Food allergen ladders: A need for standardization

Dietary Advancement Therapy Using Milk and Egg Ladders Among Children With a History of Anaphylaxis

BACKGROUND

Anaphylaxis has been increasing in recent years, with common triggers in infants being milk and eggs. Currently, the mainstay of treatment for milk and/or egg allergy is strict avoidance. Recently, new therapies have emerged including stepwise introduction of allergens via a ladder approach. The suitability of infants for the ladders is debated.

OBJECTIVE

This study aims to focus on the use of food ladders in children with anaphylaxis to egg or milk.

METHODS

Retrospective review of pediatric patients diagnosed with immunoglobulin E-mediated milk and/or egg allergy between 2011 and 2021. Inclusion and exclusion criteria were applied. Anaphylaxis was defined as per the World Allergy Organization-amended criteria 2020. Data analysis utilized SPSS Version 28.

RESULTS

We reviewed 1,552 patient charts, and excluded 1,094, leaving a total sample size of 458. Seventy infants had anaphylaxis at diagnosis (milk n = 36; egg n = 34). A range of 77.8% to 85.2% of infants with anaphylaxis successfully completed the ladder, 88.9% to 92.9% without anaphylaxis were successful. Children who successfully completed the ladder did so at similar rates. A range of 20.6% to 50% children presenting with anaphylaxis at diagnosis experienced allergic symptoms during treatment, compared with 17.3% to 40.7% without anaphylaxis. Reactions were mild, mostly cutaneous and not requiring medical attention. Patients experiencing allergic symptoms while on the ladder were less likely to successfully complete treatment.

CONCLUSIONS

Milk and egg ladders are a safe and effective way of inducing tolerance in infants, including those with a history of anaphylaxis at diagnosis. There are no obvious predictors for who will experience allergic reactions while on the ladder; however, these children are less likely to complete the ladder, so parents should be educated in management of mild allergic reactions at home.

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.

An ESPGHAN Position Paper on the Diagnosis, Management, and Prevention of Cow's Milk Allergy

A previous guideline on cow's milk allergy (CMA) developed by the European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) was published in 2012. This position paper provides an update on the diagnosis, treatment, and prevention of CMA with focus on gastrointestinal manifestations. All systematic reviews and meta-analyses regarding prevalence, pathophysiology, symptoms, and diagnosis of CMA published after the previous ESPGHAN document were considered. Medline was searched from inception until May 2022 for topics that were not covered in the previous document. After reaching consensus on the manuscript, statements were formulated and voted on each of them with a score between 0 and 9. A score of ≥6 was arbitrarily considered as agreement. Available evidence on the role of dietary practice in the prevention, diagnosis, and management of CMA was updated and recommendations formulated. CMA in exclusively breastfed infants exists, but is uncommon and suffers from over-diagnosis. CMA is also over-diagnosed in formula and mixed fed infants. Changes in stool characteristics, feeding aversion, or occasional spots of blood in stool are common and in general should not be considered as diagnostic of CMA, irrespective of preceding consumption of cow's milk. Over-diagnosis of CMA occurs much more frequently than under-diagnosis; both have potentially harmful consequences. Therefore, the necessity of a challenge test after a short diagnostic elimination diet of 2-4 weeks is recommended as the cornerstone of the diagnosis. This position paper contains sections on nutrition, growth, cost, and quality of life.

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.

The Remaining Challenge to Diagnose and Manage Cow's Milk Allergy: An Opinion Paper to Daily Clinical Practice

Guidelines and recommendations for the diagnosis and management of cow's milk allergy (CMA) in childhood are based on scientific review of the available evidence. While this approach is the most rigorous, guidelines may not fully address all scenarios encountered by clinicians. Many symptoms of CMA overlap with other common childhood illnesses and are subjectively reported by the caregivers of the infant, as is the interpretation of the dietary interventions. Additionally, many healthcare professionals and caregivers do not follow the recommendations to perform an oral food challenge or reintroduction of cow's milk after a diagnostic elimination diet because (1) the infant is doing well and (2) the carer's fear of symptoms relapsing with this procedure. As a result, CMA in infants may be either under-diagnosed leading to reduced quality of life for families or over-diagnosed, resulting in unnecessary long-term elimination diets and increasing the risk for nutritional deficiencies. This paper discusses some of these controversial topics, focusing on misdiagnosis and mismanagement in clinical practice. The lack of objective diagnostic criteria can hamper the diagnosis and management of CMA in daily practice.

The Need for Culturally Appropriate Food Allergy Management Strategies: The Indian Milk Ladder

BACKGROUND

Cow's milk allergy (CMA) is one of the most common and complex food allergies affecting children worldwide and, with a few exceptions, presents in the first few months of life. Baked-milk-containing diets are well tolerated in the majority of milk-allergic children and allow dietary restrictions to be relaxed. In addition, the early introduction of tolerated forms of allergenic foods to an infant's diet in small amounts may enhance the outgrowth of their milk allergy through oral tolerance induction. The methods of milk introduction vary widely across the globe.

