Persistent, refractory, and biphasic anaphylaxis: A multidisciplinary Delphi study

Management of Refractory Anaphylaxis: An Overview of Current Guidelines

In this review, we compare different refractory anaphylaxis (RA) management guidelines focusing on cardiovascular involvement and best practice recommendations, discuss postulated pathogenic mechanisms underlining RA and highlight knowledge gaps and research priorities. There is a paucity of data supporting existing management guidelines. Therapeutic recommendations include the need for the timely administration of appropriate doses of aggressive fluid resuscitation and intravenous (IV) adrenaline in RA. The preferred second-line vasopressor (noradrenaline, vasopressin, metaraminol and dopamine) is unknown. Most guidelines recommend IV glucagon for patients on beta-blockers, despite a lack of evidence. The use of methylene blue or extracorporeal life support (ECLS) is also suggested as rescue therapy. Despite recent advances in understanding the pathogenesis of anaphylaxis, the factors that lead to a lack of response to the initial adrenaline and thus RA are unclear. Genetic factors, such as deficiency in platelet activating factor-acetyl hydrolase or hereditary alpha-tryptasaemia, mastocytosis may modulate reaction severity or response to treatment. Further research into the underlying pathophysiology of RA may help define potential new therapeutic approaches and reduce the morbidity and mortality of anaphylaxis.

A systematic review and expert Delphi Consensus recommendation on the use of vaccines in patients receiving dupilumab: A position paper of the American College of Allergy, Asthma and Immunology

BACKGROUND

Dupilumab is a monoclonal antibody that targets the interleukin (IL)-4 receptor alpha subunit, thus blocking the effects of IL-4 and IL-13, and has shown efficacy in treating various conditions including asthma, atopic dermatitis, eosinophilic esophagitis, and others. Because of its immune modulatory effects, clinical trials that studied dupilumab did not allow patients to receive live vaccines during the clinical trials because of an abundance of caution, and thus package inserts recommend that patients who are being treated with dupilumab should avoid live vaccines. Because dupilumab is now approved for use in patients from 6 months of age for the treatment of atopic dermatitis, this reported contraindication is now posing a clinical dilemma for patients and clinicians.

OBJECTIVE

To perform a systematic review of literature on the safety and efficacy of vaccinations in patients who are receiving dupilumab and to provide expert guidance on the use of vaccines in patients who are receiving dupilumab.

METHODS

A systematic review of the literature was performed, and an expert Delphi Panel was assembled.

RESULTS

The available literature on patients who received vaccinations while using dupilumab overall suggests that live vaccines are safe and that the vaccine efficacy, in general, is not affected by dupilumab. The expert Delphi panel agreed that the use of vaccines in patients receiving dupilumab was likely safe and effective.

CONCLUSION

Vaccines (including live vaccines) can be administered to patients receiving dupilumab in a shared decision-making capacity.

Anaphylaxis: A 2023 practice parameter update

This practice parameter update focuses on 7 areas in which there are new evidence and new recommendations. Diagnostic criteria for anaphylaxis have been revised, and patterns of anaphylaxis are defined. Measurement of serum tryptase is important for diagnosis of anaphylaxis and to identify underlying mast cell disorders. In infants and toddlers, age-specific symptoms may differ from older children and adults, patient age is not correlated with reaction severity, and anaphylaxis is unlikely to be the initial reaction to an allergen on first exposure. Different community settings for anaphylaxis require specific measures for prevention and treatment of anaphylaxis. Optimal prescribing and use of epinephrine autoinjector devices require specific counseling and training of patients and caregivers, including when and how to administer the epinephrine autoinjector and whether and when to call 911. If epinephrine is used promptly, immediate activation of emergency medical services may not be required if the patient experiences a prompt, complete, and durable response. For most medical indications, the risk of stopping or changing beta-blocker or angiotensin-converting enzyme inhibitor medication may exceed the risk of more severe anaphylaxis if the medication is continued, especially in patients with insect sting anaphylaxis. Evaluation for mastocytosis, including a bone marrow biopsy, should be considered for adult patients with severe insect sting anaphylaxis or recurrent idiopathic anaphylaxis. After perioperative anaphylaxis, repeat anesthesia may proceed in the context of shared decision-making and based on the history and results of diagnostic evaluation with skin tests or in vitro tests when available, and supervised challenge when necessary.

A Puzzling Mast Cell Trilogy: Anaphylaxis, MCAS, and Mastocytosis

Our knowledge of biology and mast cell (MC) function, as well as disorders associated with the pathologic activation of MCs, has evolved over the last few decades. Anaphylaxis, mast cell activation syndrome (MCAS), and mastocytosis are interrelated yet distinct conditions within the spectrum of mast cell activation disorders. Nevertheless, all three conditions can co-exist in one and the same patient, as pathologic MC activation is the key finding in all three. When mediator release is excessive and involves multiple systems, anaphylaxis and MCAS may occur. Furthermore, mastocytosis is a clonal disorder of MCs and often presents with anaphylaxis and MCAS. Nevertheless, in some cases, even the proliferative and accumulative features of MCs in mastocytosis can account for symptoms and disease progression. In each case, diagnosis can be only made when the diagnostic consensus criteria are fulfilled. The current article aims to provide a concise clinical update and pinpoint the main difficulties in diagnosing these puzzling disorders of MCs in medical practice.

