Dietary baked egg accelerates resolution of egg allergy in children

A comprehensive guide to food allergy management for the general pediatrician

There has been an increase in the prevalence of food allergy among children in the United States. Pediatricians play a pivotal role in caring for children with food allergy, as they are often the first point of contact and enjoy longitudinal relationships with families. In this review, we discuss the epidemiology, risk factors, presentation, diagnosis, and management of food allergy. We also discuss special considerations for patients with food allergy, including nutritional risks and psychosocial stressors that may negatively influence children's wellbeing. Our goal is to provide a concise yet comprehensive guide for general pediatricians so they may feel confident providing high-quality care for patients with food allergy.

The Rising Incidence of Food Allergies and Infant Food Allergies

Infant food allergies have become a continually rising global health issue. There is a lack of global standardized recommendations on measures for prevention and treatment of infant food allergies because of the variations in ethnic, social, educational, and healthcare practices that affect the outcomes of research studies. Food allergies can cause mild to severe reactions and can affect social and emotional aspects of life up to the adolescent stage and are sometimes never outgrown. Maternal factors such as in utero supply of antibodies, dietary diversity, genetics, food allergen consumption during pregnancy, gut microbiota, and breastfeeding characteristics are the cornerstones of the development of an infant's immune system. In this review, we discuss how prenatal and postnatal factors affect the gut microbiota and development of an infant's immune system, and the current therapies available. The importance of food processing and education of stakeholders in the care of infants with food allergies is also discussed.

Tolerance to cooked egg in infants with risk factors for egg allergy after early introduction of baked egg

Egg allergy (EA),along with cow's milk allergy (CMA) and atopic dermatitis (AD is one of the most frequent allergies in children. Tolerance to food allergens seems to be related to the early and regular intake and the cooking method. The objective of this study is to prove that the introduction of baked eggs at 4-6 months of age and its daily maintenance for 6 months prevents EA. Controlled randomized clinical trial from February 2019 to November 2023 was done for all patients under 6 months of age, including those with CMA and/or AD without previous egg consumption. Skin prick test (SPT), specific immunoglobulin E (sIgE), basophil activation test (BAT), and oral food challenge (OFC) on baked eggs were performed at the beginning of the study (T0). Patients were classified into group A (nontolerant to baked egg) following an egg-free diet and group B (tolerant to baked egg). These were randomized into B1 who ate baked egg daily and B2 who avoided egg. Six months later, at time 1 (T1), an OFC to hard-boiled egg was performed. There were 27 patients in all. Those who ate baked egg daily for 6 months tolerated boiled eggs and only 47.4% of patients who followed an egg-free diet tolerated boiled eggs (P-value 0.012). All three tests-sIgE, SPT, and BAT-are considered good techniques to discriminate between tolerant versus not tolerant patients toward eggs.Patients under 6 months of age with CMA and/or AD who ate baked eggs daily for 6 months tolerated cooked eggs more frequently than patients who avoided eggs. Early introduction of baked eggs could prevent EA.

The evolution of nutritional care in children with food allergies - With a focus on cow's milk allergy

Cow's milk allergy (CMA) remains one of the most common and complex paediatric food allergies. In the last decade, our understanding has advanced in terms of immunoglobulin E (IgE)-mediated CMA and focus is now also paid to non-IgE-mediated CMA, particularly in some Western countries where incidence rates are high. We have had significant progress in the last 10 years in relation to our understanding of existing supportive tests for IgE-mediated CMA, with the advancement of newer tests, such as the basophil activation test (BAT), which have shown great promise. However, little advancement has been made in terms of tests for non-IgE-mediated CMA, and controversy still exists around symptoms. Our understanding of the natural history of CMA has also advanced with more awareness of different phenotypes. While the mainstay of management remains cow's milk elimination, the importance of supporting breastfeeding and avoidance of unwarranted cow's milk elimination diets in breastfeeding mothers has been highlighted. For non-breastfed children, there has been some advancement in the formulas offered for the management of CMA, including the recognition of hydrolysed rice-based formulas and increased demand for nutritionally complete plant-based options, some of which are currently being assessed. The addition of pro, pre and synbiotics is considered safe to use, although research and guidance on routine use remain absent. Knowledge of tolerance induction from studies on the early introduction of peanuts has also highlighted the importance of a more active approach to managing CMA with the use of milk ladders, primarily in non-IgE-mediated CMA and baked milk (BM) introduction in IgE-mediated CMA. In addition, modulation of the microbiome and diet diversity during complementary feeding has been a major advancement in the last 10 years. While data on poor growth and feeding difficulties in children with CMA has not changed much, increased rates of obesity are now also reported. Finally, novel approaches, including oral immunotherapy, the use of milk ladders and earlier consideration of BM, have advanced somewhat in the last decade, although the risks and benefits of these novel approaches require further research. While CMA remains a complicated allergy to diagnose and manage, the evolution of science has advanced our knowledge and brought some novel innovations, which combined have enhanced our practice.

Conflicting predictions of whole egg versus egg component testing: A case report

The results of component testing for patients with egg allergy may conflict with the results of whole allergen testing, with the potential of influencing patients' decision to undergo high-risk ingestion challenge.

Egg allergen-specific T-cell and cytokine responses in healthy and egg-allergic children naturally tolerating baked egg

BACKGROUND

Type 1 regulatory T (Tr1) cells are critical players in maintaining peripheral tolerance, by producing high IL-10 levels in association with inducible T-cell co-stimulator (ICOS) expression. Whether these cells play a role in naturally acquired baked egg tolerance is unknown.

OBJECTIVES

Evaluate frequencies of egg-responsive Tr1 and Th2 cells in egg-allergic children that naturally acquired baked egg tolerance (BET) versus non-egg-allergic (NEA) children.

METHODS

Peripheral blood mononuclear cells from 70 natural BET and 15 NEA children were stimulated for 7 days with ovalbumin and ovomucoid. By flowcytometry, egg-responsive Tr1 cells were identified by co-expression of CD49b and LAG3, and Th2 cells by expression of CD49b but absence of LAG3. Seven-day cultured supernatant was analyzed for Th1, Th2, Tr1, and Th17 cytokines by MSD.

RESULTS

Natural BET children had a higher percentage of egg-responsive Th2 cells vs. NEA children (6.75% vs. 10.35%, p = .006). No significant difference was found in frequencies of egg-responsive Tr1 cells between NEA and natural BET children (11.40% vs. 12.55%, p = .42), although Tr1-related IL-10 and IL-21 production was higher in BET children. Interestingly, egg-responsive Tr1 cells from NEA children expressed higher ICOS levels vs. natural BET children (97.90 vs. 88.20, p < .0001). Supernatant from natural BET children showed elevated levels of Th2 cytokines IL-5, IL-9 and IL-13 and Th17 cytokine IL-17A.

CONCLUSION

Natural BET children maintain increased egg-specific Th2 responses, along with comparable proportions of egg-responsive Tr1 cells exhibiting higher IL-10 but lower ICOS expression in comparison with NEA children.

