identify potential barriers to the de-labeling process.

METHODS

All patients with reported allergies to prespecified beta-lactam antibiotics were eligible for a -beta-lactam allergy interview. Following the interview, patients were grouped into 4 risk categories-no risk, low risk, moderate risk, and high risk-and assessed for intervention eligibility. Potential interventions included de-labeling based on the interview alone or proceeding to an oral amoxicillin challenge with or without penicillin allergy skin testing.

RESULTS

Of the 62 patients eligible for beta-lactam allergy interviews, 40% (n = 25) were de-labeled. Among de-labeled patients, 60% (n = 15) were de-labeled on the basis of the interview alone. Additionally, no failures were documented in patients who underwent an oral amoxicillin challenge or penicillin skin testing. Barriers to performing oral amoxicillin challenges or penicillin skin testing included concomitant systemic steroid or antihistamine use, refusal of intervention, and insufficient resources to perform penicillin skin testing.

CONCLUSIONS

There was a high frequency of patients de-labeled of their beta-lactam allergies in this study. Increased education to patients, parents, and providers on the de-labeling process, as well as increased personnel available to coordinate and perform de-labeling interventions, may result in more beta-lactam allergy de-labeling.

Introduction of a penicillin allergy de-labelling program with direct oral challenge and its effects on utilization of beta-lactam antimicrobials: a multicenter retrospective parallel cohort study

BACKGROUND

Self-reported penicillin allergy labels are common and often inaccurate after assessment. These labels can lead to reduced use of first-line beta-lactam antibiotics and worse outcomes. We measured the impact of a previously performed inpatient proactive systematic penicillin allergy de-labelling program on subsequent antibiotic use. This prior program included assessment, risk-stratification, and low risk direct oral amoxicillin challenge.

METHODS

We performed a retrospective comparison of parallel cohorts from two separate tertiary care hospital campuses in Ottawa, Canada across two penicillin de-labelling intervention periods across April 15th to April 30th, 2021, and February 15th to March 8th, 2022. Outcomes, including penicillin allergy labelling and antibiotic use, were collected for the index admission and the subsequent 6-month period. Descriptive statistics and multivariate regression analyses were performed.

RESULTS

A total of 368 patients with penicillin allergy label were included across two campuses and study periods. 24 (13.8%) patients in the intervention groups had sustained penicillin allergy label removal at 30 days from admission vs. 3 (1.5%) in the non-intervention group (p < 0.001). In the 6-months following admission, beta-lactams were prescribed more frequently in the intervention groups vs. the non-intervention groups for all patients (28 [16.1%] vs.15 [7.7%], p = 0.04) and were prescribed more frequently amongst those who received at least one antibiotic (28/46 [60.9%] vs.15/40 [37.5%], p = 0.097). In a multivariate regression analysis, the intervention groups were found to be associated with an increased odds of beta-lactam prescribing in all patients (OR 2.49, 95%CI 1.29-5.02) and in those prescribed at least one antibiotic (OR 2.44, 95%CI 1.00-6.15). No drug-related adverse events were reported.

CONCLUSIONS

Proactive penicillin allergy de-labelling for inpatients was associated with a reduction in penicillin allergy labels and increased utilization of beta-lactams in the subsequent 6-months.

Safety of direct oral provocation test to delabel reported mild beta-lactam allergy in infants

BACKGROUND

Around 10% of people report a drug allergy and avoid some medications because of fear of allergic reactions. However, only after a proper diagnostic workup can some of these reactions be confirmed as allergic or nonallergic hypersensitivities. Beta-lactams (BLs) are the most common medication suspected of being involved in drug hypersensivity reactions (DHRs) in children. Recently, direct oral provocation tests (DPT) with BLs gained popularity within pediatric populations as a tool for delabeling children with suspected BL allergies. This study aimed to evaluate the safety of direct provocation tests in infants with mild cutaneous non-immediate reactions to BLs.

METHODS

The authors retrospectively analyzed the data of 151 infants between 2015 and 2022, referred for evaluating a suspected allergy to BLs that occurred before age 24 months.

RESULTS

The mean age of the children, including 55% male kids, at the suspected reaction was 15.9 months and the mean age at the time of the DPT was 39.6 months. In most cases, antibiotics were prescribed to treat common upper respiratory infections, such as acute otitis (54.3%) and acute tonsillitis (27.2%). Amoxicillin was considered the culprit drug in 62.9% of the cases, and the combination of amoxicillin-clavulanic acid in the case of 33.8% of children. The most frequent associated cutaneous clinical manifestations were maculopapular exanthema in 74.8% and delayed urticaria/angioedema in 25.2%. Of the 151 infants evaluated, parents of 149 infants agreed for a direct DPT, and only three had a positive test (2%). Symptoms resulting from the DPT were mild and easily treatable.

CONCLUSIONS

A direct DPT without prior tests is a safe and effective procedure to delabel BL allergy, even in infants. The authors wish to emphasize the importance of properly validating BL allergy suspicions by promoting appropriate diagnostic procedures in infants as, in most cases, DHRs can be excluded and there is no need for further therapeutic restrictions.

The importance of clinical history in the diagnosis of drug hypersensitivity in children

BACKGROUND

In case of suspected hypersensitivity reactions (HRs) to drugs, a challenging area for pediatricians is detecting relevant elements in the parent-reported history, in order to reach a definite diagnosis. We analyzed the concordance between the description of the HR and the medical reports documented at the time of the event. Furthermore, we studied any correlation between clinical history variables and the prediction of true allergy.