Avoidable Care Transitions: A Consensus-Based Definition Using a Delphi Technique

Background and Objectives

Older adults are at increased risk of frequent transitions between care settings, even though some care transitions are avoidable. The term "avoidable care transitions" is not clearly defined in the research literature. This study aimed to find a consensus-based definition for "avoidable care transitions."

Research Design and Methods

This study was conducted as part of the TRANS-SENIOR research network. A 4-round Delphi survey was based on a literature review that identified existing definitions of "avoidable care transitions." Articles in MEDLINE via PubMed and CINAHL were searched. In total 95 references were included, and 106 definitions were identified. Definitions were coded to find themes, resulting in 3 themes with 2 codes for each.

Results

In total, 99 experts from 9 countries were invited, and the response rates in Delphi Rounds 1, 2, 3, and 4 were 37.5%, 19.1%, 33.3%, and 23.3%, respectively. Upon reaching the predefined minimum of 90% agreement, the following definition was declared as final: "Avoidable care transitions (a) are without significant patient-relevant benefits or with a risk of harm outweighing patient-relevant benefits and/or (b) are when a comparable health outcome could be achieved in lower resource settings using the resources available in that place/health care system, and/or (c) violate a patient's/informal caregiver's preference or an agreed care plan."

Discussion and Implications

Consensus on a definition for "avoidable care transitions" was reached by a multidisciplinary and international panel of experts comprising researchers and providers. The resulting definition consists of 3 distinct dimensions relating to the balance of benefit and harm to a patient, resource consumption, and a patient's or informal caregiver's preferences. The new definition might enhance the common understanding of avoidable care transitions and is now ready for application in research and quality and safety management in health care.

Severe Anaphylactic Reactions to Home Doses of Oral Immunotherapy for Food Allergy

BACKGROUND

Severe anaphylactic reactions to home doses may occur during food allergy oral immunotherapy (OIT).

OBJECTIVE

To study the rate and risk factors for such reactions.

METHODS

We studied all patients aged greater than 3.5 years who completed OIT in a single center between April 2010 and January 2020. All home epinephrine-treated reactions (HETRs) were identified. High-grade HETRs (HG-HETRs) were defined as HETRs involving respiratory (SpO2 of 94% or less), cardiovascular (low blood pressure), or central nervous system impairment (loss of consciousness). We investigated the rate and risk factors for HG-HETRs.

RESULTS

A total of 1,637 OIT treatments were studied: milk (880), peanut (346), tree nuts (221), sesame (115), and egg (75). Of 390 identified HETRs, 30 HG-HETRs occurred during 27 treatments (1.65% of all treatments). Nearly all (26 of 30) were during milk OIT in patients with house dust mite (HDM) sensitization and asthma (26 of 30 each). Of the 30 patients with HG-HETRs, 21 recovered with one or two epinephrine treatments, but nine (0.55% of all treatments) did not respond to a second dose of epinephrine and were deemed to have refractory anaphylaxis. Three patients required intensive care unit admission and three received epinephrine drip, but none required ventilatory support. Risk factors for HG-HETRs included milk OIT (P = .031), asthma (P = .02) and HDM sensitization (P = .02). No specific triggers for HG-HETR were identified. Of patients with HG-HETRs, 25.9% were fully desensitized, including the four non-milk treated patients; 22.2% were partially desensitized; and 51.9% failed.

CONCLUSIONS

High-grade HETRs are uncommon, particularly refractory anaphylactic reactions to home OIT doses. Although milk OIT, asthma, and HDM sensitization are the main risk factors for such reactions, identification of patients who are at risk is challenging.

Contextual community epinephrine prescribing: Is more always better?

OBJECTIVE

Prompt administration of epinephrine is first-line management of anaphylaxis. Although severe anaphylaxis may require more than 1 epinephrine dose, multiple epinephrine device packs may not be necessary for all patients at risk for allergic reactions.

DATA SOURCES

A narrative review was used to describe key considerations to contextualize community epinephrine prescribing.

RESULTS

Anaphylaxis has a lifetime prevalence of 1.6% to 5.1%. Meeting diagnostic criteria for anaphylaxis is not required for epinephrine treatment of a severe allergic reaction. A "1-2-3" approach to anaphylaxis treatment is important to clearly relay central management steps: promptly administer a first dose of intramuscular epinephrine with proper positioning, and activate emergency medical services if immediate symptom resolution does not occur; consider a second dose of intramuscular epinephrine with consideration of oxygen administration and intravenous fluid if initial epinephrine response is not adequate; and consider a third intramuscular epinephrine dose together with consideration of intravenous fluid support and oxygen for continued lack of appropriate response. Although multiple epinephrine doses may be required to treat severe anaphylaxis, 90% of anaphylaxis cases do not require more than 1 epinephrine dose. A universal requirement for multiple epinephrine devices in patients without a history of anaphylaxis is not cost-effective. Patients without a history of anaphylaxis may be managed without multiple device prescriptions within a patient-preference sensitive paradigm of care.