Characterization of the Gut and Skin Microbiome over Time in Young Children with IgE-Mediated Food Allergy

BACKGROUND/OBJECTIVES

The prevalence of food allergy (FA) in children is increasing. Dysbiosis of the microbiome has been linked to FA but needs to be better understood. We aimed to characterize the gut and skin microbiome of young food-allergic children over time and within different types of immunoglobulin E (IgE)-mediated FA.

METHODS

We studied 23 patients, as a pilot study of an ongoing prospective multicenter cohort study including children < 2y with newly diagnosed IgE-mediated FA. Samples (feces/skin swabs) were collected at enrollment and at 1-year follow-up and sequenced for the bacterial 16S rRNA gene (hypervariable v1-v2 region).

RESULTS

Gut and skin bacterial diversity was significantly higher in patients compared with controls and increased over time (beta test, Shannon diversity, p < 0.01). Within different types of IgE-mediated FA, bacterial diversity was similar. Community composition differed significantly over time and within IgE-mediated FA types (PERMANOVA: p < 0.01). Several significantly different genus abundances were revealed. We observed a positive correlation between high total IgE and a high abundance of the genus Collinsella in patients with a higher number of allergies/sensitizations (≥3), and patients with tree nut and/or peanut allergy.

CONCLUSIONS

This study revealed an increased bacterial diversity in children with FA compared with non-atopic children. Importantly, the gut and skin microbiome differed in their composition over time and within different types of IgE-mediated FA. These findings contribute to the understanding of microbiome changes in children with FA and indicate the potential of the genus Collinsella as a biomarker for tree nut and/or peanut allergy and possibly for allergy persistence.

Hen's egg ladder: Therapy option for the gradual introduction of hen's eggs in cases of hen's egg allergy

More than 10 years ago, the British Society for Allergy and Clinical Immunology (BSACI) published guidelines for the management of egg allergy [1]. For the first time, these included a stepwise plan for the reintroduction of egg for egg-allergic children who could already tolerate well-cooked egg, such as cakes and cookies. Since then, various egg ladders have been developed [2, 3, 4, 5, 6, 7, 8, 9]. In the past 3 years, several studies have been published suggesting that a gradual introduction of highly processed to less processed egg containing foods contribute to the acceleration of tolerance development [2, 3, 4, 5]. However, depending on the study and egg ladder, the egg products vary in their level of processing (wheat matrix, degree, and location of heating (e.g., oven, pan, pot), egg quantity, and egg protein). In the UK, the introduction of the egg ladder is recommended at the age of 12 months or if the last reaction occurred 6 months before. The benefits of introducing egg at home include an early increase in the variety of foods, reduction of food fears, improved nutrient intake, and the avoidance of hospitalization fears in children [10]. Children with mild reactions in the past can start with small amounts of baked goods at home. Food challenges in an inpatient setting to exclude or reconfirm the allergy should be conducted if the patients have previously had severe allergic reactions, i.e., anaphylaxis, or if the smallest amounts triggered an allergic reaction or if existing asthma is poorly controlled [10, 11]. The present work includes, in addition to the evaluation of study results, a presentation of the recent studies regarding egg ladders. From these, a new egg ladder as therapeutic option for the German-speaking region has been developed. As already done for the milk ladder a detailed step-by-step plan, selection criteria, a recipe collection, and also ideas for commercial prepackaged food items can be found in the appendices [11].

The Safety and Efficacy of Baked Egg and Milk Dietary Advancement Therapy: A Systematic Review and Meta-Analysis

BACKGROUND

Cow's milk and egg allergy affect approximately 1.9% and 0.9% of children, respectively. Dietary advancement therapies (DATs), including milk (ML) and egg (EL) ladders, and baked milk (BM-OIT) and baked egg (BE-OIT) oral immunotherapy, are potential therapeutic options for these patients.

OBJECTIVE

To perform systematic review and meta-analysis of the safety and efficacy of DATs in children with IgE-mediated milk or egg allergy.

METHODS

A systematic literature review was conducted, exploring 22 potential outcomes, with meta-analysis performed where ≥3 studies reported data. The GRADE approach was used to determine the certainty of evidence for each outcome, and the Johanna Briggs Institute tools were used for determining risk of bias.

RESULTS

Twenty-nine studies met inclusion criteria among 9946 titles screened. Tolerance occurred in 69% of EL, 58% of ML, 49% of BE-OIT, and 29% of BM-OIT patients. All-severity allergic reactions occurred in 21% of EL, 25% of ML, 20% of BE-OIT, and 61% of BM-OIT patients, with epinephrine use in 3% of EL, 2% of ML, and 9% of BM-OIT patients. At-home reactions occurred in 19% of BE-OIT and 10% of BM-OIT patients. Discontinuation occurred in 14% of EL, 17% of ML, 17% of BE-OIT, and 20% of BM-OIT patients. The mean time to BE egg and BE-OIT tolerance was 13.25 months (4 studies) and 19.1 months (3 studies). Certainty of evidence was very low, and risk of bias high. Study heterogeneity was high, attributable to multiple factors.

CONCLUSIONS

There is very low certainty of evidence supporting DAT safety and efficacy. We cannot conclude that DAT accelerates tolerance development.

Management of food allergy based on oral food challenge

PURPOSE OF REVIEW

Food allergy is a growing health problem that affects both patients and society in multiple ways. Despite the emergence of novel diagnostic tools, such as component-resolved diagnostics (CRD) and basophil activation tests (BAT), oral food challenge (OFC) still plays an indispensable role in the management of food allergies. This review aimed to highlight the indications and safety concerns of conducting an OFC and to provide insights into post-OFC management based on recent findings.

RECENT FINDINGS

Standardized OFC protocols have regional diversification, especially in Japan and Western countries. Recent studies suggested that the interval between doses should be at least more than an hour. Furthermore, applying a stepwise method tailored to the patient's specific immunoglobulin E level and history of anaphylaxis seems to mitigate these risks. Recent surveys have shown that, following a positive OFC, options other than strict avoidance are also selected.

SUMMARY

OFC serves diverse purposes, yet the risks it carries warrant caution. The stepwise protocol appears promising for its safety. Subthreshold consumption following OFC shows potential; however, further research on its efficacy and safety is required. Management following OFC should be tailored and well discussed between clinicians and patients.

The Natural History and Risk Factors for the Development of Food Allergies in Children and Adults

PURPOSE OF REVIEW

This narrative review explores food allergy prevalence and natural history stratified by life stages, especially in context of evolving knowledge over the last few decades.

RECENT FINDINGS

The prevalence of food allergy remains highest in early childhood with common food triggers being cow's milk, soy, hen's egg, wheat, peanut, tree nuts, sesame, fish, and shellfish. This correlates with certain risk factors especially pertinent in the postnatal period which appear to predispose an individual to developing a food allergy. Some allergies (such as milk and egg) were previously thought to be easily outgrown in early life; however, recent studies suggest increasing rates of persistence of these allergies into young adulthood; the reason behind this is unknown. Despite this, there is also evidence demonstrating that food allergies can be outgrown in adolescents and adults. An understanding of the paradigm shifts in the natural history of food allergy allows clinicians to provide updated, age-appropriate, and tailored advice for patients on the management and prognosis of food allergy.