METHODS

We retrospectively collected 50 charts of children referred to our Allergy Unit, after a previous access to the Emergency Department. We compared the description of the HR at acute phase to the history told by parents. Type and timing of the HR and culprit drug were classified as "known" or "unknown." The diagnosis was confirmed or excluded at the end of the investigations. Logistic regression analysis was performed to find any significant association.

RESULTS

The type of the HR was known in 74%, the timing in 28%, and the culprit drug in 98%. We showed that having had a severe HR had an increased odds of remembering the timing; being older >6 years and having had an immediate HR had an increased odds of remembering the type; time to diagnostic was lower in patients whose parents remembered the type of HR.

CONCLUSION

Our paper underlines the importance of an accurate anamnesis at the time of the event. Providing the physicians with a standardized Case Report Form could be a useful tool to simplify the diagnostic work-up and minimize mistakes due to lack of memory.

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.

Is a Prolonged Drug Provocation Test Better Than a Single-Day Drug Provocation Test? A Systematic Review and Meta-Analysis

BACKGROUND

There is currently no standardized duration of drug provocation test (DPT) for confirming/delabeling beta-lactam hypersensitivity reaction (BL-HSR).

OBJECTIVES

This meta-analysis and systematic review aimed to investigate the added diagnostic value of extended-day over single-day DPT for confirming/delabeling BL-HSR in adults and children.

METHODS

The MEDLINE, EMBASE, Web of Science, and CINAHL online databases were searched from inception to March 15, 2023, for studies that performed extended-day DPT to confirm/delabel BL-HSR. Risk difference and risk ratio were used to compare the proportions of patients with confirmed BL-HSR by single-day or extended-day DPT.

RESULTS

A total of 10,371 DPTs from 42 studies were included. Extended-day DPTs ranged from 2 to 7 days, or as long as index reactions were reported (maximum 10 days). The overall prevalence of confirmed BL-HSR was 6.96% (3.31% during the first-day DPT, and 3.65% during extended-day DPT). Approximately half of the positive reactions during extended-day DPT occurred during the second/third day. The increased detected pool prevalence of confirmed BL-HSR yielded by extended-day DPT was 0.03 (95% CI, 0.02%-0.04%; I2 = 57.69%; P < .001), and the risk ratio of positive reactions between extended-day and single-day DPT was 1.94 (95% CI, 1.62-2.33; I2 = 36.26%; P < .001). The risk difference increased per 1% increase in prevalence of BL-HSR by 0.6% (95% CI, 0.4%-0.7%; P < .001). Twenty-three severe reactions occurred during DPT, and only 2 severe reactions (0.02%) occurred during extended-day DPT. An additional 28 extended-day DPTs were needed to identify 1 mild reaction.

CONCLUSIONS

The increased prevalence of confirmed BL-HSR observed during extended-day DPT could be attributed to the first-day DPT. As a result, our findings do not conclusively support the use of extended-day DPT over single-day DPT. Further studies, incorporating a washout period, are required to comprehensively compare these 2 approaches.

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.

Cemental and alveolar bone defects after chronic exposure to amoxicillin in rats (histopathologic and radiographic study)

OBJECTIVES

This study aimed to shed new light on the potential detrimental effects on cementum and adjacent alveolar bone after chronic exposure to amoxicillin.

METHODS

Six pregnant adult Albino rats were equally divided into two groups. Saline solution and amoxicillin (100 mg/Kg) were given to rats of control and amoxicillin group, respectively from the 13th to the 21st day of pregnancy. The same treatment was given to the pups till the 42nd day. The cementum of the first molar teeth and the surrounding alveolar bone were examined qualitatively by histopathological and scanning electron microscope, and quantitatively by energy dispersive X-ray spectroscopy and cone beam computed tomography.

RESULTS

Amoxicillin group depicted cemental and alveolar bone defects along with resorption lacunae. Statistically significant decreases in calcium and calcium/phosphorus ratio in cementum and in calcium only in alveolar bone were evident (p ≤ 0.05). Overall cementum and alveolar bone densities also showed statistically significant decreases (p ≤ 0.05).

CONCLUSION

Chronic amoxicillin administration displayed destructive effects on cementum and the surrounding alveolar bone which may disturb tooth attachment integrity. Therefore, it is recommended to minimize its haphazard usage during pregnancy and early childhood.

Resource utilization and cost assessment of a proactive penicillin allergy de-labeling program for low-risk inpatients

BACKGROUND

Resource utilization and costs can impede proactive assessment and de-labeling of penicillin allergy among inpatients.

METHODS

Our pilot intervention was a proactive penicillin allergy de-labeling program for new inpatients with penicillin allergy. Patients deemed appropriate for a challenge with a low-risk penicillin allergy history were administered 250 mg amoxicillin and monitored for 1 h. We performed an explorative economic evaluation using various healthcare professional wages.

