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

Prediction of pediatric peanut oral food challenge outcomes using machine learning

Background

Clinical testing, including food-specific skin and serum IgE level tests, provides limited accuracy to predict food allergy. Confirmatory oral food challenges (OFCs) are often required, but the associated risks, cost, and logistic difficulties comprise a barrier to proper diagnosis.

Objective

We sought to utilize advanced machine learning methodologies to integrate clinical variables associated with peanut allergy to create a predictive model for OFCs to improve predictive performance over that of purely statistical methods.

Methods

Machine learning was applied to the Learning Early about Peanut Allergy (LEAP) study of 463 peanut OFCs and associated clinical variables. Patient-wise cross-validation was used to create ensemble models that were evaluated on holdout test sets. These models were further evaluated by using 2 additional peanut allergy OFC cohorts: the IMPACT study cohort and a local University of Michigan cohort.

Results

In the LEAP data set, the ensemble models achieved a maximum mean area under the curve of 0.997, with a sensitivity and specificity of 0.994 and 1.00, respectively. In the combined validation data sets, the top ensemble model achieved a maximum area under the curve of 0.871, with a sensitivity and specificity of 0.763 and 0.980, respectively.

Conclusions

Machine learning models for predicting peanut OFC results have the potential to accurately predict OFC outcomes, potentially minimizing the need for OFCs while increasing confidence in food allergy diagnoses.

Anaphylaxis in Practice: A Guide to the 2023 Practice Parameter Update

This review summarizes new research developments and clinical practice recommendations for the diagnosis and management of anaphylaxis presented in the Joint Task Force on Practice Parameters 2023 Anaphylaxis practice parameter Update. It is intended to serve as a high-level summary of the 2023 practice parameter, which makes clinically impactful recommendations based on evidence that has emerged since the 2015 practice parameter. We invite clinicians to explore the full 2023 practice parameter to understand the research methods and underlying evidence that have informed the recommendations summarized here. There are new and evolving diagnostic criteria for anaphylaxis, rules for defining elevated tryptase levels, and recognition of signs and symptoms particular to infants and toddlers. The administration of epinephrine should not be used as a surrogate to diagnose anaphylaxis. Risk factors for anaphylaxis should be assessed on a case-by-case basis. Patient counseling and shared decision-making are essential to support patients' treatment decisions and capacity to manage the risk of anaphylaxis at home and in other community settings. Activation of emergency medical services after home epinephrine administration may not be required in all cases, and patients should be engaged in shared decision-making to determine when home management may be appropriate.

Physician adherence to anaphylaxis guidelines among different age groups in emergency departments: 20-Year observational study

BACKGROUND

Anaphylaxis is an acute and serious allergic reaction. Little is known about physician adherence to anaphylaxis guidelines among patients across different age groups.

OBJECTIVE

To investigate real-world physician adherence to anaphylaxis guidelines among children, adults, and older adults in emergency departments.

METHODS

This study retrospectively analyzed all consecutive patients with anaphylaxis who presented to 2 emergency departments at 2 branches of the largest tertiary hospital in Taiwan, between 2001 and 2020. Patients who met the diagnostic criteria for anaphylaxis were enrolled and grouped by age: children (<18 years), adults (18-64 years), and older adults (≥65 years).

RESULTS

We enrolled 771 patients with anaphylaxis (159 children, 498 adults, and 114 older adults). Intramuscular epinephrine was administered in 294 cases (38.1%). There was a significant age-group difference in the rate of intramuscular epinephrine administration (46.5% in children, 37.3% in adults, and 29.8% in older adults; P trend = .004). When stratified by severity, 14.3% of older adults with moderate reactions received intramuscular epinephrine, whereas 35.2% of adults and 55.3% of children received intramuscular epinephrine (P trend < .001), whereas such difference was not found in patients with severe reactions. Upon discharge from emergency departments, 15.3% received allergist referral (52.2% in children, 6.6% in adults, and 1.8% in older adults; P trend < .001); 12.5% received education on avoidance of triggers (18.9%, 11.4%, and 7.9%; P trend = .01), and 16.1% received education on alarm symptoms (21.4%, 15.1%, and 13.2%; P trend = .05).

CONCLUSION

The real-world physician adherence to anaphylaxis guidelines remains suboptimal in emergency departments, particularly among older adults. Physician continuing education is needed to improve the gap between anaphylaxis guidelines and clinical practice.

Anaphylaxis: A 2023 practice parameter update

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

Factors Associated With Epinephrine Use in the Treatment of Anaphylaxis in Infants and Toddlers

BACKGROUND

Undertreatment of anaphylaxis with epinephrine continues to be an unmet need and is a particular challenge among infants and toddlers.

OBJECTIVE

To address this gap by identifying barriers and solutions to appropriate and timely administration of epinephrine.