METHODS

We convened an expert group to develop a comprehensive milk ladder based on the calculated milk protein content of Indian foods. To validate the milk ladder, the foods chosen for the ladder were analyzed and the ladder was re-evaluated based on the cooked milk protein content.

RESULTS

Combining expert consensus and validation of milk protein content, we created the world's first milk ladder containing Indian foods. This is the first ladder that provides information on the timing and temperature of cooking, with validated milk protein content.

CONCLUSIONS

This is the first milk ladder based on the unique features of Indian food habits built by the consensus of Indian experts along with international collaboration with laboratory quantification of milk protein in each step. We believe the "The Indian Milk Ladder" will be a very helpful tool for pediatricians helping manage CMA in children as well as their parents and caregivers, not only in India, but in countries world-wide where these foods are commonly consumed.

Food allergy-A holistic approach to dietary management. A joint EAACI Research & Outreach Committee and INDANA review

Following a diagnosis of IgE-mediated food allergy, to secure the best outcome, the patient should receive individualized advice tailored to their specific needs, which considers the type and presentation of the food involved, level of exclusion required, risk of cross-contamination and any variance required for age, ethnicity, financial issues, and lifestyle. Issues such as food labels "may contain" statements, and variation in the threshold of reaction and impact of cofactors should also be considered. Most important is the need to ensure that the diagnosis is robust, especially given the nutritional, psychological, and socioeconomic issues that can affect an individual with a diagnosis of food allergy. Unnecessary exclusion of one or more foods that have not triggered allergic reactions, especially in individuals with allergic comorbidities, can result in severe IgE-mediated reactions on re-exposure. Given that food allergies may change over time, the diagnosis should be reviewed, to determine whether resolution is likely, or new-food triggers are reported. Regular assessment is vital, especially during childhood, to ensure reintroduction occurs at an appropriate time, thus enabling increased diversity of the diet and improvement in the quality of life. For some, an IgE-mediated food allergy may necessitate the life-long exclusion of foods, and for others, a food habitually eaten suddenly triggers an allergic reaction in adult life. People of all ages, ethnicities, and socioeconomic backgrounds deserve individual advice on the management of their food allergy to support a healthy diet and improve quality of life.

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.

World Allergy Organization (WAO) Diagnosis and Rationale for Action against Cow's Milk Allergy (DRACMA) Guideline update - VII - Milk elimination and reintroduction in the diagnostic process of cow's milk allergy

The diagnosis of cow's milk allergy (CMA) in infants and young children remains a challenge because many of the presenting symptoms are similar to those experienced in other diagnoses. Both over- and under-diagnosis occur frequently. Misdiagnosis carries allergic and nutritional risks, including acute reactions, growth faltering, micronutrient deficiencies and a diminished quality of life for infants and caregivers. An inappropriate diagnosis may also add a financial burden on families and on the healthcare system. Elimination and reintroduction of cow's milk (CM) and its derivatives is essential for diagnosing CMA as well as inducing tolerance to CM. In non-IgE mediated CMA, the diagnostic elimination diet typically requires 2-4 weeks before reintroduction, while for IgE mediated allergy the time window may be shorter (1-2 weeks). An oral food challenge (OFC) under medical supervision remains the most reliable diagnostic method for IgE mediated and more severe types of non-IgE mediated CMA such as food protein induced enterocolitis syndrome (FPIES). Conversely, for other forms of non-IgE mediated CMA, reintroduction can be performed at home. The OFC cannot be replaced by the milk ladder after a diagnostic elimination diet. The duration of the therapeutic elimination diet, once a diagnosis was confirmed, can only be established through testing changes in sensitization status, OFCs or home reintroduction, which are directed by local protocols and services' availability. Prior non-evidence-based recommendations suggest that the first therapeutic elimination diet should last for at least 6 months or up to the age of 9-12 months, whichever is reached first. After a therapeutic elimination diet, a milk-ladder approach can be used for non-IgE mediated allergies to determine tolerance. Whilst some centers use the milk ladder also for IgE mediated allergies, there are concerns about the risk of having immediate-type reactions at home. Milk ladders have been adapted to local dietary habits, and typically start with small amounts of baked milk which then step up in the ladder to less heated and fermented foods, increasing the allergenicity. This publication aims to narratively review the risks associated with under- and over-diagnosis of CMA, therefore stressing the necessity of an appropriate diagnosis and management.

Are There Hidden Dangers Associated With Milk and Egg Dietary Advancement Therapy?