RESULTS

Over two separate 2-week periods between April 2021 and March 2022, we screened 126 new inpatients with a penicillin allergy. After exclusions, 55 were appropriate for formal assessment. 19 completed the oral challenge, and 12 were directly de-labeled, resulting in a number needed to screen of 4 and a number needed to assess of 1.8 to effectively de-label one patient. The assessor's median time in the hospital per day de-labeling was 4h08 with a range of (0h05, 6h45). A single-site annual implementation would result in 715 penicillin allergy assessments with 403 patients de-labeled assuming 20,234 annual weekday admissions and an 8.9% penicillin allergy rate. Depending on the assessor used, the annual cost of administration would be between $21,476 ($53.29 per effectively de-labeled patient) for a pharmacy technician and $61,121 ($151.67 per effectively de-labeled patient) for a Nurse Practitioner or Physician Assistant.

CONCLUSION

A proactive approach, including a direct oral challenge for low-risk in-patients with penicillin allergy, appears safe and feasible. Similar programs could be implemented at other institutions across Canada to increase access to allergy assessment.

Assessing Pediatric Cephalosporin Allergic Reactions Through Direct Graded Oral Challenges

BACKGROUND

Cephalosporins, β-lactam antibiotics, commonly cause allergic reactions.

OBJECTIVE

To assess the clinical characteristics and management of pediatric patients with suspected cephalosporin allergy using direct graded oral challenges (GOCs).

METHODS

Children referred for suspected cephalosporin allergy at 4 Canadian clinics were recruited over 10 years. Data on demographics, clinical reaction characteristics, and management were collected through a questionnaire. Patients underwent a direct GOC (initially 10% of the treatment dose, then 90% after 20 min), and reactions were monitored 1 week postchallenge. Families were contacted annually for up to 5 years to detect subsequent antibiotic reactions. Logistic regression analysis identified factors associated with positive GOC reactions.

RESULTS

Among the 136 patients reporting cephalosporin allergy, 75 (55.1%) were males with a median age of 3.9 years (interquartile range 2.3-8.7). Cefprozil represented the most common cephalosporin linked to the index reaction (67.6% of cases). Of the 136 direct GOCs, 5.1% had an immediate and 4.4% a nonimmediate reaction, respectively. Positive GOCs conducted in children with a history of skin-limited nonsevere rashes were classified as mild, benign skin rashes. Positive GOCs were more likely in children with food allergies (adjusted odds ratio 1.14; 95% confidence interval [95% CI] 1.00-1.29).

CONCLUSIONS

Direct GOCs are safe and effective for diagnosing pediatric cases that report nonvesicular skin-limited symptoms while being treated with cephalosporins.

Inpatient allergy delabeling of pediatric patients with low-risk penicillin allergy status through direct oral amoxicillin challenge

Background: Less than 5% of children who report penicillin allergy have clinically pertinent type 1 immunoglobulin E mediated hypersensitivity reaction by using direct oral amoxicillin challenge. Several pathways have been developed to delabel penicillin allergy by using direct oral amoxicillin challenge, mostly in the outpatient settings, but there is relative scarcity on published outcomes of these pathways, especially in the inpatient pediatric settings. Objective: This study aimed to evaluate the performance of an institutionally derived inpatient penicillin allergy screening tool. Methods: Patients were stratified into three penicillin allergy risk categories by using an institutional screening questionnaire. Patients with a no-risk status were delabeled without challenge testing. Patients with low-risk status underwent direct graded oral amoxicillin challenge and delabeled based on their response. Patients with high-risk status were referred to allergy service. Results: Ninety-two patients were identified with penicillin allergy. Forty of the 92 patients (43%) were screened. Of the 40 patients screened, 6 (15%) were identified as no risk, 28 (70%) were identified as low risk, and 6 (15%) were identified as high risk. Twenty-four of the 28 patients at low risk (86%) were eligible for direct amoxicillin oral challenge. Seventeen of the 24 (71%) consented to oral challenge but only 12 (71%) underwent direct amoxicillin oral challenge. Eleven of the 12 who underwent oral challenge (92%) were successfully delabeled. Five of the six patients at no risk (83%) were successfully delabeled. Three of the six patients at high risk (50%) were referred for further allergy evaluation. Overall, 16 of the 40 patients screened (40%) were successfully delabeled. Conclusion: In this small pediatric inpatient study, our institutional risk stratification screening tool identified patients at low risk for penicillin allergy and direct graded oral amoxicillin challenge was safely administered to delabel penicillin allergy in these patients.Clinical trial NCT05020327, www.clinicaltrials.gov.

Penicillin Allergy Evaluation Should Be Performed Proactively in Patients With a Penicillin Allergy Label

Penicillin allergy is the most common drug allergy in the US population. A penicillin allergy label is associated with poor patient outcomes including increased hospital length of stay, increased perioperative infections, and overall increased mortality. A penicillin allergy evaluation accurately identifies approximately 9 of 10 patients who, despite reporting a history of penicillin allergy, can receive penicillins safely. Penicillin allergy evaluations should be offered proactively to healthy patients during routine visits, including children and pregnant women, in advance of antibiotic need.