METHODS

We conducted a national online survey among primary caregivers of children who experienced a severe food-induced allergic reaction when younger than 36 months. Outcomes of interest included epinephrine use in community and health care settings to treat probable anaphylaxis.

RESULTS

Of 264 probable anaphylaxis cases, 39% of infants (aged <12 months) and 61% of toddlers (aged 12-35 months) received epinephrine at any time during the child's most severe allergic reaction (P = .001). A previous diagnosis of a food allergy was reported in 62% of cases where epinephrine was used compared with 26% of cases where epinephrine was not used (P < .001). In children with a previous diagnosis of a food allergy, epinephrine was used in 89% of those who were prescribed an anaphylaxis action plan compared with 50% of those without a plan (P = .001). The adjusted odds ratio for the association between having an anaphylaxis action plan and epinephrine use in cases of probable anaphylaxis was 5.39 (95% confidence interval, 2.18-13.30).

CONCLUSIONS

Epinephrine use at any time (including in health care settings) during probable anaphylaxis is more likely in infants and toddlers with a previously diagnosed food allergy than those without diagnosis. The provision of an anaphylaxis action plan is also associated with increased epinephrine use during probable anaphylaxis in this population.

Increasing emergency department visits for anaphylaxis in very early childhood: A canary in the coal mine

AIM

The incidence of anaphylaxis is increasing globally in tandem with changing environmental and lifestyle factors. There is very limited data on very early childhood presentations. We aim to assess changes in rates, characteristics and management of infant anaphylaxis in a paediatric ED over a 15-year period.

METHODS

We conducted a retrospective study of children <2 years of age who presented with verified anaphylaxis comparing cases in years 2003-2007 with those in 2013-2017. Standardised information was collected on demographics, clinical presentation, management and triggers.

RESULTS

Manually confirmed anaphylaxis rates in <2 year olds increased from 3.6 to 6.2 per 104 population (OR 1.7, 95% CI: 1.3-2.7; p < 0.001) with the greatest increase in <1 year olds. Anaphylaxis severity increased between 2003-2007 and 2013-2017 (OR 2.3, 95% CI: 1.2-4.3; p = 0.018). Failure to administer adrenaline was reduced in 2013-2017 (p = 0.007). Food was the leading anaphylaxis trigger (97.85%).

CONCLUSION

This is the first study to suggest an increase in the incidence and severity of ED anaphylaxis presentations in children aged <2 years. Increased awareness of specific characteristics in this age group is required to facilitate timely recognition and optimal management. Further large-scale studies are warranted to understand underlying environmental drivers and find prevention strategies to reduce the burden of disease.

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.

Transepidermal water loss rises before food anaphylaxis and predicts food challenge outcomes

BACKGROUNDFood allergy (FA) is a growing health problem requiring physiologic confirmation via the oral food challenge (OFC). Many OFCs result in clinical anaphylaxis, causing discomfort and risk while limiting OFC utility. Transepidermal water loss (TEWL) measurement provides a potential solution to detect food anaphylaxis in real time prior to clinical symptoms. We evaluated whether TEWL changes during an OFC could predict anaphylaxis onset.METHODSPhysicians and nurses blinded to the TEWL results conducted and adjudicated the results of all 209 OFCs in this study. A study coordinator measured TEWL throughout the OFC and had no input on the OFC conduct. TEWL was measured 2 ways in 2 separate groups. First, TEWL was measured using static, discrete measurements. Second, TEWL was measured using continuous monitoring. Participants who consented provided blood samples before and after the OFCs for biomarker analyses.RESULTSTEWL rose significantly (2.93 g/m2/h) during reactions and did not rise during nonreacting OFCs (-1.00 g/m2/h). Systemic increases in tryptase and IL-3 were also detected during reactions, providing supporting biochemical evidence of anaphylaxis. The TEWL rise occurred 48 minutes earlier than clinically evident anaphylaxis. Continuous monitoring detected a significant rise in TEWL that presaged positive OFCs, but no rise was seen in the OFCs that resulted in no reaction, providing high predictive specificity (96%) for anaphylaxis against nonreactions 38 minutes prior to anaphylaxis onset.CONCLUSIONSDuring OFCs, a TEWL rise anticipated a positive clinical challenge. TEWL presents a monitoring modality that may predict food anaphylaxis and facilitate improvements in OFC safety and tolerability.

