Trends, characteristics, and incidence of anaphylaxis in 2001-2010: A population-based study

Trends in Childhood Anaphylaxis in Singapore: 2015-2022

BACKGROUND

There has been limited data regarding the incidence of anaphylaxis in Asia. We aim to describe patterns in patient characteristics, triggers and clinical presentation of childhood anaphylaxis in Singapore.

METHODS

This was a retrospective review of emergency electronic medical records of children with anaphylaxis. Patients with the allergy-related diagnoses of anaphylaxis, angioedema, allergy and urticaria based on ICD-9 codes were screened. Cases fulfilling the World Allergy Organization criteria for anaphylaxis were included.

RESULTS

A total of 1188 cases of anaphylaxis were identified with a median age of 6.3 years. Extrapolating data from the study sites, from 2015 to 2022, the incidence rate of childhood anaphylaxis emergency visits in Singapore doubled from 18.9 to 38.8 per 100,000 person-years, with an incidence rate ratio (IRR) of 2.06 (95% confidence interval [CI] 1.70-2.49). In 2022, the incidence rate of food anaphylaxis was 30.1 per 100,000 person-years, IRR 2.39 (95% CI 1.90-3.01) and drug anaphylaxis was 4.6 per 100,000 person-years, IRR 1.89 (95% CI 1.11-3.25). The incidence rate in children aged 0-4 years quadrupled during the study period. Common triggers were egg (10.4%), peanut (9.3%), tree nut (8.8%), milk (8%), shellfish (7.8%) and non-steroidal anti-inflammatory drug (4.4%). The majority (88.6%) of patients were treated with intramuscular adrenaline. Total number of allergy-related visits did not increase over time between 2015 and 2019. Rates of severe anaphylaxis, namely anaphylactic shock and admission to high-dependency and intensive care, did not increase over time, with a mean incidence of 1.6, IRR 0.85 (95% CI 0.40-1.83) and 0.7, IRR 1.77 (95% CI 0.54-5.76) per 100,000 person-years, respectively.

CONCLUSION

While the number of emergency visits due to childhood anaphylaxis has increased, the number of cases of allergy-related visits, anaphylactic shock and anaphylaxis requiring high-dependency and intensive care did not rise.

Identifying patients at risk of anaphylaxis

Anaphylaxis is an acute, potentially fatal, systemic hypersensitivity reaction that warrants prompt diagnosis and management. It continues to be challenging to anticipate who may be at risk of a severe, life-threatening allergic reaction. Anaphylaxis can be caused by a range of allergens, such as certain foods, medications, latex, insect stings, etc. Cofactors that augment the severity of clinical symptoms and increase the risk of poor outcomes include exercise, stress, infectious diseases, underlying mast cell disease, active allergic disease such as asthma, advanced age, intake of certain medications, history of previous anaphylaxis, and delayed or missed administration of adrenaline. According to the European Anaphylaxis Registry, food is the major elicitor of anaphylaxis, especially eggs, cow milk, and nuts, in children and adolescents. Reaction to insect venom has also been noted in young adulthood. Early recognition of signs and symptoms and prompt treatment are crucial in anaphylaxis management to avoid serious and even fatal outcomes. It is crucial for both individuals and clinicians to identify the cause of anaphylaxis. Biomarkers of anaphylaxis, such as histamine, tryptase, platelet activation factor (PAF), chymase, carboxypeptidase A3, dipeptidyl peptidase I (DPPI), basogranulin, CCL-2, hsa-miR-451a, may be useful in diagnosis and management. The purpose of this review article is to present a comprehensive overview of current evidence and expert opinions regarding the risk factors that predispose individuals to anaphylaxis. Additionally, it provides insights into potential biomarkers and genetic markers for accurate diagnosis and management. This review underscores the significance of expert guidance in enhancing patient outcomes and enabling self-management of anaphylactic episodes.

Cardiac Arrest in Special Populations

Best practices in cardiac arrest depend on continuous high-quality chest compressions, appropriate ventilatory management, early defibrillation of shockable rhythms, and identification and treatment of reversible causes. Although most patients can be treated according to highly vetted treatment guidelines, some special situations in cardiac arrest arise where additional skills and preparation can improve outcomes. Situations covered in this section involve cardiac arrest in context of electrical injuries, asthma, allergic reactions, pregnancy, trauma, electrolyte imbalances, toxic exposures, hypothermia, drowning, pulmonary embolism, and left ventricular assist devices.

Disparities in pediatric anaphylaxis triggers and management across Asia

BACKGROUND

The epidemiology and management of anaphylaxis are not well-reported in Asia.

METHODS

A regional pediatric anaphylaxis registry was established by the Asia-Pacific Research Network for Anaphylaxis (APRA), using standardized protocols for prospective data collection, to evaluate the triggers and management of anaphylaxis in the Asia-Pacific region. Pediatric patients below 18 years presenting with anaphylaxis across four Asian countries/cities (Thailand, Singapore, Hong Kong (HK), and Qingdao) were included. Allergen triggers, symptoms, anaphylaxis severity, and management were compared.

RESULTS

Between 2019 and 2022, 721 anaphylaxis episodes in 689 patients from 16 centers were identified. The mean age at anaphylaxis presentation was 7.0 years (SD = 5.2) and 60% were male. Food was the most common trigger (62%), particularly eggs and cow's milk in children aged 3 years and below. In school-age children, nut anaphylaxis was most common in HK and Singapore, but was rare in the other countries, and wheat was the top allergen in Bangkok. Shellfish anaphylaxis was most common in children aged 7-17. Adrenaline was administered in 60% of cases, with 9% given adrenaline before hospital arrival. Adrenaline devices were prescribed in up to 82% of cases in Thailand but none in Qingdao.

CONCLUSIONS

The APRA identified food as the main trigger of anaphylaxis in children, but causative allergens differed even across Asian countries. Fewer than two-thirds of cases received adrenaline treatment, pre-hospital adrenaline usage was low, and adrenaline device prescription remained suboptimal. The registry recognizes an unmet need to strengthen anaphylaxis care and research in Asia-Pacific.

Milk-induced anaphylaxis among children presenting to Canadian emergency departments

BACKGROUND

Cow's milk is one of the most common and burdensome allergens in pediatrics, and it can induce severe anaphylactic reactions in children. However, data on cow's milk-induced anaphylaxis are sparse.

OBJECTIVE

To describe the epidemiology of pediatric cow's milk-induced anaphylaxis and to determine risk factors for repeat emergency department (ED) epinephrine administration.

METHODS

Between April 2011 and May 2023, data were collected on children with anaphylaxis presenting to 10 Canadian EDs. A standardized form documenting symptoms, triggers, treatment, and outcome was used. Multivariate logistic regression was used.

RESULTS

Of 3118 anaphylactic reactions, 319 milk-induced anaphylaxis cases were identified (10%). In the prehospital setting, 54% of patients with milk-induced anaphylaxis received intramuscular epinephrine. In those with milk-induced anaphylaxis, receiving epinephrine before presenting to the ED was associated with a reduced risk of requiring 2 or more epinephrine doses in the ED (adjusted odds ratio, 0.95 [95% CI, 0.90-0.99]). Children younger than 5 years of age were more likely to experience a mild reaction compared with that in older children, who experienced a moderate reaction more often (P < .0001). Compared with other forms of food-induced anaphylaxis, children presenting with milk-induced anaphylaxis were younger; a greater proportion experienced wheezing and vomiting, and less experienced angioedema.

CONCLUSION

Prehospital epinephrine in pediatric milk-induced anaphylaxis is underused; however, it may decrease risk of requiring 2 ED epinephrine doses. Milk-induced anaphylaxis in children younger than 5 years of age may be less severe than in older children. Wheezing and vomiting are more prevalent in milk-induced anaphylaxis compared with that of other foods.