CONCLUSION

Anaphylaxis prevention involves appropriate education to avoid allergen triggers, recognize symptoms of an allergic reaction, rapidly access and administer intramuscular epinephrine, and appropriately activate emergency medical services when needed. For patients with previous anaphylaxis, particularly those who have required more than 1 dose of epinephrine to treat an allergic reaction, possessing multiple epinephrine devices is an important part of managing community anaphylaxis risk.

Anaphylaxis:: After the Emergency Department

After treating the acute anaphylactic reaction, the clinician's next task is to prevent a recurrence. The patient should be observed in the ED. How long this observation period should last depends on their clinical course, risk factors, and social support. All patients should be discharged with a prescription for 2 epinephrine autoinjectors and counseled on appropriate use. The patient should also receive education on the signs and symptoms of anaphylaxis and avoiding triggers. The patient should follow-up with an allergy specialist who can confirm triggers and provide immunotherapy as indicated.

Overview of Allergy and Anaphylaxis

Allergic reactions and anaphylaxis occur on a severity continuum from mild and self-limited to potentially life-threatening or fatal reactions. Anaphylaxis is typically a multiorgan phenomenon involving a broad range of effector cells and mediators. Emergency department visits for anaphylaxis are increasing, especially among children. There is a broad differential diagnosis for anaphylaxis, and the diagnosis of anaphylaxis can be aided by the use of the National Institutes of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network clinical diagnostic criteria. Risk factors for severe anaphylaxis include older age, delayed epinephrine administration, and cardiopulmonary comorbidities.

Refractory Anaphylaxis: A New Entity for Severe Anaphylaxis

Anaphylaxis reactions lie on a spectrum of severity, ranging from relatively mild lower respiratory involvement (depending on the definition of anaphylaxis used) to more severe reactions that are refractory to initial treatment with epinephrine and may rarely cause death. A variety of grading scales exist to characterize severe reactions, but there is a lack of consensus about the optimal approach to define severity. More recently, a new entity called refractory anaphylaxis (RA) has emerged in the literature, characterized by the persistence of anaphylaxis despite initial epinephrine treatment. However, slightly different definitions have been proposed to date. In this Rostrum, we review these definitions as well as data relating to epidemiology, elicitors, risk factors, and management of RA. We propose a need to align the different definitions for RA, to improve epidemiological surveillance, advance our understanding of the pathophysiology of RA, and optimize management strategies to reduce morbidity and mortality.

Consensus-based recommendations on physical activity and exercise in patients with diabetes at risk of foot ulcerations: a Delphi study

BACKGROUND

Patients with diabetes mellitus are exposed to important complications. Currently little evidence exist on the guidelines that these patients, at some risk of foot ulceration, should follow for physical exercise.

OBJECTIVES

To reach a consensus among multidisciplinary and international experts on physical activity/exercise recommendations for patients with diabetes, according to foot ulcer risk.

METHODS

Using a three-round Delphi method, a panel composed of 28 multidisciplinary experts in the management of diabetic foot assessed 109 recommendations on physical activity/exercise for patients with diabetes mellitus, according to their risk of foot ulcer. Consensus was assumed when 80% of responses matched the same category (agreement/disagreement).

RESULTS

Twenty-nine experts participated in the first and second rounds of consultation, and twenty-eight did so in the third, reaching final agreement on 86 of the 109 recommendations considered (78.9%). The study, thus, generated a consensus set of recommendations concerning different aspects of diabetic footcare before, during, and after exercise (e.g. when to examine the foot, how to assess it, what type of sock and insole to use, what types of exercise to perform, and when it is advisable to return to activity after an ulceration).

CONCLUSION

This Delphi study generated recommendations based on the consensus of international experts on physical activity and exercise by patient with diabetes at risk of ulceration. Recommendations considered the state of the foot and the patient's history and status before physical activity and included information on intensity, duration, frequency, and progressions of physical activity/exercise, and the use of custom-made plantar orthoses, shoe prescription, and the convenience of returning to physical activity after an ulceration.

Development of a paediatric airway management checklist for the emergency department: a modified Delphi approach

BACKGROUND

Airway management checklists have improved paediatric patient safety in some clinical settings, but consensus on the appropriate components to include on a checklist for paediatric tracheal intubation in the ED is lacking.

METHODS

A multidisciplinary panel of 14 experts in airway management within and outside of paediatric emergency medicine participated in a modified Delphi approach to develop consensus on the appropriate components for a paediatric airway management checklist for the ED. Panel members reviewed, modified and added to the components from the National Emergency Airway Registry for Children airway safety checklist for paediatric intensive care units using a 9-point appropriateness scale. Components with a median score of 7.0-9.0 and a 25th percentile score ≥7.0 achieved consensus for inclusion. A priori, the modified Delphi method was limited to a maximum of two rounds for consensus on essential components and one additional round for checklist creation.

