Guidelines for the diagnosis and management of food allergy in the United States: summary of the NIAID-Sponsored Expert Panel report

The role of Interleukin-21 (IL-21) in allergic disorders: Biological insights and regulatory mechanisms

In recent decades, allergic diseases subsequent from an IgE-mediated response to specific allergens have become a progressively public chronic disease worldwide. They have shaped an important medical and socio-economic burden. A significant proportion of allergic disorders are branded via a form 2 immune response relating Th2 cells, type 2 natural lymphoid cells, mast cells and eosinophils. Interleukin-21 (IL-21) is a participant of the type-I cytokine family manufactured through numerous subsets of stimulated CD4+ T cells and uses controlling properties on a diversity of immune cells. Increasingly, experimental sign suggests a character for IL-21 in the pathogenesis of numerous allergic disorders. The purpose of this review is to discuss the biological properties of IL-21 and to summaries current developments in its role in the regulation of allergic disorders.

The role of pediatricians in the diagnosis and management of IgE-mediated food allergy: a review

Importance

Food allergy can often cause a significant burden on patients, families, and healthcare systems. The complexity of food allergy management requires a multidisciplinary approach involving different types of healthcare providers, including allergists, dieticians, psychologists, nurses, family practitioners and, of particular relevance for this article, pediatric primary caretakers. Pediatricians may be the first-line healthcare providers for food allergy: strategies for management and guideline adherence have been highlighted.

Observations

This review article summarizes the up-to-date recommendations on the role of pediatricians in the diagnosis, management, and prevention of IgE-mediated food allergy. Early introduction of allergenic foods like peanut is known to be of importance to reduce the development of peanut allergy in infants, and pediatricians are essential for educating and supporting parents in this decision. In scenarios of limited allergist availability, as is often the case among rural, Medicaid and minority populations, pediatricians can assist in the evaluation and management of food allergy, and provide action plans, education and counselling for patients and families.

Conclusions and relevance

Pediatric primary caretakers play a key role in the diagnosis, management, and prevention of IgE-mediated food allergy. As more diagnostic tools and therapies in food allergy become available, the need for a multidisciplinary team is paramount to optimize patient care.

Assessing and Comparing Potential Allergenicity of Two Partially Hydrolyzed Whey-Based Formulas for Infants: A Population-Based Study in China

SCOPE

In cases where breast milk is unavailable or inadequate, hydrolyzed infant formula is recommended as the primary alternative. The aim of this study is to assess and compare the allergenicity of two partially hydrolyzed whey-based formulas (PHF-Ws) using serum samples from patients with cow's milk allergy (CMA).

METHODS AND RESULTS

LC-MS/MS technology is used to investigate the peptide distribution in both samples. The immunoreactivity of two PHF-Ws in 27 serum samples from 50 Chinese infants (02 years) with CMA is analyzed. The results demonstrate that even with a similar a degree of hydrolysis (DH), primary protein sources, peptides with molecular weights <5 kDa, and differences in the number of residual allergenic epitopes in the hydrolyzed peptide segments can lead to varying immune responses.

CONCLUSION

The two PHF-Ws have notably high intolerance rates, exceeding 10% among infants with CMA. Therefore, suggesting that PHF-Ws may not be suitable for infants and children with CMA in China.

How to diagnose IgE-mediated food allergy

Immunoglobulin E (IgE)-mediated food allergy is an immune response, typically to a food protein. Accurate diagnosis reduces unnecessary dietary restrictions and economic and psychological burden on patients and caregivers but relies on a rigorous clinical history, specific IgE diagnostic tests and, where needed, oral food challenge. Increased awareness is needed around which patients to test for IgE-mediated food allergy, as well as terms commonly associated with IgE-mediated food allergy testing, in order to optimise patient diagnosis and management. Herein, we describe approaches to diagnosis of IgE-mediated food allergy, appropriate interpretation of results and risks of overtesting.

Exploring novel approaches to food allergy management

ABSTRACT

Nurse practitioners are likely to encounter pediatric and adult patients with symptoms of food allergy who need an accurate diagnosis, emergency treatment plans, and options for management. The pathophysiology of immunoglobulin E (IgE)-mediated food allergy, current and emerging diagnostics, treatment, and emergency management is briefly reviewed, and promising new and potential future treatment options are discussed. Currently, Food and Drug Administration-approved oral immunotherapy (OIT) treatment for peanut allergy, but clinical trials are underway to explore multiple-allergen OIT and alternate routes for IT such as sublingual and epicutaneous. Treatments that modulate the immune system are also potential treatments for food allergies (FAs), including biologic agents. Omalizumab, an anti-IgE therapy, dupilumab, an interleukin-4Ra receptor monoclonal antibody, and etokimab, an anti-IL-33, are all being studied for the treatment of food allergy. There is hope that these novel therapies for FAs will be a viable option translated to the practice setting in the near future, so that strict avoidance is not the only treatment plan for FAs. Nurse practitioners can support their patients with FAs and their families by keeping abreast of progress in food allergy research and assisting patients to consider novel treatment options, when appropriate, using shared decision making.

