Predictors of Repeat Epinephrine Administration for Emergency Department Patients with Anaphylaxis

Outcomes associated with prehospital epinephrine in adult and pediatric patients with anaphylaxis

BACKGROUND

Prompt epinephrine administration is important to improve outcomes in anaphylaxis.

OBJECTIVE

To assess the impact of prehospital epinephrine on clinical outcomes of hospital admission, biphasic reactions, and emergency department (ED) length of stay (LOS) in a cohort of ED patients who had anaphylaxis including both children and adults.

METHODS

We conducted a single-center prospective and retrospective cohort study of patients who had anaphylaxis from April 2008 to December 2022. Associations between prehospital epinephrine administration with biphasic reactions and ED LOS were assessed with univariable models and the association with ED disposition was assessed with both univariable and multivariable logistic regression.

RESULTS

A total of 1107 patient visits were included for analysis. The median patient age was 29 (IQR: 14-50), 593 (53.6%) patients were of female sex, and 366 (33.1%) were younger than 18 years of age. Patients in the prehospital epinephrine group were also less likely to experience a biphasic reaction (5.4% vs 9.3%; odds ratio [OR] 0.56, 95% CI: 0.34-0.92) and had a decreased ED LOS (median 4.0 hours vs 4.7 hours). There was no difference in hospital admission between patients with and without prehospital epinephrine in both the univariable (19.5% vs 15.7%; OR 1.30, 95% CI: 0.94-1.79) and multivariable (adjusted OR 1.08, 95% CI: 0.71-1.64) models.

CONCLUSION

Prehospital epinephrine administration reduced the odds of a biphasic reaction and decreased ED LOS but did not reduce hospitalization in this cohort of ED patients who had anaphylaxis. Our findings suggest that timely administration of prehospital epinephrine is associated with improved patient outcomes.

Probiotics and other adjuvants in allergen-specific immunotherapy for food allergy: a comprehensive review

This review delves into the potential of manipulating the microbiome to enhance oral tolerance in food allergy, focusing on food allergen-specific immunotherapy (FA-AIT) and the use of adjuvants, with a significant emphasis on probiotics. FA-AIT, including oral (OIT), sublingual (SLIT), and epicutaneous (EPIT) immunotherapy, has shown efficacy in desensitizing patients and achieving sustained unresponsiveness (SU). However, the long-term effectiveness and safety of FA-AIT are still under investigation. Probiotics, particularly strains of Lactobacillus, play a crucial role in enhancing immune tolerance by promoting regulatory T cells (Tregs) and modulating cytokine profiles. These probiotics can induce semi-mature dendritic cells, enhance CD40 expression, inhibit IL-4 and IL-5, and promote IL-10 and TGF-β, thus contributing to mucosal defense and immunological tolerance. Clinical trials combining probiotics with FA-AIT have demonstrated improved desensitization rates and immune tolerance in food-allergic patients. For example, the combination of Lactobacillus rhamnosus with peanut OIT resulted in a significantly higher rate of SU compared to the placebo group, along with notable immune changes such as reduced peanut-specific IgE and increased IgG4 levels. The review also explores other adjuvants in FA-AIT, such as biologic drugs, which target specific immune pathways to improve treatment outcomes. Additionally, nanoparticles and herbal therapies like food allergy herbal formula 2 (FAHF-2) are discussed for their potential to enhance allergen delivery and immunogenicity, reduce adverse events, and improve desensitization. In conclusion, integrating probiotics and other adjuvants into FA-AIT protocols could significantly enhance the safety and efficacy of FA-AIT, leading to better patient outcomes and quality of life.

Preventing food allergy fatalities

Fatal anaphylaxis to food is thankfully rare, but every death is a potentially avoidable tragedy. Usually, there will be a coronial inquest to establish the 'how and why' for each death. Reviewing these food allergy-related deaths identifies a number of common themes and risk factors. While some are non-modifiable (such as age, gender and ethnicity), others are and include delayed epinephrine administration and communication difficulties in allergen avoidance. This review highlights the key messages in food allergy-related fatality prevention for healthcare professionals and patients alike, and where available, we explain the evidence behind such recommendations. We describe the data behind the good practice points to facilitate their adoption in routine practice without generating additional anxiety for what is a comparatively rare event. We also propose an information leaflet for patients and carers, developed with patients and endorsed by two major allergy charities, to facilitate dissemination of the recommendations in this review.