Partial Egg Consumption Modifies the Diagnostic Performance of Allergy Tests to Predict Outcome of Double-Blind Placebo-Controlled Food Challenges to Egg

BACKGROUND

Many children are consuming some egg when they are diagnosed with egg allergy. We hypothesized that egg consumption could modify the diagnostic performance of allergy tests.

OBJECTIVE

To stratify diagnostic performance of tests according to egg consumption status.

METHODS

The BAT2 study (NCT03309488) participants underwent oral food challenge (OFC), food-frequency questionnaires, skin prick test (SPT), specific immunoglobulin E (sIgE) and specific immunoglobulin G4 (sIgG4) and basophil activation test (BAT).

RESULTS

At study entry, 45% of participants reported partial egg consumption ("consumers") and 55% were avoiding egg strictly ("avoiders"). Avoiders had larger SPT (P < .001), higher BAT to egg (P < .001), sIgE to egg white (EW; P = .001) and to ovalbumin (OVA; P = .001), but not to ovomucoid (P = .231). Consumers had higher levels of sIgG4 to all egg allergens (P < .001) than avoiders. In consumers, the test with the best diagnostic performance was BAT (area under the curve [AUC] = .912) followed by SPT to raw egg (AUC = 0.805), EW-sIgE (AUC = 0.738), and OVA-sIgE (AUC = 0.732). In avoiders, the best tests were BAT (AUC = 0.834) and EW-sIgE (AUC = 0.833) followed by OVA-sIgE (AUC = 0.793) and SPT to EW (AUC=0.789). Using 100% sensitivity and 100% specificity cut-offs, the proportion of patients requiring OFC were 33% for BAT, 53% for SPT to raw egg, 61% for OVA-sIgE, and 73% for EW-sIgE for consumers; and 73% for BAT, 79% for EW-sIgE, and 93% for SPT to EW for avoiders.

CONCLUSIONS

The diagnostic performance of tests is influenced by the immunomodulatory effect of egg consumption. BAT is the most reliable test and reduced the need for OFC, particularly in partial egg consumers.

Dietary management of IgE and non-IgE-mediated food allergies in pediatric patients

Food allergies (FA) consist of both IgE and non-IgE-mediated entities, with varying phenotypes and overlapping and different considerations for each specific disease presentation. In general, all FAs place children at increased risk for inadequate nutritional intake and negative impacts on their nutritional status, as well as negative impacts on the quality of life for the entire family. To minimize these untoward effects, a multidisciplinary approach should be taken, including consultation and management with a dietitian trained in the varying presentations of FA. Families should be instructed on label reading as a first line of nutritional management. During a nutrition consultation, the age of the child, growth, and nutritional status should be considered. Food refusal should be assessed and addressed. Families should be educated on avoidance and appropriate substitutions. In the case of cow's milk allergy, a suitable specialized formula should be suggested if the infant is not breastfed or if breast milk supply is not sufficient. Other mammalian milk should be avoided and careful consideration should be given before plant-based milk is used in young children. Specific food allergies may differ in terms of advice provided on the level of avoidance required, whether precautionary advisory labels should be avoided, and if a maternal avoidance of the allergen during breastfeeding should be advised. The role of immunonutrition on overall health should be discussed.

Baked milk and egg diets revisited

Most children with milk and egg allergy are nonreactive to modified forms of milk and egg in bakery products such as muffins because of conformational changes in proteins. These baked milk (BM) and baked egg (BE) diets have become commonplace in the management of milk and egg allergy, respectively. Current laboratory- and skin test-based diagnostic approaches remain limited in their ability to predict BM/BE tolerance, resulting in various approaches to introduce these foods. One approach to introduce BM/BE is to offer a medically supervised oral food challenge and then advise dietary introduction of baked products for children who have tolerance. Another approach is adapted from a home-based protocol of graded ingestion of BM or BE originally intended for non-IgE mediated allergy, often referred to as a "ladder." The ladder advises home ingestion of increasing amounts of BM or BE. For children who have allergy to BM or BE, the ladder is essentially oral immunotherapy, although not always labeled or recognized as such. Risk assessment and education of patients suitable for home introduction are essential. A home approach that may be called a ladder can also be used to escalate diets after demonstrated tolerance of baked forms by introducing lesser cooked forms of milk or egg after tolerating BM or BE. A randomized controlled trial provided clear evidence that baked diets can hasten the resolution of IgE-mediated milk allergy. Moreover, BM/BE foods have an emerging role in the treatment of non-IgE-mediated allergy. There is tangential evidence for BM and BE diets in the prevention of IgE-mediated allergy.

The future of cow's milk allergy - milk ladders in IgE-mediated food allergy

Cow's milk allergy (CMA) is one of the most common and complex presentations of allergy in early childhood. CMA can present as IgE and non-IgE mediated forms of food allergy. Non-IgE mediated CMA includes food protein-induced enterocolitis syndrome (FPIES), eosinophilic gastrointestinal disorders (EGIDs), and food protein-induced proctocolitis (FPIAP). There are recent guidelines addressing CMA diagnosis, management, and treatment. Each of these guidelines have their own strengths and limitations. To best manage CMA, individualized avoidance advice should be given. Cow's milk (CM) can be replaced in the diet by using hypoallergenic formulas or plant-based milk, depending on factors such as the child's age and their current food intake. Oral and epicutaneous immunotherapy is used to increase tolerance in children with CMA but is not without risk, and the long-term outcome of sustained unresponsiveness is still unclear. The allergenicity of CM proteins are affected differently by different forms of heating, leading to the use of baked milk or milk ladders in the management of CMA, most likely the most promising option for future management and treatment of CMA. Future management of children with CMA will also include discussion around the immunomodulatory potential of the child's dietary intake.

Allergy-associated biomarkers in early life identified by Omics techniques

The prevalence and severity of allergic diseases have increased over the last 30 years. Understanding the mechanisms responsible for these diseases is a major challenge in current allergology, as it is crucial for the transition towards precision medicine, which encompasses predictive, preventive, and personalized strategies. The urge to identify predictive biomarkers of allergy at early stages of life is crucial, especially in the context of major allergic diseases such as food allergy and atopic dermatitis. Identifying these biomarkers could enhance our understanding of the immature immune responses, improve allergy handling at early ages and pave the way for preventive and therapeutic approaches. This minireview aims to explore the relevance of three biomarker categories (proteome, microbiome, and metabolome) in early life. First, levels of some proteins emerge as potential indicators of mucosal health and metabolic status in certain allergic diseases. Second, bacterial taxonomy provides insight into the composition of the microbiota through high-throughput sequencing methods. Finally, metabolites, representing the end products of bacterial and host metabolic activity, serve as early indicators of changes in microbiota and host metabolism. This information could help to develop an extensive identification of biomarkers in AD and FA and their potential in translational personalized medicine in early life.

Variation in the Allergenicity of Scrambled, Boiled, Short-Baked and Long-Baked Egg White Proteins

BACKGROUND

Hen's egg white (HEW) is the most common cause of food allergy in children which induces mild to fatal reactions. The consultation for a proper restriction is important in HEW allergy. We aimed to identify the changes in HEW allergenicity using diverse cooking methods commonly used in Korean dishes.