Prevalence of self-reported food allergy in Tunisia: General trends and probabilistic modeling

Background

Food allergy (FA) has become a major public health concern affecting millions of children and adults worldwide. In Tunisia, published data on FA are scarce.

Methods

This study, was intended to fill the gap and estimate the frequency of allergy to different foods in the Sfax region, Tunisia, within self-reported FA. One hundred twenty-five (125) children (56% males, 1-17 years old), and 306 adults (17% males, 18-70 years old) were interviewed using a bilingual questionnaire.

Results

The number of self-reported food allergens in this sample was 105; allergens were clustered in 8 foods: fruits, seafood, eggs, milk and dairy, cereals, nuts, vegetables, and peanuts. Cutaneous reactions were the most frequent symptoms, in both children and adults. About 40% of children and 30% of adults had a family history of FA. About 81% of adults and 38% of children are allergic to at least 1 non-food allergen. The most prevalent food allergen was the fruit group in both adults and children, followed by seafood. Most food allergies were mutually exclusive and 90% of individuals have a single FA. The relationship between self-declared FA was modeled using a Bayesian network graphical model in order to estimate conditional probabilities of each FA when other FA is present.

Conclusions

Our findings suggest that the prevalence of self-reported FA in Tunisia depends on dietary habits and food availability since the most frequent allergens are from foods that are highly consumed by the Tunisian population.

Varying Approaches to Management of IgE-Mediated Food Allergy in Children Around the World

Food allergy is a chronic disease that affects individuals of all ages and is a significant public health problem globally. This narrative overview examines clinical management strategies for IgE-mediated food allergy in children around the world to understand variations in practice. Information was drawn from clinical practice guidelines, recent research, the websites of professional and governmental bodies with expertise in food allergy, and clinical experts from a broad cross-section of geographical regions. The structure and delivery of clinical services, allergen avoidance and food labeling, and resources to support the management of allergic reactions in the community are discussed in detail. The adoption of emerging food immunotherapies is also explored. Wide variations in clinical management of food allergy were apparent across the different countries. Common themes were continuing issues with access to specialist care and recognition of the need to balance risk reduction with dietary and social restrictions to avoid unnecessary detrimental impacts on the quality of life of food allergy sufferers. Findings highlight the need for standardized presentation of practice and priorities, and may assist clinicians and researchers when engaging with government and funding agencies to address gaps.

When Foods Cause Itch: Clinical Characteristics, Pathophysiology, and Recommendations for Food-Induced Skin and Mucosal Pruritus

Itch occurs in various dermatologic and systemic conditions. Many patients report that certain foods instigate itch, although there is limited published information in dermatology on food-induced pruritus. In addition, itch severity is rarely mentioned. Food can induce pruritus through either ingestion or direct contact with skin or mucosal membranes. The most common type of itch provoked by food is acute urticaria, often through the classical immunoglobulin E (IgE)-mediated pathway. Other mechanisms include non-IgE-mediated, mixed (IgE-mediated and non-IgE-mediated), T-cell-mediated, and nonimmune reactions. For patients presenting with urticaria, generalized pruritus, oral pruritus, or dermatitis, a thorough history is warranted, and possible food associations should be considered and assessed. Although any food seems to have the potential to elicit an immune response, certain foods are especially immunogenic. Treatment includes avoidance of the trigger and symptom management. Careful consideration should be used as to avoid unnecessarily restrictive elimination diets.

Atopic Dermatitis and Food Allergy: A Complex Interplay What We Know and What We Would Like to Learn

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by intense pruritus, eczematous lesions, and relapsing course. It presents with great clinical heterogeneity, while underlying pathogenetic mechanisms involve a complex interplay between a dysfunctional skin barrier, immune dysregulation, microbiome dysbiosis, genetic and environmental factors. All these interactions are shaping the landscape of AD endotypes and phenotypes. In the “era of allergy epidemic”, the role of food allergy (FA) in the prevention and management of AD is a recently explored “era”. Increasing evidence supports that AD predisposes to FA and not vice versa, while food allergens are presumed as one of the triggers of AD exacerbations. AD management should focus on skin care combined with topical and/or systemic treatments; however, in the presence of suspected food allergy, a thorough allergy evaluation should be performed. Food-elimination diets in food-allergic cases may have a beneficial effect on AD morbidity; however, prolonged, unnecessary diets are highly discouraged since they can lead to loss of tolerance and potentially increase the risk of IgE-mediated food allergy. Preventive AD strategies with the use of topical emollients and anti-inflammatory agents as well as early introduction of food allergens in high-risk infants seem promising in managing and preventing food allergy in AD patients. The current review aims to overview data on the complex AD/FA relationship and provide the most recent developments on whether food allergy interventions change the AD course and vice versa.