Approach for delabeling beta-lactam allergy in children

A considerable number of pediatric patients treated with beta-lactam (BL) antibiotics develop delayed onset of skin rashes during the course of treatment. Although the most frequent cause of these symptoms is infectious, many cases are labeled as allergic reactions to these drugs. BL allergy labels could have a negative impact, as they imply avoidance of this group of drugs and the use of second-line antibiotics, leading to a potential increase in adverse effects and the utilization of less effective therapies. This constitutes a major public health concern and economic burden, as the use of broad-spectrum antibiotics can result in multidrug-resistant organisms and prolonged hospital stays. Therefore, it is crucial to delabel patients during childhood to avoid false labeling in adult life. Although the label of BL allergy is among the most frequent causes of allergy referral, its management remains controversial, and new diagnostic perspectives are changing the paradigm of managing BL allergies in children. Traditionally, drug provocation testing (DPT) was exclusively performed in patients who had previously obtained negative results from skin tests (STs). However, the sensitivity of STs is low, and the role of in vitro testing in the pediatric population is not well defined. Recent studies have demonstrated the safety of direct DPT without prior ST or serum tests for pediatric patients who report a low-risk reaction to BLs, which is cost-effective. However, there is still a debate on the optimal allergic workup to be performed in children with a benign immediate reaction and the management of children with severe cutaneous adverse drug reactions. In this review, we will discuss the impact of the label of BL allergy and the role of the different tools currently available to efficiently address BL allergy delabeling in children.

Does thePenicillin Allergy Label Affect Outcomes of Complicated Odontogenic Infections?

PURPOSE

Penicillins are a potent antibiotic in managing odontogenic infections, but 10% of the population is labelled as allergic to these drugs. This has limited their use and resulted in increased utilization of health care resources as well as complications associated with alternative antibiotics. The purpose of the study was to measure the association between patients labeled as penicillin allergic and treatment outcomes in a sample of patients treated for complicated odontogenic infections. Additionally, we sought to investigate antibiotic resistance patterns in these patients.

MATERIALS AND METHODS

A retrospective cohort study was performed at the Michigan Medicine health care system to include patients who were treated for complicated odontogenic infections by oral and maxillofacial surgery between 2016 and 2020. Complicated odontogenic infection was defined as any odontogenic infection requiring admission and surgical management in the operating room. The primary predictor variable was the penicillin allergy label, which was determined by chart review and not confirmed with formal testing. Outcomes were measures of disease severity. The primary outcome variable was hospital length of stay. Secondary outcome variables were ICU admission (yes/no), repeat computed tomography scan(s), repeat surgery (yes/no), and re-admission (yes/no). Co-variates included were age, sex (male/female), tobacco use status, diabetes, immunocompromised state, number of spaces involved, white blood cell count upon admission and insurance status. For our secondary aim, the primary predictor variable was again penicillin allergy and outcome variable was antibiotic resistance as determined by wound culture results following surgical intervention. Negative binomial regression and logistic regression analyses were performed. P < .05 was considered significant.

RESULTS

A total of 150 patients met the inclusion criteria and of those 17.3% reported as penicillin allergic. Patients labelled as penicillin allergic did not differ significantly from patients without penicillin allergy label in terms of treatment outcomes. Age, diabetes, and immunosuppression were associated with an increased length of stay. Patients labelled as penicillin allergic were at significantly higher risk for antibiotic resistance (relative risk = 2.34; 95% confidence interval, 1.66 to 3.32; P < .001), specifically clindamycin resistance (relative risk = 3.17; 95% confidence interval, 1.93 to 5.18; P < .001).

CONCLUSIONS

Penicillin allergy was significantly associated with clindamycin resistance. There were similar outcomes amongst patients with and without a penicillin allergy label despite antibiotic differences. Delabeling efforts for patients with a reported penicillin allergy must be considered and local nomograms for antibiotic selection should be used by providers when seeking alternative antibiotics.

Direct challenges are the gold standard for most antibiotic allergy evaluations

Antibiotic allergies are frequently encountered in clinical practice, and delabeling of these allergies has individual and public health benefits. This review focuses on the evidence supporting graded challenges without preceding skin testing in adult and pediatric patients to the major groups of antibiotics including penicillins, cephalosporins, sulfamethoxazole, fluoroquinolones, tetracyclines, macrolides, metronidazole, carbapenems, and aztreonam. The cost savings, time savings, and evidence for performing graded challenges outside of an allergy/immunology office are also reviewed for graded challenges to penicillins.

Diagnosis and selection of alternative antibiotics in beta-lactams hypersensitivity reactions: Current recommendations and challenges

Beta-lactam (BLM) antibiotics, including amino-penicillin and cephalosporins, are typically the first-choice treatment for bacterial infections. However, adverse reactions to these antibiotics are frequently reported, causing non-allergist physicians to select alternative broad-spectrum antibiotics that can have harmful consequences. Patients with unclear histories of hypersensitivity reactions to BLMs should undergo an allergy workup to establish a firm diagnosis, particularly when different drugs are prescribed simultaneously. However, finding the safest, most precise, and cost-effective methods for confirming BLMs hypersensitivity and selecting the most appropriate alternative BLM is uncertain, particularly in severe delayed reactions. This review aims to provide data and recommendations on the availability and validity of skin tests (STs), drug provocation test (DPT) protocols, based on the latest published literature and guideline. To make the process more practical, we focused on cross-reactivity between BLMs and diagnostic tests. There are two main novel aspects of this document: 1) For T-cell-mediated reactions, patient stratification into high, moderate, and low-risk groups based on the mortality and morbidity of adverse drug reactions. 2) For IgE-mediated reactions, stratification of individuals with isolated limited urticarial without anaphylaxis in a low-risk group and removal of the extensive limitation.

Facilitators and Barriers to Verifying Penicillin Allergies in a Veteran Nursing Home Population

BACKGROUND

Unconfirmed penicillin allergies are common and may contribute to adverse outcomes, especially in frail older patients. Evidence-based clinical pathways for evaluating penicillin allergies have been effectively and safely applied in selected settings, but not in nursing home populations.