METHODS

Crude extract of raw and 4 types of cooked HEW extracts were produced and used for sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE), enzyme-linked immunosorbent assay (ELISA), and ELISA inhibition assays using 45 serum samples from HEW allergic and tolerant children. Extracts were prepared; scrambled without oil for 20-30 seconds in frying pan without oil, boiled at 100°C for 15 minutes, short-baked at 180°C for 20 minutes, and long-baked at 45°C for 12 hours with a gradual increase in temperature up to 110°C for additional 12 hours, respectively.

RESULTS

In SDS-PAGE, the intensity of bands of 50-54 kDa decreased by boiling and baking. All bands almost disappeared in long-baked eggs. The intensity of the ovalbumin (OVA) immunoglobulin E (IgE) bands did not change after scrambling; however, an evident decrease was observed in boiled egg white (EW). In contrast, ovomucoid (OM) IgE bands were darker and wider after scrambling and boiling. The IgE binding reactivity to all EW allergens were weakened in short-baked EW and considerably diminished in long-baked EW. In individual ELISA analysis using OVA+OM+ serum samples, the median of specific IgE optical density values was 0.435 in raw EW, 0.476 in scrambled EW, and 0.487 in boiled EW. Conversely, it was significantly decreased in short-baked (0.406) and long-baked EW (0.012). Significant inhibition was observed by four inhibitors such as raw, scrambled, boiled and short-baked HEW, but there was no significant inhibition by long-baked HEW (IC50 > 100 mg/mL).

CONCLUSION

We identified minimally reduced allergenicity in scrambled EW and extensively decreased allergenicity in long-baked EW comparing to boiled and short-baked EW as well as raw EW. By applying the results of this study, we would be able to provide safer dietary guidence with higher quality to egg allergic children.

Basophil activation test as predictor of severity and threshold of allergic reactions to egg

BACKGROUND

Identifying patients at risk of severe allergic reactions and/or low threshold of reactivity is very important, particularly for staple foods like egg.

METHODS

One hundred and fifty children underwent double-blind placebo-controlled food challenge (DBPCFC) to baked egg (BE), skin prick testing and blood collection for serology and basophil activation test (BAT). Patients who passed BE DBPCFC underwent loosely cooked egg (LCE) DBPCFC. Severity of allergic reactions was classified following Practall guidelines and threshold dose was determined during DBPCFC.

RESULTS

Sixty out of 150 (40%) children reacted to BE and 16 out of 77 (21%) to LCE on DBPCFC. Considering DBPCFC to BE, 23 children (38%) had severe reactions and 33 (55%) reacted to 0.13 g or less of egg protein (low threshold group). Two children (2 out of 16 = 12%) had severe reactions to LCE. Demographic, clinical and most immunological features were not significantly different between severe/non-severe BE reactors or low/high threshold groups. Severe BE reactors had higher ovomucoid-sIgE (p = .009) and higher BAT to BE (p = .001). Patients with lower threshold to BE had higher IgE-specific activity (p = .027) and BAT to egg (p = .007) but lower severity score (p = .008). Optimal cut-offs for ovomucoid-sIgE had 100% sensitivity, 35% specificity and 60% accuracy and for BAT 76% sensitivity, 74% specificity and 75% accuracy to identify BE severe reactors. Optimal cut-offs for specific activity had 70% sensitivity, 68% specificity and 69% accuracy and for BAT 70% sensitivity, 72% specificity and 71% accuracy to identify low threshold patients.

CONCLUSIONS

BAT was the best biomarker to predict severity and threshold of allergic reactions to BE and can be useful when making decisions about management of egg allergy.

Tolerance to heated egg in egg allergy: Explanations and implications for prevention and treatment

Hen's egg allergy is the second most frequent food allergy found in children. Allergic symptoms can be caused by raw or heated egg, but a majority of egg-allergic children can tolerate hard-boiled or baked egg. Understanding the reasons for the tolerance towards heated egg provides clues about the molecular mechanisms involved in egg allergy, and the differential allergenicity of heated and baked egg might be exploited to prevent or treat egg allergy. In this review, we therefore discuss (i) why some patients are able to tolerate heated egg; by highlighting the structural changes of egg white (EW) proteins upon heating and their impact on immunoreactivity, as well as patient characteristics, and (ii) to what extent heated or baked EW might be useful for primary prevention strategies or oral immunotherapy. We describe that the level of immunoreactivity towards EW helps to discriminate patients tolerant or reactive to heated or baked egg. Furthermore, the use of heated or baked egg seems effective in primary prevention strategies and might limit adverse reactions. Oral immunotherapy is a promising treatment strategy, but it can sometimes cause significant adverse events. The use of heated or baked egg might limit these, but current literature is insufficient to conclude about its efficacy.

Standardization of food allergen ladders for optimal effectiveness and patient safety

The use of extensively heated (EH) milk and egg products, and dietary advancement therapies such as milk and egg ladders is increasingly common for the management of milk and egg allergies. Although the majority of patients with milk and egg allergies will outgrow their allergies, the ability to tolerate extensively hydrolyzed forms of these allergens is an early indicator of developing long-term tolerance. The denaturation of conformational epitopes during the heating process reduces the allergenicity of these proteins, which makes patients who are EH tolerant more likely to tolerate progressively more of these proteins.

Diagnostic utility of allergy tests to predict baked egg and lightly cooked egg allergies compared to double-blind placebo-controlled food challenges

BACKGROUND

Double-blind placebo-controlled food challenges (DBPCFC) are the gold-standard to diagnose food allergy. However, they can cause allergic reactions of unpredictable severity. We assessed accuracy of current and new diagnostic tests compared to DBPCFC to baked egg (BE) and to lightly cooked egg (LCE).

METHODS

Children aged 6 months to 15 years were assessed for possible egg allergy as part of the BAT2 study (NCT03309488). They underwent clinical assessment, skin prick test (SPT), specific IgE (sIgE) and basophil activation test (BAT). The results of the tests were compared with DBPCFC outcomes to both BE and LCE.

RESULTS

A total of 150 children underwent DBPCFC to BE, 60 (40%) reacted to and 85 (57%) tolerated BE and 5 (3%) had inconclusive oral food challenges (OFC). Seventy-seven children tolerant to BE had DBPCFC to LCE and 16 reacted. The test within each modality with the best diagnostic performance for BE allergy was as follows: SPT to egg white (EW) (AUC = 0.726), sIgE to EW (AUC = 0.776) and BAT to egg (AUC = 0.783). BAT (AUC = 0.867) was the best test in the younger than 2 years age group. Applying 100% sensitivity and 100% specificity cut-offs, followed by OFC, resulted in 100% diagnostic accuracy. BAT enabled the greatest reduction in OFC (41%). Using sIgE followed by BAT allowed to reduce the number of BATs performed by about 30% without significantly increasing the number of OFC.

CONCLUSIONS

The best diagnostic test was BAT to egg in terms of diagnostic accuracy and reduction in number of OFC. Using sIgE to EW followed by BAT required fewer BATs with sustained OFC reduction and diagnostic accuracy.