RESULTS

All experts participated in both rounds. Consensus was achieved on 22 components. Twelve were original candidate items and 10 were newly suggested or modified items. Consensus components included the following categories: patient assessment and plan (5 items), patient preparation (5 items), pharmacy (2 items), equipment (7 items) and personnel (3 items). The components were formatted into a 17-item clinically usable checklist.

CONCLUSIONS

Using the modified Delphi method, consensus was established among airway management experts around essential components for an airway management checklist intended for paediatric tracheal intubation in the ED.

Trends and Variation in Pediatric Anaphylaxis Care From 2016 to 2022

BACKGROUND

Variation in the use of treatments and hospitalization for anaphylaxis would suggest a lack of consensus in therapeutic approach.

OBJECTIVE

To evaluate trends and practice variation in the emergency department (ED) care of children with anaphylaxis in a large US cohort.

METHODS

We conducted a 48-site retrospective cohort study using the Pediatric Health Information System from January 2016 through September 2022. Children younger than 18 years with a primary diagnosis of anaphylaxis were included. Care trends were assessed using negative binomial regression modeling. Rates of medication use, hospitalizations, and revisits were reported as medians with interquartile ranges (IQRs).

RESULTS

There were 42,909 ED visits for anaphylaxis, with a 4.2% per-year increase in visit incidence (95% CI, 1.8-6.7) during the study period. The median hospitalization rate was 3.5% (IQR, 2.2-6.0), and the 3-day ED revisit rate was 0.6% (IQR, 0.4-0.9). The hospital-level median use of therapies included intramuscular epinephrine (55.3%; IQR, 50.1-59.9), systemic steroids (73.8%; IQR, 63.9-81.4), antihistamines (59.9%; IQR, 53.5-65.5), H2-receptor antagonists (56.8%; IQR, 42.3-66.2), bronchodilators (15.1%; IQR, 12.5-17.0), inhaled epinephrine (1.1%; IQR, 0.6-1.9), and fluid boluses (19.8%; IQR, 11.3-29.3). Severe reactions requiring intensive care unit admission (1.5%; IQR, 0.8-2.2), vasopressors (0.3%; IQR, 0.0-0.6), and intubation (0.2%; IQR, 0.0-0.3) were rare.

CONCLUSIONS

ED visits for anaphylaxis increased during the study period, but hospitalization rates were low. Substantial variation exists between EDs regarding the use of anaphylaxis therapies, supporting the need for future research to evaluate the efficacy of these medications.

Who Needs Epinephrine? Anaphylaxis, Autoinjectors, and Parachutes

International guidelines stipulate that intramuscular (IM) epinephrine (adrenaline) is the first-line treatment for anaphylaxis, with an established good safety profile. The availability of epinephrine autoinjectors (EAI) has greatly facilitated the lay administration of IM epinephrine in community settings. However, key areas of uncertainty remain around epinephrine usage. These include variations in prescribing EAI, what symptoms should prompt epinephrine administration, whether emergency medical services (EMS) need to be contacted after administration, and whether epinephrine administered via EAI reduces mortality from anaphylaxis or improves quality of life measures. We provide a balanced commentary on these issues. There is increasing recognition that a poor response to epinephrine, particularly after 2 doses, is a useful marker of severity and the need for urgent escalation. It is likely that patients who respond to a single epinephrine dose do not require EMS activation or emergency department transfer, but data are needed to demonstrate the safety of this approach. Lastly, patients at risk of anaphylaxis must be counseled against over-reliance on EAI alone.

Anaphylaxis: Advances in the Past 10 Years

In the past 10 years, anaphylaxis has grown into its own special area of study within Allergy-Immunology, both at the bench and at the bedside. This review focuses on some of the most clinically relevant advances over the past decade. These include simplified and more inclusive diagnostic criteria for adults and children, uniform definition of biphasic anaphylaxis, and improved systems for objective severity grading. Studies reported in the past decade have led to improved understanding of normal and abnormal regulation of mast cell function, translating into better diagnostic and therapeutic approaches to patients with anaphylaxis. Research has provided improved recognition and treatment of mast cell disorders and has identified a new condition, hereditary α-tryptasemia, that may impact anaphylactic syndromes. We have learned to recognize new causes (α-gal), new pathways (Mas-related G protein-coupled receptor-X2), and many risk factors for severe anaphylaxis. The stability of epinephrine in autoinjectors was reported to be very good for several years after the labeled expiry date, and it can tolerate freezing and thawing. Repeated and prolonged exposure to excessive heat leads to degradation of epinephrine activity. New treatments to prevent severe anaphylaxis have been described, using new ways to block the IgE receptor or modulate intracellular signaling pathways.