OBJECTIVE

To identify potential facilitators and barriers to implementing a strategy to verify penicillin allergies in Veterans Health Administration nursing homes, known as Community Living Centers (CLCs).

METHODS

We conducted semistructured interviews with staff, patients, and family members at 1 CLC to assess their understanding of penicillin allergies and receptiveness to verifying the allergy. We also asked staff about the proposed allergy assessment strategy, including willingness to delabel by history and feasibility of performing oral challenges or skin testing on their unit.

RESULTS

From 24 interviews (11 front-line staff, 4 leadership, 3 patients, 6 family members), we identified several facilitators or barriers. Staff recognized the importance of allergy verification and were willing to support and assist in implementing verification strategies. The CLC residents were willing to have their allergy status verified. However, some family members expressed reluctance to verifying their relative's allergy status owing to safety concerns. Front-line staff also expressed concern over having the necessary resources, including time and expertise, to implement the strategy. Staff suggested involving clinical pharmacists and educating staff, patients, and family members as ways to overcome these barriers.

CONCLUSIONS

Concerns about safety and staff resources are important potential barriers to implementing verification strategies. Involvement of pharmacists and education of both staff and patients and family members will be important components of any successful intervention.

Drug provocation tests in children: All that glitters is not gold

A proper allergy work-up, based on the gold standard drug provocation test (DPT), usually rules out suspected drug hypersensitivity in children. These tests are generally open, given their high efficiency compared with double-blind placebo-controlled DPTs. Although their negative predictive value is excellent, no studies have calculated their positive predictive value, highly dependent on the prevalence of the disease. Most studies have found a rate of <5%-10% of true beta-lactam hypersensitivity in children. Given this low prevalence (pre-test probability), a few false-positive results can significantly reduce the estimated positive predictive value. False positives may arise from the nocebo effect during the test, including nocebo by proxy, or from observer bias, which depends on professional expertise and organizational circumstances. Some studies have found a high rate of tolerance on a second DPT in children who failed the first, but these results may be affected by the interval between the two tests, of a year or more in most cases, reflecting a loss of hypersensitivity over time. Taking into account the low rate of positive DPTs, with commonly mild reactions, we suggest confirming nonsevere positive DPTs with a second provocation performed soon after the first, especially in the case of beta-lactam antibiotics, in order to improve the diagnostic accuracy, de-label more patients, and achieve a better estimation of true drug hypersensitivity prevalence. In case of mild immediate reactions, the potential benefits of a second DPT should be carefully weighed against the risk of anaphylaxis.

Use of a beta-lactam graded challenge process for inpatients with self-reported penicillin allergies at an academic medical center

Background

The Antimicrobial Stewardship Program (ASP) at Nebraska Medicine collaborated with a board-certified allergist to develop a penicillin allergy guidance document for treating inpatients with self-reported allergy. This guidance contains an algorithm for evaluating and safely challenging penicillin-allergic patients with beta-lactams without inpatient allergy consults being available.

Methods

Following multi-disciplinary review, an order set for beta-lactam graded challenges (GC) was implemented in 2018. This contains recommended monitoring and detailed medication orders to challenge patients with various beta-lactam agents. Inpatient orders for GC from 3/2018-6/2022 were retrospectively reviewed to evaluate ordering characteristics, outcomes of the challenge, and whether documentation of the allergy history was updated. All beta-lactam challenges administered to inpatients were included, and descriptive statistics were performed.

Results

Overall, 157 GC were administered; 13 with oral amoxicillin and 144 with intravenous (IV) beta-lactams. Ceftriaxone accounted for the most challenges (43%). All oral challenges were recommended by an Infectious Diseases consult service, as were a majority of IV challenges (60%). Less than one in five were administered in an ICU (19%). Almost all (n = 150, 96%) were tolerated without any adverse event. There was one reaction (1%) of hives and six (4%) involving a rash, none of which had persistent effects. Allergy information was updated in the electronic health record after 92% of the challenges.

Conclusion

Both intravenous and oral beta-lactam graded challenges were implemented successfully in a hospital without a regular inpatient allergy consult service. They were well-tolerated, administered primarily in non-ICU settings, and were often ordered by non-specialist services. In patients with a self-reported penicillin allergy, these results demonstrate the utility and safety of a broadly adopted beta-lactam GC process.

The state and consideration for skin test of β-lactam antibiotics in pediatrics

β-lactam antibiotics are the most frequently used drugs and the most common drugs that cause allergic reactions in pediatrics. The occurrence of some allergic reactions can be predicted by skin testing, especially severe adverse reactions such as anaphylactic shock. Thus, penicillin and cephalosporin skin tests are widely used to predict allergic reactions before medication in pediatrics. However, false-positive results from skin tests were more often encountered in pediatrics than in adults. In fact, many children labeled as allergic to β-lactam are not allergic to the antibiotic, leading to the use of alternative antibiotics, which are less effective and more toxic, and the increase of antibiotic resistance. There has been controversy over whether β-lactam antibiotics should be tested for skin allergies before application in children. Based on the great controversy in the implementation of β-lactam antibiotic skin tests, especially the controversial cephalosporin skin tests in pediatrics, the mechanism and reasons of anaphylaxis to β-lactam antibiotics, the significance of β-lactam antibiotic skin tests, the current state of β-lactam antibiotic skin tests at home and abroad, and the problems of domestic and international skin tests were analyzed to determine a unified standard of β-lactam antibiotic skin tests in pediatrics to prevent and decrease adverse drug reactions, avoid waste of drugs, and a large amount of manpower and material resource consumption.