When Foods Cause Itch: Clinical Characteristics, Pathophysiology, and Recommendations for Food-Induced Skin and Mucosal Pruritus

ABSTRACT

Itch occurs in various dermatologic and systemic conditions. Many patients report that certain foods instigate itch, although there is limited published information in dermatology on food-induced pruritus. In addition, itch severity is rarely mentioned. Food can induce pruritus through either ingestion or direct contact with skin or mucosal membranes. The most common type of itch provoked by food is acute urticaria, often through the classical immunoglobulin E (IgE)-mediated pathway. Other mechanisms include non-IgE-mediated, mixed (IgE-mediated and non-IgE-mediated), T-cell-mediated, and nonimmune reactions. For patients presenting with urticaria, generalized pruritus, oral pruritus, or dermatitis, a thorough history is warranted, and possible food associations should be considered and assessed. Although any food seems to have the potential to elicit an immune response, certain foods are especially immunogenic. Treatment includes avoidance of the trigger and symptom management. Careful consideration should be used as to avoid unnecessarily restrictive elimination diets.

Inorganic food additive nanomaterials alter the allergenicity of milk proteins

While inorganic nanomaterials are copiously incorporated in food products, their impact on the allergenicity food proteins is largely unknown. This study analyzed the effect of widely used food additive nanomaterials (silica and titania) on the antigenicity and allergenicity of milk proteins (β-lactoglobulin and casein) and skimmed milk. Changes in the antigenicity of milk proteins in the presence of dietary nanomaterials were identified using an indirect-ELISA assay, while the change in allergenicity was studied using mast cell (LAD2) sensitized using allergic human sera. Results showed an enhancement in the allergenicity of milk proteins/skimmed milk interacted with particles (both silica and titania). Similarly, mast cell degranulation (a proxy for allergenicity) was higher when exposed to particle interacted skim milk where nanomaterials of titania showed the highest effect, and this tendency was retained even after subjecting to simulated gut digestion. Particles induced alterations in the structure of milk proteins, as evidenced by our studies, are reasoned to expose epitopes that increase allergenicity of milk proteins.

Soybean allergy: characteristics, mechanisms, detection and its reduction through novel food processing techniques

Human beings have consumed soybean as an excellent food source for thousand years due to its rich protein, fatty acids, minerals, and fibers. However, soybeans were recognized as one of the big eight allergens resulting in allergic symptoms and even could lead to death. With the increasing demand for soybean products, the challenges caused by soybean allergy need to be solved urgently. This review detailly described the pathogenesis and clinical characteristics of soybean allergy, and also the advantages and disadvantages of four different diagnostic methods were summarized. The major soybean allergens and their structures were summarized. Three types of soybean allergy including Type I, III, and IV, which could trigger allergic reactions were reported in this review. Summary in four different diagnostic methods showed that double-blind, placebo-controlled food challenge is recognized as a gold standard for diagnosing soybean allergy. Three types of processing techniques in reducing soybean allergy were discussed, and the results concluded that some novel food processing techniques such as ultrasound, cold-plasma treatment, showed potential application in the reduction of soybean allergenicity. Further, some suggestions regarding the management and treatment of food allergies were addressed in this review.

Population-based incidence of food allergies in Olmsted County over 17 years

Background: There is growing concern about the rising incidence and prevalence of food allergy globally. We previously reported the incidence of food allergy in Olmsted County, Minnesota, between 2002 and 2011. We sought to update the incidence and temporal trends of food allergies in our region through 2018. Methods: By using the Rochester Epidemiology Project, all Olmsted County residents, with an incident diagnosis of food allergy between January 2, 2012, and December 31, 2018, were identified and their medical records were reviewed. These cases were combined with the previously collected incidence cases from January 2, 2002, and December 31, 2011, to understand longitudinal trends in food allergy incidence rates. Results: Over the 17-year study period, 1076 patients (58.0% male patients, 72.1% white) were diagnosed with an incident food allergy. The median (interquartile range) age at first diagnosis was 2.0 years (1.1-8.4 years). The overall annual incidence rate for all ages was 3.9 (95% confidence interval [CI], 3.6-4.1) per 10,000 person-years and was significantly higher in male than in female patients (4.4 [95% CI, 4.0-4.7] and 3.3 [95% CI, 3.0-3.6], respectively; p < 0.001). The most common food allergen was egg in infancy (57.7%), peanuts in ages 1-4 years (58.3%), tree nuts in ages 5-18 years (57.4%), and seafood in adults (≥19 years) (45.3%). Conclusion: The incidence of food allergy in Olmsted County steadily increased from 2002 to 2008, then remained relatively stable between the years 2008 and 2013, and again presented a rising trend over the next 5 years until 2018. This warrants further investigations into the effects of changes in guidelines for early introductions of allergenic foods and other factors that affect causality.