Baked Milk and Baked Egg Survey: A Work Group Report of the AAAAI Adverse Reactions to Foods Committee

Most milk- and egg-allergic children can tolerate milk and egg in baked forms. Some allergists have extended the use of baked milk (BM) and baked egg (BE) to advocating for the stepwise introduction of small amounts of BM and BE to children who are reactive to larger amounts of BM and BE. Little is known about the practice of introducing BM and BE and existing barriers to this approach. The purpose of this study was to gather a current assessment of the implementation of BM and BE oral food challenges and diets for milk- and egg-allergic children. We conducted an electronic survey of North American Academy of Allergy, Asthma & Immunology members offering BM and BE introduction in 2021. The response rate was 10.1% of distributed surveys (72 of 711). Surveyed allergists had a similar approach to both BM and BE introduction. Demographic features of time in practice and region of practice were significantly associated with the odds of introducing BM and BE. A wide variety of tests and clinical features guided decisions. Some allergists determined BM and BE to be appropriate for home introduction and offered this for BM and BE more often than other foods. The use of BM and BE as a food for oral immunotherapy was endorsed by almost half of respondents. Less time in practice was the most significant factor associated with offering this approach. Published recipes were used and written information was widely provided to patients by most allergists. The wide practice variabilities reveal a need for more structured guidance about oral food challenges, in-office versus home procedures, and patient education.

Specific and nonspecific nutritional interventions enhance the development of oral tolerance in food allergy

The goal of food allergy (FA) prevention and treatment is to induce oral tolerance (OT). Appropriate nutritional interventions are essential to induce OT to food allergens. This review introduces the mechanism of OT and the importance of early nutritional interventions, and then firstly summarizes specific nutritional factors to induce the development of OT of FA, including proteins, vitamins, fatty acids, saccharides and probiotics. The regulatory mechanism mainly induces the development of tolerance by increasing local or systemic protective regulatory T cells (Tregs) to suppress FA, while the gut microbiota may also be changed to maintain intestinal homeostasis. For allergens-specific OT, the disruption to the structure of proteins and epitopes is critical for the induction of tolerance by hydrolyzed and heated proteins. Vitamins (vitamin A, D), fatty acids, saccharides and probiotics as allergens nonspecific OT also induce the development of OT through immunomodulatory effects. This review contributes to our understanding of OT in FA through nutritional interventions. Nutritional interventions play an important role in the induction of OT, and offer promising approaches to reduce allergy risk and alleviate FA. Moreover, due to the importance and diversity of nutrition, it must be the future trend of induction of OT in FA.

EAACI Molecular Allergology User's Guide 2.0

Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE-mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE-mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well-defined, highly pure molecules for component-resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the "EAACI Molecular Allergology User's Guide" (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state-of-the-art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.

Retail Food Equivalents for Post-Oral Immunotherapy Dosing in the Omalizumab as Monotherapy and as Adjunct Therapy to Multi-Allergen Oral Immunotherapy in Food-Allergic Children and Adults (OUtMATCH) Clinical Trial

BACKGROUND

Patients with food allergy may be advised to introduce specific foods into their diets, both to increase tolerance gradually and as next steps after completing oral immunotherapy or other therapeutic interventions. However, the safe use of retail foods depends on the ability to establish the specific allergen protein content of these foods.

OBJECTIVE

To develop a systematic approach to estimate the protein content of peanut, milk, egg, wheat, cashew, hazelnut, and walnut in a variety of retail food equivalents for each allergen and associated patient education materials.

METHOD

We created an algorithm that used a multistep process with information from product food labels, nutrient databases, independent weighing and measuring of foods, and information provided by manufacturers, including certificates of analysis, and e-mail communication to estimate the allergen protein content of multiple retail foods for each of seven allergens. Once a variety of retail food equivalents for each allergen and allergen serving size was determined, we developed participant education handouts, which were reviewed by study teams at 10 food allergy centers, the National Institute of Allergy and Infectious Diseases, and the Consortium for Food Allergy Research coordinating center. After 1 year of use, multiple queries were addressed and the retail food equivalents and educational materials were reviewed and edited.

RESULTS

We identified a variety of retail food equivalents for seven allergens at six serving sizes, and created 48 unique patient education materials.

CONCLUSION

Our results provide extensive guidance on a variety of retail equivalents for seven foods, and a method to estimate retail food protein equivalents systematically with ongoing reassessment.

Home Introduction of Baked Egg After Oral Food Challenge

BACKGROUND

Baked egg (BE) introduction may accelerate resolution of egg allergy. Long-term data regarding the safety and success of BE introduction in the real world are limited.

OBJECTIVE

To identify predictors of future egg consumption and barriers to advancement based on characteristics during and after BE oral food challenges (OFCs).

METHODS

We performed a retrospective review of consecutive BE OFCs with a minimum 24-month follow-up. Goal doses ranged from 1/16 to 1/4 egg. Outcomes were categorized as pass (no reaction), fail (but allowed BE introduction), or fail (avoid). Status of egg introduction and reactions were recorded.

RESULTS

A total of 243 patients were included; 134 passed and 109 failed (70 of whom were instructed to introduce BE). At follow-up (median, 47 months), 90 (37%) were consuming direct egg, 26 (11%) lightly cooked egg, 39 (16%) BE, and 88 (36%) avoiding; 58% who failed versus 81% who passed were consuming some form of egg. Median egg white IgE level was significantly higher among avoiders versus introducers (8.7 vs 5.8; P = .008). Lower egg white IgE level and younger age were predictors of egg consumption in some form at follow-up (median IgE, 5.8 vs 8.4; P = .03; median age, 4.0 vs 8.0 years; P < .001). A total of 94 patients had a total of 136 reactions (132 mild, 4 severe); 22 (16.2%) were accidental exposures, 42 (30.9%) planned escalations, and 72 (52.9%) with previously tolerated doses.

CONCLUSIONS

Most patients who underwent a BE OFC continued to consume some form of egg, often advancing to direct egg. However, many reverted to avoidance and adverse reactions were common.

Allergen immunotherapy for food allergy: Evidence and outlook

Food allergy represents a significant health issue characterized by a sizeable epidemiological burden, involving up to 5% of adults and up to 8% of children in the Western world. The elimination diet of the trigger food is the cornerstone of food allergy management. However, novel treatment options are most wanted to provide alternative strategies for this potentially fatal medical condition. Allergen immunotherapy for food allergy (FA-AIT) is considered an immunomodulatory intervention where regular exposure to increasing doses of food is performed in the context of an allergist's supervised protocol. The main objective is to decrease reactivity, attenuate life-threatening allergic episodes and reduce frequent access to the emergency department. Achieving food tolerance off-treatment is, however, the ultimate aim. In this review, we aim to summarize FA-AIT evidence and outlook.

Phenotyping of immediate-type food allergies based on 10 years of research: A latent class analysis

BACKGROUND

Food allergy is a disease with a diverse and variable natural history, and some patients may react to two or more food antigens. This study aimed to classify and characterize the long-term prognosis of infantile-onset, immediate-type food allergies, focusing on three major antigens in Japan: egg, milk, and wheat.