The Application of Knowledge-Based Clinical Decision Support Systems to Detect Antibiotic Allergy

Prevention of drug allergies is important for patient safety. The objective of this study was to evaluate the outcomes of antibiotic allergy-checking clinical decision support system (CDSS), K-CDSTM. A retrospective chart review study was performed in 29 hospitals and antibiotic allergy alerts data were collected from May to August 2022. A total of 15,535 allergy alert cases from 1586 patients were reviewed. The most frequently prescribed antibiotics were cephalosporins (48.5%), and there were more alerts of potential cross-reactivity between beta-lactam antibiotics than between antibiotics with the same ingredients or of the same class. Regarding allergy symptoms, dermatological disorders were the most common (38.8%), followed by gastrointestinal disorders (28.4%). The 714 cases (4.5%) of immune system disorders included 222 cases of anaphylaxis and 61 cases of severe cutaneous adverse reactions. Alerts for severe symptoms were reported in 6.4% of all cases. This study confirmed that K-CDS can effectively detect antibiotic allergies and prevent the prescription of potentially allergy-causing antibiotics among patients with a history of antibiotic allergies. If K-CDS is expanded to medical institutions nationwide in the future, it can prevent an increase in allergy recurrence related to drug prescriptions through cloud-based allergy detection CDSSs.

Examination of Pediatric Nurses' Knowledge of Anaphylaxis: A Descriptive Study

Anaphylaxis is a vital systemic allergic reaction. A rapid diagnosis of anaphylaxis is lifesaving. In most cases, nurses are the first to encounter and intervene in anaphylaxis. Therefore, they have a vital responsibility in such cases. The aim of this study is to create a questionnaire and evaluate the anaphylaxis knowledge levels of pediatric nurses. This is a descriptive type of study. The study took place in Turkey. 80 pediatric nurses who work in pediatric intensive care, neonatal intensive care, child service, and pediatric emergency service participated in the study. The sociodemographic data collection form and the anaphylaxis knowledge level assessment form was used for the study. ANOVA and t-test are used to evaluate the data. The average anaphylaxis knowledge score of the pediatric nurses was found 12.61 ± 2.61, therefore it's moderate. The reliability of the questionnaire was high. Knowledge levels were moderately sufficient in diagnoses and insufficient in treatment and follow-up. Considering how critical anaphylaxis is, the moderately sufficient and insufficient knowledge levels are not substantial and should be increased advancedly. The questionnaire created for this study can be used in future studies. Health institutions should plan training regarding anaphylaxis and recompose anaphylaxis training in general, elaborate treatment and follow-up, and assess pediatric nurses' knowledge periodically.

Population-based incidence of all-cause anaphylaxis and its development over time: a systematic review and meta-analysis

Introduction

It is extremely difficult to compare studies investigating the frequency of anaphylaxis making it challenging to satisfactorily assess the worldwide incidence rate. Using a systematic review and meta-analysis, this publication aims to determine the current incidence of all-cause anaphylaxis worldwide. Additionally, we investigated whether the incidence of anaphylaxis has changed over time and which factors influence the rates determined by individual studies.

Methods

A literature search was performed in four databases. All articles that reported relevant information on population-based incidence rates of all-cause anaphylaxis were included. The protocol was published on INPLASY, the International Platform of Registered Systematic Review and Meta-analysis Protocols.

Results

The database query and screening process resulted in 46 eligible articles on anaphylaxis. The current incidence worldwide was found to be approximately 46 cases per 100,000 population per year (95% CI 21-103). Evaluating confounding factors showed that studies using allergy clinics and hospitalizations as data source result in comparably low rates. Moreover, children are less prone to develop anaphylaxis compared to the general population. Using a random effects Poisson model we calculated a yearly increase of anaphylaxis incidence by 7.4% (95% CI 7.3-7.6, p < 0.05).

Discussion

This seems to be the first approach to analyze every reported all-cause anaphylaxis incidence rate until 2017 for an at most accurate determination of its epidemiology. Based on these results, future research could investigate the underlying causes for the rising incidence in order find ways to decrease the condition's frequency.

Systematic Review Registration

inplasy.com, identifier [INPLASY202330047].

Contemporary trends in anaphylaxis burden and healthcare utilisation in Western Australia: A linked data study

Background

Anaphylaxis is a growing public health problem in Australia. To determine the extent of the problem, we linked multiple health datasets to examine temporal trends in anaphylaxis events across the health system in Western Australia (WA).

Methods

We identified an anaphylaxis cohort from 1980 to 2020 using linked datasets from ambulance, emergency departments, hospital inpatients and deaths. Age-standardised anaphylaxis event rates were calculated from 2010 to 2020. Dataset-specific rates for anaphylaxis were also examined, to show differences in health care utilisation. Annual percent change in rates (2010-2019) were estimated using age-adjusted Poisson regression models.

Results

A total of 19 140 individuals (mean age 31 years; 51% female) experienced 24 239 anaphylaxis events between 2010 and 2020. From 2010 to 2019, the average annual percent increase (95% CI) in rates was 5.3% (4.8-5.8%), from 70.3 to 113.9, with rates reducing to 76.5/100 000 population in 2020. Adolescents and young adults aged 5-14 years and 15-24 years had the greatest increase of 6.9% (5.6-8.1%) and 6.8% (5.6-8.0) respectively, with those over 25 years increasing by approximately 5% per year and children 1-4 years showing the lowest annual increase of 2.6% (1.1-4.2%). The highest absolute rates were seen in under 1 year (269.7/100 000; 2019). There has been an acceleration of trends from 2015 to 2019, underpinned by large increases in 15-24 and 25-34 years. All databases, show similar increasing trends, with ambulance attendance (33.7 per 100 000), emergency presentation (89.8 per 100 000) and hospital admissions (46.2 per 100 000), for anaphylaxis highest in 2019. However, whilst ambulance and emergency presentations have grown by 8.9% (95%CI 7.9-9.8%) and 6.6% per year (95%CI 6.0-7.2%), respectively, hospitalisations appear to be steadying with only a 0.9% (95%CI 0.2-1.6%) yearly rise.

Conclusion

Rates of anaphylaxis continue to increase, with WA having higher rates than previous estimates for Australia. Whilst rates are still high in infants, lower trends in children compared to older ages may indicate better prevention of allergy. Results show more people experiencing anaphylaxis now receive care in emergency and ambulance, rather than hospital. Further exploration of the patient care journey through prehospital and inpatient care is required, to understand the changing health demands of people who experience anaphylaxis.

Cardiac Arrest in Special Populations

Best practices in cardiac arrest depend on continuous high-quality chest compressions, appropriate ventilatory management, early defibrillation of shockable rhythms, and identification and treatment of reversible causes. Although most patients can be treated according to highly vetted treatment guidelines, some special situations in cardiac arrest arise where additional skills and preparation can improve outcomes. Situations covered in this section involve cardiac arrest in context of electrical injuries, asthma, allergic reactions, pregnancy, trauma, electrolyte imbalances, toxic exposures, hypothermia, drowning, pulmonary embolism, and left ventricular assist devices.

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.

