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.

Citrin: a novel food allergen in citrus seeds and citrus-derived pectin that shows cross-reactivity with cashew and pistachio.

BACKGROUND: Patients exquisitely sensitive to cashew/pistachio are at risk for allergic reactions to citrus seeds and pectin. OBJECTIVE: In this study, we sought to evaluate whether pectin is contaminated with citrus seeds, to identify a culprit antigen in citrus seeds, and to assess for cross-reactivity among allergens in citrus seeds, citrus pectin, and cashew or pistachio. METHODS: Proteins from orange seed coats, orange seed endosperms, lemon seeds, grapefruit seeds, citrus pectin, apple pectin, and grapefruit pectin were extracted. Protein concentrations in all extracts were determined and visualized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique. Immunoglobulin E-binding capacity was determined with Western blot analyses and tandem mass spectrometry for the identification of the culprit allergen in citrus seeds and pectin. RESULTS: In subjects with citrus seed, pectin, and cashew allergies, there was strong immunoglobulin E-reactivity to bands between 17 to 28 kDa and 28 to 38 kDa. The tandem mass spectrometry analysis of these bands indicated the presence of citrin as the culprit allergen. Citrin and Ana o 2 are both 11S globulins belonging to the cupin superfamily, and significant homology was found between these proteins. CONCLUSION: Citrus pectin may be contaminated with citrus seeds. Citrin, a newly identified allergen in citrus seeds, seems to be the culprit antigen in citrus seeds and contaminated citrus pectin. Citrin is highly homologous with Ana o 2 in cashew and Pis v 2 in pistachio, suggesting potential for cross-reactivity and providing an explanation for co-allergenicity of cashew or pistachio, citrus seeds, and citrus pectin.

Phase 3 Trial of Epicutaneous Immunotherapy in Toddlers with Peanut Allergy.

BACKGROUND: No approved treatment for peanut allergy exists for children younger than 4 years of age, and the efficacy and safety of epicutaneous immunotherapy with a peanut patch in toddlers with peanut allergy are unknown. METHODS: We conducted this phase 3, multicenter, double-blind, randomized, placebo-controlled trial involving children 1 to 3 years of age with peanut allergy confirmed by a double-blind, placebo-controlled food challenge. Patients who had an eliciting dose (the dose necessary to elicit an allergic reaction) of 300 mg or less of peanut protein were assigned in a 2:1 ratio to receive epicutaneous immunotherapy delivered by means of a peanut patch (intervention group) or to receive placebo administered daily for 12 months. The primary end point was a treatment response as measured by the eliciting dose of peanut protein at 12 months. Safety was assessed according to the occurrence of adverse events during the use of the peanut patch or placebo. RESULTS: Of the 362 patients who underwent randomization, 84.8% completed the trial. The primary efficacy end point result was observed in 67.0% of children in the intervention group as compared with 33.5% of those in the placebo group (risk difference, 33.4 percentage points; 95% confidence interval, 22.4 to 44.5; P<0.001). Adverse events that occurred during the use of the intervention or placebo, irrespective of relatedness, were observed in 100% of the patients in the intervention group and 99.2% in the placebo group. Serious adverse events occurred in 8.6% of the patients in the intervention group and 2.5% of those in the placebo group; anaphylaxis occurred in 7.8% and 3.4%, respectively. Serious treatment-related adverse events occurred in 0.4% of patients in the intervention group and none in the placebo group. Treatment-related anaphylaxis occurred in 1.6% in the intervention group and none in the placebo group. CONCLUSIONS: In this trial involving children 1 to 3 years of age with peanut allergy, epicutaneous immunotherapy for 12 months was superior to placebo in desensitizing children to peanuts and increasing the peanut dose that triggered allergic symptoms. (Funded by DBV Technologies; EPITOPE ClinicalTrials.gov number, NCT03211247.).

Updated anaphylaxis guidelines: management in infants and children.

Severe allergic reactions (anaphylaxis) are unpredictable, and initial signs of what could be fatal anaphylaxis can be mild Adrenaline (epinephrine) remains the first-line drug of choice for the acute management of anaphylaxis and should be administered early There are no contraindications to intramuscular adrenaline in the treatment of anaphylaxis Correct positioning of the patient is vital as death can occur within minutes if a patient stands, walks or sits up suddenly. Position the patient correctly first and then promptly administer intramuscular adrenaline Updated guidelines by the Australasian Society of Clinical Immunology and Allergy now recommend that the 0.15 mg adrenaline injector device may be prescribed for infants and children weighing 7.5-10 kg. The recommendation to use the 0.3 mg adrenaline injector device for those over 20 kg remains unchanged The adrenaline doses in Australian Prescriber's anaphylaxis wallchart remain valid.

Long-term, open-label extension study of the efficacy and safety of epicutaneous immunotherapy for peanut allergy in children: PEOPLE 3-year results.