Canadian Anaphylaxis Network-Predicting Recurrence after Emergency Presentation for Allergic REaction (CAN-PREPARE): a prospective, cohort study protocol

INTRODUCTION

Anaphylaxis is a severe, potentially fatal multiorgan system manifestation of an allergic reaction. The highest incidence of anaphylaxis is in children and adolescents. Biphasic anaphylaxis (BA) is defined as the recurrence of allergic symptoms after resolution of an initial reaction. It has been reported to occur in 10%-20% of cases within 1-48 hours from the onset of the initial reaction. The dilemma for physicians is determining which patients with resolved anaphylaxis should be observed for BA and for how long. Guidelines for duration of postanaphylaxis monitoring vary, are based on limited evidence and can have unintended negative impacts on patient safety, quality of life and healthcare resources. The objectives of this study are to derive a prognostic model for BA and to develop a risk-scoring system that informs disposition decisions of children who present to emergency departments (ED) with anaphylaxis.

METHODS AND ANALYSIS

This prospective multicentre cohort study will enrol 1682 patients from seven paediatric EDs that are members of the Paediatric Emergency Research Canada network. We will enrol patients younger than 18 years of age with an allergic reaction meeting anaphylaxis diagnostic criteria. Trained ED research assistants will screen, obtain consent and prospectively collect study data. Research assistants will follow patients during their ED visit and ascertain, in conjunction with the medical team, if the patient develops BA. A standardised follow-up survey conducted following study enrolment will determine if a biphasic reaction occurred after ED disposition. Model development will conform to the broad principles of the PROGRESS (Prognosis Research Strategy) framework and reporting will follow the Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis Statement.

ETHICS AND DISSEMINATION

Ethics approval has been received from all participating centres. Our dissemination plan focuses on informing clinicians, policy makers and parents of the results through publication in peer-reviewed journals and broadcasting on multiple media platforms.

TRIAL REGISTRATION NUMBER

NCT05135377.

Acute At-Home Management of Anaphylaxis: 911: What Is the Emergency?

The appropriate at-home management of anaphylaxis begins with patient education on recognition and treatment, especially when and how to use epinephrine. Delayed administration of epinephrine as well as having severe symptoms and needing multiple doses of epinephrine to treat symptoms are risk factors for biphasic anaphylaxis. The successful implementation of at-home management of anaphylaxis requires appropriate patient selection and an algorithmic approach that recommends activation of emergency medical services (EMS) when the patient does not adequately respond to at-home administration of epinephrine or there are extenuating patient-related circumstances. Fortunately, approximately 98% of anaphylactic episodes respond to 2 or fewer doses of epinephrine, the standard prescription used for epinephrine autoinjectors; fatal anaphylaxis is very rare, as low as 0.002 deaths/million person-years; and biphasic reactions are uncommon (∼5%), and only extremely rarely lethal. Thus, most common concerns leading to recommended EMS activation and emergency department visits after epinephrine administration are generally unsubstantiated. Furthermore, emergency department visits do not always lead to better treatment and drive health care costs higher. Open communications with patients and families regarding risks and benefits of at-home management and observation versus EMS activation and emergency department evaluation after epinephrine administration for anaphylaxis are essential. However, we believe the data indicate that it is time to reconsider the often used and taught approach that recommends EMS activation whenever epinephrine is used.

Anaphylaxis After Consumption of Guar Gum-Containing Food: A Report of Two Cases

Guar gum is a food additive that acts as a thickening agent. Although the relationship between guar gum and occupational rhinitis/asthma has already been established, only very few cases of anaphylaxis were associated with guar gum ingestion. We present two examples of anaphylaxis induced by guar gum. Both cases were successfully treated with adrenaline. Moreover, serum-specific immunoglobulin E (IgE) with the culprit agent was detected in blood samples. To the best of our knowledge, here we present the first case of class 6 guar gum-specific IgE-positive anaphylaxis. This report aims to raise awareness of rare food additive allergies such as guar gum.

Emergency department opioid discharge instructions: a multidisciplinary national Delphi study

OBJECTIVES

Currently, there are no Canadian guidelines for discharge instruction to be given to patients receiving an opioid prescription in the ED. This likely contributes to inadequate discharge instructions for these potentially dangerous medications. The principal goal of this study was to develop an interdisciplinary Canadian consensus regarding important concepts to be included in written opioid discharge instructions within the ED setting.

METHODS

We conducted a modified Delphi study between May and August 2021. The national multidisciplinary panel consisted of 23 healthcare professionals and one patient partner. The survey consisted of 19 initial concepts developed after a review of the literature and a meeting with local experts. The panel added four new concepts after the first survey round. Three rounds of online surveys were distributed in total. Panel consensus was defined a priori as a disagreement index score less than 1, in accordance with the RAND/UCLA Appropriateness Method.

RESULTS

We achieved a 100% response rate in round one and a 96% response rate in rounds two and three of our Delphi study. There was group consensus (disagreement index = 0.66, median importance = 9) that all patients receiving opioid prescriptions from the ED should receive written discharge instructions. The interdisciplinary panel arrived at a consensus on 21/23 concepts for ED opioid discharge instructions. The concepts with the highest level of agreement were related to minimizing the use of the prescribed opioid medication and opioid use safety (mixing with drugs/alcohol, storage, and impairment).