Recent insights into the mechanisms of anaphylaxis

Anaphylaxis is an acute life-threatening systemic allergic reaction that can have a wide range of clinical manifestations. The most common triggers for anaphylaxis include food, medication, and venom. What is curious regarding anaphylaxis is how so many different agents can induce a severe systemic clinical response but only in a select subgroup of patients. Over the past decade, several important advances have been made in understanding the underlying cellular and molecular mechanisms contributing to anaphylaxis, with mast cells (MCs) being an essential component. Classically, cross-linked immunoglobulin E (IgE) bound to its high- affinity receptor induces MC mediator release. However, toll-like, complement, or Mas-related G-protein-coupled receptors also activate mouse and human MCs. While anaphylaxis secondary to foods historically has been more extensively characterized clinically and mechanistically, more recent studies have shifted focus toward understanding drug-induced anaphylaxis. The focus of this review is to highlight recent basic science developments and compare what is currently known regarding anaphylaxis to food, medications, and venom.

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS): Focus on the Pathophysiological and Diagnostic Role of Viruses

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a heterogeneous, multiorgan and potentially life-threatening drug-hypersensitivity reaction (DHR) that occurs several days or weeks after drug initiation or discontinuation. DHRs constitute an emerging issue for public health, due to population aging, growing multi-organ morbidity, and subsequent enhanced drug prescriptions. DRESS has more consistently been associated with anticonvulsants, allopurinol and antibiotics, such as sulphonamides and vancomycin, although new drugs are increasingly reported as culprit agents. Reactivation of latent infectious agents such as viruses (especially Herpesviridae) plays a key role in prompting and sustaining aberrant T-cell and eosinophil responses to drugs and pathogens, ultimately causing organ damage. However, the boundaries of the impact of viral agents in the pathophysiology of DRESS are still ill-defined. Along with growing awareness of the multifaceted aspects of immune perturbation caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the ongoing SARS-CoV-2-related disease (COVID-19) pandemic, novel interest has been sparked towards DRESS and the potential interactions among antiviral and anti-drug inflammatory responses. In this review, we summarised the most recent evidence on pathophysiological mechanisms, diagnostic approaches, and clinical management of DRESS with the aim of increasing awareness on this syndrome and possibly suggesting clues for future research in this field.

Effect of early postnatal supplementation of newborns with probiotic strain E. coli O83:K24:H31 on allergy incidence, dendritic cells, and microbiota

Introduction

Probiotic administration seems to be a rational approach to promote maturation of the neonatal immune system. Mutual interaction of the microbiota with the host immune system is critical for the setting of appropriate immune responses including a tolerogenic one and thevmaintenance of homeostasis. On the other hand, our knowledge on the modes of actions of probiotics is still scarce.

Methods

In our study, probiotic strain Escherichia coli O83:K24:H31 (EcO83) was administered to neonates of allergic mothers (AMs; neonates with increased risk for allergy development) within 48 h after the delivery, and the impact of this early postnatal supplementation on allergy incidence and selected immune markers has been analyzed 10 years after the primary EcO83 administration.

Results

We have observed decreased allergy incidence in 10-year-old children supplemented with EcO83 (13 of 52 children were allergic) in comparison with non-supplemented children of AMs (16 of 42 children were allergic). The early postnatal EcO83 supplementation appeared to limit the allergy in the high-risk group (children of AMs) compared to that in the low-risk group (children of healthy mothers). Dendritic cells (DCs) in the peripheral blood of EcO83-supplemented children do not differ significantly in cell surface presence of CD83. The immunomodulatory capacity of EcO83 on DCs was tested in vitro as well. Both directly isolated myeloid and in vitro monocyte-derived DCs from cord blood increased CD83 expression together with interleukin (IL)-10 secretion after EcO83 stimulation. The effect of early postnatal EcO83 supplementation on the microbiota composition of 10-year-old children was characterized by next-generation sequencing, and we have not observed significant changes in the microbiota composition of EcO83-supplemented and non-supplemented children at the age of 10 years.

Conclusions

Early postnatal EcO83 supplementation appears to lower allergy incidence in children of AMs. It seems that the beneficial effect of EcO83 is mediated via modulation of DC functional capacities without impacting the microbiota composition. Larger-scale studies will be necessary to confirm these preliminary findings.

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.

Overview of registries for anaphylaxis: a scoping review

OBJECTIVE

This review aimed to describe the scope and operational features of anaphylaxis registries, and to assess their contribution to improving knowledge of anaphylaxis and care of patients who experience anaphylaxis by measuring their research output.

INTRODUCTION

Structured data collection and reporting systems, such as registries, are needed to better understand the burden of anaphylaxis and to protect the growing number of patients with severe allergy. There is a need to characterize current anaphylaxis registries to identify their value in anaphylaxis surveillance, management, and research. Information synthesized in this review will provide knowledge on benefits and gaps in current registries, which may inform the implementation and global standardization of future anaphylaxis reporting systems.

INCLUSION CRITERIA

This scoping review considered literature describing registries worldwide that enroll patients who have experienced anaphylaxis. Published and gray literature sources were included if they described the scope and operational features of anaphylaxis registries.

METHODS

This review followed the JBI methodology for scoping reviews. Embase, MEDLINE, Scopus, and CINAHL were searched for relevant articles. Identified keywords and index terms were adapted for searches of gray literature sources, using Google advanced search functions. Only full-text studies in English were considered for inclusion. Two independent reviewers conducted title and abstract screening and those that did not meet the inclusion criteria were excluded. The full text of potentially relevant articles were retrieved; full-text screening and data extraction were also conducted by two independent reviewers. Any discrepancies were resolved through discussion or with a third reviewer. Tables and a narrative summary were used to describe and compare the scope and features (eg, inclusion criteria, patient demographics, clinical symptoms) of the identified anaphylaxis registries, and to outline their output to assess their contribution to research and clinical practice for anaphylaxis.

RESULTS

A total of 77 full-text publications and eight gray literature sources were used to extract data. The literature search identified 19 anaphylaxis registries, with sites in 28 countries including Europe, the United Kingdom, Canada, the United States, Korea, and Australia. The main purposes of the identified registries were to collect clinical data for research; provide clinical support tools to improve patient care; and operate as allergen surveillance systems to protect the wider community with allergies. Differences in inclusion and health care settings exist, with 11 collecting data on anaphylaxis of any cause, two on food reactions alone, three on fatal anaphylaxis, one on perioperative anaphylaxis, and two on allergic reactions (including anaphylaxis). Five registries enroll cases in allergy centers, five in hospital settings, one in schools, and others target a combination of general practitioners, specialists in emergency departments, and other relevant hospital departments and allergy outpatient clinics. Only three registries operate under a mandatory framework. A total of 57 publications were considered research outputs from registries. All registries except two have published studies from collected data, with the greatest number of articles published from 2019 to the present. Publications mostly addressed questions regarding demographic profile, causes and cofactors, severity, fatal reactions, and gaps in management.

CONCLUSIONS

This review demonstrated that anaphylaxis registries differ in their scope and operation, having been established for different purposes. Importantly, registries have contributed significantly to research, which has highlighted gaps in anaphylaxis management, provoking allergens, and informed targets for prevention for severe and fatal events. Beyond this, registries relay information about anaphylaxis to clinicians and regulatory bodies to improve patient care and protect the community. The ability to link registry data with other health datasets, standardization of data across registries, and incorporation of clinical care indicators to promote quality health care across the health system represent important targets for future systems.

Improving epinephrine autoinjector usability and carriage frequency among patients at risk of anaphylaxis: a quality improvement initiative

Although epinephrine autoinjectors (EAIs) are crucial for the management of anaphylaxis, patient carriage frequency of EAI is as low as 57% and usage of EAIs is erroneous 35%–43% of the time. Our objective was to improve patient carrying frequency of EAI and understanding of EAI usage.

We implemented a quality improvement initiative using consistent closed-loop education, redesigned clinic workflow, electronic medical record reminder-based interventions, and educational materials to improve patient EAI carriage compliance and understanding of EAI indications and proper technique.