Pearls for practice from the 2022 joint task force drug allergy practice parameter

PURPOSE OF REVIEW

To review updated recommendations in the 2022 Drug Allergy Practice Parameters for the evaluation and management of drug hypersensitivity reactions.

RECENT FINDINGS

Adverse drug reactions have become increasingly prominent with the advent of new and emerging pharmacologic therapies. Hypersensitivity reactions encompass a significant proportion of adverse drug reactions and negatively impact both the individual patient and overall health system. Reactions are heterogeneous in presentation and may be immediate (onset of symptoms ≤6 h) or delayed (onset of symptoms >6 h to months) after drug exposure. The 2022 Drug Allergy Practice Parameter provides consensus-based statements for evaluation of hypersensitivity reactions to antibiotics, NSAIDs, cancer chemotherapies, immune checkpoint inhibitors, biologics, and excipients. In general, the guideline highlights the importance of patient history in elucidating the phenotype and severity of the index reaction. Drug challenge remains the gold standard for diagnosis and is increasingly favored over skin testing in patients with nonsevere, nonanaphylactic drug reaction histories.

SUMMARY

The 2022 Drug Allergy Practice Parameter provides an updated framework for physicians to reference in clinical practice when managing patients with drug hypersensitivity reactions.

Relationship of Reaction History to Positive Penicillin Skin Tests

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Impact of penicillin allergy labels among pneumonia admissions at an academic children's center

Background: Pneumonia is the most common reason for pediatric hospitalizations. The impact of penicillin allergy labels among children with pneumonia has not been well studied. Objective: This study assessed the prevalence and impact of penicillin allergy labels among children admitted with pneumonia over a 3-year period at a large academic children's center. Methods: Inpatient charts of pneumonia admissions with a documented allergy to a type of penicillin from January to March in 2017, 2018, and 2019 were reviewed and compared with pneumonia admissions without the label over the same time with regard to days of antimicrobial treatment, route of antimicrobial therapy, and days of hospitalization. Results: There were 470 admissions for pneumonia during this time period, of which 48 patients (10.2%) carried a penicillin allergy label. Hives and/or swelling comprised 20.8% of the allergy labels. Other labels included nonpruritic rashes, gastrointestinal GI symptoms, unknown/undocumented reactions, or other reasons. There were no significant differences between those with a penicillin allergy label to those without regarding days of antimicrobial treatment (inpatient and outpatient), route of antimicrobial therapy, and days of hospitalization. Those with a penicillin allergy label were less likely to be prescribed a penicillin product (p < 0.002). Of the 48 patients who were allergy labeled, 23% (11/48) were given a penicillin medication without adverse reaction. Conclusion: Ten percent of pediatric admissions for pneumonia had a label of penicillin allergy, similar to the overall population. The hospital course and clinical outcome were not significantly affected by the penicillin allergy label. The majority of documented reactions were of low risk for immediate allergic reactions.

Virtually supported penicillin allergy de-labelling during COVID-19

BACKGROUND

Penicillin allergy is a commonly listed medication allergy despite rare overall incidence. Many patients erroneously have this label, which has personal, health, and societal costs. Penicillin allergy delabelling requires an oral challenge, which can be a rate limiting step in the de-labeling process; this is even more relevant with the reduction of in-person visits during the COVID-19 pandemic.

OBJECTIVE

To identify the utility and broader applicability of using a virtually supported platform, initially adopted given COVID-19 restrictions, to expedite penicillin oral provocation challenge and penicillin de-labeling in patients at low to moderate risk of immediate hypersensitivity reaction and based on shared decision making.

METHODS

Patients in Vancouver catchment area were referred for penicillin allergy and virtually assessed by the consulting allergist between July 2020 and April 2021. Those deemed appropriate for oral challenge based on the allergist consultant were offered the option of a virtual oral provocation challenge to oral amoxicillin in a subsequent virtual visit. Patients who agreed and were consented underwent a virtually supervised oral amoxicillin challenge during the second virtual visit. Findings are summarized in this case series.

RESULTS

Twenty-three patients, both adult and pediatric, ranging from no to significant co-morbidities were consented and underwent the virtual challenge. One hundred percent of patients were successful with no reaction after an hour post virtual oral provocation challenge with amoxicillin.

CONCLUSION

Virtual medicine is likely to remain in the allergist's practice. Virtually supported penicillin allergy delabelling, based on shared decision making and risk stratification, presents another pathway for penicillin allergy delabelling.

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.

The Safety of the Direct Drug Provocation Test in Beta-Lactam Hypersensitivity in Children: A Systematic Review and Meta-Analysis

BACKGROUND

Direct drug provocation test (DPT) without prior skin testing (ST) has been investigated in children suspected of being at risk for beta-lactam (BL) hypersensitivity reaction (HSR). However, no systematic review and meta-analysis has investigated the efficacy and safety of direct DPT for BL-HSR in children.

OBJECTIVE

To investigate the prevalence of BL-HSR by direct DPT and the safety of direct DPT in children.