Nutrition and urticaria

Urticaria is a distressing dermatologic condition for many. Although the wheals of urticaria are characteristically evanescent, lasting less than 24 hours, patients tend to have recurrent episodes. Hives that last less than 6 weeks are considered acute urticaria. Acute urticaria does not routinely require supplementary work-up because the history often identifies a convincing, inciting allergen. Chronic urticaria is defined as episodes that occur for longer than 6 weeks, and there is often not an easily identifiable trigger. For both acute and chronic urticaria, patients frequently report food as a precipitating cause. For acute urticaria, the foods that are associated with true allergies, such as nuts and shellfish, are the most frequent offenders. The relationship between diet and chronic urticaria is not as firmly defined. Many patients unnecessarily restrict their diets, so it becomes the role of dermatologists to help patients identify if there is a reproducible link between their symptoms and their dietary exposures. The literature suggests that diets free from pseudoallergens and histamine-releasing foods may attenuate urticaria. Supplements such as fats, vitamin D, iron, and flavonoids have also been studied and may diminish symptoms.

Combining Anti-IgE Monoclonal Antibodies and Oral Immunotherapy for the Treatment of Food Allergy

Immunoglobulin E (IgE)-mediated food allergy is a real public health problem worldwide. The prevalence of food allergy is particularly high in children. Patients with food allergy experience high morbidity with a change in quality of life due to the risk of severe anaphylaxis. Current treatment options are poor. Allergen avoidance is widely recommended but exposes patients to accidental ingestion. Oral immunotherapy is also used in patients with food allergies to the most common allergens. Oral immunotherapy consists of a daily administration of small, gradually increasing amounts of allergens to induce desensitisation. This procedure aims at inducing immune tolerance to the ingested food allergens. However, some patients experience adverse reactions and discontinue oral immunotherapy.Given that IgE plays a crucial role in food allergy and anti-IgE are effective in allergic asthma, the use of anti-IgE therapeutic monoclonal antibodies (mAbs) such as omalizumab has been assessed in food allergy patients. The use of omalizumab as a monotherapy in food allergy has not been extensively studied but looks promising. There is more published evidence regarding the effect of omalizumab and oral immunotherapy in food allergy. Given the promising results of oral immunotherapy regarding sustained tolerance in clinical trials and the potential capacity of omalizumab to reduce symptoms in case of accidental exposure, a strategy combining oral immunotherapy with omalizumab pre-treatment has been suggested as a safer option in patients with severe food allergy compared to isolated therapy. Omalizumab seems useful in ensuring safer administration of oral immunotherapy with the oral immunotherapy maintenance dose being reached more rapidly. Quality-of-life improvement is greater with oral immunotherapy + omalizumab compared to oral immunotherapy alone. Moreover, sustained unresponsiveness is achieved more frequently with omalizumab. Considering that precision medicine and personalised therapy are major goals for allergic diseases, predictive biomarkers are crucial in order to identify food allergy patients more likely to benefit from anti-IgE therapies.

An Updated Overview of Almond Allergens

Tree nuts are considered an important food in healthy diets. However, for part of the world’s population, they are one of the most common sources of food allergens causing acute allergic reactions that can become life-threatening. They are part of the Big Eight food groups which are responsible for more than 90% of food allergy cases in the United States, and within this group, almond allergies are persistent and normally severe and life-threatening. Almond is generally consumed raw, toasted or as an integral part of other foods. Its dietary consumption is generally associated with a reduced risk of cardiovascular diseases. Several almond proteins have been recognized as allergens. Six of them, namely Pru du 3, Pru du 4, Pru du 5, Pru du 6, Pru du 8 and Pru du 10, have been included in the WHO-IUIS list of allergens. Nevertheless, further studies are needed in relation to the accurate characterization of the already known almond allergens or putative ones and in relation to the IgE-binding properties of these allergens to avoid misidentifications. In this context, this work aims to critically review the almond allergy problematic and, specifically, to perform an extensive overview regarding known and novel putative almond allergens.