METHODS

All children who visited our hospital with food allergies, including suspected cases, were prospectively registered in our medical database. Among the children in this database, subjects registered by the age of 1 year with immediate-type symptoms or sensitization to the above three antigens were included. The course of the subjects up to the age of 6 years was analyzed. Cox regression analysis and repeated-measures latent class analysis (LCA) were performed to reveal risk factors and tolerance patterns for food allergies.

RESULTS

We included 915 patients with immediate-type food allergy symptoms and 276 sensitized asymptomatic patients in this study. The number of patients with immediate-type symptoms to egg, milk, and wheat was 609, 443, and 235, respectively. The number of patients with multiple food allergies was 302. The proportion of patients with tolerance to egg, milk, and wheat at 6 years of age was 74%, 69%, and 75%, respectively. LCA revealed 7 classes of prognosis for food allergies. The largest class was transient egg allergy alone (19.6%), and there were severe cases of multiple food allergies (6.5%).

CONCLUSIONS

This study demonstrated the prognosis of food allergy classes in Japan, including multiple food allergies, with 7 classes with its own characteristics.

Assessment of Selected Intestinal Permeability Markers in Children with Food Allergy Depending on the Type and Severity of Clinical Symptoms

Background: Food allergy (FA) has a broad range of symptoms, and clinical manifestations may concern several reactions from one system or organ. Aim: The aim of the study was to assess intestinal permeability (IP) based on the analysis of serum zonulin and bacterial lipopolysaccharides (LPS) levels in children with FA, taking into account the pathomechanism of immune reaction, clinical symptoms of FA and their severity. Material and methods: The study comprised 103 patients aged 7–60 months (median 34); 49 children with IgE-mediated allergy and 25 children with non-IgE-mediated allergy; the reference group comprised 29 children with functional gastrointestinal disorders. IP markers were determined using ELISA. Results: There was no correlation between the severity of clinical symptoms and the level of IP markers in children with FA. Zonulin and LPS levels were significantly higher in children with FA and gastrointestinal symptoms. Zonulin levels in the subgroup of children with non-IgE-mediated FA and gastrointestinal symptoms were significantly higher than in the subgroup of children with IgE-mediated FA and these symptoms. The level of LPS was significantly higher in the subgroup with IgE-mediated FA and atopic dermatitis. Conclusions: Zonulin and LPS levels were significantly higher in children with FA compared to children from the reference group. Zonulin levels were significantly higher in children with non-IgE-mediated FA than in children with IgE-mediated FA.

Guided Gradual Egg-Tolerance Induction in Hen's Egg Allergic Children Tolerating Baked Egg: A Prospective Randomized Trial

Background

Over the last few years, studies have shown that the majority of egg allergic children tolerate baked egg (e.g., cake), and that consuming baked egg accelerates the resolution of egg allergy. However, few prospective studies demonstrate the step-wise reintroduction of egg at home after developing baked egg tolerance. Although this could have a positive impact on the children's quality of life and nutrition. Additionally, research supporting the theoretical concept that heating in the presence or absence of wheat causes reduced allergenicity of egg proteins is limited.

Objective

To investigate the clinically most favorable duration of gradual egg-tolerance induction in baked egg tolerant children at home, with regard to complete raw egg tolerance.

Methods

Baked egg tolerant children above 12 months of age were randomly assigned to a short- or long arm protocol. In the short arm, egg-tolerance induction was studied over 18 months compared to 30 months in the long arm. Children were guided through this protocol involving the step-wise introduction of increasingly allergenic forms of egg starting with baked egg offered as cake, followed by hard-boiled egg, omelet/waffle/pancake, soft-boiled egg, and finally raw egg. We hereby designed this protocol based on the influence of thermal processing in the presence or absence of wheat on egg proteins, as investigated by ELISA, SDS-PAGE, and immunoblotting. At inclusion, children either passed an in-hospital cake challenge or had ovomucoid sIgE ≤1.2 kUA/L, which was considered safe for introduction at home.

Results

Gel electrophoresis revealed that the ovalbumin band became weaker with heating, while the ovomucoid band remained stable. In accordance, the IgE-binding to ovalbumin decreased with extensive heating, as opposed to ovomucoid. However, heating in the presence of wheat led to a decreased IgE reactivity to ovomucoid. Of the 78 children in the intention-to-treat group, 39 were randomized to each arm. Fifty-eight children reached the raw egg tolerance endpoint, of which 80% were in the short arm and 69% in the long arm. Within the short arm, the median time to raw egg tolerance was 24 months (95% CI, 21–27 months) compared to 30 months (95% CI, 28–32 months) in the long arm (p = 0.005). No grade IV reactions or cases of eosinophilic esophagitis were observed. The short arm was considered to be non-inferior to the long arm.

Conclusion

Our gradual short arm protocol appears to be safe and allows clinicians to guide baked egg tolerant children toward raw egg tolerance at home. The allergenicity of the egg proteins was affected by heating temperature and duration, as well as the presence of wheat.

Oropharyngeal symptoms without systemic reactions as a risk factor for food allergen intolerance: a longitudinal pediatric study

Background

The determinants of tolerance to food allergens are not fully understood. We aimed to elucidate the longitudinal association between oropharyngeal symptoms without systemic reactions (OSw/oS) and tolerance to food allergens.

Methods

We included all patients diagnosed with single food allergy to egg (n = 121), milk (n = 55), and wheat (n = 41) using the oral food challenge test (OFC) from 2014 to 2017. These patients received oral immunotherapy at home and/or in the hospital after diagnosis by OFC. We compared the incidence proportion of tolerance within 2 years by OSw/oS and other variables for 217 patients with food allergy. We defined OSw/oS as isolated symptoms of oropharyngeal discomfort that occurred after ingestion of a safe dose of the allergenic food determined by the OFC in the first 6 months.

Results

Of the 217 patients (median age 37.5 months, male 64.5%), 53 developed OSw/oS (24.4%), and 151 (egg, 85 milk, 36 and wheat, 30) attained tolerance in 2 years. Patients without OSw/oS showed a significantly higher incidence of tolerance than those with the symptoms (crude hazard ratio [HR] 5.62, 95% confidence interval [CI] 3.58–8.82, p < 0.001). The association was consistently significant in the multivariable model (adjusted HR 9.50, 95% CI 5.25–17.20, p < 0.001) independent of other risk factors for intolerance, such as concomitant bronchial asthma (adjusted HR 3.33), history of anaphylaxis (adjusted HR 2.16), milk allergy (adjusted HR 2.02), and allergic symptoms with low dose OFC (adjusted HR 1.52).

Conclusion

Our results suggest that OSw/oS may be a risk factor for intolerance to food allergens. To reveal a high risk of food allergen intolerance may help patients and their families as well as healthcare professionals prepare for the challenge of continuing oral immunotherapy.

Food allergen ladders: A need for standardization

INTRODUCTION

The process of gradually reintroducing food allergens into an individual's diet is referred to as food allergen "ladders". There remain many questions regarding the foods chosen, structure and composition of the ladder, and medical and safety considerations. The COVID-19 pandemic has propelled us into an era where medicine is increasingly practiced via online platforms, highlighting the need for standardized food allergen ladder approaches for successful and safe introduction of food allergens.

