World Allergy Organization (WAO) Diagnosis and Rationale for Action against Cow's Milk Allergy (DRACMA) guidelines update - X - Breastfeeding a baby with cow's milk allergy

Cow's milk allergy is rare in exclusively breastfed infants. To support the continuation of breastfeeding an infant after diagnosis with a cow's milk allergy, it is critical to examine the evidence for and against any form of cow's milk elimination diet for lactating mothers. In this narrative review, we highlight the lack of high-quality evidence, hence subsequent controversy, regarding whether the minuscule quantities of cow's milk proteins detectable in human milk cause infant cow's milk allergy symptoms. Current clinical practice recommendations advise a 2-4 week trial of maternal cow's milk dietary elimination for: a) IgE-mediated cow's milk allergy only if the infant is symptomatic on breastfeeding alone; b) non-IgE-mediated associated symptoms only if the history and examination strongly suggest cow's milk allergy; and c) infants with moderate to severe eczema/atopic dermatitis, unresponsive to topical steroids and sensitized to cow's milk protein. There should be a clear plan for home reintroduction of cow's milk into the maternal diet for a period of 1 week to determine that the cow's milk elimination is responsible for resolution of symptoms, and then subsequent reoccurrence of infant symptoms upon maternal cow's milk reintroduction. The evidence base to support the use of maternal cow's milk avoidance for the treatment of a breastfed infant with cow's milk allergy is of limited strength due to a lack of high-quality, adequately powered, randomised controlled trials. It is important to consider the consequences of maternal cow's milk avoidance on reducing immune enhancing factors in breast milk, as well as the potential nutritional and quality of life impacts on the mother. Referral to a dietitian is advised for dietary education, along with calcium and vitamin D supplementation according to local recommendations, and a maternal substitute milk should be advised. However, for most breastfed infants with cow's milk allergy maternal cow's milk dietary elimination will not be required, and active support of the mother to continue breastfeeding is essential.

Australian Infant Food Allergy Emergency Presentations Following Updated Early Food Introduction Guidelines

BACKGROUND

The Australasian Society of Clinical Immunology and Allergy food allergy prevention guidelines were updated in 2016 to recommend home introduction of allergenic foods actively in the first year of life, including to infants at high risk of allergy. An important consideration for parents and providers is whether this practice increases food allergy reactions or anaphylaxis.

OBJECTIVE

We aimed to determine whether the 2016 update of food allergy prevention guidelines was associated with an increase in food allergy or anaphylaxis emergency department (ED) presentations.

METHODS

We obtained hospital electronic medical records for infants aged 4 to 12 months who attended the Royal Children's Hospital Melbourne ED in 2015 or in 2018 with a presenting problem or an encounter diagnosis of food allergy or anaphylaxis.

RESULTS

Emergency department presentations owing to food allergy increased from 1.0% (95% CI, 0.85-1.23) in 2015 to 1.4% (95% CI, 1.22-1.67) in 2018 (P = .006). There was no increase in the number of anaphylaxis presentations (28 in 2015 and 22 in 2018) or peanut anaphylaxis presentations (three in 2015 and three in 2018). Overall, the proportion of food allergy presentations attributed to IgE-mediated food allergy was similar (82.1% in 2015 and 84.1% in 2018), whereas peanut allergy presentations increased slightly, although not statically significantly, from 14.6% to 21.2% (P = .09). Food protein-induced enterocolitis syndrome ED presentations were five in 2015 (4.3%) and 12 in 2018(7.6%), although not statistically significant (P = .25).

CONCLUSIONS

Changes to food allergy prevention guidelines recommending the earlier introduction of allergenic food may have led to a small increase in ED presentations for food allergy but not anaphylaxis.

Cashew Allergy Prevalence and Sensitization in 1-Year-Old Infants

BACKGROUND

Cashew allergy is the most common tree nut allergy in Australia, but there are limited data on the population-level prevalence and risk factors.

OBJECTIVE

Describe the prevalence of cashew sensitization and allergy in 12-month-old infants and identify risk factors.

METHODS

Data were from the EarlyNuts cohort, a population-based sample of infants recruited in Melbourne, Australia. Families completed a questionnaire and infants underwent a skin prick test (SPT) to cashew. Infants with positive SPTs were offered food challenges. Questionnaires collected demographic data and allergy risk factors. Allergy outcomes were determined by challenge outcomes or a convincing history of an allergic reaction. We used weights to adjust estimated prevalence to reflect the distribution of risk factors among the combined sample of participants and nonparticipants.