CONCLUSION

This Delphi study with a national, multidisciplinary panel achieved consensus on 21 concepts that should be included in written discharge instructions to patients receiving an opioid prescription upon discharge from the ED.

Peri‐operative refractory anaphylactic shock during hepatic hydatid cyst surgery

Serious intra-operative anaphylactic shock is an unusual complication. Identification of causative agents can be difficult due to the number of anaesthetic drugs administered in quick succession, many of which can potentially cause anaphylaxis. Most anaphylactic reactions respond to, and resolve with, adrenaline and steroids. However, they can be prolonged and life-threatening. Refractory anaphylaxis, unresponsive to repeated doses of adrenaline, is rare and associated with a high risk of mortality. Rupture of a hydatid cyst during surgery can cause anaphylaxis. Here, we present a rare case of refractory anaphylactic shock during surgical resection of a hepatic hydatid cyst, with severe haemodynamic instability requiring prolonged postoperative ventilation and triple inotropic support for seven days in the intensive care unit. We describe the management of this condition, primarily based on steroid therapy and escalating vasopressor support, particularly where limited response to adrenaline is encountered. Refractory anaphylaxis is a rare but life-threatening complication of hydatid cyst surgery. Therefore, anaphylactic reactions should always be anticipated, with the appropriate treatment and facilities readily available.

Anaphylaxis knowledge gaps and future research priorities: A consensus report

BACKGROUND

Despite a better understanding of the epidemiology, pathogenesis, and management of patients with anaphylaxis, there remain knowledge gaps. Enumerating and prioritizing these gaps would allow limited scientific resources to be directed more effectively.

OBJECTIVE

We sought to systematically describe and appraise anaphylaxis knowledge gaps and future research priorities based on their potential impact and feasibility.

METHODS

We convened a 25-member multidisciplinary panel of anaphylaxis experts. Panelists formulated knowledge gaps/research priority statements in an anonymous electronic survey. Four anaphylaxis themed writing groups were formed to refine statements: (1) Population Science, (2) Basic and Translational Sciences, (3) Emergency Department Care/Acute Management, and (4) Long-Term Management Strategies and Prevention. Revised statements were incorporated into an anonymous electronic survey, and panelists were asked to rate the impact and feasibility of addressing statements on a continuous 0 to 100 scale.

RESULTS

The panel generated 98 statements across the 4 anaphylaxis themes: Population Science (29), Basic and Translational Sciences (27), Emergency Department Care/Acute Management (24), and Long-Term Management Strategies and Prevention (18). Median scores for impact and feasibility ranged from 50.0 to 95.0 and from 40.0 to 90.0, respectively. Key statements based on median rating for impact/feasibility included the need to refine anaphylaxis diagnostic criteria, identify reliable diagnostic, predictive, and prognostic anaphylaxis bioassays, develop clinical prediction models to standardize postanaphylaxis observation periods and hospitalization criteria, and determine immunotherapy best practices.

CONCLUSIONS

We identified and systematically appraised anaphylaxis knowledge gaps and future research priorities. This study reinforces the need to harmonize scientific pursuits to optimize the outcomes of patients with and at risk of anaphylaxis.

Wilderness Medical Society Clinical Practice Guidelines on Anaphylaxis

The Wilderness Medical Society convened a panel to review the literature and develop evidence-based clinical practice guidelines on the treatment of anaphylaxis, with an emphasis on a field-based perspective. The review also included literature regarding the definition, epidemiology, clinical manifestations, and prevention of anaphylaxis. The increasing prevalence of food allergies in the United States raises concern for a corresponding rise in the incidence of anaphylaxis. Intramuscular epinephrine is the primary treatment for anaphylaxis and should be administered before adjunctive treatments such as antihistamines, corticosteroids, and inhaled β agonists. For outdoor schools and organizations, selecting a method to administer epinephrine in the field is based on considerations of cost, safety, and first responder training, as well as federal guidelines and state-specific laws.

Management of Anaphylaxis

The key to managing anaphylaxis is early epinephrine administration. This can improve outcomes and prevent progression to severe and fatal anaphylaxis. Delayed or lack of administration of epinephrine is associated with fatal reactions. Positioning in a recumbent supine position, airway management, and intravenous fluids are essential in its management. Antihistamines and glucocorticosteroids should not be prescribed in place of epinephrine. β-adrenergic agonists by inhalation are indicated for bronchospasm associated with anaphylaxis despite optimal epinephrine treatment. Long-term management of anaphylaxis includes the identification and avoidance of triggers; identification of cofactors, such as mast cell disorders; patient, parent, and caregiver education, and interventions to reduce allergen sensitivity, such as the use of venom immunotherapy for Hymenoptera hypersensitivity. Long-term management is covered in other articles. Consultation with an allergist/immunologist is recommended when necessary.

