Parent-Reported Penicillin Allergy Symptoms in the Pediatric Emergency Department

Drug Allergy in Children: What Should We Know?

The drug allergy "label" may have a lifetime of consequences for a child. Many children with alleged drug allergies are proven to be tolerant to the culprit medication when challenged. The field of drug hypersensitivity is a recently evolving field of research, but studies on its epidemiology and diagnostic tools are lacking in children. Clinical history is significant in the diagnosis and classification of drug hypersensitivity in children. Diagnostic tools have been evaluated in a limited number of children; therefore, the guidelines are mainly in line with those for adults. Here, we review the clinical characteristics, main drugs, risk factors, and diagnosis of drug hypersensitivity to aid in its accurate diagnosis in children.

Update on penicillin allergy delabeling

PURPOSE OF REVIEW

To review phenotyping and risk classification of penicillin allergy and provide an update on penicillin allergy delabeling strategies for primary care.

RECENT FINDINGS

Beta-lactams are considered the treatment of choice for a wide range of bacterial pathogens; however, many patients receive second-line agents due to being labeled as having an allergy to penicillin. This approach can lead to antibiotic resistance and inferior health outcomes. While 10% of the population is labeled as penicillin allergic, penicillin anaphylaxis occurs in less than 1% of patients. For patients with delayed benign skin rashes (e.g., urticaria or maculopapular exanthem >1 h after administration) attributable to beta-lactam administration occurring more than 12 months ago, direct oral challenge (rechallenge with antibiotic in the clinical setting) can be a safe and effective strategy, with immediate reactions occurring in less than 5% of such low-risk patients and delayed reactions appearing infrequently. In patients with penicillin-associated immediate urticaria, other IgE-mediated features, or anaphylaxis, further allergy evaluation and penicillin skin testing is warranted. Any severe idiosyncratic cutaneous adverse reaction is rare, but can be dangerous so prompt removal of the inciting agent is required.

SUMMARY

Penicillin allergy delabeling is a high-value service that can be effectively delivered through a multidisciplinary collaborative approach.

Children with reported penicillin allergy: Public health impact and safety of delabeling

OBJECTIVE

To review the relevant literature related to children with reported penicillin allergy and highlight the different ways in which children could be delabeled and to evaluate the public health impact that a penicillin allergy has for children.

DATA SOURCES

Data for this review were obtained via PubMed searches and then retrieval of articles from their respective journals for further review.

STUDY SELECTIONS

Studies regarding the safety of different ways to evaluate penicillin allergy in children were identified via PubMed searches. Any study that reported different ways of testing (3-tier, direct oral challenge, 5-day oral challenges) were included. This same format was used when selecting relevant articg:les related to the costs, prescription patterns, and stewardship trends associated with a penicillin allergy label.

RESULTS

This review found that penicillin allergy testing is a safe and effective way to delabel those with reported allergy. In children with low-risk allergy symptoms, a direct oral challenge approach may be optimal. In those children with a history of high-risk allergy symptoms, a 3-tiered approach is ideal. The review also found that there is a significant cost associated with reported penicillin allergy and that there are increased negative health benefits to those children with reported allergy.

CONCLUSION

Penicillin allergy is overdiagnosed, often incorrectly, and the label is frequently first applied during childhood. Targeting children for the removal of the incorrect penicillin allergy label provides a mechanism to reduce the use of broader-spectrum and less effective antibiotics.

The challenge of de-labeling penicillin allergy

BACKGROUND

Even though 8%-25% of most populations studied globally are labeled as penicillin allergic, most diagnoses of penicillin allergy are made in childhood and relate to events that are either not allergic in nature, are low risk for immediate hypersensitivity, or are a potential true allergy that has waned over time. Penicillin allergy labels directly impact antimicrobial stewardship by leading to use of less effective and broader spectrum antimicrobials and are associated with antimicrobial resistance. They may also delay appropriate antimicrobial therapy and lead to increased risk of specific adverse healthcare outcomes. Operationalizing penicillin allergy de-labeling into a new arm of antimicrobial stewardship programs (ASPs) has become an increasing global focus.

METHODS

We performed an evidence-based narrative review of the literature of penicillin allergy label carriage, the adverse effects of penicillin allergy labels, and current approaches and barriers to penicillin allergy de-labeling. Over the period 1928-2018 in Pubmed and Medline, search terms used included "penicillin allergy" or "penicillin hypersensitivity" alone or in combination with "adverse events," "testing," "evaluation," "effects," "label," "de-labeling," "prick or epicutaneous," and "intradermal" skin testing, "oral challenge or provocation," "cross-reactivity," and "antimicrobial stewardship".

RESULTS

Penicillin allergy labels are highly prevalent, largely inaccurate and their carriage may lead to unnecessary treatment and inferior outcomes with alternative agents as well as adverse public health outcomes such as antibiotic resistance.