RESULTS

We recruited 1,933 participants and identified 1,414 cashew allergy outcomes. Of these, 1.96% (95% CI, 1.28-2.99) had an SPT result of 3 mm or greater and 1.49% (95% CI, 0.91-2.44) were allergic to cashew. Infants with eczema or peanut allergy in the first year of life were more likely to be allergic to cashew (adjusted odds ratio = 5.75; 95% CI, 2.08-15.88; P = .001; and adjusted odds ratio = 19.30; 95% CI, 5.44-68.43; P < .001, respectively). Twenty-five percent of participants had cashew introduced before 12 months (95% CI, 22.7-27.8). There was no association between the timing of cashew introduction and cashew allergy.

CONCLUSIONS

To our knowledge, this is the first study describing the prevalence of and risk factors for cashew allergy in a population-based infant cohort. Eczema and peanut allergy were associated with an increased risk of cashew allergy. Few infants were introduced to cashew before age 12 months, which suggests that infant feeding guidelines have not yet translated to the earlier introduction of all allergens.

Systematic Review of the Incidence and/or Prevalence of Eating Disorders in Individuals With Food Allergies

BACKGROUND

Chronic diseases involving strict dietary adherence have been associated with an increased risk of eating disorders (EDs). This is the first systematic review investigating the rate of EDs among individuals with food allergies (FAs).

OBJECTIVE

To report the incidence, prevalence, and types of EDs in individuals with FAs.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched 4 databases for studies published to January 2022 that reported the prevalence or incidence of EDs in samples with immunoglobulin E (IgE) or non-IgE-mediated allergy. Risk of bias was assessed and evidence qualitatively synthesized.

RESULTS

From 1,180 papers identified, 9 met inclusion criteria. There were 4,161 adult and pediatric participants with IgE-mediated FAs or eosinophilic esophagitis. Avoidant/Restrictive Food Intake Disorder (ARFID) or anorexia nervosa/bulimia nervosa were the main EDs identified. The prevalence of EDs in samples with FA ranged from 0.8% to 62.9%. Among studies investigating IgE-mediated FA (n = 6), the prevalence of anorexia nervosa and/or bulimia nervosa ranged from 17.6 to 61%, ARFID was 62.9%, and unspecified EDs was 0.8% to 6%. Among samples with eosinophilic esophagitis (n = 3), ARFID prevalence ranged from 4.5% to 51%. Most studies were limited by small sample size, possible selection bias, and lack of diagnostic EDs tools validated for food allergic populations.

CONCLUSIONS

Eating disorders appear prevalent in individuals with FA; however, prevalence estimates varied widely. Large studies with healthy control groups and validated measures to identify EDs in individuals with FA are needed to accurately determine the prevalence of EDs.

Epigenomic variability is associated with age-specific naïve CD4 T cell response to activation in infants and adolescents

Childhood is a critical period of immune development. During this time, naïve CD4 (nCD4) T cells undergo programmed cell differentiation, mediated by epigenetic changes, in response to external stimuli leading to a baseline homeostatic state that may determine lifelong disease risk. However, the ontogeny of epigenetic signatures associated with CD4 T cell activation during key developmental periods are yet to be described. We investigated genome-wide DNA methylation (DNAm) changes associated with nCD4 T activation following 72 h culture in media+anti-CD3/CD28 beads in healthy infants (aged 12 months, n = 18) and adolescents (aged 10-15 years, n = 15). We integrated these data with transcriptomic and cytokine profiling from the same samples. nCD4 T cells from both age groups show similar extensive epigenetic reprogramming following activation, with the majority of genes involved in the T cell receptor signaling pathway associated with differential methylation. Additionally, we identified differentially methylated probes showing age-specific responses, that is, responses in only infants or adolescents, including within a cluster of T cell receptor (TCR) genes. These encoded several TCR alpha joining (TRAJ), and TCR alpha variable (TRAV) genes. Cytokine data analysis following stimulation revealed enhanced release of IFN-γ, IL-2 and IL-10, in nCD4 T cells from adolescents compared with infants. Overlapping differential methylation and cytokine responses identified four probes potentially underpinning these age-specific responses. We show that DNAm in nCD4T cells in response to activation is dynamic in infancy and adolescence, with additional evidence for age-specific effects potentially driving variation in cytokine responses between these ages.