Anaphylaxis: Epidemiology and Differential Diagnosis

Anaphylaxis-related emergency department (ED) visits and hospitalizations are increasing. Triggers for anaphylaxis include food, medications, and stinging insects. Idiopathic anaphylaxis accounts for 30% to 60% of cases of anaphylaxis in adults and up to 10% of cases in children with novel allergens such as galactose-α-1,3 galactose reclassifying these cases. Recent practice guidelines have recommended against the routine use of systemic corticosteroids and antihistamines for the prevention of biphasic reactions and recommend an extended observation, up to 6 hours, for those with risk factors for biphasic anaphylaxis and those with lack of access to epinephrine and to emergency medical services.

Anaphylaxis: Definition, Epidemiology, Diagnostic Challenges, Grading System

There are many definitions of anaphylaxis in the medical literature. The authors propose a modified definition of anaphylaxis to be used for clinical decision making that promotes the early utilization of intramuscular epinephrine. Anaphylaxis can be a result of an allergic or nonallergic mechanism. In general, allergic reactions are more severe; however, any type of anaphylaxis can result in death and improve with IM epinephrine. The World Allergy Organization's Grading Criteria for allergic systemic reactions are adapted as a guide to identify manifestations that may progress to anaphylaxis. The intent is to promote and encourage the use of IM epinephrine in the health care setting before the progression of manifestations and the onset of life-threatening respiratory or cardiovascular dysfunction generally recognized as meeting the definition of anaphylaxis.

Anaphylaxis: Data Gaps and Research Needs

There are significant anaphylaxis data and knowledge gaps that result in suboptimal patient care and outcomes. To address these gaps there is need for collaborative, multidisciplinary research networks to strategically design practice changing research specific to the following anaphylaxis themes: Population Science, Basic and Translational Sciences, Acute Management, and Long-Term Management. Top priorities are to refine anaphylaxis diagnostic criteria, identify accurate diagnostic and predictive anaphylaxis biomarkers, standardize postanaphylaxis care (observation periods, hospitalization criteria), and determine immunotherapy best practices. Addressing these gaps will result in improved, optimal care and clinical outcomes for patients with or at risk of anaphylaxis.

Overview of Allergy and Anaphylaxis

Allergic reactions and anaphylaxis occur on a severity continuum from mild and self-limited to potentially life-threatening or fatal reactions. Anaphylaxis is typically a multiorgan phenomenon involving a broad range of effector cells and mediators. Emergency department visits for anaphylaxis are increasing, especially among children. There is a broad differential diagnosis for anaphylaxis, and the diagnosis of anaphylaxis can be aided by the use of the National Institutes of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network clinical diagnostic criteria. Risk factors for severe anaphylaxis include older age, delayed epinephrine administration, and cardiopulmonary comorbidities.

Anaphylaxis:: After the Emergency Department

After treating the acute anaphylactic reaction, the clinician's next task is to prevent a recurrence. The patient should be observed in the ED. How long this observation period should last depends on their clinical course, risk factors, and social support. All patients should be discharged with a prescription for 2 epinephrine autoinjectors and counseled on appropriate use. The patient should also receive education on the signs and symptoms of anaphylaxis and avoiding triggers. The patient should follow-up with an allergy specialist who can confirm triggers and provide immunotherapy as indicated.

A Delphi Study Protocol to Identify Recommendations on Physical Activity and Exercise in Patients with Diabetes and Risk of Foot Ulcerations

Patients with diabetes mellitus are exposed to important complications, such as diabetic neuropathy or peripheral vascular disease. The evidence on the guidelines that these patients, with a certain risk of suffering foot ulcerations, should follow before, during and after physical exercise is scarce. The objective of this study is to identify the physical exercise guidelines to recommend based on the risk of the foot of the patient with diabetes through a consensus of experts. A three-round Delphi study will be conducted. A scientific committee (multidisciplinary group of four national experts) will review the proposal of experts and the Delphi questionnaire before submitting. A group of experts in the management and approach of the diabetic foot of an international and multidisciplinary nature will form the panel of experts, who must express their degree of (dis)agreement with each of the statements contained in the Delphi questionnaire. The percentage will be calculated in response categories, and a cut-off point of 80% will be set to define the consensus of (dis)agreement of the panelists. The results of the study could provide a series of recommendations on the realization of physical exercise in diabetic patients at risk of suffering foot ulcerations.

State-of-the-Art on Biomarkers for Anaphylaxis in Obstetrics

Anaphylaxis is an unpredictable systemic hypersensitivity reaction and constitutes a high risk of maternal and fetal morbidity and mortality when occurring during pregnancy. Currently, the acute management of anaphylaxis is based on clinical parameters. A total serum tryptase is only used to support an accurate diagnosis. There is a need to detect other biomarkers to further assess high-risk patients in obstetrics. Our objective is to present biomarkers in this complex interdisciplinary approach beyond obstetrician and anaesthetic management. Candidate biomarkers derive either from mediators involved in immunopathogenesis or upcoming molecules from systems biology and proteomics. Serum tryptase is determined by singleplex immunoassay method and is important in the evaluation of anaphylactic mast cell degranulation but also in the assessment of other risk factors for anaphylaxis such as systemic mastocytosis. Another category of biomarkers investigates the IgE-mediated sensitization to triggers potentially involved in the etiology of anaphylaxis in pregnant women, using singleplex or multiplex immunoassays. These in vitro tests with natural extracts from foods, venoms, latex or drugs, as well as with molecular allergen components, are useful because in vivo allergy tests cannot be performed on pregnant women in such a major medical emergency due to their additional potential risk of anaphylaxis.

