Food-Induced Anaphylaxis in Infants: Can New Evidence Assist with Implementation of Food Allergy Prevention and Treatment?

Anaphylaxis: A 2023 practice parameter update

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

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Early Introduction of Novel and Less-Studied Food Allergens in the Plant-Based Era: Considerations for US and EU Infant Formula Regulations

Early life feeding practices may affect the long-term health of individuals, particularly in terms of the development of non-communicable diseases, such as metabolic and allergic diseases. Accumulating evidence suggests that the interplay of breastfeeding and/or formula feeding followed by the introduction of solids plays a role in the occurrence of non-communicable diseases both in the short and long term. International food allergy guidelines recommend that breastfeeding women do not need to avoid food allergens and do not recommend any infant formula for allergy prevention. Guidelines regarding solid food introduction for food allergy prevention recommend the introduction of well-cooked eggs and peanuts around 4-6 months of age, and not to delay the introduction of other food allergens. There is also an increasing trend to feed infants a plant-based or plant-forward diet and have access to infant formulas based on plant-based ingredients. The use of novel plant-based infant formulas raises a few questions reviewed in this paper: (1) Do fortified, plant-based infant formulas, compliant with US Food and Drug Administration (FDA) regulations and European Food Safety Authority (EFSA) (European) guidelines, support adequate infant growth? (2) Are plant-based infant formulas suitable for the management of cow's milk allergy? (3) Does feeding with novel, plant-based infant formulas increase the risk of food allergies to the food allergens they contain? (4) Does feeding infants plant-based food allergens in early life increase the risk of allergic and severe allergic reactions? The review of the literature indicated that (1) plant-based formulas supplemented with amino acids and micronutrients to comply with FDA regulations and EFSA guidelines, evaluated in sufficiently powered growth studies, can support adequate growth in infants; (2) currently available plant-based infant formulas are suitable for the management of CMA; (3) an early introduction and continuous intake of food allergens are more likely to prevent food allergies than to increase their risk; and (4) an early introduction of food allergens in young infants is safe.

Challenges implementing recent recommendations of daily formula supplementation for allergy prevention and practical real-world options

The Canadian Paediatric Society's Position statement 'Dietary exposures and allergy prevention in high-risk infants' December 2021 provides recommendations for regular ingestion of cow's milk protein (CMP) once introduced in early infancy. These recommendations are based on evidence from randomized controlled trials (RCTs) where researchers supported participants in adhering to diet recommendations. Real-life dilemmas that relate to dietary adherence including cost, food wastage, and practicality are not addressed and are the crux of where -evidence-based recommendations fail. This commentary highlights the difficulties in carrying out the proposed recommendation for regular ingestion of CMP in practice and offers three practical real-world options instead.

Impact of public health interventions for food allergy prevention on rates of infant anaphylaxis

BACKGROUND

Eleven percent of Australian infants have confirmed food allergy. We hypothesized earlier introduction may lead to higher rates of infant anaphylaxis, irrespective of whether the overall rate of food allergy in the population was ultimately reduced.

OBJECTIVE

To determine whether a public health campaign, targeting earlier introduction of allergenic foods, affected rates of infant anaphylaxis.

METHODS

Data were obtained from St John Ambulance (SJA) Western Australia and Western Australian emergency departments (ED) on infant (≤12 months) anaphylaxis over a 5-year period (July 1, 2015 to June 30, 2020). Adrenaline administration data were collected in the SJA dataset. Poisson regression was undertaken to assess trends in anaphylaxis over time. Segmented regression analysis was undertaken to assess differences in anaphylaxis rates before and after intervention.

RESULTS

The SJA and ED datasets included 172 and 294 events, respectively, coded as infant anaphylaxis. Rates of infant anaphylaxis increased over time for both SJA and ED datasets, with a 1-year increase rate ratio of 1.21 (95% confidence interval, 1.09-1.35; P value < .01) and 1.11 (95% confidence interval, 1.02-1.20; P = .01), respectively. Segmented regression indicated no significant difference in rates after intervention. Adrenaline was not coded as being administered in 109 of the 172 anaphylaxis events.

CONCLUSION

Rates of infant anaphylaxis increased over the 5-year reporting period; however, there was no clear increase related to the timing of the public health campaign implementation. Reported adrenaline use was suboptimal. Assessing rates of food allergy in all age groups is required to determine whether there has been an overall reduction in food allergy owing to the intervention.