Extrinsic and Intrinsic Modulators of Anaphylaxis

The severity of anaphylaxis is determined by many factors. The allergenic source as well as the age of the affected individual and the route of allergen exposure encompass the major contributors of the clinical outcome. Moreover, the severity can be modulated further by intrinsic and extrinsic factors. Among these, the genetic predisposition, certain comorbidities such as uncontrolled asthma, and hormonal fluctuations have been proposed as intrinsic and antihypertensive medications or physical activity as extrinsic factors. Recent advances have highlighted immunologic pathways that may exacerbate the response to allergens through receptors on mast cells, basophils, platelets, and other granulocytes. Atopy, platelet-activating factor acetylhydrolase deficiency, hereditary alpha tryptasemia, and clonal mast cell disorders are examples associated with genetic alterations that may predispose to severe anaphylaxis. Identifying risk factors that lower the threshold of reactivity or increase the severity of multisystem reactions is important in the management of this patient population.

Pattern of admissions and outcome in the children emergency department of a tertiary health institution in Southwestern Nigeria: A four-year review

Introduction

Pediatrics and adolescents are susceptible to illnesses that often necessitate emergency attention. Morbidity and mortality from illnesses in these ages have attracted much interest globally, particularly in Africa. Knowledge of pattern and outcomes of admissions may guide policy and interventions especially in resource constrained settings. The study aimed to determine the pattern of admissions, outcomes and seasonal variations of conditions that presented at the children emergency of a tertiary health institution over a four-year period.

Methods

A retrospective descriptive study of children emergency admissions from January 2016 to December 2019. Information obtained included age, diagnosis, month and year of admission, and outcome. Descriptive statistics were used to describe the demographic characteristics and Chi-squared test to assess their associations with the diagnoses made.

Results

There were 3,223 admissions. There were more males (1866; 57.9%) and more toddlers (1181; 36.6%). The highest number of admissions were observed in the year 2018 (951; 29.6%) and during the wet season (1962; 60.9%). There was an overall mortality rate of 7%; complicated malaria, gastroenteritis and meningitis were the leading causes of death. Malaria (χ2 = 135.522, p value < 0.001), and gastroenteritis (χ2 = 130.883, p value < 0.001) were predominant among the toddlers while sepsis (χ2 = 71.530, p value < 0.001) and pneumonia (χ2 = 133.739, p value < 0.001) were more among the infants. Typhoid enteritis (χ2 = 26.629, p value < 0.001) and HIV (χ2 = 16.419, p value = 0.012) were commoner among the early adolescents.

Conclusion

The major causes of death in the study area are preventable with more of these amongst the children under the age of 5 years. There are seasonal and age-related patterns to admissions and the need for policy formulations and emergency preparations to be tailored towards these observed patterns through the year.

Cow's milk and hen's egg anaphylaxis: A comprehensive data analysis from the European Anaphylaxis Registry

BACKGROUND

Cow's milk (CM) and hen's egg (HE) are leading triggers of anaphylaxis in early childhood. The aim of this study was to identify clinical phenotypes and therapeutic measures for CM anaphylaxis (CMA) compared to HE anaphylaxis (HEA) in children up to 12 years of age, based on a large pan-European dataset from the European Anaphylaxis Registry.

METHODS

Data from 2007 to 2020 on clinical phenotypes and treatment from 10 European countries, as well as Brazil, were analysed. The two-step cluster analysis was used to identify the most frequent phenotypes. For each trigger, three clusters were extracted based on sex, age, and existence of symptoms in four vitally important systems.

RESULTS

Altogether 284 children with CMA and 200 children with HEA were identified. They were characterised as male (69% vs. 64%), infants (65% vs. 61%), with a most frequent grade III of Ring&Messmer classification (62% vs. 64%), in CMA versus HEA, respectively. Respiratory symptoms occurred more often in CMA (91% vs. 83%, p = 0.010), especially in infants (89% vs. 79%, p = 0.008). Cardiovascular symptoms were less frequent in CMA (30% vs. 44%, p = 0.002), in both infants (33% vs. 46%, p = 0.027), and older children (25% vs. 42%, p = 0.021). The clusters extracted in the CMA group were characterised as: (1) mild dermal infants with severe GI (40%), 2. severe dermal (35%), 3. respiratory (25%). While in HEA group: 1. infants with severe GI and/or reduction of alertness (40%), (2) conjunctival (16%), (3) mild GI without conjunctivitis (44%). The severity of the reaction was independent from the amount of ingested allergen protein, regardless of trigger. The first-line adrenaline application differed between the countries (0%-92%, as well as the reasons for not administering adrenaline, p < 0.001).

CONCLUSIONS

Despite the similarity of their age, sex, and severity grade, the clinical profiles differed between the CMA and HEA children. Adrenaline was underused, and its administration was country dependent. Further studies are needed to assess to what extent the differences in the clinical profiles are related to matrix and/or absorption effects, and/or the allergen itself.