Early peanut introduction: To test or not to test?

OBJECTIVE

To review recent evidence and international guidelines on early peanut introduction for preventing peanut allergy and provide an update on the status of the debate around testing before early peanut introduction.

DATA SOURCES

Review of published literature documenting: infant feeding guidelines; impact of early peanut introduction on peanut allergy; risk factors for peanut allergy; and impact of early peanut introduction guidelines on infant feeding practices and allergy.

STUDY SELECTION

We used a narrative approach and present both pro and con arguments for testing before peanut introduction. Data from randomized controlled trials and post-hoc analyses of these trials and observational studies were included.

RESULTS

Allergy prevention guidelines around the world now consistently recommend introducing peanut into an infant's diet before 12 months of age for countries with high peanut allergy prevalence. In the US, guidelines recently shifted away from recommending allergy testing before introduction for those at risk of peanut allergy. There is evidence primarily from Australia that recommending early introduction without prior testing is safe and effective in increasing early peanut introduction for both high and low-risk infants, although the subsequent reduction in peanut allergy prevalence at the population level was less than expected.

CONCLUSION

Current evidence supports recommending early peanut introduction without routinely testing for peanut allergy. If testing is offered, this should be based on shared decision making between families and practitioners and only be undertaken where there is provision for rapid access to definitive diagnosis including oral food challenges.

Complementary and Allergenic Food Introduction in Infants: An Umbrella Review

BACKGROUND

Multiple systematic reviews examine the introduction of foods in relation to individual health outcomes, but the balance of harms and benefits has not been overviewed systematically.

OBJECTIVES

We aimed to perform an overview of systematic reviews on age of introduction of complementary and allergenic foods to the infant diet and long and short-term health outcomes.

DATA SOURCES

We searched Medline, Embase, Cochrane, and PubMed (July 25, 2022).

STUDY SELECTION

Included systematic reviews examining the introduction of complementary or allergenic foods before age 1. Outcomes included allergic, autoimmune, and inflammatory diseases, neurodevelopment, nutrition, and weight.

DATA EXTRACTION

Extraction and quality assessment were performed in duplicate (A Measurement Tool to Assess Systematic Reviews) and strength of evidence was assessed.

RESULTS

We screened 4015 articles and included 32 systematic reviews. There was moderate evidence that peanut and egg should be introduced from 4 to 11 months to prevent food allergy (6 of 10 reviews). Complementary food introduction was not associated with food allergy. Moderate certainty evidence suggested age of complementary food introduction was not associated with eczema. Age at introduction of gluten was not associated with celiac disease (high certainty evidence; 3 of 4 reviews). Low certainty evidence indicated that introducing solids before 4 months may increase the risk of childhood obesity, but not growth. There was insufficient evidence regarding an association between any food introduction and bone health, gastrointestinal diseases, autoimmune disorders, asthma, or allergic rhinitis.

LIMITATIONS

Gray literature was not included.

CONCLUSIONS

Current evidence supports introducing complementary foods around 6 months and allergenic foods before 11 months.

Immuno-epigenomic analysis identifies attenuated interferon responses in naïve CD4 T cells of adolescents with peanut and multi-food allergy

BACKGROUND

IgE-mediated food allergies have been linked to suboptimal naïve CD4 T (nCD4T) cell activation in infancy, underlined by epigenetic and transcriptomic variation. Similar attenuated nCD4T cell activation in adolescents with food allergy have also been reported, but these are yet to be linked to specific epigenetic or transcriptional changes.

METHODS

We generated genome-wide DNA methylation data in purified nCD4 T cells at quiescence and following activation in a cohort of adolescents (aged 10-15 years old) with peanut allergy (peanut only or peanut + ≥1 additional food allergy) (FA, n = 29), and age-matched non-food allergic controls (NA, n = 18). Additionally, we assessed transcriptome-wide gene expression and cytokine production in these cells following activation.

