Factors associated with negative histamine control for penicillin allergy skin testing in the inpatient setting

Oral challenge vs routine care to assess low-risk penicillin allergy in critically ill hospital patients (ORACLE): a pilot safety and feasibility randomised controlled trial

PURPOSE

Critically ill patients are vulnerable to penicillin allergy labels that may be incorrect. The validity of skin testing in intensive care units (ICUs) is uncertain. Many penicillin allergy labels are low risk, and validated tools exist to identify those amenable to direct oral challenge. This pilot randomised controlled trial explored the feasibility, safety, and validity of direct enteral challenge for low-risk penicillin allergy labels in critical illness.

METHODS

Consenting patients with a low-risk penicillin allergy label (PAL) (PEN-FAST risk assessment score < 3) in four ICUs (Melbourne, Australia) were randomised 1:1 to penicillin (250 mg amoxicillin or implicated penicillin) direct enteral challenge versus routine care (2-h post-randomisation observation for each arm). Repeat challenge was performed post -ICU in the intervention arm. Patients were reviewed at 24 h and 5 days after each challenge/observation.

RESULTS

We screened 533 patients. 130 (24.4%) were eligible and 80/130 (61.5%) enrolled (age median 64.5 years (interquartile range, IQR 53.5, 74), PEN-FAST median 1 (IQR 0,1)), with 40 (50%) randomised to direct enteral challenge. A positive challenge rate of 2.5% was identified. No antibiotic-associated serious adverse events were identified. 32/40 (80%) received a repeat challenge (zero positive). Post-randomisation, 13 (32%) of the intervention arm and 4 (10%) of the control arm received penicillin (odds ratio, OR 4.33 [1.27, 14.78] p = 0.019).

CONCLUSION

These findings support the safety, validity, and feasibility of direct enteral challenge for critically ill patients with PEN-FAST assessed low-risk penicillin allergy. The absence of false negative results was confirmed by subsequent negative repeat challenges. A relatively low recruitment to screened ratio suggests that more inclusive eligibility criteria and integration of allergy assessment into routine ICU processes are needed to optimise allergy delabelling in critical illness.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Penicillin Allergy Delabeling: A Multidisciplinary Opportunity

The penicillin allergy label has been consistently linked with deleterious effects that span the health care spectrum, including suboptimal clinical outcomes, the emergence of bacterial resistance, and increased health care expenditures. These risks have recently motivated professional organizations and public health institutes to advocate for the implementation of penicillin allergy delabeling initiatives; however, the burden of delabeling millions of patients is too expansive for any one discipline to bear alone. This review presents the unique perspectives and roles of various stakeholder groups involved in penicillin allergy diagnosis, assessment, and delabeling; we emphasize opportunities, barriers, and promising areas of innovation. We summarize penicillin allergy methods and tools that have proven successful in delabeling efforts. A multidisciplinary approach to delabeling patients with reported penicillin allergy, bolstered by evidence-based clinical practices, is recommended to reduce the risks that associate with the penicillin allergy label.

H2-antagonist in IgE-mediated type I hypersensitivity reactions: what literature says so far?

Histamine is a monoamine synthesized from the amino acid histidine that is well-known for its role in IgE-mediated anaphylaxis but has shown pleiotropic effects on the immune system, especially in order to promote inflammatory responses. H₁-receptor antagonist are common drugs used in mild/moderate allergic reactions whereas H₂-receptor antagonist are commonly administered in gastric ulcer but showed some properties in allergy too. The EAACI guidelines for diagnosis and treatment of anaphylactic reactions recommend their use as third-line therapy in adjunct to H₁-antagonists. The purpose of this article is to produce a complete summary of findings and evidence known so far about the usefulness of H₂-receptor antagonist in allergic reactons.

The democratization of de-labeling: a review of direct oral challenge in adults with low-risk penicillin allergy

INTRODUCTION

Penicillin antibiotic allergy labels (AALs) are common and lead to significant negative health and health system outcomes. Direct oral challenge offers a rapid and cost-effective way of removing inaccurate AALs and improving outcomes.

AREAS COVERED

A narrative review (Medline, May 2020) of direct oral challenge in low-risk penicillin allergy in adults is described, and the evidence for the safety and efficacy of this approach in inpatients, outpatients, and special patient groups is presented.

EXPERT OPINION

Whilst the current literature demonstrates the safety and efficacy of direct oral challenge in de-labeling low-risk penicillin allergy in adults, novel approaches are needed to improve access to antibiotic allergy assessment and address the growing global need.