The percentage of our patients who carried the EAI at all times increased from 55% to 93% in 6 months. Participants knowledge of EAI indications also improved from 22% to 91%. Patient demonstration scores of the EAI device improved from 21% to 91% as well.

Our quality improvement interventions demonstrated a significant improvement>80% in EAI carriage frequency, knowledge of indications, and proper device technique.

Economic burden of drug-induced anaphylaxis: what can we do better?

PURPOSE OF REVIEW

This systematic review evaluates published data related to the economic burden of drug-induced anaphylaxis (DIA) to understand preventive cost saving measures that could reduce the burden of these conditions.

RECENT FINDINGS

Although DIA has a relevant societal impact, there are limited and heterogenous available data related to its cost. Direct costs related to the management of acute phase of DIA was estimated by $529.6 to $3125, depending on the number of emergency room visits/hospitalizations, emergency kits and transports in ambulance. Direct costs of investigations of DIA varied from $288 to $2292.95 and the desensitization was estimated by $6796. Main variables for this were: personnel, allergy screening procedures, medical consumables and space cost. The mean indirect cost was based on a mean absenteeism of 3 days per DIA corresponding to $381.2.

SUMMARY

More than reviewing the published data, we were able to identify variables that, if correctly managed, can reduce the economic burden of DIA, such as adjusting the timing of referral and etiological diagnosis, identification of potential risk and/or co-factors, correct written recommendations to patients. The evidence presented highlights the need of optimization of healthcare patients to patients suffering from DIA.

Anaphylaxis among elderly emergency department patients in a large health system in New York

BACKGROUND

Anaphylaxis in the elderly is poorly understood.

OBJECTIVE

To elucidate demographic, clinical, and management characteristics of older adults presenting to emergency departments (EDs) with National Institute of Allergy and Infectious Diseases (NIAID) criteria-confirmed anaphylaxis vs milder, non-anaphylactic acute allergic reactions (AARs).

METHODS

A retrospective analysis of ED patients more than or equal to 65 years was conducted, using anaphylaxis International Classification of Diseases, Ninth Revision (ICD-9) codes or ICD-9-based algorithms incorporating the NIAID diagnostic criteria. Descriptive statistics were generated, and the abovementioned characteristics were compared between cohorts.

RESULTS

Of 164 eligible visits, 71 (43.3%), 90 (54.9%), and 3 (1.8%) cases were identified by ICD-9 codes, the algorithms, or both, respectively. Only half fulfilled NIAID diagnostic criteria. Compared with the non-anaphylactic AAR group, criteria-confirmed anaphylaxis group had lower drug allergy rates (43.9% vs 61.0%, P = .03) but higher food allergy rates (26.8% vs 12.2%, P = .02). For the criteria-confirmed anaphylaxis group, presenting signs and symptoms in descending frequency were mucocutaneous, respiratory, cardiovascular, and gastrointestinal. Criteria-confirmed anaphylaxis group had higher rates of prior anaphylaxis (13.4% vs 2.4%, P = .009), pre-ED (12.2% vs 0.0%, P = .001) or ED (72.0% vs 4.9%, P < .001) epinephrine administration, and allergy referral (17.1% vs 2.4%, P = .002). Tryptase levels were rarely ordered, occurring once in the criteria-confirmed anaphylaxis group and never in the non-anaphylactic AAR group. Despite low mortality (n = 1), 64.6% of the criteria-confirmed anaphylaxis cohort required hospitalization, with 23.2% admitted to intensive care unit.

CONCLUSION

Diagnosis of elderly ED patients with anaphylaxis remains suboptimal. Identifying NIAID criteria-confirmed cases remain challenging, using the existing methods. Management of these patients poorly adheres to current guidelines.

Sex differences in carcinoid syndrome: A gap to be closed

The incidence of neuroendocrine neoplasms and related carcinoid syndrome (CS) has markedly increased over the last decades and women seem to be more at risk than men for developing CS. Nevertheless, very few studies have investigated sex differences in clinical presentation and outcomes of CS. However, as per other tumours, sex might be relevant in influencing tumour localization, delay in diagnosis, clinical outcomes, prognosis and overall survival in CS. The present review was aimed at evaluating sex differences in CS, as they emerge from an extensive search of the recent literature. It emerged that CS occurs more frequently in female than in male patients with NENs and women seem to have a better prognosis and a slight advantage in overall survival and response to therapy. Moreover, the disease likely impacts differently the quality of life of men and women, with different psychological and social consequences. Nevertheless, sex differences, even if partially known, are deeply underestimated in clinical practice and data from clinical trials are lacking. There is urgent need to increase our understanding of the sex-related differences of CS, in order to define tailored strategies of management of the disease, improving both the quality of life and the prognosis of affected patients.

A Clinical Practice Guideline for the Emergency Management of Anaphylaxis (2020)

Background: For anaphylaxis, a life-threatening allergic reaction, the incidence rate was presented to have increased from the beginning of the 21st century. Underdiagnosis and undertreatment of anaphylaxis are public health concerns. Objective: This guideline aimed to provide high-quality and evidence-based recommendations for the emergency management of anaphylaxis. Method: The panel of health professionals from fifteen medical areas selected twenty-five clinical questions and formulated the recommendations with the supervision of four methodologists. We collected evidence by conducting systematic literature retrieval and using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. Results: This guideline made twenty-five recommendations that covered the diagnosis, preparation, emergency treatment, and post-emergency management of anaphylaxis. We recommended the use of a set of adapted diagnostic criteria from the American National Institute of Allergy and Infectious Diseases and the Food Allergy and Anaphylaxis Network (NIAID/FAAN), and developed a severity grading system that classified anaphylaxis into four grades. We recommended epinephrine as the first-line treatment, with specific doses and routes of administration for different severity of anaphylaxis or different conditions. Proper dosage is critical in the administration of epinephrine, and the monitor is important in the IV administration. Though there was only very low or low-quality evidence supported the use of glucocorticoids and H1 antagonists, we still weakly recommended them as second-line medications. We could not make a well-directed recommendation regarding premedication for preventing anaphylaxis since it is difficult to weigh the concerns and potential effects. Conclusion: For the emergency management of anaphylaxis we conclude that: • NIAID/FAAN diagnostic criteria and the four-tier grading system should be used for the diagnosis • Prompt and proper administration of epinephrine is critical.

Evaluation of adrenaline auto-injector prescription profiles: A population-based, retrospective cohort study within the National Insurance Claims Database of Japan

BACKGROUND

Adrenaline is the first-line medication for managing anaphylaxis. A better understanding of prescription trends for adrenaline auto-injectors (AAIs) is important to improving patient care as well as information on health education interventions and medical guidelines. However, it has been difficult to gather comprehensive data in a sustainable manner. Thus, we aimed to investigate trends in AAI prescriptions in Japan.

METHODS

We searched the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB), a unique and comprehensive database of health insurance claims, and investigated prescriptions for AAIs for all ages (April 2017 to March 2018). We assessed the annual number of prescriptions per person as well as prescription rates per 100,000 population per year by age, sex, and geographic region.

RESULTS

A total of 88,039 subjects (56,109 males, 31,930 female) and 116,758 devices (1.33 AAIs per patient per year) were prescribed AAIs at least once a year for all ages. The prescription rate for AAIs was 69.5 per 100,000 population-years. Patients aged 0-9 years were prescribed AAIs at the rate of 278.9 per 100,000 population-years. Patients aged 0-19 years were 6.4 times more likely to be prescribed AAIs than those over 20 years of age. Males were more frequently prescribed AAIs than females in all age groups, except for those aged 20-24 years. We also evaluated differences in prescription rates by geographic region.

CONCLUSIONS

This comprehensive evaluation revealed trends in AAI prescriptions, thus helping develop preventive strategies with respect to anaphylaxis in Japan.