Growth and tolerance of healthy, term infants fed lower protein extensively hydrolyzed or amino acid-based formula: double-blind, randomized, controlled trial

Background

Optimal protein level in hypoallergenic infant formulas is an area of ongoing investigation. The aim was to evaluate growth of healthy term infants who received extensively hydrolyzed (EH) or amino acid (AA)-based formulas with reduced protein.

Methods

In this prospective, multi-center, double-blind, controlled, parallel group study, infants were randomized to receive a marketed EH casein infant formula at 2.8 g protein/100 kcal (Control) or one of two investigational formulas: EH casein formula at 2.4 g protein/100 kcal (EHF) or AA-based formula at 2.4 g total protein equivalents/100 kcal (AAF). Control and EHF each had 2 × 10⁷ CFU Lactobacillus rhamnosus GG/100 kcal. Anthropometrics were measured and recall of formula intake, tolerance, and stool characteristics was collected at 14, 30, 60, 90, 120 days of age. Primary outcome was weight growth rate (g/day) between 14 and 120 days of age (analyzed by ANOVA). Medically confirmed adverse events were recorded throughout the study.

Results

No group differences in weight or length growth rate from 14 to 120 days were detected. With the exception of significant differences at several study time points for males, no group differences were detected in mean head circumference growth rates. However, mean achieved weight, length, and head circumference demonstrated normal growth throughout the study period. No group differences in achieved weight or length (males and females) and head circumference (females) were detected and means were within the WHO growth 25th and 75th percentiles from 14 to 120 days of age. With the exception of Day 90, there were no statistically significant group differences in achieved head circumference for males; means remained between the WHO 50th and 75th percentiles for growth at Days 14, 30, and 60 and continued along the 75th percentile through Day 120. No differences in study discontinuation due to formula were detected. The number of participants for whom at least one adverse event was reported was similar among groups.

Conclusions

This study demonstrated hypoallergenic infant formulas at 2.4 g protein/100 kcal were safe, well-tolerated, and associated with appropriate growth in healthy term infants from 14 to 120 days of age.

Trial registration

ClinicalTrials.gov, ClinicalTrials.gov Identifier: NCT01354366. Registered 13 May 2011.

Whey allergens: Influence of nonthermal processing treatments and their detection methods

Whey and its components are recognized as value-added ingredients in infant formulas, beverages, sports nutritious foods, and other food products. Whey offers opportunities for the food industrial sector to develop functional foods with potential health benefits due to its unique physiological and functional attributes. Despite all the above importance, the consumption of whey protein (WP) can trigger hypersensitive reactions and is a constant threat for sensitive individuals. Although avoiding such food products is the most successful approach, there is still a chance of incorrect labeling and cross-contamination during food processing. As whey allergens in food products are cross-reactive, the phenomenon of homologous milk proteins of various species may escalate to a more serious problem. In this review, nonthermal processing technologies used to prevent and eliminate WP allergies are presented and discussed in detail. These processing technologies can either enhance or mitigate the impact of potential allergenicity. Therefore, the development of highly precise analytical technologies to detect and quantify the existence of whey allergens is of considerable importance. The present review is an attempt to cover all the updated approaches used for the detection of whey allergens in processed food products. Immunological and DNA-based assays are generally used for detecting allergenic proteins in processed food products. In addition, mass spectrometry is also employed as a preliminary technique for detection. We also highlighted the latest improvements in allergen detection toward biosensing strategies particularly immunosensors and aptasensors.

Adult skin acute stress responses to short-term environmental and internal aggression from exposome factors

Exposome factors that lead to stressed skin can be defined as any disturbance to homeostasis from environmental (meteorological factors, solar radiation, pollution or tobacco smoke) and/or internal exposure (unhealthy diet, hormonal variations, lack of sleep, psychosocial stress). The clinical and biological impact of chronic exposome effects on skin functions has been extensively reviewed, whereas there is a paucity of information on the impact of short‐term acute exposure. Acute stress, which would typically last minutes to hours (and generally no more than a week), provokes a transient but robust neuroendocrine‐immune and tissue remodelling response in the skin and can alter the skin barrier. Firstly, we provide an overview of the biological effects of various acute stressors on six key skin functions, namely the skin physical barrier, pigmentation, defences (antioxidant, immune cell‐mediated, microbial and microbiome maintenance), structure (extracellular matrix and appendages), neuroendocrine and thermoregulation functions. Secondly, we describe the biological and clinical effects on adult skin from individual exposome factors that elicit an acute stress response and their consequences in skin health maintenance. Clinical manifestations of acutely stressed skin may include dry skin that might accentuate fine lines, oily skin, sensitive skin, pruritus, erythema, pale skin, sweating, oedema and flares of inflammatory skin conditions such as acne, rosacea, atopic dermatitis, pigmentation disorders and skin superinfection such as viral reactivation. Acute stresses can also induce scalp sensitivity, telogen effluvium and worsen alopecia.