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.

IgE-mediated cow's milk allergy in Brazilian children: Outcomes of oral food challenge

Background

Oral food challenge (OFC) is useful for diagnosing food allergies and assessing tolerance, but severe reactions may occur during the procedure.

Objective

To characterize the frequency and severity of reactions during cow's milk (CM) OFCs.

Methods

A cross-sectional study was conducted to analyze the outcome of cow's milk oral food challenges (CMOFCs) performed to confirm IgE-mediated CM allergy or to assess food tolerance. CM was given first as baked milk (BM), followed by whole CM if there was no prior reaction to BM. An OFC was considered positive if IgE-mediated symptoms developed up to 2 h after ingestion. Symptoms were described and variables including age at OFC, prior anaphylaxis, other atopic diseases, and skin test results were compared according to the OFC outcomes.

Results

A total of 266 CMOFCs were performed, including 159 patients with a median age of 6.3 years old. One hundred thirty-six tests were positive and 62 resulted in anaphylaxis. Thirty-nine anaphylactic reactions were observed up to 30 min after the first dose. Severe anaphylaxis (cardiovascular and/or neurological involvement) was reported in 5 tests. A second dose of epinephrine was required in 3 tests, and 1 presented a biphasic response. Younger patients had a higher risk of anaphylaxis during baked milk oral food challenge (BMOFC) (p = 0.009). The frequency of anaphylaxis was higher in patients submitted to BM (p = 0.009).

Conclusions

Anaphylaxis is a known complication of CMOFCs even when there is no prior anaphylaxis or when conducted with baked products. This study reinforces the importance of conducting OFC in appropriate settings with a well-trained team.

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.

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.

Repeated adrenaline requirements for anaphylaxis

We examined the pattern of adrenaline administration in patients presenting with anaphylaxis. Forty-four percent required repeated adrenaline administration, among whom there had been greater cardiorespiratory compromise. Repeated administration was more frequent in males and older patients, and those triggered by insect sting or unknown cause; no other patient factors were identified. This study supports the provision of two adrenaline auto-injectors to all anaphylaxis patients.

Use of multiple epinephrine doses in anaphylaxis: A systematic review and meta-analysis

BACKGROUND

Regulatory bodies recommend that all patients at risk of anaphylaxis be prescribed 2 epinephrine autoinjectors, which they should carry at all times. This is in contrast to some guidelines. The proportion of anaphylaxis reactions that are treated with multiple doses of epinephrine has not been systematically evaluated.

OBJECTIVE

Our aim was to undertake a systematic review and meta-analysis of published studies reporting epinephrine treatment for anaphylaxis in which data relating to the number of doses administered were available.

METHODS

We searched the Medline, Embase, and Cochrane databases for relevant studies reporting at least 10 anaphylaxis events (due to food or venom) from 1946 until January 2020. Data were extracted in duplicate for the meta-analysis, and the risk of bias was assessed. The study was registered under the PROSPERO identifier CRD42017069109.

RESULTS

A total of 86 studies (36,557 anaphylaxis events) met the inclusion criteria (20 of the studies [23%] were prospective studies; 64 [74%] reported reactions in the community, and 22 [26%] included food challenge data). Risk of bias was assessed as low in 50 studies. Overall, 7.7% of anaphylaxis events from any cause (95% CI = 6.4-9.1) were treated with multiple doses of epinephrine. When only epinephrine-treated reactions for which subsequent doses were administered by a health care professional were considered, 11.1% of food-induced reactions (95% CI = 9.4-13.2) and 17.1% of venom-induced reactions (95% CI = 11.3-25.0) were treated with more than 1 epinephrine dose. Heterogeneity was moderate to high in the meta-analyses, but at sensitivity analysis this estimate was not affected by study design or anaphylaxis definition.

CONCLUSION

Around 1 in 10 anaphylaxis reactions are treated with more than 1 dose of epinephrine.