RESULTS

We found widespread changes in DNA methylation in both NA and FA nCD4T cells in response to activation, associated with the T cell receptor signaling pathway. Adolescents with FA exhibit unique DNA methylation signatures at quiescence and post-activation at key genes involved in Th1/Th2 differentiation (RUNX3, RXRA, NFKB1A, IL4R), including a differentially methylated region (DMR) at the TNFRSF6B promoter, linked to Th1 proliferation. Combined analysis of DNA methylation, transcriptomic data and cytokine output in the same samples identified an attenuated interferon response in nCD4T cells from FA individuals following activation, with decreased expression of several interferon genes, including IFN-γ and a DMR at a key downstream gene, BST2.

CONCLUSION

We find that attenuated nCD4T cell responses from adolescents with food allergy are associated with specific epigenetic variation, including disruption of interferon responses, indicating dysregulation of key immune pathways that may contribute to a persistent FA phenotype. However, we recognize the small sample size, and the consequent restraint on reporting adjusted p-value statistics as limitations of the study. Further study is required to validate these findings.

A pragmatic approach to infant feeding for food allergy prevention

Early introduction of allergenic foods into an infant's diet is currently the most promising strategy to prevent food allergy, with infant guidelines around the world shifting from promoting avoidance to actively encourage the introduction of allergenic foods in the infant diet. Infant feeding guidelines vary according to regional public health priorities, and knowledge gaps remain, resulting in ongoing challenges for clinicians and families to translate guidelines into practical strategies for the introduction of complementary foods for food allergy prevention. Evidence from Australia demonstrates high community support and uptake of revised guidelines with most parents introducing allergenic foods in the first year of life, although this has not had the expected impact on substantially reducing food allergy prevalence. To uptake of guidelines from other countries is less clear, and several barriers have been noted in infant feeding RCTs, which may warrant intervention strategies. Further research is needed to understand additional strategies for food allergy prevention, particularly in infants who develop food allergy prior to when they are developmentally ready to commence solids. Several RCTs are underway investigating preventative strategies that target the window before allergen ingestion, such as vitamin D supplementation, emollient use, and immunizations that prime the immune response away from a Th2-driven allergic phenotype. Further research is also needed to understand the role of the environment and the host environment in the development of tolerance to foods.

Ana o 3 sIgE and diagnostic algorithms reduce cost of cashew allergy diagnosis in children compared with skin prick test: A cost comparison analysis

BACKGROUND

In the absence of a clear clinical history of reaction, diagnosis of cashew allergy using skin prick tests (SPT) or cashew-specific IgE requires a high number of oral food challenges (OFC). By using Ana o 3 sIgE alone, or a two-step diagnostic algorithm using cashew sIgE followed by Ana o 3 sIgE, there is a reduced need for OFC. We aimed to perform a cost comparison for both of these approaches compared with cashew SPT alone.

METHODS

Pooled individual-level data from 6 studies were used to determine diagnostic accuracy and OFC rate. Two studies used cashew SPT (n = 567, 198 allergic), with 95% positive and negative predictive values of ≥12 mm and <3 mm. Four studies were included in the pathways for Ana o 3 sIgE alone or a 2-step algorithm incorporating cashew and Ana o 3 sIgE (n = 271, 156 allergic). Cut-offs used were ≥8.5kUA/L and ≤0.1kUA/L for cashew sIgE and ≥0.35kUA/L and ≤0.1kUA/L for Ana o 3 sIgE. Costs were constructed based on unit prices from hospital inpatient admissions, expenses incurred by families, individual patient data on allergic reaction types and rates, and adrenaline autoinjector carriage, applying a health system perspective.

RESULTS

Modeled data through the Ana o 3 pathway resulted in a 46.43% cost reduction (€307,406/1000 patients) compared with using cashew SPT alone (€573,854/1000 patients). The 2-step algorithm resulted in a 44.94% cost reduction compared with SPT alone (€315,952.82/1000 patients). Both the Ana o 3 pathway and 2-step algorithm resulted in a 79%-80% reduction in OFCs compared with SPT.

CONCLUSIONS

Using Ana o 3 as a standalone test for cashew allergy diagnosis or a 2-step algorithm incorporating cashew sIgE and Ana o 3 sIgE is accurate and results in a large reduction in both OFCs and health system costs compared with cashew SPT alone.