METHODS

We searched MEDLINE, EMBASE, Web of Science, and CINAHL from their inception to July 23, 2022, for studies that performed direct DPT in children with suspected BL-HSR, or for studies that performed DPT in all cases with ST results, but they ignored the ST results. The true prevalence was defined as the proportion of children who experienced an HSR during direct DPT. Safety was determined according to the proportion of children who developed a dangerous reaction following DPT.

RESULTS

Twenty-eight studies with 8,334 direct challenges were included. Fifteen studies included patients who presented with either immediate or nonimmediate HSR, and the majority of the index reactions were nonsevere. Amoxicillin/amoxicillin-clavulanic acid was the most commonly used during the DPT. The pooled prevalence of confirmed BL-HSR was 5.23% (95% CI 4.17-6.39; I² = 72%). Immediate and nonimmediate HSR were reported in 0.8% (95% CI 0.43-1.25; I² = 55.1%) and 3.69% (95% CI 2.66-4.87; I² = 79.77%), respectively. Severe reactions were found in 3 cases with the frequency of 0.036% (95% CI 0.012-0.112; I² = 0%).

CONCLUSIONS

The prevalence of BL-HSR by direct DPT was 5.23%, and the frequency of severe reactions from direct DPT was very low (0.036%). Our findings support direct DPT as a safe and effective delabeling tool in children with suspected nonsevere BL-HSR.

Drug Allergy Practice Parameter Updates to Incorporate Into Your Clinical Practice

The drug allergy practice parameter was developed to provide guidance on the diagnosis and management of drug hypersensitivity reactions. It was last updated in 2010. With the growth of research and evidence-based data since then, experts came together to update the practice parameter with a focus on sections that the work group deemed to have significant changes (or were not addressed) in the previous practice parameter. This review is a focused update on aspects of the practice parameter deemed to have the greatest impact on clinical practice and includes significant updates on diagnosis of antibiotic allergy including penicillin, cephalosporin, sulfonamide, fluoroquinolone, and macrolide allergies. Other topics include the evolution in our management approach to patients with aspirin/nonsteroidal anti-inflammatory drug allergy, diagnostic testing for delayed drug hypersensitivity and allergy to chemotherapeutics and biologics, and the key consensus-based statements for clinical practice. Specifically, the updated practice parameter helps allergists understand the place of 1- or 2-step drug challenges that are valuable tools often without the need for skin testing in many clinical situations. A proactive approach to delabeling penicillin allergy as well as unnecessary avoidance of safe antibiotic alternatives for patients with proven penicillin allergy is emphasized. New guidance is provided on management of patients with different phenotypes of aspirin and nonsteroidal anti-inflammatory drug hypersensitivity reactions. Approaches to delayed drug hypersensitivity and use of delayed intradermal and patch testing for specific phenotypes are reviewed. Lastly, practical approaches to management of patients with reactions to chemotherapeutics and biologics are discussed.

Penicillin Allergy

Allergy to penicillin can occur via any of the 4 types of Gel-Coombs hypersensitivity reactions, producing distinct clinical histories and physical examination findings. Treatments include penicillin discontinuation, and depending on the type of reaction, epinephrine, antihistamines, and/or glucocorticoids. Most beta-lactams may be safely used in penicillin-allergic patients, with the possible exception of first-generation and second-generation cephalosporins. Penicillin testing includes skin testing, patch testing, and graded challenge. The selection of the type of testing depends on the clinical setting, equipment availability, and type of hypersensitivity reaction. Desensitization may be used in some cases where treatment with penicillins is essential.

Beta-Lactam Allergy Association with Surgical Site Infections in Pediatric Procedures: A Matched Cohort Study

BACKGROUND

Little is known about surgical site infection (SSI) risk among pediatric patients with reported beta-lactam allergy (BLA).

METHODS

We performed a retrospective cohort study at a quaternary children's hospital and compared procedures in patients ages 1-19-years-old with and without BLA that required antimicrobial prophylaxis (AMP) during 2010-2017. Procedures were matched 1:1 by patient age, complex chronic conditions, year of surgery, and National Surgical Quality Improvement Program current procedural terminology category. The primary outcome was SSI as defined by National Healthcare Safety Network. The secondary outcome was AMP protocol compliance as per American Society of Health-System Pharmacists.

RESULTS

Of the 11,878 procedures identified, 1021 (9%) had a reported BLA. There were 35 (1.8%) SSIs in the matched cohort of 1944 procedures with no significant difference in SSI rates in BLA procedures (1.8%) compared to no BLA (1.9%) procedures. Tier 3 AMP was chosen more frequently among BLA procedures (p<0.01). Unmatched analysis of all procedures showed that 23.7% of BLA procedures received beta-lactam-AMP (vs. 93.7% of procedures without BLA). There were no major differences in SSI on sensitivity analysis of BLA procedures that did not receive beta-lactam AMP (1.4%) compared to no BLA procedures with beta-lactam AMP (1.6%) .

CONCLUSIONS

Our retrospective matched analysis of 1944 pediatric procedures found no increase in SSIs in procedures with reported BLA, which differs from studies in adults. We observed that choice of beta-lactam-AMP was common, even in BLA procedures. More data are needed to delineate an association of non-beta-lactam AMP and SSI in children.

Beta-lactam allergy and drug challenge test in children: a systematic review and meta-analysis

BACKGROUND

Most cases of beta-lactam allergy in children are likely to be mislabeled. This study aimed to assess the prevalence of true positives, as determined by drug challenge tests, and the rate of false negatives in children with suspected allergies and confirm the safety of the drug challenge test.