Dietary advancement therapies (DATs) constitute a continuum spanning extensively heated item ingestion, progressive milk or egg ladders, and oral immunotherapy (OIT). These represent an evolution in food allergy management from strict avoidance to an active therapy that may modulate the immune system to develop tolerance to particular forms of the allergen. Many egg or milk individuals are tolerant to baked egg or milk at baseline, and regular consumption (at home ingestion) of baked milk or egg is a safe process with potential quality of life and immunologic benefit. Milk and egg ladders, developed for non-IgE mediated allergy, are increasingly being adapted to IgE-mediated allergy as a potentially safe at-home option for gradual dietary advancement. However, data are limited regarding how safe and effective these approaches are or what patient is best suited for which DAT. It is also unclear whether extensively heated allergen consumption and ladders are susceptible to the same patient-specific factors that affect day-to-day tolerance and safety in OIT. Several recent events involving near-fatal or fatal reactions to milk or egg products (all among patients with asthma) have highlighted that DATs are not risk-free, and that physician guidance in these therapies is essential. Such guidance may include obtaining informed consent before starting any DAT and instituting the same safe dosing rules for OIT across any form of DAT. This rostrum discusses practical concerns about the safety of DAT, and considerations regarding how clinicians can maximize patient protection while defining the safety and efficacy of real-world implementation of these concepts.

Will Oral Food Challenges Still Be Part of Allergy Care in 10 Years' Time?

Oral food challenges (OFCs) are currently the definitive diagnostic procedure in food allergy. Their design has evolved over the decades to maximize safety, optimize convenience, and address several specific clinical questions. However, they are a resource-intensive investigation that carry a risk for severe allergic reaction in which fatal outcomes, although rare, have been reported. In this review, we explore the many roles that OFC fulfil in the clinical and research settings. We also discuss progress that has been made in developing alternative diagnostic tools and how far these have reached in offering a viable replacement to OFC in clinical practice. Finally, we discuss the ongoing importance of research OFC to improve the future diagnostic capabilities of novel diagnostic tools.

Mediterranean Milk Ladder: Integrating a Healthy Eating Plan While Reintroducing Cow's Milk

The process of gradually reintroducing food allergens into an individual's diet is referred to as a food allergen "ladder", and the most recent edition of the original Milk Allergy in Primary (MAP) Care Guidelines, as well as the International Milk Allergy in Primary Care (IMAP), includes a shortened, improved, and international version with specific recipes, indicating the exact milk protein content, as well as the duration of heating and the temperature for each step of the ladder. Food allergen ladders are being used increasingly in clinical practice. The aim of this study was to develop a Mediterranean milk ladder based on the principles of the Mediterranean eating pattern. The protein content delivered in a portion of the final food product in each step of the ladder in the Mediterranean version corresponds to that provided in the IMAP ladder. Different recipes for the various steps were provided to increase acceptability and variety. Quantification of the total milk protein, casein content, and beta-lactoglobulin by Enzyme-linked immunosorbent assay (ELISA) could detect the gradual increase in concentrations, but the accuracy of the method was affected by the presence of the other ingredients in the mixtures. When developing the Mediterranean milk ladder, a key consideration was to reduce the amount of sugar by using limited amounts of brown sugar and substituting sugar with fresh fruit juice or honey for children aged older than one year. The proposed Mediterranean milk ladder includes principles of (a) healthy eating based on the Mediterranean diet and (b) the acceptability of foods across different age groups.

The potential role of preventive and therapeutic immunonutrition strategies for pediatric food allergy: A mini-review

Food allergy (FA) represents one of the main chronic conditions of the pediatric population. The gut microbiome (GM)-immune system axis is a milestone in affecting FA susceptibility. The dynamic and bidirectional crosstalk between the GM and immune system starts early in life, and it is deeply modulated during the first 1,000 days of life. Nutritional factors during this crucial period mainly influence the proper GM-immune system development and function across the lifespan, with potential beneficial or detrimental effects on health status. Immunonutrition strategies, applied from conception, could represent an innovative target for prevention and treatment of pediatric FA. Here we described the potential role of preventive and therapeutic immunonutrition strategies for pediatric FA, highlighting putative future perspectives in this field.

Update on Nutrition and Food Allergy

Food-induced anaphylaxis is an immediate adverse reaction, primarily triggered by the cross-linking of allergen-specific immunoglobulin (Ig) E bound to the high-affinity IgE receptor (FcεRI) on mast cells (MCs) after re-exposure to the same food allergen [...]

Oral immunotherapy for food allergy in children: is it worth it?

INTRODUCTION

Oral immunotherapy (OIT) is effective at inducing desensitization in food-allergic individuals, and is a valid therapeutic option for those allergic to peanut, cow's milk and egg. However, there is a high rate of dose-related adverse events, and at least one fatality to OIT has been reported.

AREAS COVERED

We provide an update on the broader framework of issues which will impact on the availability and uptake of OIT.

EXPERT OPINION

The need for standardized products remains controversial. A licensed product exists for peanut-OIT, but OIT can also be safely achieved using peanut-containing foods at much lower cost. For other allergens, OIT can only be done with non-pharma products - something which has been done safely for over 2 decades. There is a need to develop personalized protocols for OIT, particularly for the 20% of patients unable to tolerate standard OIT. Cost-effectiveness is dependent on improved quality of life, but evidence for this is currently lacking, and is a key evidence gap. OIT is likely to be cost-effective, particularly if noncommercial products are used. There may be a trade-off: in patients with lower reaction thresholds, a commercial product may be needed for initial updosing, until a level of desensitization is achieved when they can be switched to natural food products.