Factors influencing emergency department observation time following anaphylaxis: a systematic review

OBJECTIVE

Anaphylaxis is a condition that warrants an observation period after symptoms resolution to detect rare but life-threatening delayed complications. There is a need for evidence to identify patients who would benefit from prolonged observation time. The purpose of this review was to identify factors that may influence the need for longer observation in the emergency department.

METHODS

PubMed, Embase, EBM Review, and Cochrane Library were searched using controlled vocabulary and keywords to cover all relevant data. Titles, abstract, and full text were reviewed for inclusion and exclusion criteria. Data were extracted from the included articles regarding case definitions, prognosis, treatment and time factors, and recommended observation time. Factors linked to observation time or complications were tabulated and compared between studies.

RESULTS

The search retrieved 2443 citations of which 49 were included. Twenty-one were primary studies and were used to identify factors influencing observation time or complications. Biphasic anaphylaxis was the only adverse event that warranted prolonged observation. The five risk factors often associated with biphasic reactions were time to first epinephrine, history of anaphylaxis, symptom severity, number of epinephrine doses, and unknown trigger. Biphasic reactions happened mostly within the first 72 h with most severe reactions occurring earlier than the milder ones. Heterogeneity in the definition of biphasic anaphylaxis made comparisons challenging.

CONCLUSIONS

Observation time should be based on the provider's best estimation of the risk of biphasic anaphylaxis, although no single factor can predict their occurrence. The identified factors will allow the development of an early discharge screening tool.

A case report: anaphylaxis to cefazolin during renal transplant surgery

Background

While there exist case reports of anaphylaxis occurring during renal transplant surgery, descriptions of continuing transplant surgery post-anaphylaxis have been scarce. Anaphylactic reactions that present solely with hypotension without pulmonary or mucocutaneous signs have yet to be described during renal transplant surgery.

Case presentation

Here we report a case of a 33-year-old female with end-stage renal disease who underwent cadaveric renal transplant. She developed anaphylaxis following the administration of cefazolin. Despite this reaction, the surgery was ultimately completed after patient stabilization, and the patient had excellent graft function postoperatively. The patient had an elevated tryptase at the time of the reaction and postoperative allergy testing revealed a positive intradermal test to cefazolin. Written informed consent was obtained from the patient for all procedures, studies, and publication of this case report.

Conclusions

This is the first case of a successful zero-mismatch cadaveric renal transplant following an anaphylactic reaction to cefazolin. Although anaphylaxis during transplant surgery typically warrants cancellation due to the hemodynamic effects that may lead to graft dysfunction, here we describe a case where surgery was continued following patient stabilization. The decision to proceed with surgery despite an intraoperative emergency along with the management and workup of intraoperative anaphylaxis are described, which can be beneficial for others who are presented with similar scenarios in the future.

Precision Medicine in Hymenoptera Venom Allergy: Diagnostics, Biomarkers, and Therapy of Different Endotypes and Phenotypes

Allergic reactions to stings of Hymenoptera species may be severe and are potentially fatal deviations of the immunological response observed in healthy individuals. However, venom-specific immunotherapy (VIT) is an immunomodulatory approach able to cure venom allergy in the majority of affected patients. An appropriate therapeutic intervention and the efficacy of VIT not only depend on a conclusive diagnosis, but might also be influenced by the patient-specific manifestation of the disease. As with other diseases, it should be borne in mind that there are different endotypes and phenotypes of venom allergy, each of which require a patient-tailored disease management and treatment scheme. Reviewed here are different endotypes of sting reactions such as IgE-mediated allergy, asymptomatic sensitization or a simultaneous presence of venom allergy and mast cell disorders including particular considerations for diagnosis and therapy. Additionally, phenotypical manifestations of venom allergy, as e.g. differences in age of onset and disease severity, multiple sensitization or patients unsusceptible to therapy, are described. Moreover, biomarkers and diagnostic strategies that might reflect the immunological status of the patient and their value for therapeutic guidance are discussed. Taken together, the increasing knowledge of different disease manifestations in venom hypersensitivity and the growing availability of diagnostic tools open new options for the classification of venom allergy and, hence, for personalized medical approaches and precision medicine in Hymenoptera venom allergy.