PrEggNut Study: protocol for a randomised controlled trial investigating the effect of a maternal diet rich in eggs and peanuts from <23 weeks' gestation during pregnancy to 4 months' lactation on infant IgE-mediated egg and peanut allergy outcomes

INTRODUCTION

Clinical studies supported by immunological data indicate early life intervention strategies to be promising in reducing the growing global burden of food allergies. The events that predispose to food allergy, including the induction of allergen-specific immune responses, appear to be initiated early in development. Early exposure to food allergens in utero and via breast milk is likely to be important in initiating oral tolerance. We aim to determine the effectiveness of higher maternal food allergen consumption during pregnancy and lactation on infant food allergy outcomes.

METHODS AND ANALYSIS

This is a multisite, parallel, two-arm (1:1 allocation), single-blinded (outcome assessors, statistical analyst and investigators), randomised controlled trial. Pregnant women (<23 weeks' gestation) whose (unborn) infants have at least two biological family members (mother, father or siblings) with medically diagnosed allergic disease are eligible to participate. After obtaining written informed consent, pregnant women are randomised to either a high egg and peanut diet (at least 6 eggs and 60 peanuts per week) or standard (low) egg and peanut diet (no more than 3 eggs and 30 peanuts per week). The women are asked to follow their allocated diet from <23 weeks' gestation to 4 months' lactation. The primary outcome is food challenge proven IgE-mediated egg and/or peanut allergy in the infants at 12 months of age. Key secondary outcomes include infant sensitisation to egg and/or peanut and infant eczema. Our target sample size is 2136 women. Analyses will be performed on an intention-to-treat basis according to a pre-specified statistical analysis plan.

ETHICS AND DISSEMINATION

Ethical approval has been granted from the Women's and Children's Health Network Human Research Ethics Committee (approval number HREC/18/WCHN/42). Trial results will be presented at scientific conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry ACTRN12618000937213.

Ana o 3 sIgE testing increases the accuracy of cashew allergy diagnosis using a two-step model

BACKGROUND

Measurement of cashew-specific IgE (sIgE) is often used to confirm sensitization but does not reliably diagnose clinical allergy. Ana o 3 is the dominant cashew allergen detected in 75-100% of patients with cashew allergy but not currently used in clinical practice.

OBJECTIVES

To determine if component-resolved diagnostics using specific IgE to the 2 S albumin from cashew, Ana o 3, improves the accuracy of diagnosing cashew allergy, thereby circumventing the need for an oral food challenge (OFC) in some patients.

METHODS

A population-based sample of 5276 children was recruited at age 1 year and followed up at age 6 years. Children with positive cashew skin prick test at age 6 underwent an OFC to clarify allergy status. Forty-seven children (mean age 5.02 ± 0.2) (33 cashew-allergic and 14 cashew-tolerant) had cashew sIgE and Ana o 3 sIgE quantified by ImmunoCAP System FEIA.

RESULTS

A cutoff of >0.32 kUA/L for Ana o 3 sIgE provided 95% specificity and 90% sensitivity and correctly identified 90% of clinical cashew allergy. At the same specificity, the sensitivity for cashew sIgE (>8.5 kUA/L) was only 26%. Sequential measurement of cashew sIgE followed by Ana o 3 sIgE diagnosed 90% of children with cashew allergy without the need for an OFC.

CONCLUSION

Ana o 3 sIgE testing provides higher diagnostic accuracy than cashew sIgE. Sequential measurement of cashew sIgE followed by Ana o 3 removed the need for a food challenge from 66% down to 12.8% (5-fold) of children compared with cashew sIgE testing alone.

Epigenetic programming underpins B-cell dysfunction in peanut and multi-food allergy

OBJECTIVE

Rates of IgE-mediated food allergy (FA) have increased over the last few decades, and mounting evidence implicates disruption of epigenetic profiles in various immune cell types in FA development. Recent data implicate B-cell dysfunction in FA; however, few studies have examined epigenetic changes within these cells.

METHODS

We assessed epigenetic and transcriptomic profiles in purified B cells from adolescents with FA, comparing single-food-allergic (peanut only), multi-food-allergic (peanut and ≥1 other food) and non-allergic (control) individuals. Adolescents represent a phenotype of persistent and severe FA indicative of a common immune deviation.