CONCLUSIONS

Operationalizing penicillin allergy de-labeling as an aspect of ASP has become an increasing global focus. There is a need for validated approaches that optimally combine the use of history and ingestion challenge with or without proceeding formal skin testing to tackle penicillin allergy efficiently within complex healthcare systems. At the same time, there is great promise for penicillin allergy evaluation and de-labeling as an individual and public health strategy to reduce adverse healthcare outcomes, improve antimicrobial stewardship, and decrease healthcare costs.

Cost and Risk Analysis of Lifelong Penicillin Allergy

Patients labeled as being penicillin-allergic require the use of alternative antibiotics. The objective of this study was to estimate the lifetime antibiotic costs of patients labeled as being penicillin allergic prior to age 10 compared with those who were not penicillin allergic and to compare antibiotic utilization between these 2 groups with regard to risks of adverse effects. Using the low end of the antibiotic cost range, penicillin-allergic patients had a mean lifetime antibiotic cost of $8171 per patient, compared with $6278 for non-penicillin-allergic patients, a difference of $1893. Penicillin-allergic patients utilized more moderate-spectrum antibiotics, more fluoroquinolones, and had a higher estimated Clostridium difficile risk.

Reported Knowledge and Management of Potential Penicillin Allergy in Children

BACKGROUND

Pediatric emergency medicine (PEM) and primary care provider (PCP) providers are the most likely physicians to initially label a child as allergic to penicillin. Differences in knowledge and management of reported penicillin allergy between these 2 groups have not been well characterized.

METHODS

A cross-sectional, 20-question survey was administered to PEM and PCPs to ascertain differential knowledge and management of penicillin allergy. Knowledge regarding high- and low-risk symptoms for true allergy and extent of history taking regarding allergy were compared between the 2 groups using t tests, Chi-square, and Wilcoxon tests.

RESULTS

In total, 182 PEM and 54 PCPs completed the survey. PEM and PCPs reported that 74.1 ± 19.5% and 69.0 ± 23.8% of patients with remote low-risk symptoms of allergy could tolerate penicillin without an allergic reaction. PEM and PCPs incorrectly identified low-risk symptoms of allergy as high-risk, including vomiting with medication administration and delayed skin rash. PCPs took more detailed allergy histories when compared with PEM providers. In total, 143 (78.5%) of PEM providers and 51 (94.4%) PCPs were interested in using a penicillin allergy questionnaire to segregate children into high- or low-risk categories.

CONCLUSIONS

Most pediatric providers believe that children with a remote history of low-risk allergy symptoms could tolerate penicillin without an allergic reaction; however, this is infrequently acted upon. Both PEM and PCP providers were likely to classify low-risk symptoms as high-risk and infrequently referred children for further detailed allergy assessment. Both groups were receptive to decision support measures to facilitate improved penicillin allergy classification and labeling and support antibiotic appropriateness in their patients.

Rate of Recurrence of Adverse Events Following Immunization: Results of 19 Years of Surveillance In Quebec, Canada

BACKGROUND

While adverse events following immunization (AEFI) are frequent, there are limited data on the safety of reimmunizing patients who had a prior AEFI. Our objective was to estimate the rate and severity of AEFI recurrences.

METHODS

We analyzed data from the AEFI passive surveillance system in Quebec, Canada, that collects information on reimmunization of patients who had a prior AEFI. Patients with an initial AEFI reported to the surveillance system between 1998 and 2016 were included. Rate of AEFI recurrence was calculated as number of patients with recurrence/total number of patients reimmunized.

RESULTS

Overall, 1350 patients were reimmunized, of which 59% were 2 years of age or younger. The AEFI recurred in 16% (215/1350) of patients, of whom 18% (42/215) rated the recurrence as more severe than the initial AEFI. Large local reactions extending beyond the nearest joint and lasting 4 days or more had the highest recurrence rate (67%, 6/9). Patients with hypotonic hyporesponsive episodes had the lowest rate of recurrence (2%, 1/50). Allergic-like events recurred in 12% (76/659) of patients, but none developed anaphylaxis. Of 33 patients with seizures following measles mumps rubella with/without varicella vaccine, none had a recurrence. Compared with patients with nonserious AEFIs, those with serious AEFIs were less often reimmunized (60% versus 80%; rate ratio: 0.8; 95% confidence interval: 0.66-0.86).

CONCLUSIONS

Most patients with a history of mild or moderate AEFI can be safely reimmunized. Additional studies are needed in patients with serious AEFIs who are less likely to be reimmunized.

Pediatric Drug Hypersensitivity

PURPOSE OF REVIEW

Pediatric drug hypersensitivity is a rapidly evolving field. The purpose of this paper is to review the current state of pediatric drug hypersensitivity and highlight new developments in diagnosis and management.

RECENT FINDINGS

This paper will discuss the safety and use of risk stratification to proceed directly to oral challenge without prior skin testing for β-lactam reactions. We review unique aspects of pediatric drug challenges and desensitizations. It is important to accurately diagnose pediatric drug hypersensitivity reactions through a detailed history, physical examination, and available diagnostic testing. Understanding of the underlying mechanism leads to appropriate classification which is necessary to direct management. The decision to perform drug challenge, desensitization, or recommend avoidance of a medication can have a significant impact on a patient's treatment. Utilization of weight-based dose and infusion rate adjustments for current drug challenge and desensitization protocols optimize success.