Assessment of ED triage of anaphylaxis patients based on the Emergency Severity Index

OBJECTIVES

To describe the emergency department (ED) triage of anaphylaxis patients based on the Emergency Severity Index (ESI), assess the association between ESI triage level and ED epinephrine administration, and determine characteristics associated with lower acuity triage ESI assignment (levels 3 and 4).

METHODS

We conducted a cohort study of adult and pediatric anaphylaxis patients between September 2010 and September 2018 at an academic ED. Patient characteristics and management were compared between Emergency Severity Index (ESI) triage level 1 or 2 versus levels 3 or 4 using logistic regression analysis. We adhered to STROBE reporting guidelines.

RESULTS

A total of 1090 patient visits were included. There were 26 (2%), 515 (47%), 489 (45%), and 60 (6%) visits that were assigned an ESI triage level of 1, 2, 3, and 4, respectively. Epinephrine was administered in the ED to 53% of patients triaged ESI level 1 or 2 and to 40% of patients triaged ESI level 3 or 4. Patients who were assigned a lower acuity ESI level of 3 or 4 had a longer median time from ED arrival to epinephrine administration compared to those with a higher acuity ESI level of 1 or 2 (28 min compared to 13 min, p < .001). A lower acuity ESI level was more likely to be assigned to visits with a chief concern of hives, rash, or pruritus (OR 2.33 [95% CI, 1.20-4.53]) and less likely to be assigned to visits among adults (OR, 0.43 [0.31-0.60]), patients who received epinephrine from emergency medical services (OR 0.56 [0.38-0.82]), presented with posterior pharyngeal or uvular angioedema (OR, 0.56 [0.38-0.82]), hypoxemia (OR, 0.34 [0.18-0.64]), or increased heart (OR 0.83 [0.73-0.95]) or respiratory (OR 0.70 [0.60-0.82]) rates.

CONCLUSION

Patients triaged to lower acuity ESI levels experienced delays in ED epinephrine administration. Adult and pediatric patients with skin-related chief concerns were more likely to be to be assigned lower acuity ESI levels. Further studies are needed to identify interventions that will improve ED anaphylaxis triage.

Second Dose of Epinephrine for Anaphylaxis in the First Aid Setting: A Scoping Review

Anaphylaxis is a life-threatening hypersensitivity reaction where rapid, early administration of epinephrine (adrenaline) can be lifesaving in the first aid setting. There are instances where a single dose of epinephrine does not relieve symptoms and a second dose may be required to further mitigate symptoms and preserve life. We performed a scoping review as part of an update to a previously conducted International Liaison Committee on Resuscitation First Aid Task Force (ILCOR) review. PubMed and Embase were searched using the strategy from the 2015 ILCOR review (dates January 1, 2015 to October 22, 2019) and a review of the grey literature (all dates up to November 18, 2019) was performed to identify data on the requirement, use, and effectiveness of a second dose of epinephrine. Each search was rerun on June 26, 2020. We included all human studies of adults and children with an English abstract. Critical outcomes included resolution of symptoms, adverse effects, and complications of second dosing of epinephrine in the treatment of acute anaphylaxis. Included studies are presented descriptively. Our updated search identified 909 potential sources, 890 from the published literature and 19 from the grey literature. After full text review, two studies met our eligibility criteria (Campbell et al. and Akari et al.). For the outcome of resolution of symptoms, both studies found that two or more doses of epinephrine were required in 8% of 582 patients and 28% of 18 patients, respectively, with anaphylaxis requiring treatment with epinephrine. The other a priori outcomes were not reported. This scoping review identified limited evidence regarding the use of a second dose of epinephrine for anaphylaxis in the first aid setting, however, due to the potential benefit, it is reasonable to administer a second dose when symptoms of severe anaphylaxis fail to resolve following an initial dose. Given the potential mortality associated with anaphylaxis, further research is needed to better identify individuals who may benefit from a second dose of epinephrine.