Crystal Structure Analysis of Sarcoplasmic-Calcium-Binding Protein: An Allergen in Scylla paramamosain

The structure of allergenic proteins provides important information about the binding of allergens to antibodies. In this study, the crystal structure of Scy p 4 with a resolution of 1.60 Å was obtained by X-ray diffraction. Epitope mapping of Scy p 4 revealed that linear epitopes are located on the surface of Scy p 4. Also, conformational epitopes are mostly located in the structural conservative region. Further structural comparison, surface electrostatic potential, and hydrogen bond force analysis showed that mutation of Asp₇₀ and Asp_18/20/70 would lead to calcium-binding capacity being lost and destruction of allergenicity. Furthermore, a comparative analysis of structure showed that sarcoplasmic-calcium-binding protein (SCP) had high sequence, secondary, and spatial structural identity in crustaceans, which may be an important factor leading to cross-reactivity among crustaceans. The structure of Scy p 4 provides a template for epitope evaluation and localization of SCPs, which will help to reveal cross-reactivity among species.

The Case for Prompt Salvage Infant Peanut Oral Immunotherapy Following Failed Primary Prevention

Recent guideline recommendations have shifted from recommending prolonged avoidance of allergenic foods in the first 3 years of life to a primary prevention approach involving the deliberate early introduction to infants at risk of developing food allergy. Despite this, some infants, especially those with severe eczema who are at highest risk for developing peanut allergy, fail to receive the preventative benefits of early peanut introduction due to hesitancy and other factors. Difficulty adhering to regular ingestion after introduction further reduces the effectiveness of primary prevention. As emerging real-world evidence has demonstrated that performing peanut oral immunotherapy (OIT) among infants is effective and safe, peanut OIT could be a treatment option for infants with peanut allergy. This review discusses the benefits, risks, and barriers to offering peanut OIT to infants who fail primary prevention strategies. We propose the novel concept that infants with peanut allergy be offered peanut OIT as soon as possible after failed peanut introduction through a shared decision-making process with the family, where there is a preference for active management rather than avoidance.

How primary care providers can help prevent food allergies

PURPOSE OF REVIEW

IgE-mediated food allergy rates have increased in recent decades, yet treatment options remain limited. Prevention strategies are thus essential. We will review recent research and consensus guidelines for food allergy prevention.

RECENT FINDINGS

Research has continued to support that early introduction of allergens via the gastrointestinal tract induces tolerance and prevents development of food allergy. In contrast, allergen sensitization may occur via transcutaneous allergen exposure. This is supported by research that shows a decreased risk of food allergy with aggressive treatment of atopic dermatitis. More recent research suggests that transcutaneous sensitization could also be facilitated by frequent emollient use in the absence of atopic dermatitis but definitive research is lacking. Murine models have shown a likely role of dysbiosis, or disruption of the body's normal healthy microbiome, in development of food allergy, yet human studies have yet to show a conclusive benefit of probiotics in the prevention of food allergy.

SUMMARY

Important approaches for food allergy prevention are: introduction of peanut and cooked egg at 4-6 months, early introduction of other allergenic foods, and early diagnosis and treatment of atopic dermatitis (because of a predisposition to food sensitization through the damaged skin barrier). More research is needed to clarify the role, if any, of emollient use and probiotics.

Dietary exposures and allergy prevention in high-risk infants

Infants at high risk for developing a food allergy have either an atopic condition (such as eczema) themselves or an immediate family member with such a condition. Breastfeeding should be promoted and supported regardless of issues pertaining to food allergy prevention, but for infants whose mothers cannot or choose not to breastfeed, using a specific formula (i.e., hydrolyzed formula) is not recommended to prevent food allergies. When cow's milk protein formula has been introduced in an infant's diet, make sure that regular ingestion (as little as 10 mL daily) is maintained to prevent loss of tolerance. For high-risk infants, there is compelling evidence that introducing allergenic foods early-at around 6 months, but not before 4 months of age-can prevent common food allergies, and allergies to peanut and egg in particular. Once an allergenic food has been introduced, regular ingestion (e.g., a few times a week) is important to maintain tolerance. Common allergenic foods can be introduced without pausing for days between new foods, and the risk for a severe reaction at first exposure in infancy is extremely low. Pre-emptive in-office screening before introducing allergenic foods is not recommended. No recommendations can be made at this time about the role of maternal dietary modification during pregnancy or lactation, or about supplementing with vitamin D, omega 3, or pre- or probiotics as means to prevent food allergy.