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.

Controversies in Drug Allergy: Drug Allergy Pathways

Drug allergy pathways are standardized approaches for patients reporting prior drug allergies with the aim of quality improvement and promotion of antibiotic stewardship. At the International Drug Allergy Symposium during the 2018 American Academy of Allergy, Asthma, and Immunology/World Allergy Organization Joint Congress in Orlando, Florida, drug allergy pathways were discussed from international perspectives with a focus on beta-lactam allergy pathways and pragmatic approaches for acute care hospitals. In this expert consensus document, we review current pathways, and detail important considerations in devising, implementing, and evaluating beta-lactam allergy pathways for hospitalized patients. We describe the key patient and institutional factors that must be considered in risk stratification, the central feature of pathway design. We detail shared obstacles to widespread beta-lactam allergy pathway implementation and identify potential solutions to address these challenges.

The Burden and Impact of Antibiotic Prescribing in Ambulatory Pediatrics

Antibiotics are one of the most commonly prescribed classes of medication for children and adolescents. While they are arguably the most powerful tool we possess against bacterial infections, they are frequently given to children whose illnesses are due to viruses or other non-infectious etiologies. When antibiotics are not used judiciously, the consequences can be serious and accumulate over time. This review article quantifies the burden of antimicrobial use in the pediatric outpatient setting in the United States, reviews recommended first line antibiotic regimens for common outpatient pediatric and adolescent conditions, investigates the reasons for inappropriate prescribing of antibiotics in outpatient healthcare settings, and explores the range of consequences of overuse and inappropriate use of antibiotics, from adverse drug reactions to impact on the microbiome to rising rates of antimicrobial resistance in common ambulatory conditions.

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.

Antibiotic Use After Removal of Penicillin Allergy Label

BACKGROUND

Penicillin allergy is commonly reported in the pediatric emergency department. We previously performed 3-tier penicillin allergy testing on children with low-risk symptoms, and 100% tolerated a penicillin challenge without an allergic reaction. We hypothesized that no serious allergic reactions would occur after re-exposure to penicillin and that prescription practices would change after testing.

METHODS

We performed a follow-up case series of 100 children whose test results were negative for penicillin allergy. Research staff administered a brief follow-up phone survey to the parent and primary care provider of each patient tested. We combined the survey data and summarized baseline patient characteristics and questionnaire responses. We then completed a 3-tier economic analysis from the prescription information gathered from surveys in which cost savings, cost avoidance, and potential cost savings were calculated.

RESULTS

A total of 46 prescriptions in 36 patients were reported by the primary care provider and/or parents within the year after patients were tested for penicillin allergy. Twenty-six (58%) of the prescriptions filled were penicillin derivatives. One (4%) child developed a rash 24 hours after starting the medication; no child developed a serious adverse reaction after being given a penicillin challenge. We found that the cost savings of delabeling patients as penicillin allergic was $1368.13, the cost avoidance was $1812.00, and the total potential cost savings for the pediatric emergency department population was $192 223.00.

CONCLUSIONS

Children with low-risk penicillin allergy symptoms whose test results were negative for penicillin allergy tolerated a penicillin challenge without a severe allergic reaction developing. Delabeling children changed prescription behavior and led to actual health care savings.

Allergy Testing in Children With Low-Risk Penicillin Allergy Symptoms

BACKGROUND

Penicillin allergy is commonly reported in the pediatric emergency department (ED). True penicillin allergy is rare, yet the diagnosis results from the denial of first-line antibiotics. We hypothesize that all children presenting to the pediatric ED with symptoms deemed to be low-risk for immunoglobulin E-mediated hypersensitivity will return negative results for true penicillin allergy.

METHODS

Parents of children aged 4 to 18 years old presenting to the pediatric ED with a history of parent-reported penicillin allergy completed an allergy questionnaire. A prespecified 100 children categorized as low-risk on the basis of reported symptoms completed penicillin allergy testing by using a standard 3-tier testing process. The percent of children with negative allergy testing results was calculated with a 95% confidence interval.

RESULTS

Five hundred ninety-seven parents completed the questionnaire describing their child's reported allergy symptoms. Three hundred two (51%) children had low-risk symptoms and were eligible for testing. Of those, 100 children were tested for penicillin allergy. The median (interquartile range) age at testing was 9 years (5-12). The median (interquartile range) age at allergy diagnosis was 1 year (9 months-3 years). Rash (97 [97%]) and itching (63 [63%]) were the most commonly reported allergy symptoms. Overall, 100 children (100%; 95% confidence interval 96.4%-100%) were found to have negative results for penicillin allergy and had their labeled penicillin allergy removed from their medical record.

CONCLUSIONS

All children categorized as low-risk by our penicillin allergy questionnaire were found to have negative results for true penicillin allergy. The utilization of this questionnaire in the pediatric ED may facilitate increased use of first-line penicillin antibiotics.