RESULTS

We identified 144 differentially methylated probes (DMPs) and 116 differentially expressed genes (DEGs) that distinguish B cells of individuals with FA from controls, including differential methylation of the PM20D1 promoter previously associated with allergic disorders. Subgroup comparisons found 729 DMPs specific to either single-food- or multi-food-allergic individuals, suggesting epigenetic distinctions between allergy groups. This included two regions with increased methylation near three S100 genes in multi-food-allergic individuals. Ontology results of DEGs specific to multi-food-allergic individuals revealed enrichment of terms associated with myeloid cell activation. Motif enrichment analysis of promoters associated with DMPs and DEGs showed differential enrichment for motifs recognised by transcription factors regulating B- and T-cell development, B-cell lineage determination and TGF-β signalling pathway between the multi-food-allergic and single-food-allergic groups.

CONCLUSION

Our data highlight epigenetic changes in B cells associated with peanut allergy, distinguishing features of the epigenome between single-food- and multi-food-allergic individuals and revealing differential developmental pathways potentially underpinning these distinct phenotypes.

Dietary Management of Food Allergy

Worldwide food allergy prevalence is increasing, especially in children. Food allergy management strategies include appropriate avoidance measures and identifying suitable alternatives for a nutritionally sound diet. Individualized dietary intervention begins teaching label reading, which differs among countries or regions. Dietary intervention must result in a nutritionally sound plan including alternatives to support optimal growth and development. Inappropriate or incomplete dietary advice may increase the risk of adverse reactions, growth faltering, and nutrient deficiencies. Evidence indicates input from a registered dietitian improves nutritional outcomes. Nutritional input plays a critical role managing nutritional disorders related to food allergy.

The global incidence and prevalence of anaphylaxis in children in the general population: A systematic review

BACKGROUND

Despite an increasing number of publications from individual countries and regions, there is still no systematic review of the global epidemiology of anaphylaxis in the general paediatric population.

METHODS

We conducted a systematic review, using a protocol registered and published with the international prospective register of systematic reviews (PROSPERO). Results were reported following PRISMA guidelines. The search strategy was designed in Medline (ovid) and modified for Embase (ovid) and PubMed. Papers were screened by two independent reviewers following selection and exclusion criteria. Data extraction and risk of bias assessment were completed by the same two reviewers. Studies in adults only or those that did not report data in children separately were excluded.

RESULTS

A final total of 59 articles were included. Of these, 5 reported cumulative incidence, 39 reported incidence rate and 17 reported prevalence data. The incidence of anaphylaxis in children worldwide varied widely, ranging from 1 to 761 per 100 000 person-years for total anaphylaxis and 1 to 77 per 100 000 person-years for food-induced anaphylaxis. The definition of anaphylaxis from NIAID/FAAN was the most commonly used. Gender and ethnicity were demographic risk factors associated with anaphylaxis in children. Increasing total or food-induced anaphylaxis incidence over time was reported by 19 studies.

CONCLUSION

The reported incidence of anaphylaxis in children varied widely. Studies in developing countries are underrepresented. To accurately compare anaphylaxis incidence between countries and investigate the time trends, further studies using a standardized definition across different countries are required.

Anaphylaxis management in Australian schools: Review of guidelines and adrenaline autoinjector use

Food allergy and anaphylaxis is increasing in Australian children, and anaphylaxis is relatively common in Australian schools. This review aims to provide an overview of current policies and practices for anaphylaxis management in Australian schools, including approaches to risk mitigation and anaphylaxis training. We reviewed literature related to anaphylaxis training in the school setting published between 2010 and 2018. Current anaphylaxis policies/guidelines were obtained from Australian education and health departments, and reports of suspected anaphylaxis and adrenaline autoinjector (AAI) use for 2016-2017 were obtained from education departments where available. Our review of policies/guidelines across Australian jurisdictions indicates inconsistent approaches to anaphylaxis management training. Almost half of Australian school anaphylaxis events required a general-use AAI, administered to students not identified as at risk of anaphylaxis. Development of clear, evidence-based, consistent guidelines related to anaphylaxis management and training in the school setting is imperative to minimise risk.