The Peanut Allergy Burden Study: Impact on the quality of life of patients and caregivers

Background

Peanut allergy (PA) places significant burden on peanut-allergic individuals and their families, yet limited research in the United States has quantitatively examined the impact on peanut-allergic individuals and their families' health-related quality of life (HRQoL). The Peanut Allergy Burden Study (PABS) aimed to quantify the impact of PA on the general and disease-specific HRQoL of children, adolescents, and adults with PA, as well as caregivers of children with PA.

Methods

A cross-sectional survey design was employed to examine the real-world impact of PA in children, adolescents, and adults with PA, and caregivers of children with PA.

Results

Of 153 adult patients, 102 adolescents, and 382 caregivers of peanut-allergic children (n = 382), 6.8% and 24.8% of participants indicated being dissatisfied or somewhat dissatisfied, respectively, with current approaches to avoid or prevent PA reactions. Approximately two-thirds of patients and caregivers indicated that PA interferes at least somewhat with daily living. In terms of general HRQoL, adolescents, adult patients, and caregivers indicated that mental/psychosocial health was more problematic than physical health. PA patients and caregivers indicated worse HRQoL in all domains compared to healthy samples, and worse overall HRQoL, psychosocial, emotional, and social functioning than a sample of chronically ill patients. Results from the allergy-specific HRQoL measures showed that adolescents experienced greater impairment in overall HRQoL due to PA and in allergen avoidance and dietary restriction than adults.

Conclusion

PA negatively affects the general and PA-specific HRQoL of both patients and caregivers. The high emotional and psychosocial burden, in particular, demonstrates significant unmet need for patients with PA and their caregivers. Future work on treatment and preventive options to improve HRQoL for PA patients, particularly adolescents and their families, is needed.

A systematic review of psychological, clinical and psychosocial correlates of perceived food intolerance

OBJECTIVE

Perceived food intolerance (PFI) is a distressing condition reported by 3% - 35% of individuals, whereas prevalence of food allergy is 0.9%-3%. The present paper aims to systematically review the evidence for psychological, clinical and psychosocial factors associated with PFI in order to advance the current understanding.

METHODS

Articles published from 1970 until October 2020 were identified. Case-control, prospective cohort, cross-sectional and retrospective studies published in English that a) included a subject population of adults over 18 with PFI and b) examined psychological, clinical and/or psychosocial factors of PFI were reviewed against inclusion criteria. Methodological quality was assessed, data extracted, and a narrative synthesis conducted.

RESULTS

Of 2864 abstracts identified, thirty-six articles met inclusion criteria. Evidence consistently found PFI is associated with female sex, and individuals with PFI often report physical health complaints including gastrointestinal and extraintestinal symptoms, and gastrointestinal and atopic conditions. Evidence for an association between psychological factors and PFI was inconsistent, although some suggested increased levels of common mental disorders and distress. Findings regarding psychosocial factors were mixed and sociodemographic data were infrequently collected.

CONCLUSIONS

PFI is associated with female sex and gastrointestinal and extraintestinal complaints. Limited high-quality evidence supports the role of psychological factors associated with PFI. High-quality research using prospective and longitudinal designs with multivariate analyses is needed. Future research should explore modifiable psychological factors as potential targets for intervention and identify clinical and psychosocial risk factors of PFI to aid in formulating a biopsychosocial model of PFI.

Comparative study of concatemer efficiency as an isotope-labelled internal standard for allergen quantification

Mass spectrometry-based methods coupled with stable isotope dilution have become effective and widely used methods for the detection and quantification of food allergens. Current methods target signature peptides resulting from proteolytic digestion of proteins of the allergenic ingredient. The choice of appropriate stable isotope-labelled internal standard is crucial, given the diversity of encountered food matrices which can affect sample preparation and analysis. We propose the use of concatemer, an artificial and stable isotope-labelled protein composed of several concatenated signature peptides as internal standard. With a comparative analysis of three matrices contaminated with four allergens (egg, milk, peanut, and hazelnut), the concatemer approach was found to offer advantages associated with the use of labelled proteins, ideal but unaffordable, and circumvent certain limitations of traditionally used synthetic peptides as internal standards. Although used in the proteomic field for more than a decade, concatemer strategy has not yet been applied for food analysis.