BACKGROUND: The PEPITES (Peanut EPIT Efficacy and Safety) trial, a 12-month randomized controlled study of children with peanut allergy and 4 to 11 years old, previously reported the safety and efficacy of epicutaneous immunotherapy (EPIT) for peanut allergy (250 µg, daily epicutaneous peanut protein; DBV712 250 µg). OBJECTIVE: We sought to assess interim safety and efficacy of an additional 2 years of EPIT from the ongoing (5-year treatment) PEOPLE (PEPITES Open-Label Extension) study. METHODS: Subjects who completed PEPITES were offered enrollment in PEOPLE. Following an additional 2 years of daily DBV712 250 µg, subjects who had received DBV712 250 µg in PEPITES underwent month-36 double-blind, placebo-controlled food challenge with an optional month-38 sustained unresponsiveness assessment. RESULTS: Of 213 eligible subjects who had received DBV712 250 µg in PEPITES, 198 (93%) entered PEOPLE, of whom 141 (71%) had assessable double-blind, placebo-controlled food challenge at month 36. At month 36, 51.8% of subjects (73 of 141) reached an eliciting dose of ≥1000 mg, compared with 40.4% (57 of 141) at month 12; 75.9% (107 of 141) demonstrated increased eliciting dose compared with baseline; and 13.5% (19 of 141) tolerated the full double-blind, placebo-controlled food challenge of 5444 mg. Median cumulative reactive dose increased from 144 to 944 mg. Eighteen subjects underwent an optional sustained unresponsiveness assessment; 14 of those (77.8%) maintained an eliciting dose of ≥1000 mg at month 38. Local patch-site skin reactions were common but decreased over time. There was no treatment-related epinephrine use in years 2 or 3. Compliance was high (96.9%), and withdrawals due to treatment-related adverse events were low (1%). CONCLUSIONS: These results demonstrate that daily EPIT treatment for peanut allergy beyond 1 year leads to continued response from a well-tolerated, simple-to-use regimen.

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

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

Recommendations for the management of food allergies in a preschool/childcare setting and prevention of anaphylaxis.

Food allergy and anaphylaxis occur most commonly in children under five, the majority of whom attend preschool and early childcare. Children under five differ significantly from school-aged children, as do their care environments, yet specific strategies for managing food allergies in early childcare settings are generally lacking in existing guidelines and legislation. In this review, we outline the scope of the problem, the unique challenges encountered in the preschool environment and existing policy and legislation in Australia, the US, Canada and the UK. We outline the management guidelines and resources available from specialist societies, and the evidence base for specific management strategies including voluntary versus legislative approaches, staff training and education, banning of foods, and availability of multiple and generic adrenaline auto-injectors. We call for greater uniformity and consistency of policy in regards to the recognition and management of infants and children with food allergy in the preschool environment and specific programmes and policies tailored to this environment.

Basophil reactivity, wheal size, and immunoglobulin levels distinguish degrees of cow's milk tolerance.

BACKGROUND: In our previous study about 75% of children with cow's milk allergy tolerated baked milk products, which improved their prognosis and quality of life. OBJECTIVE: We sought to identify biomarkers of varying degrees of clinical tolerance among a cohort of children with cow's milk allergy. METHODS: One hundred thirty-two subjects were initially classified as baked milk-reactive, baked milk-tolerant, or having "outgrown milk allergy" based on the results of oral food challenges. The baked milk-tolerant group was then divided into 3 groups based on the amount and degree of heat-denatured milk protein that they could tolerate. Serum was analyzed for allergen-specific IgE and IgG(4) levels, basophil reactivity was assessed in whole blood stimulated with serial 10-fold dilutions of milk protein, and skin prick tests (SPTs) were performed to commercial milk extract. Activated basophils were defined by using flow cytometry as CD63(bright)CD203c(+)CD123(+)HLA-DR(dim/-)CD41a(-)lineage(-). Data were analyzed by using the Jonckheere-Terpstra test. RESULTS: Significant differences across the 5 clinical groups were seen for median casein- and milk-specific IgE levels, casein-specific IgG(4) levels, and casein IgE/IgG(4) ratios; milk-specific to nonspecific basophil activation ratio, median basophil reactivity, and spontaneous basophil activation (CD203c expression after stimulation with RPMI); and milk SPT wheal diameters. Casein- and milk-specific IgE level, milk-specific basophil reactivity, and milk SPT wheal diameter are all significantly greater among patients with milk allergy who react to baked milk than among those who tolerate it. CONCLUSIONS: The majority of patients with milk allergy are able to tolerate some forms of baked milk in their diets. Different phenotypes of children with cow's milk allergy can be distinguished by casein- and milk-specific IgE levels, milk-specific basophil reactivity, and milk SPT mean wheal diameters. Spontaneous basophil activation is greater among patients with more severe clinical milk reactivity.

Persistent linear bands in infancy acquired after local pressure: a consequence of mast cell activation?

A 10-month-old girl with marked symptomatic dermographism presented with linear bands at the sock line noted to have developed following an episode of localized urticaria and angioedema at the sock line. We speculate that release of mast cell mediators associated with the dermographism may have triggered the development of the linear bands.