Emergency medicine updates: Anaphylaxis

INTRODUCTION

Anaphylaxis is a potentially deadly condition that requires emergent therapy. While frequently treated in the emergency department (ED), recent evidence updates may improve the diagnosis and management of this condition.

OBJECTIVE

This paper evaluates key evidence-based updates concerning the diagnosis and management of anaphylaxis for the emergency clinician.

DISCUSSION

The presentation of anaphylaxis can vary. Current diagnostic criteria can be helpful when evaluating patients for anaphylaxis, though multiple criteria exist. While the most common causes of anaphylaxis include medications, insect venom, and foods, recent literature has identified an IgE antibody response to mammalian galactose alpha-1,3-galactose, known as alpha-gal anaphylaxis. Epinephrine is the first-line therapy and is given in doses of 0.01 mg/kg (up to 0.5 mg in adults) intramuscularly (IM) in the anterolateral thigh. Intravenous (IV) epinephrine administration is recommended in patients refractory to IM epinephrine and IV fluids, or those with cardiovascular collapse. Antihistamines and glucocorticoids should not delay administration of epinephrine and do not demonstrate a significant reduction in risk of biphasic reactions. Biphasic reactions may affect 1-7% of patients with anaphylaxis. Risk factors for biphasic reaction include severe initial presentation and repeated doses of epinephrine. Disposition of patients with anaphylaxis requires consideration of several factors.

CONCLUSIONS

Emergency clinicians must be aware of current updates in the evaluation and management of this disease.

Severity grading system for acute allergic reactions: A multidisciplinary Delphi study

BACKGROUND

There is no widely adopted severity grading system for acute allergic reactions, including anaphylactic and nonanaphylactic reactions, thus limiting the ability to optimize and standardize management practices and advance research.

OBJECTIVE

The aim of this study was to develop a severity grading system for acute allergic reactions for use in clinical care and research.

METHODS

From May to September 2020, we convened a 21-member multidisciplinary panel of allergy and emergency care experts; 9 members formed a writing group to critically appraise and assess the strengths and limitations of prior severity grading systems and develop the structure and content for an optimal severity grading system. The entire study panel then revised the grading system and sought consensus by utilizing Delphi methodology.

RESULTS

The writing group recommended that an optimal grading system encompass the severity of acute allergic reactions on a continuum from mild allergic reactions to anaphylactic shock. Additionally, the severity grading system must be able to discriminate between clinically important differences in reaction severity to be relevant in research while also being intuitive and straightforward to apply in clinical care. Consensus was reached for all elements of the proposed severity grading system.

CONCLUSION

We developed a consensus severity grading system for acute allergic reactions, including anaphylactic and nonanaphylactic reactions. Successful international validation, refinement, dissemination, and application of the grading system will improve communication among providers and patients about the severity of allergic reactions and will help advance future research.

PEMCRC anaphylaxis study protocol: a multicentre cohort study to derive and validate clinical decision models for the emergency department management of children with anaphylaxis

INTRODUCTION

There remain significant knowledge gaps about the management and outcomes of children with anaphylaxis. These gaps have led to practice variation regarding decisions to hospitalise children and length of observation periods following treatment with epinephrine. The objectives of this multicentre study are to (1) determine the prevalence of and risk factors for severe, persistent, refractory and biphasic anaphylaxis, as well as persistent and biphasic non-anaphylactic reactions; (2) derive and validate prediction models for emergency department (ED) discharge; and (3) determine data-driven lengths of ED and inpatient observation prior to discharge to home based on initial reaction severity.

METHODS AND ANALYSIS

The study is being conducted through the Pediatric Emergency Medicine Collaborative Research Committee (PEMCRC). Children 6 months to less than 18 years of age presenting to 30 participating EDs for anaphylaxis from October 2015 to December 2019 will be eligible. The primary outcomes for each objective are (1) severe, persistent, refractory or biphasic anaphylaxis, as well as persistent or biphasic non-anaphylactic reactions; (2) safe ED discharge, defined as no receipt of acute anaphylaxis medications or hypotension beyond 4 hours from first administered dose of epinephrine; and (3) time from first to last administered dose of epinephrine and vasopressor cessation. Analyses for each objective include (1) descriptive statistics to estimate prevalence and generalised estimating equations that will be used to investigate risk factors for anaphylaxis outcomes, (2) least absolute shrinkage and selection operator regression and binary recursive partitioning to derive and validate prediction models of children who may be candidates for safe ED discharge, and (3) Kaplan-Meier analyses to assess timing from first to last epinephrine doses and vasopressor cessation based on initial reaction severity.

ETHICS AND DISSEMINATION

All sites will obtain institutional review board approval; results will be published in peer-reviewed journals and disseminated via traditional and social media, blogs and online education platforms.