Patterns of Carriage of Prescribed Adrenaline Autoinjectors in 10- to 14-Year-Old Food-Allergic Students: A Population-Based Study

BACKGROUND

Adolescence is well recognized as a period of increased risk for severe and fatal food-induced anaphylaxis. Current Australian adrenaline autoinjector (AAI) prescription guidelines therefore suggest that consideration be given to AAI prescription in all adolescents with a food allergy. To date, however, few studies have assessed the AAI carriage behavior of adolescents prescribed AAI devices.

OBJECTIVE

To determine the carriage behavior of prescribed AAI devices in a population-based sample of young Australian adolescents.

METHODS

Students aged 10 to 14 years (and their parents) from randomly selected schools in metropolitan Melbourne completed self-administered questionnaires regarding the history and management of food allergy, including prescription and carriage of AAI device in different domains of school and social life.

RESULTS

A total of 9816 students completed the questionnaire (46% response): 620 students were assessed to have likely IgE-mediated food allergy and 234 (38%) of these had been prescribed an AAI. Most students (93%; 95% CI, 89%-96%) who were prescribed AAIs reported that they provided their AAI and anaphylaxis action plan to their school. Adherence to AAI carriage in other domains of social life was poor, with 49% (95% CI, 42%-56%) never carrying their AAI in 1 or more locations. Carriage of the AAI device was particularly poor when students were independent of parental supervision: 32% (95% CI, 25%-39%) never carried it when they were by themselves, 28% (95% CI, 22%-36%) never carried it while out with friends, and 36% (95% CI, 30%-43%) never carried their AAI to sporting activities.

CONCLUSIONS

Carriage of AAI devices is suboptimal in young adolescents prescribed AAIs, particularly when young adolescents are independent of parental supervision.

An Australian Consensus on Infant Feeding Guidelines to Prevent Food Allergy: Outcomes From the Australian Infant Feeding Summit

BACKGROUND

Infant feeding in the first postnatal year of life has an important role in an infant's risk of developing food allergy. Consumer infant feeding advice is diverse and lacks consistency.

AIM

The Australian Infant Feeding Summit was held with the aim of achieving national consensus on the wording of guidelines for infant feeding and allergy prevention.

METHODS

Two meetings were hosted by the Centre for Food and Allergy Research, the Australasian Society of Clinical Immunology and Allergy, and the Australian National Allergy Strategy. The first meeting of 30 allergy researchers, clinicians, and consumers assessed the evidence. The second consensus meeting involved 46 expert stakeholders including state and federal health care agencies, consumers, and experts in allergy, infant feeding, and population health.

RESULTS

Partner stakeholders agreed on consensus wording for infant feeding advice: CONCLUSIONS: Consensus was achieved in a context in which there is a high prevalence of food allergy. Guidelines for other countries are being updated. Provision of consistent wording related to infant feeding to reduce food allergy risk will ensure clear consumer advice.

Nut allergy prevalence and differences between Asian-born children and Australian-born children of Asian descent: a state-wide survey of children at primary school entry in Victoria, Australia

BACKGROUND

Asian infants born in Australia are three times more likely to develop nut allergy than non-Asian infants, and rates of challenge-proven food allergy in infants have been found to be unexpectedly high in metropolitan Melbourne. To further investigate the risk factors for nut allergy, we assessed the whole-of-state prevalence distribution of parent-reported nut allergy in 5-year-old children entering school.

METHODS

Using the 2010 School Entrant Health Questionnaire administered to all 5-year-old children in Victoria, Australia, we assessed the prevalence of parent-reported nut allergy (tree nut and peanut) and whether this was altered by region of residence, socio-economic status, country of birth or history of migration. Prevalence was calculated as observed proportion with 95% confidence intervals (CI). Risk factors were evaluated using multivariable logistic regression and adjusted for appropriate confounders.

RESULTS

Parent-reported nut allergy prevalence was 3.1% (95% CI 2.9-3.2) amongst a cohort of nearly 60 000 children. It was more common amongst children of mothers with higher education and socio-economic index and less prevalent amongst children in regional Victoria than in Melbourne. While children born in Australia to Asian-born mothers (aOR 2.67, 95% CI 2.28-3.27) were more likely to have nut allergy than non-Asian children, children born in Asia who subsequently migrated to Australia were at decreased risk of nut allergy (aOR 0.1, 95% CI 0.03-0.31).

CONCLUSION

Migration from Asia after the early infant period appears protective for the development of nut allergy. Additionally, rural regions have lower rates of nut allergy than urban areas.