Antibiotic allergy labels in hospitalized and critically ill adults: A review of current impacts of inaccurate labelling

Antibiotic allergy labels (AALs) are reported by approximately 20% of hospitalized patients, yet over 85% will be negative on formal allergy testing. Hospitalized patients with an AAL have inferior patient outcomes, increased colonization with multidrug-resistant organisms and frequently receive inappropriate antimicrobials. Hospitalized populations have been well studied but, to date, the impact of AALs on patients with critical illness remains less well defined. We review the prevalence and impact of AALs on hospitalized patients, including those in in critical care.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

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

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

Management around invasive procedures in mastocytosis: An update

OBJECTIVE

Mastocytosis is a chronic hematologic disorder that is characterized by the accumulation of aberrant mast cells and typically involves the skin and/or bone marrow. Patients with mastocytosis are at increased risk of anaphylaxis. Based on theoretical assumptions, medical procedures requiring general anesthesia or radiocontrast media are deemed hazardous for patients with mastocytosis. The objective of this article is to provide a comprehensive overview of the actual risk of iatrogenic anaphylaxis and provide recommendations for daily practice.

DATA SOURCES

Various scientific search engines were used (eg, PubMed and Medline).

STUDY SELECTIONS

Because of the paucity of high-level studies on this topic, all available evidence was considered, including case reports.

RESULTS

Reliable data on the incidence of iatrogenic anaphylaxis in mastocytosis are lacking. However, although the incidence as reported in (retrospective) cohort studies is higher than in the general population, it is still lower than commonly anticipated, with an incidence of 5.4% in 1 study. Adequate premedication and avoidance of certain physical stimuli can further decrease this risk by 10-fold. The role of drugs as elicitors of anaphylaxis is perhaps overestimated, and physical stimuli are at least as important in inducing release of mast cell mediators.

CONCLUSION

This article provides practical recommendations for the management of invasive procedures in patients with mastocytosis based on current knowledge of this topic.

Feasibility, Benefits, and Limitations of a Penicillin Allergy Skin Testing Service

OBJECTIVE

To critically examine the feasibility, benefits, and limitations of an inpatient penicillin skin testing service and how pharmacists can be utilized.

DATA SOURCES

A PubMed search was performed from July 2016 through September 2016 using the following search terms: penicillin skin testing, penicillin allergy, β-lactam allergy. Additional references were identified from a review of literature citations.

STUDY SELECTION AND DATA EXTRACTION

All English-language studies assessing the use of penicillin skin testing as well as management and clinical outcomes of patients with a β-lactam allergy were evaluated.

DATA SYNTHESIS

The prevalence of people self-identifying as penicillin allergic ranges from 10% to 20% in the United States. Being improperly labeled as penicillin allergic is associated with higher health care costs, worse clinical outcomes, and an increased prevalence of multidrug-resistant infections. Penicillin skin testing can be a tool used to clarify penicillin allergies and has been demonstrated to be a successful addition to antimicrobial stewardship programs in multiple health care settings. Prior to implementing a penicillin skin testing service, institutions will need to perform a feasibility analysis of who will supply labor and accept the financial burden as well as identify if the positive benefits of a penicillin skin testing service overcome the limitations of this diagnostic test.

CONCLUSION

We conclude that institutions with high percentages of patients receiving non-β-lactams because of penicillin allergy labels would likely benefit the most from a penicillin skin testing service.

Implementation of an Infectious Disease Fellow-Managed Penicillin Allergy Skin Testing Service

An inpatient penicillin allergy skin testing program can be successfully managed by infectious diseases fellows under attending supervision offering a novel practice area for infectious diseases practitioners.

Background. A large percentage of patients presenting to acute care facilities report penicillin allergies that are associated with suboptimal antibiotic therapy. Penicillin skin testing (PST) can clarify allergy histories but is often limited by access to testing. We aimed to implement an infectious diseases (ID) fellow-managed PST program and to assess the need for PST via national survey.

Methods. We conducted a prospective observational study of the implementation of an ID fellow-managed penicillin allergy skin testing service. The primary outcome of the study was to assess the feasibility and acceptability of an ID fellow-managed PST service and its impact on the optimization of antibiotic selection. In addition, a survey of PST practices was sent out to all ID fellowship program directors in the United States.

Results. In the first 11 months of the program, 90 patients were assessed for PST and 76 patients were tested. Of the valid tests, 96% were negative, and 84% with a negative test had antibiotic changes; 63% received a narrower spectrum antibiotic, 80% received more effective therapy, and 61% received more cost-effective therapy. The majority of survey of respondents (n = 50) indicated that overreporting of penicillin allergy is a problem in their practice that affects antibiotic selection but listed inadequate personnel and time as the main barriers to PST.

Conclusions. Inpatient PST can be successfully managed by ID fellows, thereby promoting optimal antibiotic use in patients reporting penicillin allergies. This model can increase access to PST at institutions without adequate access to allergists while also providing an important educational experience to ID trainees.