Managing food allergy and anaphylaxis: A new model for an integrated approach

There is an increasing public concern on food allergy and related anaphylactic reactions that occur mainly at the community level. The perception of the disease is huge among parents who believe that 1 out of 20 children suffers from severe food allergy. The discrepancy between this self-reported prevalence and the real one when a food challenge is performed, points out the gap in the implementation of guidelines for clinical practice. Health professionals as well show scarce adherence to the guidelines both at the Emergency Departments and at the primary care level. Anaphylactic reaction are not recognized, adrenaline is under-used and self-injectable devices are not prescribed. Although education and training are limited to local, spontaneous initiatives from patient's organization and few allergists, the data so far available demonstrate that improvement in knowledge and attitudes can be achieved further to a structured program. There is the need to establish good evidence -based practices for educational intervention that should be adopted in the context of public health policies for food allergy. This would imply a change in legislation in many countries to prevent prosecution for liability of lay people administering adrenaline when properly trained. In parallel an integrated clinical care pathway should be developed by multidisciplinary and multi-professional teams in the context of national Centres of Excellence -CoE. These CoE could drive the progression to digital health create, creating networks of CoE for best practices of care and for clinical trials.

Atopy patch tests may identify patients at risk for systemic contact dermatitis

Background

A subset of patients with positive patch tests demonstrates systemic contact dermatitis (SCD) upon ingestion or inhalation of the allergen. Concern has been raised about the use of patch tests for protein allergens (APTs) to detect SCD in atopic dermatitis (AD) patients.

Methods

We present atopy patch test (APT) data for 97 people. We reviewed APTs and tests for antigen‐specific immunoglobulin E (IgE) to the same allergen in pediatric AD patients. We compared the frequency of APTs as a function of age in AD patients. To study the irritancy potential of APTs, we prospectively tested consenting non‐AD dermatitis patients undergoing evaluation for allergic contact dermatitis and healthy controls to an APT panel.

Results

APT demonstrated fewer positive results than serum‐specific IgE or skin prick tests to the same allergen. Positive APT to food was more common in children under 3 years, whereas positive APT to aeroallergens were more common in teens and adults. Only positive APTs to dust mite were significantly more common positive in subjects without AD.

Conclusion

Our aggregate findings suggest that most APTs, but not dust mite, behave like conventional patch tests to low‐potency allergens. They are more likely to be positive in patients with chronically inflamed skin and to identify allergens that cause SCD. The higher prevalence of APT positivity to foods in young children is consistent with food allergy as a trigger of AD (also known as SCD) being more common in children than adults. Positive APTs define patients who may have SCD; negative APTs may guide elimination diets.

Food Allergy Testing

Although the gold standard for diagnosis of immunoglobulin E (IgE)-mediated food allergy is an oral food challenge, clinically relevant biomarkers of IgE sensitization, including serum-specific IgE and skin prick testing, can aid in diagnosis. Clinically useful values have been defined for individual foods. More recently, specific IgE to particular protein components has provided additional diagnostic value. In summary, food allergy diagnostics to evaluate IgE sensitization are clinically useful and continue to evolve to improve evaluation of IgE-mediated food allergies.

Perspective: Should Exclusive Breastfeeding Still Be Recommended for 6 Months?

The WHO recommends exclusive breastfeeding of infants for the first 6 mo of life (EBF-6). We reviewed the evidence behind concerns related to this recommendation. The risk of iron deficiency among EBF-6 infants can be significantly reduced if delayed cord clamping is performed in all newborns. At the moment there is no population-level evidence indicating that exclusive breastfeeding for 6 mo compared with <6 mo increases the risk of developing food allergies. Mild to moderate maternal undernutrition may reduce amounts of some nutrients in breast milk but does not directly diminish milk volume. Persistent reports of insufficient milk by women globally are likely to be the result of lack of access to timely lactation counseling and social support rather than primary biological reasons. All newborns should have their growth, hydration status, and development carefully monitored. In instances where formula supplementation is required, it should be done under the guidance of a qualified provider taking into account that early introduction of breast-milk supplements is a risk factor for early termination of exclusive breastfeeding and any breastfeeding. We found no evidence to support changes to the EBF-6 public health recommendation, although variability in inter-infant developmental readiness is recognized. We suggest that infant and young feeding guidelines make clear that complementary foods should be introduced at around 6 mo of age, taking infant developmental readiness into account.

Intestinal transcriptional profiling reveals fava bean-induced immune response in DBA/1 mice

Background

Fava beans (FBs) have long been used as food, and their principal disadvantage is derived from their haemotoxicity. We hypothesized that FB ingestion alters the intestinal gene expression pattern, thereby inducing an immune response.

Results

In-depth sequence analysis identified 769 differentially expressed genes (DEGs) associated with the intestine in FB-treated DBA/1 mouse intestines. The identified genes were shown to be associated with biological processes (such as response to stimulus and immune system processes), human disease pathways (such as infectious diseases, endocrine and metabolic diseases, and immune diseases), and organismal system pathways (such as the digestive system, endocrine system, environmental adaptation, and immune system). Moreover, plasma total immunoglobulin E (IgE), histamine, interleukin (IL)-4 and IL-13 levels were significantly increased when the mice were treated with FBs.