Angioedèmes et médecine d’urgence

Les angioedèmes (AE) sont un motif de recours fréquent aux urgences. Leur morbimortalité n’est pas négligeable compte tenu de l’atteinte fréquente des voies aériennes supérieures. On distingue les AE histaminiques et bradykiniques. Aux urgences, la démarche diagnostique et la conduite à tenir doit être systématique et standardisée afin de ne pas méconnaître un potentiel AE bradykinique. Les AE histaminiques, accompagnés dans la plupart des cas d’une urticaire superficielle, sont de loin les plus fréquents et sont associés parfois à une anaphylaxie, ce qui nécessite alors un traitement par adrénaline immédiat. Ils peuvent être allergiques (médiés par les IgE) et sont alors associés à une anaphylaxie ou non allergiques, et se traduisent cliniquement par une urticaire aiguë ou chronique associée à l’AE. Les AE bradykiniques, d’incidence plus rare, sont également pourvoyeurs de recours aux urgences et particulièrement les AE secondaires aux inhibiteurs de l’enzyme de conversion de l’angiotensine compte tenu de leur importante prescription et de leurs atteintes cliniques de la face, de la langue et du larynx, elles-mêmes pourvoyeuses de recours aux urgences. Les traitements spécifiques d’urgence comprennent principalement l’icatibant et le concentré de C1-inhibiteur. Ils doivent être administrés le plus tôt possible devant l’inefficacité des traitements antiallergiques. Un avis auprès d’un expert du centre de référence pour les AE à kinines peut améliorer les prises en charge en aidant à la démarche diagnostique et en organisant la mise à disposition des traitements spécifiques d’urgence.

Safely Reducing Hospitalizations for Anaphylaxis in Children Through an Evidence-Based Guideline

BACKGROUND

Emergency department visits for anaphylaxis have increased considerably over the past few decades, especially among children. Despite this, anaphylaxis management remains highly variable and contributes to significant health care spending. On the basis of emerging evidence, in this quality improvement project we aimed to safely decrease hospitalization rates, increase the use of cetirizine, and decrease use of corticosteroids for children with anaphylaxis by December 31, 2019.

METHODS

A multipronged intervention strategy including a revised evidence-based guideline was implemented at a tertiary children's teaching hospital by using the Model for Improvement. Statistical process control was used to evaluate for changes in key measures. Length of stay and unplanned return visits within 72 hours were monitored as process and balancing measures, respectively. As a national comparison, hospitalization rates were compared with other hospitals' data from the Pediatric Health Information System.

RESULTS

Hospitalizations decreased significantly from 28.5% to 11.2% from preimplementation to implementation, and the balancing measure of 72-hour revisits was stable. The proportion of patients receiving cetirizine increased significantly from 4.2% to 59.7% and use of corticosteroids decreased significantly from 72.6% to 32.4% in patients without asthma. The proportion of patients meeting length of stay criteria increased from 53.3% to 59.9%. Hospitalization rates decreased nationally over time.

CONCLUSIONS

We reduced hospitalizations for anaphylaxis by 17.3% without concomitant increases in revisits, demonstrating that unnecessary hospitalizations can be safely avoided. The use of a local evidence-based guideline paired with close outcome monitoring and sustained messaging and feedback to clinicians can effectively improve anaphylaxis management.

Reproducibility of Symptom Sequences Across Episodes of Recurrent Anaphylaxis

BACKGROUND

Anaphylactic reactions may present with varying levels of severity, ranging from mild multisystem involvement to severe, and sometimes fatal, anaphylaxis. The severity of anaphylaxis is variable from one reaction to the next within the same individuals.

OBJECTIVE

To compare the temporal sequence of symptoms within individuals and between individuals across multiple anaphylactic reactions.

METHODS

Patients were evaluated for recurrent anaphylaxis in a tertiary care allergy clinic between 2012 and 2018. At each visit, patients were asked to record the temporal sequence in which symptoms of anaphylaxis appeared. These data were recorded at each visit and retrieved through retrospective chart review. Patients with a history of ≥2 anaphylactic reactions were included; those with anaphylaxis due to multiple allergens were excluded. The Fleiss Kappa method was used to assess reproducibility of the order of appearance of specific symptoms during anaphylaxis within individual patients and between individuals with similar triggers.

RESULTS

The mean patient age was 35.6 years (standard deviation = 13.9; range: 1-68 years); 113 of 149 (76%) patients were female. The mean Fleiss Kappa reproducibility score within individuals was 0.94, 5th percentile was 0.53, and 95th percentile was 1.0. The mean Kappa score between individuals was -0.03 (range, -0.14 to 0.05). Among the 16 of 149 patients who recorded reactions of varying severity grades, the mean within-patient Kappa score was 0.96.

CONCLUSION

Individual patients experience reproducibly stereotypic anaphylactic reactions over time, which are unique to a given patient, irrespective of the cause of anaphylaxis, including foods, medications, mast cell disorders, and idiopathic anaphylaxis. In contrast, symptom sequences during anaphylaxis are not reproducible between individuals.

Changing pattern of pediatric anaphylaxis in Hong Kong, 2010-2019

BACKGROUND

Anaphylaxis is a significant health burden in most Western countries, but there are little published data on the incidence and pattern of anaphylaxis in Asia. We aim to determine the incidence rate and pattern of anaphylaxis over the past decade among the pediatric population in Hong Kong.

METHODS

Medical records of patients presenting with allergy-related symptoms during the period 2010 to 2019 were examined. Pediatric patients aged below 18 years who fulfilled the diagnostic criteria for anaphylaxis laid out by the NIAID/FAAN were analyzed. Incidence rates were calculated using population statistics as the denominator. All information pertaining to the anaphylaxis events and patients' characteristics was retrieved using standardized data collection forms.

RESULTS

The overall 10-year estimated incidence of anaphylaxis was 9.76 per 100,000 person-years, with a rising trend of anaphylaxis incidence across time. Food-induced anaphylaxis accounted for the majority of hospital presentations, of which peanut and shellfish were the top food triggers in our population. Majority of anaphylaxis episodes were of Grade 4 severity, and young age was a significant predictor of severe allergic reactions. Half of the anaphylaxis episodes were misdiagnosed and adrenaline was only utilized in 42.2% of cases, of which 9.4% were administered adrenaline prior to hospital arrival.

CONCLUSIONS

An increasing trend of anaphylaxis incidence over the past decade is evident in Hong Kong children, with a discrepantly low accuracy in diagnosis and suboptimal management of anaphylaxis. There is a pressing need to heighten public and physicians' awareness of the distinctive features of anaphylaxis in the pediatric age-group.

The Vista of Application of Specific Anaphylaxis Accurate Diagnosis Based on DNA Single-Nucleotide Methylation Sites

Anaphylaxis has rapidly spread around the world in the last several decades. Environmental factors seem to play a major role, and epigenetic marks, especially DNA methylation, get more attention. We discussed several GEO opening data classifications with TOP 100 specific methylation region values (normalized M-values on line) by machine learning, which are remarkable to classify specific anaphylaxis after monoallergen exposure. Then, we sequenced the whole-genome DNA methylation of six people (3 wormwood monoallergen atopic rhinitis patients and 3 normal-immune people) during the pollen season and analyzed the difference of the single nucleotide and DNA region. The results' divergences were obvious (the differential single nucleotides were mostly distributed in nongene regions but the differential DNA regions of GWAS, on the other hand), which may have caused most single nucleotides to be concealed in the regions' sequences. Therefore, we suggest that we should conduct more “pragmatic” and directly find special single-nucleotide changes after exposure to atopic allergens instead of complex correlativity. It is possible to try to use DNA methylation marks to accurately diagnose anaphylaxis and form a machine learning classification based on the single methylated CpGs.