Maillard Reaction Induced Changes in Allergenicity of Food

Food allergy is increasing in prevalence, posing aheavier social and financial burden. At present, there is still no widely accepted treatment for it. Methods to reduce or eliminate the allergenicity of trigger foods are urgently needed. Technological processing contributes to producing some hypoallergenic foods. Among the processing methods, the Maillard reaction (MR) is popular because neither special chemical materials nor sophisticated equipment is needed. MR may affect the allergenicity of proteins by disrupting the conformational epitope, disclosing the hidden epitope, masking the linear epitope, and/or forming a new epitope. Changes in the allergenicity of foods after processing are affected by various factors, such as the characteristics of the allergen, the processing parameters, and the processing matrix, and they are therefore variable and difficult to predict. This paper reviews the effects of MR on the allergenicity of each allergen group from common allergenic foods.

Management of Anaphylaxis in Infants and Toddlers

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

Advanced glycation end product intake during pregnancy and offspring allergy outcomes: A Prospective cohort study

BACKGROUND

Associations have been shown between concurrent assessment of dietary intake of advanced glycation end products (AGEs) and childhood allergic outcomes. We examined the association between maternal AGEs intake and development of offspring asthma, wheeze, atopic dermatitis, allergic rhinitis and food allergies, and sought to determine whether the intake of AGEs was associated with cord sera cytokines/chemokines.

METHODS

Pregnant women ≥16 years were recruited in the Healthy Start study, a prospective pre-birth cohort from Colorado (N = 1410). The analysis included 962 dyads with adequate diet (≥2 recalls) and allergy outcome details. AGEs intake was estimated for each mother by matching intakes reported using 24-h dietary recalls during pregnancy to a reference database of commonly consumed foods' AGEs values. Child diagnoses of asthma and allergies up to 8 years were obtained from electronic medical records. Cord sera cytokines and chemokines were analysed in a subset (N = 462) of children.

RESULTS

The median [IQR] AGEs intake for the overall sample was 11,919 kU/day [8293, 16,573]. Unadjusted analysis showed a positive association between maternal AGEs intake in pregnancy and rhinitis up to 8 years of age (HR = 1.03; 95% CI: 1.01, 1.06), but the association was attenuated and no longer significant in adjusted models (HR = 1.01; 95% CI: 0.98, 1.04). Both adjusted and unadjusted models showed no associations between AGEs intake in pregnancy and any of the other outcomes (p > .05). There were no significant associations between any cytokine or chemokine measured and AGEs intake or any of the outcomes studied (p > .05).

CONCLUSION

The study showed that maternal AGEs intake was not associated with offspring asthma and allergy outcomes. AGEs exposure during pregnancy may not have the same impact on child development as postnatal exposure.

Home-Based Peanut Oral Immunotherapy for Low-Risk Peanut-Allergic Preschoolers During the COVID-19 Pandemic and Beyond

The coronavirus disease 2019 (COVID-19) pandemic has led to the deprioritization of non-emergency services, such as oral food challenges and the initiation of oral immunotherapy (OIT) for food-allergic children. Recent studies have suggested that home-based peanut OIT could be a safe and effective option for low-risk peanut-allergic children. In the period between September 1, 2020, and January 31, 2021, nine preschoolers with a history of mild allergic reactions to peanut underwent home-based peanut OIT. Eight of them (88.9%) completed the build-up phase at home in 11–28 weeks, tolerating a daily maintenance dose of 320 mg peanut protein. During the build-up, six patients (75.0%) reported urticaria, three (33.3%) reported gastrointestinal tract symptoms, and one (14.3%) reported oral pruritis. None of the patients developed anaphylaxis, required epinephrine, or attended emergency services related to OIT. One or two virtual follow-up visits were completed per patient during the build-up phase. Our case series shows that home-based OIT could be offered to the low-risk preschoolers during the COVID-19 pandemic when non-emergency services are limited and could be considered beyond the pandemic, especially for the families living in the rural or remote areas that may otherwise be unable to access OIT.

Allergic Food Sensitization and Disease Manifestation in the Fetus and Infant: A Perspective

Even though allergic disease is identified in the first year of life, it is often in a less forward fashion, with elements of a wait and see approach. If the infant does not have an anaphylactic food reaction, other less dramatic allergic phenomenon is often under-emphasized, waiting for additional concerns. We approached this with a conception to first conduct birthday surveys, attempting to link intrauterine and peri-birth circumstances to affect better allergy recognition in young infants.