METHODS

We performed a search of currently published food allergen ladders and obtained published information and clinical expertise to summarize current knowledge and suggest future standardized approaches for using food allergen ladders.

RESULTS

There are currently a limited number of published milk, egg, wheat, and soy ladders. We suggest the following points should be considered when developing food ladders: (1) Food allergen: dose, time, and temperature of heating of the food allergen, simplicity of the ladder and recipes, the possible role of the wheat matrix, and testing for allergenic protein levels to standardize doses; (2) Nutritional factors: health and nutritional value of the foods in the ladder, taste, texture, and cultural appropriateness of foods should be considered; and (3) Medical aspects: consideration of which patients are safe to undergo ladders outside of the clinical setting, other safety aspects and risk factors for severe reactions, number of days suggested per steps, and availability and provision of rescue medication. Written instructions and recipes should be provided to families who wish to use food allergen ladders.

DISCUSSION

Food allergen ladders used for gradual reintroduction of food allergens into a food allergic individual's diet are increasingly being used internationally. Standardization regarding the foods included in the ladder and medical considerations are required to practice patient-centered care, best assist patients and families, and ensure safety.

Difficulties in interpretation of oral food challenge results

Oral food challenge is the gold standard in diagnosing food allergies; however, many testing protocols are available. The present article illustrates the difficulties associated with interpreting oral challenge tests with the example of a six-year-old boy with allergy to hen’s eggs. The symptoms observed on the first day of challenge indicated a negative result; however, the consumption of the cumulative dose resulted in anaphylaxis. The interpretation of the oral food challenge can be complicated. The criteria used to determine a positive or negative result are sometimes ambiguous. An accurate interpretation of the results is key to determining correct management in children with food allergy.

BSACI 2021 guideline for the management of egg allergy

This guideline advises on the management of patients with egg allergy. Most commonly egg allergy presents in infancy, with a prevalence of approximately 2% in children and 0.1% in adults. A clear clinical history will confirm the diagnosis in most cases. Investigation by measuring egg-specific IgE (by skin prick testing or specific IgE assay) is useful in moderate-severe cases or where there is diagnostic uncertainty. Following an acute allergic reaction, egg avoidance advice should be provided. Egg allergy usually resolves, and reintroduction can be achieved at home if reactions have been mild and there is no asthma. Patients with a history of severe reactions or asthma should have reintroduction guided by a specialist. All children with egg allergy should receive the MMR vaccine. Most adults and children with egg allergy can receive the influenza vaccine in primary care, unless they have had anaphylaxis to egg requiring intensive care support. Yellow Fever vaccines should only be considered in egg-allergic patients under the guidance of an allergy specialist. This guideline was prepared by the Standards of Care Committee (SOCC) of the British Society for Allergy and Clinical Immunology (BSACI) and is intended for allergists and others with a special interest in allergy. The recommendations are evidence based. Where evidence was lacking, consensus was reached by the panel of specialists on the committee. The document encompasses epidemiology, risk factors, diagnosis, treatment, prognosis and co-morbid associations.

Distinct differences in analytical performance of two commercially available assays for specific IgE to egg white and house dust mite allergens

Background

Measurements of allergen-specific IgE antibodies with different manufacturers’ assays show modest or poor agreement. This study compares analytical performance of specific IgE tests for whole allergen extracts and individual allergen components of two assay systems, IMMULITE and ImmunoCAP, using human sera as well as monoclonal antibodies.

Methods

Comparisons were performed for specific IgE to house dust mite (HDM, n = 44), egg white (EW, n = 36) and the allergen components rDer p 1, rDer p 2, nGal d 1, nGal d 2 and nGal d 4 in human sera and with monoclonal mouse/human chimeric IgE antibodies specific for the same allergen components. Competitive interference with IgE measurement was investigated using allergen-specific monoclonal IgG and IgG4 antibodies.

Results

Measurements of IgE to HDM and EW in serial dilutions of human sera revealed weaker dilution linearity with IMMULITE than with ImmunoCAP. Analysis of five different monoclonal IgE antibodies with total and specific IgE assays, expected to return similar levels, gave an average specific/total IgE ratio of 0.96 (range 0.71–1.14) with ImmunoCAP and 1.89 (range 0.76–2.85) with IMMULITE, indicating overestimation of specific IgE by IMMULITE. With the EW IgE tests of both assay systems, measurements of a chimeric anti-Gal d 2 IgE antibody were unaffected by a competing mouse IgG antibody. While the same was true for measurement of a chimeric anti-Der p 1 IgE antibody using the HDM test in ImmunoCAP, a suppression of measured concentrations by up to 42% was observed in IMMULITE. Similarly, measurement of HDM-specific IgE in human sera by ImmunoCAP was unaffected by a competing monoclonal anti-Der p 2 IgG4 antibody while IMMULITE displayed a reduction of HDM-specific IgE values by up to 30%.

Conclusions

In this evaluation of analytical performance of two widely used assay systems, ImmunoCAP showed higher accuracy in quantitation of specific IgE and greater resistance against competing allergen-specific non-IgE antibodies which may arise through natural or dietary exposure, or as a result of allergen immunotherapy treatment.

Update of the S2k guideline on the management of IgE-mediated food allergies

Not available.

Evaluation of baked egg oral immunotherapy in French children with hen's egg allergy

BACKGROUND

Introduction and gradual incremental escalation of a low dose of baked egg may accelerate the resolution of severe hen's egg (HE) allergy for some children. The purpose of our study was to evaluate the efficacy and safety of baked egg oral immunotherapy (OIT) in children with HE allergy after a low-dose baked egg oral food challenge (OFC).

METHODS

In a retrospective analysis of OFC performed between 2013 and 2018 at the Children's Hospital of Toulouse (France), we identified 71 children with HE allergy and high egg-white (EW) and ovomucoid specific IgE levels, who underwent a total of 164 OFC (71 baked egg, then 93 unbaked egg). Mean age at first low-dose baked egg OFC was 6 years. Median EW specific IgE was 14.0 kUA/L, and median ovomucoid specific IgE was 11.7 kUA/L.

RESULTS

Most children were treated with baked egg OIT. Our study shows that 78.9% of the children did not react to first low-dose baked egg OFC (702 mg of HE protein). 8.7% of children discontinued OIT at home. Finally, desensitization to unbaked HE was achieved in 47 children (66.2% of children allergic to HE). Children with lower EW specific IgE levels had a significantly higher probability of becoming desensitized to HE. We did not report any anaphylactic reactions to baked egg OIT.

CONCLUSION

Most children with HE allergy and high egg-white (EW) and ovomucoïd specific IgE levels tolerate the introduction of baked egg. Baked egg OIT is safe, and anaphylaxis to baked egg OIT has not been observed.