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.

Incidence of anaphylaxis and accidental peanut exposure: A systematic review

BACKGROUND

Peanut allergy (PA), a common food allergy, is increasing in prevalence and is associated with high rates of anaphylaxis. Prevalence of food-related anaphylaxis is higher in children and adolescents than in adults, and the pediatric incidence is increasing. We conducted a systematic literature review and meta-analysis to determine the incidence of peanut-induced anaphylaxis in children and/or adolescents with PA.

METHODS

Literature searches were conducted using the PubMed database and through supplemental methods. Eligible articles for inclusion were peer-reviewed studies published in English that reported the incidence of anaphylaxis in pediatric PA using the 2006 National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network criteria, sample size, and follow-up duration. Incidence rates were calculated as person-years at risk or a crude incidence rate was calculated. Meta-analyses of pooled data were conducted using the I² statistic as the measure of heterogeneity.

RESULTS

A total of 830 citations were screened; 8 met the study inclusion criteria and were selected for review. Pooled meta-analysis estimates of the incidence of (1) anaphylaxis among children/adolescents with food allergies, (2) anaphylaxis among children/adolescents with PA, and (3) accidental exposure to peanuts among children/adolescents with PA were 3.72 cases per 100 person-years (95% confidence interval [CI] = 2.35, 5.10), 2.74 cases per 100 person-years (95% CI = 1.42, 4.05), and 12.28 cases per 100 person-years (95% CI = 11.51, 13.05), respectively.

CONCLUSIONS

The risks of anaphylaxis among children with food allergies and those with PA contribute to the serious overall burden of PA and food allergy for children and their families.

Comprehensive hospital-based regional survey of anaphylaxis in Japanese children: Time trends of triggers and adrenaline use

BACKGROUND

Since few studies have analyzed time trends in pediatric anaphylaxis, including triggers and adrenaline usage, this study aimed to reveal these issues in a comprehensive analysis of pediatric anaphylaxis cases.

METHODS

The Aichi Medical Association performed a comprehensive survey of pediatric anaphylaxis cases aged under 15 years from 87 secondary and 25 tertiary emergency care hospitals in Aichi Prefecture (population 7.5 million), Japan.

RESULTS

Between April 2016 and March 2020, 3423 cases of anaphylaxis were identified. Food items were the most frequent trigger (73%), followed by exercise after food ingestion (4.3%), and drugs (2.2%). Egg (19%) and milk (17%) specifically were the most frequent among food triggers, while the largest proportional increase was observed in tree nuts from 6.0% in 2017 to 15% in 2019. Overall, 1647 (48%) cases were admitted to the hospital, of which 26 (0.8%) were admitted to the intensive care unit. Drug-induced anaphylaxis was associated with the highest admission rate (71%). Of the 2493 food-induced anaphylaxis cases, 1107 (44%) were treated with adrenaline. Among them, 343 cases included previously prescribed adrenaline auto-injectors (AAI), with 225 (66%) usages prior to hospital arrival. There was no significant difference in the admission rate between the cases in which AAIs were used and those with adrenaline administered in the hospital (68% and 72%, respectively).

CONCLUSIONS

The proportion of tree nuts in food-induced anaphylaxis increased significantly. Although prehospital AAI use has become widespread, it was not associated with lower admission rate compared to in-hospital adrenaline usage.

Seeing the Forest for the Trees: Evaluating Population Data in Allergy-Immunology

A population-level study is essential for understanding treatment effects, epidemiologic phenomena, and health care best practices. Evaluating large populations and associated data requires an analytic framework, which is commonly used by statisticians, epidemiologists, and data scientists. This document will serve to provide an overview of these commonly employed methods in allergy and immunology research. We will draw upon recent examples from the allergy-immunology literature to contextualize discrete principles of relevance to population-level analysis that include statistical features of a study population, elements of statistical inference, regression analysis, and an overview of machine learning practices. Our intent is to guide the reader through a practical description of this important quantitative discipline and facilitate greater understanding about data and result display in the medical literature.

Epidemiology of anaphylaxis and biphasic reaction in Japanese children

Aim

Anaphylaxis is common, but can sometimes be fatal. However, data on the epidemiology and characteristics of anaphylaxis are limited. Although 0.9%–14.7% of anaphylactic reactions in children are biphasic, it is unclear what the characteristics of biphasic reaction are and how long patients with this reaction should be observed. The present study aimed to investigate the epidemiology of anaphylaxis and biphasic reactions and identify the characteristics of the latter.

Methods

We conducted an observational study of patients who visited the pediatric emergency department (PED) and were hospitalized for anaphylaxis between March 2010 and March 2017.

Results

Of the 264,689 children who visited our PED, 353 (1.3 per 1,000 patient) were hospitalized for anaphylaxis, and six (1.7%) had a biphasic reaction. Of the patients with a biphasic reaction, the median time from initial anaphylaxis to the biphasic reaction was 5.9 (interquartile range [IQR] = 3.3–7.6) hours. Symptoms of the initial episode and the biphasic reaction varied. One (0.3%) of the 353 patients developed a clinically important biphasic reaction that required epinephrine administration.

Conclusions

The rate of biphasic reactions was 1.7%, and that of clinically important biphasic reactions was 0.3%. Patients with anaphylaxis need to be carefully monitored because of the regular occurrence of biphasic reactions.

Specialist confirmed allergic reactions to COVID-19 mRNA vaccines at a mass vaccination site

Healthcare providers can play a key role in reaching the target for vaccine uptake through educating the public on the risk may be of severe allergic reactions to COVID-19 vaccines. Thus, it is important to resolve reports in the literature which present conflicting data on vaccine safety. We performed a prospective study of Pfizer-BioNTech vaccinations administered at the Albany Community Vaccination Center. All potential vaccinees to the site were screened for allergic history prior to triage by a board-certified allergist. In the first 14 days of operation, our site vaccinated 14,655 individuals, 3.9% of which had a personal history of anaphylaxis. While some vaccine recipients had non-allergic complications, none of the visitors suffered any objective, immediate allergic symptoms. Our findings indicate that specialist-confirmed rates of immediate allergic reaction to mRNA SARS-CoV-2 vaccination are far lower than self-reported rates defined by subjective, unconfirmed symptoms.

EAACI statement on the diagnosis, management and prevention of severe allergic reactions to COVID-19 vaccines

The first approved COVID‐19 vaccines include Pfizer/BioNTech BNT162B2, Moderna mRNA‐1273 and AstraZeneca recombinant adenoviral ChAdOx1‐S. Soon after approval, severe allergic reactions to the mRNA‐based vaccines that resolved after treatment were reported. Regulatory agencies from the European Union, Unites States and the United Kingdom agree that vaccinations are contraindicated only when there is an allergy to one of the vaccine components or if there was a severe allergic reaction to the first dose. This position paper of the European Academy of Allergy and Clinical Immunology (EAACI) agrees with these recommendations and clarifies that there is no contraindication to administer these vaccines to allergic patients who do not have a history of an allergic reaction to any of the vaccine components. Importantly, as is the case for any medication, anaphylaxis may occur after vaccination in the absence of a history of allergic disease. Therefore, we provide a simplified algorithm of prevention, diagnosis and treatment of severe allergic reactions and a list of recommended medications and equipment for vaccine centres. We also describe potentially allergenic/immunogenic components of the approved vaccines and propose a workup to identify the responsible allergen. Close collaboration between academia, regulatory agencies and vaccine producers will facilitate approaches for patients at risks, such as incremental dosing of the second injection or desensitization. Finally, we identify unmet research needs and propose a concerted international roadmap towards precision diagnosis and management to minimize the risk of allergic reactions to COVID‐19 vaccines and to facilitate their broader and safer use.