2020 International Consensus on First Aid Science With Treatment Recommendations

This is the summary publication of the International Liaison Committee on Resuscitation's 2020 International Consensus on First Aid Science With Treatment Recommendations. It addresses the most recent published evidence reviewed by the First Aid Task Force science experts. This summary addresses the topics of first aid methods of glucose administration for hypoglycemia; techniques for cooling of exertional hyperthermia and heatstroke; recognition of acute stroke; the use of supplementary oxygen in acute stroke; early or first aid use of aspirin for chest pain; control of life- threatening bleeding through the use of tourniquets, haemostatic dressings, direct pressure, or pressure devices; the use of a compression wrap for closed extremity joint injuries; and temporary storage of an avulsed tooth. Additional summaries of scoping reviews are presented for the use of a recovery position, recognition of a concussion, and 6 other first aid topics. The First Aid Task Force has assessed, discussed, and debated the certainty of evidence on the basis of Grading of Recommendations, Assessment, Development, and Evaluation criteria and present their consensus treatment recommendations with evidence-to-decision highlights and identified priority knowledge gaps for future research. The 2020 International Consensus on Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care (ECC) Science With Treatment Recommendations (CoSTR) is the fourth in a series of annual summary publications from the International Liaison Committee on Resuscitation (ILCOR). This 2020 CoSTR for first aid includes new topics addressed by systematic reviews performed within the past 12 months. It also includes updates of the first aid treatment recommendations published from 2010 through 2019 that are based on additional evidence evaluations and updates. As a result, this 2020 CoSTR for first aid represents the most comprehensive update since 2010.

2020 International Consensus on First Aid Science With Treatment Recommendations

This is the summary publication of the International Liaison Committee on Resuscitation's 2020 International Consensus on First Aid Science With Treatment Recommendations. It addresses the most recent published evidence reviewed by the First Aid Task Force science experts. This summary addresses the topics of first aid methods of glucose administration for hypoglycemia; techniques for cooling of exertional hyperthermia and heatstroke; recognition of acute stroke; the use of supplementary oxygen in acute stroke; early or first aid use of aspirin for chest pain; control of life-threatening bleeding through the use of tourniquets, hemostatic dressings, direct pressure, or pressure devices; the use of a compression wrap for closed extremity joint injuries; and temporary storage of an avulsed tooth. Additional summaries of scoping reviews are presented for the use of a recovery position, recognition of a concussion, and 6 other first aid topics. The First Aid Task Force has assessed, discussed, and debated the certainty of evidence on the basis of Grading of Recommendations, Assessment, Development, and Evaluation criteria and present their consensus treatment recommendations with evidence-to-decision highlights and identified priority knowledge gaps for future research.

Are Children with a History of Asthma More Likely to Have Severe Anaphylactic Reactions? A Retrospective Cohort Study

OBJECTIVE

To assess whether a history of asthma was associated with anaphylaxis severity in children hospitalized for anaphylaxis.

STUDY DESIGN

Retrospective cohort study of children ≤21 years old hospitalized for anaphylaxis from 2009 to 2016. The primary outcome was severe anaphylactic reactions defined by examination findings (stridor, respiratory distress, or hypotension) or administered therapies (≥2 dose of intramuscular epinephrine, continuous albuterol, vasopressors, or positive pressure ventilation). Multivariable analyses were used to assess whether a history of asthma was associated with severe anaphylactic reactions, adjusting for patient age, allergen, and history of atopic dermatitis or anaphylaxis.

RESULTS

Among 603 children hospitalized for anaphylaxis, 231 (38.3%) had a history of asthma. Children with a history of asthma were older (median age, 6.6 years [IQR, 3.6-12.1] vs 4.0 years [IQR, 1.6-9.3]), more likely to have a history of anaphylaxis (38.1% vs 18.0%), and have food as the inciting allergen (68.0% vs 52.2%). Children with a history of asthma were not more likely to have severe anaphylactic reactions (OR, 0.97; 95% CI, 0.67-1.39).

CONCLUSIONS

Children hospitalized for anaphylaxis with a history of asthma were not more likely to have severe anaphylactic reactions compared with children without asthma. This study supports managing children with anaphylaxis based on the severity of symptomatology, and, if validated, clinicians should not consider asthma comorbidity as a stand-alone criterion for hospitalization.