Optimizing Patient Care in Egg Allergy Diagnosis and Treatment

Egg allergy occurs frequently in childhood with a reported prevalence of 1.3-1.6%. Providing optimal care to egg-allergic patients requires knowledge of the most up-to-date developments in both diagnosis and management, as well as effective communication skills, which will engage the patient in the shared decision-making process. This review aims to provide up-to-date information on egg allergy and also serve as a concise guide on optimal patient diagnosis and management. The field of food allergy has seen multiple advances in recent years, including use of component resolved diagnostics, early egg introduction into the infant diet as a way of preventing egg allergy, baked egg introduction and oral immunotherapy as a form of active therapy. Faced with a variety of options and treatment paths, it is important to ensure that patients and families taking part in the decision-making process have fully understood the potential outcomes and trade-offs and can undertake a detailed discussion of all options that are available to them. Shared decision-making remains the cornerstone of optimal patient care.

Managing Food Allergy When the Patient Is Not Highly Allergic

Few patients with food allergy are "highly allergic," meaning they always have severe reactions and always react to very small amounts of allergen. Standard medical approaches for allergy management have focused on the safety and lifestyle modifications this group truly needs, but consequently families with food allergy are typically advised to strictly avoid any exposure to their implicated allergens. Most food-allergic subjects are actually not reactive to very low doses, and many never experience severe reactions. There are also notable conditions where a different care plan is already commonly offered: patients with pollen-related food allergy syndrome, with food-associated exercise-induced anaphylaxis, and with resolving or mild milk or egg allergy might be advised to ingest the allergens in specific circumstances with detailed instructions. Because oral immunotherapy and allergy prevention by early exposure have emphasized alternatives to strict avoidance, there is increasing interest in prospects to forego strict avoidance in those with food allergy. For patients with a high threshold of reactivity (low-dose tolerant, high-dose mildly reactive), there may be options such as allowing the ingestion of products with precautionary allergen labels, allowing dietary indiscretions with small amounts of the allergen, or even encouraging ingestion of subthreshold amounts with therapeutic intent. These practices have not been extensively studied and could be considered controversial. If these approaches are considered, shared decision making is needed in discussing them with patients and families. This review considers the potential approaches to those who are "not highly allergic": the risks, benefits, shared decision making, and research needs.

Conducting an Oral Food Challenge: An Update to the 2009 Adverse Reactions to Foods Committee Work Group Report

Oral food challenges are an integral part of an allergist's practice and are used to evaluate the presence or absence of allergic reactivity to foods. A work group within the Adverse Reactions to Foods Committee of the American Academy of Allergy, Asthma & Immunology was formed to update a previously published oral food challenge report. The intention of this document was to supplement the previous publication with additional focus on safety, treatment of IgE-mediated allergic reactions, guidance for challenges in infants and adults, psychosocial considerations for children and families participating in an oral food challenge, specific guidance for baked milk or baked egg challenges, masking agents and validated blinding recipes for common food allergens, and recommendations for conducting and interpreting challenges in patients with suspected food protein-induced enterocolitis syndrome. Tables and figures within the report and an extensive online appendix detail age-specific portion sizes, appropriate timing for antihistamine discontinuation, serum and skin test result interpretation, written consents, and instructional handouts that may be used in clinical practice.

Biomarkers of diagnosis and resolution of food allergy

Food allergy is increasing in prevalence, affecting up to 10% of children in developed countries. Food allergy can significantly affect the quality of life and well-being of patients and their families; therefore, an accurate diagnosis is of extreme importance. Some food allergies can spontaneously resolve in 50%-60% of cow's milk and egg-allergic, 20% of peanut-allergic and 9% of tree nut-allergic children by school age. For that reason, food-allergic status should be monitored over time to determine when to reintroduce the food back into the child's diet. The gold-standard to confirm the diagnosis and the resolution of food allergy is an oral food challenge; however, this involves the risk of causing an acute-allergic reaction and requires clinical experience and resources to treat allergic reactions of any degree of severity. In the clinical setting, biomarkers have been used and validated to enable an accurate diagnosis when combined with the clinical history, deferring the oral food challenge, whenever possible. In this review, we cover the tools available to support the diagnosis of food allergies and to predict food allergy resolution over time. We review the latest evidence on different testing modalities and how effective they are in guiding clinical decision making in practice. We also evaluate predictive test cut-offs for the more common food allergens to try and provide guidance on when challenges might be most successful in determining oral tolerance in children.

A Randomized, Open-Label Trial of Hen's Egg Oral Immunotherapy: Efficacy and Humoral Immune Responses in 50 Children

BACKGROUND

Egg allergy is the second most common food allergy in children. Persistent food allergy increases the risk of anaphylaxis and reduces the quality of life.

OBJECTIVE

To determine the efficacy of oral immunotherapy (OIT) with raw egg white powder and study its effects on humoral responses in children with persistent egg allergy.

METHODS

Fifty children aged 6 to 17 years with egg allergy, diagnosed by double-blind, placebo-controlled food challenge, were randomized 3:2 to 8 months of OIT with a maintenance dose of 1 g of egg white protein or 6 months of avoidance after which the avoidance group crossed over to OIT. We examined changes in IgE, IgG₄, and IgA concentrations to Gal d 1-4 during OIT compared with avoidance and assessed clinical reactivity at 8 and 18 months.

RESULTS

After 8 months, 22 of 50 children (44%) on OIT and 1 of 21 (4.8%) on egg avoidance were desensitized to the target dose, 23 of 50 (46%) were partially desensitized (dose <1 g), and 5 of 50 (10%) discontinued. IgG₄ concentrations to Gal d 1-4 and IgA to Gal d 1-2 increased significantly, whereas IgE to Gal d 2 decreased. A heatmap analysis of the IgE patterns revealed 3 distinct clusters linked with the clinical outcome. High baseline egg white-specific IgE and polysensitization to Gal d 1-4 related with failure to achieve the maintenance dose at 8 months. After 18 months of treatment, 36 of 50 patients (72%) were desensitized and 8 of 50 (16%) partially desensitized.

CONCLUSIONS

OIT with raw egg enables liberation of egg products into the daily diet in most patients. Subjects with high egg white-specific IgE concentrations and sensitization to multiple egg allergen components at baseline benefit from prolonged treatment.

The Gut Microbiome and the Big Eight

Food allergies are increasing at an alarming rate, with 6.5% of the general population affected. It has been hypothesized that the increase in allergies stems from the “hygiene hypothesis”. The gut microbiome, a collection of microbiota and their genetic contents from the gastrointestinal tract, has been shown to play a part in the development of food allergies. The Food and Drug Administration requires all regulated food companies to clearly state an inclusion of the major, or “big eight” food allergens on packaging. This review is to provide information on the significant advancements related to the gut microbiome and each of the eight major food allergies individually. Establishment of causal connection between the microbiome and food allergies has uncovered novel mechanisms. New strategies are discussed to prevent future sensitization and reaction through novel treatments involving functional additives and dietary changes that target the microbiome.

Nutritional management of food allergies

Food allergy is a significant public health concern, with a rising prevalence. Elimination diets remain the cornerstone of food allergy management, and they are not without nutritional risk. Children who avoid nutritionally important foods, such as milk or multiple foods allergens, may be at greater risk. Even adults with food allergies may encounter challenges to meet current recommended dietary guidelines for health and reduced risk of chronic disease. The type of food allergy disorder will also impact nutritional risk. A food allergy affects food choices, nutritional intake, and health; therefore, guidance to provide nutritionally appropriate substitutes within the context of the elimination diet is invaluable.