The impact of modernization on allergy and asthma development

Background: In recent years, an increase of allergies and asthma has been observed throughout the world, more so in Western countries than in less developed ones. Although genetics may play a role in this increase, there are many other factors that may have contributed to the upsurge. Objective: The purpose of the present report was to review the many factors associated with modernization and lifestyle that may have contributed to the allergy and/or asthma epidemic, with a particular focus on those aspects that have particular relevance for the allergist/immunologist. Results: The marked rise in allergy and asthma has been significantly seen in more-developed countries, greater in urban than in rural areas, more pronounced in affluent than in poorer societies, and in individuals who have migrated from developing countries to industrialized countries. A widely accepted explanation for this rise is the "hygiene hypothesis," which postulates a critical dependence on microbial infection for maintenance of a healthy balanced immune system and that extremely clean external environments, often found in the developed world, can derail equilibrated immune development. With the control of infectious diseases, the immune system shifts from a balanced equilibrated immunologic structure to a more Th2 driven proinflammatory state often associated with IgE and eosinophil-related disorders. Conclusion: Modernization has been associated with increased development of allergies and asthma through a cleaner environment and more exposure to allergens and to multiple other contributory factors. The marked reduction in infectious diseases in recent decades permitted the immune system to switch from fighting infectious disease agents and parasites to reacting adversely (hypersensitivity) to benign environmental agents (allergens) and even to self-antigens (autoimmunity).

Children at risk of anaphylaxis: A mixed-studies systematic review of parents' experiences and information needs

Objective

To explore parents' self-reported experiences and information needs regarding recognition and management of pediatric anaphylaxis.

Methods

We searched Ovid Medline, Ovid PsychInfo, CINAHL Plus, the Cochrane Library, and grey literature to identify primary studies in English or French published since 2000. We used a mixed-method appraisal tool and convergent integrated approach to assess quality and synthesize data, respectively.

Results

43 studies were included (22 quantitative, 19 qualitative, and 2 mixed-method); 77% of studies had high methodological quality. Parents' experiences were categorized as: recognizing an anaphylactic reaction; managing and responding to a reaction; emotional impact of caring for a child at risk of anaphylaxis; and interaction with the health system and healthcare providers. Parents' information needs were categorized into themes relating to: gaps in knowledge and information; type of information desired; information sources; and information delivery format.

Conclusion

Negative emotional experiences and a general lack of information were commonly reported by parents of included studies. Provision of relevant and comprehensible information may help parents to make informed decisions and manage reactions promptly.

Innovation

The findings of this review are guiding the development of an innovative knowledge translation tool (KT) as part of a larger initiative of developing a suite of parent-focused KT tools for acute childhood conditions.

Anaphylaxis in Brazil between 2011 and 2019

BACKGROUND

There is a lack of population-based studies of anaphylaxis from low- and middle-income countries. This hampers public health planning and investments and may influence availability of adrenaline auto-injectors.

OBJECTIVE

We conducted the first national population-based study of anaphylaxis hospitalization in Brazil.

METHODS

Descriptive study using routinely reported data to the Brazilian Hospital Information System for the years 2011-2019. Information available is coded based on the International Classification of Diseases (ICD)-10 and covers main cause of hospitalization (primary cause) and any conditions contributing to it (secondary cause).

RESULTS

Over 9 years, we identified 5716 admissions due to anaphylaxis for all causes. The average hospitalization rate related to anaphylaxis was 0.71/100,000 population per year, with a 2.4% (95% CI 1.9%, 2.9%) increase per annum over the study period. Admissions were more frequent among females (52.8%), except for cases due to insect sting. Most admissions occurred in adulthood, from 30 to 59 years (36.3%) but 13.8% in preschool children (0-4 years). There were more young children admitted for food-related anaphylaxis, and more adults admitted for drug/iatrogenic-related anaphylaxis. There were 334 cases (5.8% of admissions) of fatal anaphylaxis over the study period, with increased case fatality rate over time.

CONCLUSIONS AND CLINICAL RELEVANCE

This is the first study of anaphylaxis hospital admissions using nation-wide data from a low- or middle-income country. Hospital admissions and fatalities from anaphylaxis in Brazil appear to be increasing.

Management of Anaphylaxis in Infants and Toddlers

Anaphylaxis is a systemic allergic reaction that can be caused by food, drugs, insect bites, or unknown triggers in infants and toddlers. Anaphylaxis rates are increasing. Infants and toddlers may have increased exposure to known and unknown allergens, decreased ability to describe their symptoms, and an expanded differential diagnosis for consideration on presentation. The most common symptoms in these age groups are cutaneous and gastrointestinal. Age-specific language may be helpful for caregivers to identify and describe the symptoms of anaphylaxis in infants and toddlers. Long-term management of anaphylaxis includes allergy evaluation to guide avoidance and assess prognosis and education on allergic reaction management; this incorporates the prescription of epinephrine autoinjector and provision of an allergy emergency plan.