Identification and Validation of Anaphylaxis Using Electronic Health Data in a Population-based Setting

BACKGROUND

Anaphylaxis is a life-threatening allergic reaction that is difficult to identify accurately with administrative data. We conducted a population-based validation study to assess the accuracy of ICD-10 diagnosis codes for anaphylaxis in outpatient, emergency department, and inpatient settings.

METHODS

In an integrated healthcare system in Washington State, we obtained medical records from healthcare encounters with anaphylaxis diagnosis codes (potential events) from October 2015 to December 2018. To capture events missed by anaphylaxis diagnosis codes, we also obtained records on a sample of serious allergic and drug reactions. Two physicians determined whether potential events met established clinical criteria for anaphylaxis (validated events).

RESULTS

Out of 239 potential events with anaphylaxis diagnosis codes, the overall positive predictive value (PPV) for validated events was 64% (95% CI = 58 to 70). The PPV decreased with increasing age. Common precipitants for anaphylaxis were food (39%), medications (35%), and insect bite or sting (12%). The sensitivity of emergency department and inpatient anaphylaxis diagnosis codes for all validated events was 58% (95% CI = 51 to 65), but sensitivity increased to 95% (95% CI = 74 to 99) when outpatient diagnosis codes were included. Using information from all validated events and sampling weights, the incidence rate for anaphylaxis was 3.6 events per 10,000 person-years (95% CI = 3.1 to 4.0).

CONCLUSIONS

In this population-based setting, ICD-10 diagnosis codes for anaphylaxis from emergency department and inpatient settings had moderate PPV and sensitivity for validated events. These findings have implications for epidemiologic studies that seek to estimate risks of anaphylaxis using electronic health data.

U.S. Population-Based background incidence rates of medical conditions for use in safety assessment of COVID-19 vaccines

The Coronavirus Disease 2019 (COVID-19) pandemic has had a devastating impact on global health, and has resulted in an unprecedented, international collaborative effort to develop vaccines to control the outbreak, protect human lives, and avoid further social and economic disruption. Mass vaccination campaigns are underway in multiple countries and are expected worldwide once more vaccine becomes available. Some early candidate vaccines use novel platforms, such as mRNA encapsulated in lipid nanoparticles, and relatively new platforms, such as replication-deficient viral vectors. While these new vaccine platforms hold promise, limited safety data in humans are available. Serious health outcomes linked to vaccinations are rare, and some outcomes may occur incidentally in the vaccinated population. Knowledge of background incidence rates of these medical conditions is a critical component of vaccine safety monitoring to aid in the assessment of adverse events temporally associated with vaccination and to put these events into context with what would be expected due to chance alone. A list of 22 potential adverse events of special interest (AESI), including neurologic, autoimmune, and cardiovascular disorders, was compiled by subject matter experts at the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention. The most recently available U.S. background rates for these medical conditions, overall and by age, sex, and race/ethnicity (when available), were sourced from reported statistics (data published by medical panels/ associations or federal government reports), and literature reviews in PubMed. This review provides estimates of background incidence rates for medical conditions that may be monitored or studied as AESI during safety surveillance and research for COVID-19 vaccines and other new vaccines.

Digital technology for anaphylaxis management impact on patient behaviour: A randomized clinical trial

BACKGROUND

Epinephrine is the first-line treatment for anaphylaxis. Patients at risk should always carry an epinephrine autoinjector (EAI). Several EAI gaps have been identified. We sought to evaluate satisfaction using a medical device (digital technology comprising an EAI smart case connected to a mobile APP) with functions that overcome most of the EAI limitations and to determine whether patient behaviour and anaphylaxis management improve with its use.

METHODS

This was a randomized, open-label, crossover clinical trial in a tertiary hospital involving patients with history of anaphylaxis carrying an EAI. The study was conducted in two three-month periods, one with and one without the medical device. The primary endpoint was satisfaction with the medical device. Usability, adherence, anxiety and anaphylaxis episodes were evaluated as secondary endpoints.

RESULTS

A total of 100 patients were included (mean age 38.1 years, 74% female), and 95 completed the trial. The satisfaction visual analogue scale (VAS) after using the medical device was higher than before its use (89.1 [95% CI, 60.2-99.1] vs 56.3 [95% CI, 48.1-81.4]; P < .0001). The adherence VAS improved from 59.7 (95% CI, 54.0-65.3) to 88.6 (95% CI, 84.2-92.9) (P < .0001). Overall, 90% patients found the medical device easy to use. Patients' anxiety decreased from 52.2% to 29.3% (P < .001). Seven episodes of anaphylaxis occurred during the study, all in patients without the medical device (P = .025). Eighty-eight per cent of patients felt more involved in the management of anaphylaxis when using the medical device.

CONCLUSION

This is the first clinical trial evaluating digital technology for EAIs, showing a change of behaviour in patients at risk of anaphylaxis, increasing satisfaction, improving adherence, and reducing anxiety, with good usability.

Current practices in diagnosis of Hymenoptera venom allergy in Poland

Introduction

Hymenoptera venom allergy (HVA) is associated with a high risk of anaphylaxis. Effective treatment of HVA patients requires allergologists' familiarity with the latest HVA recommendations.

Aim

Evaluation of current practices in HVA diagnosis in Poland.

Material and methods

A survey questionnaire was conducted in 32 HVA centres in Poland.

Results

The response rate was 97%. There were 1829 patients evaluated due to HVA in 2015. Sixty six percent (n = 21) of the centres used skin prick tests, out which 90% (n = 19) used 100 µg/ml of the venom extract as the highest concentration. All the centres performed intradermal tests (IDT) and serum specific IgE (sIgE), an initial diagnostic tool in 91% (n = 29). The highest venom concentration in IDT was 1 µg/ml in 75% (n = 24), 0.1 µg/ml in 16% (n = 5), 0.01 µg/ml in 3% (n = 1) and 10 µg/ml in 6% (n = 2). Baseline serum tryptase was assessed in 84% of the centres (n = 27), out of which 53% (n = 17) tested all their patients, whereas 31% (n = 10) checked only those with life-threatening reactions. In case of negative IDT/sIgE, 59% of the centres (n = 19) performed components evaluation, while 19% (n = 6) did the basophil activation test. In case of no identification of the culprit insect and sensitization to both venoms, VIT employed venom with higher sIgE.

Conclusions

Most allergology centres in Poland follow HVA guidelines. We identified two inaccuracies in their HVA management including non-adequate venom concentration in IDT and a false belief in correspondence between sIgE concentration and severity of allergic reactions.

Trends in Emergency Department Visits and Hospitalizations for Acute Allergic Reactions and Anaphylaxis Among US Older Adults: 2006-2014

BACKGROUND

The US older adult population (age ≥65 years) is increasing and may be at increased risk for severe anaphylaxis. Little is known about the health care use for acute allergic reactions (AAR), including anaphylaxis, among older adults.

OBJECTIVE

To characterize trends in emergency department (ED) visits and hospitalizations for AAR and anaphylaxis among US older adults from 2006 to 2014 and examine factors associated with severe anaphylaxis.

METHODS

We performed cross-sectional analyses of trends in ED visits and hospitalizations among older adults using data from the Nationwide Emergency Department Sample and the National (Nationwide) Inpatient Sample in 2006 to 2014. We used International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic codes to identify visits for AAR, including anaphylaxis. Multivariable logistic regression modeling was used to identify factors associated with severe anaphylaxis (cardiac arrest, intubation, and death).