Identification of children with anaphylaxis at low risk of receiving acute inpatient therapies

OBJECTIVE

Opportunity exists to reduce unnecessary hospitalizations for children with anaphylaxis given wide variation in admission rates across U.S. emergency departments (EDs). We sought to identify children hospitalized with anaphylaxis at low risk of receiving epinephrine and other acute inpatient therapies, as these patients may be candidates for ED discharge rather than inpatient hospitalization.

METHODS

We conducted a single-center retrospective cohort study of children 1-21 years of age hospitalized with anaphylaxis from 2009 to 2016. Acute inpatient therapies included intramuscular (IM) or racemic epinephrine, bronchodilators, fluid boluses, vasopressors, non-invasive ventilation, or intubation. We derived age-specific (pre-verbal [<36 months] vs. verbal [≥ 36 months]) prediction rules using recursive partitioning to identify children at low risk of receiving acute inpatient therapies.

RESULTS

During the study period 665 children were hospitalized for anaphylaxis, of whom 108 (16.2%) received acute inpatient therapies. The prediction rule for patients < 36 months (no wheezing, no cardiac involvement [hypotension or wide pulse pressure]) had a sensitivity of 90.5% (CI 69.6-98.8%) and a negative predictive value of 98.3% (CI 94.1-99.8%) for identifying children at low risk of receipt of acute inpatient therapies during hospitalization. For children ≥ 36 months, the prediction rule (no wheezing, no cardiac involvement, presence of gastrointestinal symptoms) had a sensitivity of 90.8% (CI 82.7-96.0%) and a negative predictive value of 92.4% (CI 85.6-96.7%).

CONCLUSIONS

We derived age specific prediction rules for children hospitalized with anaphylaxis at low risk of receiving epinephrine and other acute inpatient therapies. These children may be candidates for ED discharge rather than inpatient hospitalization.

Risk factors for multiple epinephrine doses in food-triggered anaphylaxis in children

BACKGROUND

Food-related anaphylactic reactions may require treatment with more than 1 dose of epinephrine. Current guidelines advise patients at risk of anaphylaxis to carry 2 epinephrine autoinjectors.

OBJECTIVE

The objective of this study was to determine risk factors of multiple-dose epinephrine treatment in pediatric food-related anaphylaxis.

METHODS

Parents of children with physician-confirmed diagnosis of food allergy were administered a standardized questionnaire at the time of their clinic visit. These patients were then followed-up prospectively by phone.

RESULTS

Six hundred forty-two subjects had allergic reactions. Twenty-six percent of patients reported at least 1 reaction treated with epinephrine, for a total of 221 reactions. Among reactions treated with epinephrine, 24 reactions (11%) received 2 or more doses of epinephrine. The most common triggers were milk (30%) and peanut (18%). Milk-triggered allergic reactions (odds ratio [OR] 3.2; 95% confidence interval [CI] 1.2-8.4) and treatment with oxygen (OR 5.0, 95% CI 2.0-12.4) were significant risk factors for requiring multiple doses of epinephrine to treat an allergic reaction.

CONCLUSION

This study demonstrates that treatment of anaphylaxis may require more than 1 epinephrine injection. Reactions triggered by milk or requiring treatment with oxygen are at higher risk for needing more than 1 dose of epinephrine. Families of food-allergic children should be counseled on the importance of carrying 2 epinephrine auto-injectors.

Critical view of anaphylaxis epidemiology: open questions and new perspectives

In contrast to the majority of allergic or hypersensitivity conditions, worldwide anaphylaxis epidemiological data remain sparse with low accuracy, which hampers comparable morbidity statistics. Data can differ widely depending on a number of variables. In the current document we reviewed the forms on which anaphylaxis has been defined and classified; and how it can affect epidemiological data. With regards to the methods used to capture morbidity statistics, we observed the impact of the anaphylaxis coding utilizing the World Health Organization's International Classification of Diseases. As an outcome and depending on the anaphylaxis definition, we extracted the cumulative incidence, which may not reflect the real number of new cases. The new ICD-11 anaphylaxis subsection developments and critical view of morbidity statistics data are discussed in order to reach new perspectives on anaphylaxis epidemiology.