METHODS

We conducted a systematic review and meta-analysis according to established procedures. Study participants were children with suspected beta-lactam allergy who underwent a drug challenge. PubMed MEDLINE, Dialog EMBASE, Cochrane Central Register of Controlled Trials, World Health Organization International Clinical Trials Registry Platform, and clinicaltrials.gov were searched from inception until March 5, 2021.

RESULTS

The pooled prevalence of (a) positive results in the first challenge was 0.049 (95% CI, 0.041-0.057; I² = 71%) from 78 studies; (b) serious adverse events was 0.00 (95% CI, 0.00-0.00; I² = 0.0%) from 62 studies; and (c) positive results in the second challenge after the first negative result was 0.028 (95% CI, 0.016-0.043; I² = 38%) from 18 studies.

CONCLUSIONS

The prevalence of children with suspected beta-lactam allergy with true-positive results and false-negative results from the drug challenge test was very low. Serious adverse events resulting from drug challenge tests were also very rare.

IMPACT

Most children with suspected beta-lactam allergy were likely to be mislabeled. Serious adverse events caused by the drug challenge test were rare. Few false-negative results were obtained from the drug challenge test.

Drug reintroduction testing and beta-lactam hypersensitivity in children: Protocols and results, a 12-year experience

Introduction: Oral provocation test (OPT) to beta-lactam antibiotics (BL) is a gold standard in allergology investigation. We aimed to demonstrate the contribution of OPT in BL hypersensitivity (HS) indicated as a first step in diagnosis. Methods: We conducted a retrospective study from 2007 to 2019, in a single Tunisian tertiary care academic center. It concerned children with presumed non-severe allergic manifestations to BL, with a reaction that has occurred at least 6 months before the OPT. Results: We identified 35 children for inclusion. After the first OPT, a second OPT with a different BL was performed in case of a positive result of the first one. In 12 cases (34.2%), the OPT elicited a reaction. In eight cases the allergy was to penicillin and in two cases to cephalosporins (cefixim). Cross-reactivity was noted in two cases. Conclusion: An OPT to BL indicated in the first instance in non-severe reaction in children will allow a rapid diagnosis in case of suspicion of HS to BL.

Drug allergy evaluation in children with suspected mild antibiotic allergy

Background

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

Methods

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

Results

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

Conclusion

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

Advances in immunoglobulin E mediated antibiotic allergy

PURPOSE OF REVIEW

The purpose of this review is to identify recent advances in our understanding and management of immunoglobulin E (IgE)-mediated antibiotic allergy.

RECENT FINDINGS

Antibiotics remain a leading cause of fatal anaphylaxis reported to the FDA. However, recent advances have defined the features of adult and pediatric patients without true IgE-mediated allergy or any mechanism of anaphylaxis when tested. This has created opportunities to use direct challenges to disprove these allergies at the point-of-care and improves antibiotic stewardship. Additional advances have highlighted cross-reactive structural considerations within classes of drugs, in particular the R1 side-chain of cephalosporins, that appear to drive true immune-mediated cross-reactivity. Further advances in risk-based approaches to skin testing, phenotyping, and re-exposure challenges are needed to standardize antibiotic allergy evaluation.

SUMMARY

Recent advances in defining true IgE-mediated drug allergy have helped to identify patients unlikely to be skin-test positive. In turn, this has identified patients who can skip skin testing and proceed to direct ingestion challenge using history risk-based approaches. The ability to identify the small number of patients with true IgE-mediated allergy and study their natural history over time, as well as the vast majority without true allergy will facilitate important and novel mechanistic discoveries.

Predictors of Acute Care Reutilization in Pediatric Patients With Amoxicillin-Associated Reactions

BACKGROUND

Amoxicillin-associated reactions (AARs) contribute to substantial health care utilization, with a reutilization rate of 10% in pediatric emergency department (ED) and urgent care (UC) settings.

OBJECTIVE

To identify predictors of ED/UC reutilization by examining patients' clinical features and providers' management of AARs.

METHODS

Through a retrospective chart review of 668 patients presenting with AARs over 2 years to the pediatric ED/UC, we examined clinical features associated with ED/UC reutilization, including rash phenotype, systemic symptoms (fever, angioedema, joint involvement, gastrointestinal symptoms), and providers' management (pharmacologic treatment and counseling). We then constructed a statistical model to predict ED/UC reutilization using stepwise backward model selection.

RESULTS

ED/UC reutilizers were more likely to be male (P = .008) and have fever (P = .0001), angioedema (P < .0001), joint involvement (P < .0001), and gastrointestinal symptoms (P = .0001) during their AAR course. Rash phenotypes differed between groups (P < .0001), as ED/UC reutilizers more frequently exhibited urticaria. However, there were no differences in clinical management between groups, including pharmacologic recommendations, at the initial ED/UC encounter. In addition, our statistical model identified younger patients <2 years of age as more likely to reutilize ED/UC resources if providers did not document specific return precautions (odds ratio, 3.6; 95% confidence interval, 1.7-7.7).

CONCLUSION

Recognition of clinical features and treatment gaps associated with ED/UC reutilization will guide interventions to optimize care in children presenting with AARs, such as improved anticipatory guidance and early allergy consultation. Prospective studies are needed to determine whether these interventions will reduce ED/UC reutilization and facilitate timely allergy testing.