RESULTS

In 2006 to 2014, older adults experienced approximately 1,019,967 AAR-related ED visits, 173,844 AAR-related hospitalizations, 93,795 anaphylaxis-related ED visits, and 72,677 anaphylaxis-related hospitalizations. Whereas AAR-related ED visit and hospitalization rates remained stable (P = .28 and .16, respectively), anaphylaxis-related ED visit and hospitalization rates increased significantly over time (37 visits/100,000 in 2006 to 51 in 2014, P < .001; and from 13 hospitalizations/100,000 in 2006 to 23 in 2014, P < .001), especially hospitalization rates for drug-related anaphylaxis (47 hospitalizations/100,000 in 2006 to 85 in 2014; P < .001). Risk factors for anaphylaxis-related death included older age and drug-related trigger.

CONCLUSIONS

In a nationally representative sample of US older adults, the rate of anaphylaxis-related ED visits and hospitalizations increased over time. Drug-related triggers represented a substantial portion of increased health care use and are a growing risk in this vulnerable population.

Lower Functional and Proportional Characteristics of Cord Blood Treg of Male Newborns Compared with Female Newborns

Understanding the early events involved in the induction of immune tolerance to harmless environmental antigens and microbiota compounds could reveal potential targets for allergic disease therapy or prevention. Regulatory T cells (Treg), particularly induced Treg (iTreg), are crucial for the induction and maintenance of tolerance against environmental antigens including allergens. A decrease in the number and/or function of Treg or iTreg could represent an early predictor of allergy development. We analyzed proportional and functional properties of Treg in the cord blood of children of allergic mothers (neonates at high risk of allergy development) and healthy mothers (neonates with relatively low risk of allergy development). We observed a higher number of induced Treg in the cord blood of females compared to males, suggesting an impaired capacity of male immunity to set up tolerance to allergens, which could contribute to the higher incidence of allergy observed in male infants. The decreased proportion of iTreg in cord blood compared with maternal peripheral blood documents the general immaturity of the neonatal immune system. We observed a positive correlation in the demethylation of the Treg-specific demethylated region (TSDR) and the proportion of Treg in cord blood. Our data suggest that immaturity of the neonatal immune system is more severe in males, predisposing them to increased risk of allergy development.

Trends in US Emergency Department Visits for Anaphylaxis Among Infants and Toddlers: 2006-2015

BACKGROUND

Anaphylaxis is a potentially life-threatening allergic reaction. The overall prevalence of anaphylaxis appears to be rising in children, but temporal trends among infants and toddlers are not well studied.

OBJECTIVE

To characterize the trends in US emergency department (ED) visits and hospitalizations among infants and toddlers with anaphylaxis from 2006 to 2015.

METHODS

We conducted a study of temporal trends in anaphylaxis among children (age <18 years) and, more specifically, infants and toddlers (age <3 years) presenting to the ED between 2006 and 2015 using a large, nationally representative database. For internal consistency, we defined anaphylaxis using International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes and excluded visits with International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis codes (late 2015). We calculated trends in the number and proportion of ED visits and hospitalizations and used multivariable logistic regression to identify predictors of hospitalization.

RESULTS

Among infants and toddlers, the proportion of ED visits for anaphylaxis per year increased from 20 per 100,000 visits to 50 per 100,000 visits (P_trend < .001). The rate of ED visits for anaphylaxis increased from 15 to 32 ED visits per 100,000 population of infants and toddlers (P_trend < .001). Food was the most commonly identified trigger. The proportion of hospitalization among anaphylaxis-related ED visits decreased from 19% to 6% (P_trend < .001). Among ED patients, those more likely to be hospitalized were male, privately insured, from higher income families, and presenting to urban, metropolitan teaching hospital EDs.

CONCLUSIONS

In a large, nationally representative US database, from 2006 to 2015, ED visits by infants and toddlers with anaphylaxis increased, whereas hospitalization of these patients decreased.

Anaphylaxis: Five Years' Experience in the Emergency Rooms of Five University Hospitals in Korea

Background: Anaphylaxis is an allergic disease that requires special handling due to its potential fatality. Recent epidemiological data indicate that the incidence of anaphylaxis is rising. However, actual data on the prevalence or causes of anaphylaxis in Korea are limited. Methods: The emergency room attendees diagnosed with anaphylaxis between 2011 and 2015 in five university hospitals were included. Medical records were reviewed retrospectively. Results: During the 5 years, a total of 505 subjects were diagnosed with anaphylaxis. Respiratory presentations were more common in children than in adults, while adults presented more frequently with cardiovascular symptoms. Intraoral angioedema was more often observed in the countryside than in the city. Insect stings/bites were more common in the countryside than in the city. Drugs were much more common in adults than in children. In the countryside, the frequency of anaphylaxis was higher in summer and autumn than in spring and winter. The use of corticosteroids was less common in children than in adults, while children more frequently got treatment with inhaled beta 2 agonist. Conclusions: The principal causes of anaphylaxis in Korean patients were food, drugs, and stings/bites. The cause, clinical features and management of anaphylaxis were significantly different depending on age and region. These real-world data on anaphylaxis could be helpful to deepen that understanding of this condition for physicians and patients.

Increasing anaphylaxis events in Western Australia identified using four linked administrative datasets

Background

Anaphylaxis events are increasing worldwide, based on studies of single administrative datasets including hospital admissions, emergency room presentations, and prescription and medical claims data. Linking multiple administrative datasets may provide better epidemiological estimates, by capturing a greater number of anaphylaxis events occurring at the individual level. In this linked data study in Western Australia, we combined 4 population-based datasets to identify anaphylaxis events, factors influencing occurrence, and change in event rates from 2002 to 2013.

Methods

Four linked administrative datasets from the Western Australian Data Linkage System were used, representing ambulance attendances, emergency department presentations, hospital inpatient admissions and death registrations. An anaphylaxis cohort was identified using ICD-9-CM, ICD-10-AM and additional anaphylaxis diagnosis codes, with event rates calculated. We explored the impact of age, gender, cause, Indigenous status and socioeconomic index on event rates. Standard Poisson regression models were used to examine the significance of the change in anaphylaxis event rates over time.

Results

A total 12,637 individuals (mean age 31.8 years, 49.6% female) experienced 15,462 anaphylaxis events between 2002 and 2013 (97.5% in non-Indigenous patients and 59.5% residing in the area of greatest socioeconomic advantage). Anaphylaxis event rates increased from 15.4 to 82.5/10⁵ population between 2002 and 2013. The greatest increase in anaphylaxis events was seen in those coded as unspecified anaphylaxis (all ages, males and females combined, p < 0.001), with the highest rates of unspecified anaphylaxis in males 0–4 years (171.9/10⁵ population in 2013), and females 15–19 years (104.0/10⁵ in 2013). The average annual percent increase (95% CI) for food-related anaphylaxis was 9.2% (6.6–12.0); for medication-related anaphylaxis was 5.8% (4.5–7.1); and for unspecified anaphylaxis was 10.4% (9.8–11.0); all p < 0.001. There was a significant increase in ambulance attendance, emergency presentations and inpatient admissions for anaphylaxis between 2002 and 2013, with emergency presentations (56.0/10⁵ population), inpatient admissions (43.2/10⁵), and ambulance attendance (21.6/10⁵) highest in 2013. Only 25 anaphylaxis-related deaths were recorded in the mortality register with no significant change in rates over time.

Conclusion

Using multiple linked administrative datasets, we identified significantly higher rates of total anaphylaxis than previously reported, with more than 5-fold increases in anaphylaxis events between 2002 and 2013. While the combination of 4 population-level datasets provides a more comprehensive capture of cases, even at the individual dataset level, admission rates for anaphylaxis in Western Australia are substantially higher than those previously reported for similar time periods, both in Australia and worldwide.