Conclusions

These results demonstrated that FBs affect the intestinal immune response and IgE and cytokine secretion in DBA/1 mice.

Electronic supplementary material

The online version of this article (10.1186/s40659-019-0216-9) contains supplementary material, which is available to authorized users.

Clinical Features and Culprit Food Allergens of Korean Adult Food Allergy Patients: A Cross-Sectional Single-Institute Study

Purpose

To investigate the causative allergens and clinical characteristics of Korean adult patients with food allergy (FA).

Methods

This retrospective, cross-sectional single-institutional study enrolled Korean adult patients (n = 812) suspected of having FA. For diagnosis, causality assessment history taking, ImmunoCAP specific immunoglobulin E measurement and/or skin prick test were performed.

Results

Among 812 patients, 415 were diagnosed as having FA. The most common causative allergen was fruit, with a diagnosis of pollen food allergy syndrome (PFAS: 155, 37.3%), followed by crustaceans (111, 26.7%), wheat (63, 15.1%), fruits in patients without PFAS(43, 10.3%), buckwheat (31, 7.4%), peanut (31, 7.4%), walnut (25, 6.0%), red meat due to reaction to galactose-α-1,3-galactose (α-Gal) (8, 1.9%), and silkworm pupa (13, 3.1%). Allergy to egg, milk, fish, or shellfish was rare in Korean adults. One-third of patients with FA exhibited multiple FAs (238/415, 57.3%); the average number of causative allergens was 2.39. About 129 patients (31.0%) were diagnosed as having anaphylaxis; in these patients, wheat was the most frequent causative food. Twenty patients were further diagnosed with food-dependent exercise-induced anaphylaxis (FDEIA); all were due to wheat. In particular, crustaceans, wheat, PFAS, buckwheat, and red meat (α-Gal) were also frequent causes of anaphylaxis.

Conclusions

Wheat, fruits with or without PFAS, and crustaceans are important and frequent causative allergens in Korean adult FA; these allergens differ from those found in childhood FA. It is notable that non-classic allergies, such as PFAS, FDEIA, and α-Gal allergy, are the important causes of anaphylaxis in Korean adult FA.

Basophil Activation Test: Old and New Applications in Allergy

PURPOSE OF REVIEW

The basophil activation test (BAT) using flow cytometry has supplanted traditional methods of measuring basophil degranulation using histamine and other mediator release, and can be used for clinical applications as well as to explore the immune mechanisms of effector cell response to allergen. This review discusses the advancements made in clinical, diagnostic and laboratory research of allergy utilizing an ever-evolving BAT.

RECENT FINDINGS

Being an in vitro surrogate of the allergic reaction that happens in vivo in the sick patient, the BAT can be used to support the diagnosis of various allergic conditions, such as food, drug, respiratory and insect venom allergies, and the assessment of clinical response to allergen-specific immunotherapy and other immunomodulatory treatments. The BAT can also be used for research purposes to explore the mechanisms of allergy and tolerance at the level of the basophil, for instance by manipulating IgE and IgG and their receptors and by studying intracellular signalling cascade in response to allergen. This review covers the applications of the BAT to the clinical management of allergic patients and the increased understanding of the mechanisms of immune response to allergens as well as technological advancements made in recent years.

Food Allergy: A Comprehensive Population-Based Cohort Study

OBJECTIVE

To determine the incidence and temporal trends of food allergies.

PATIENTS AND METHODS

We performed a historical cohort study to describe the epidemiology of food allergies among residents of all ages in Olmsted County, Minnesota, during a 10-year period from January 2, 2002, through December 31, 2011, using the Rochester Epidemiology Project database. Overall incidence and trends in biannual incidence rates over time were evaluated.

RESULTS

During the 10-year study period, 578 new cases of food allergies were diagnosed. The average annual incidence rate was significantly higher among males compared with females (4.1 [95% CI, 3.6-4.5] vs 3.0 [95% CI, 2.7-3.4]; P<.001; per 10,000 person-years; 3.6 per 10,000 person-years overall). The pediatric incidence rate of food allergy increased from 7.0 (95% CI, 6.2-8.9) to 13.3 (95% CI, 10.9-15.7) per 10,000 person-years between the 2002-2003 and 2006-2007 calendar periods and then stabilized at 12.5 and 12.1 per 10,000 person-years in the last 2 calendar periods. Milk, peanut, and seafood were the most common allergen in infancy, in children between ages 1 and 4 years, and in the adult population, respectively.

CONCLUSION

This is one of the first population-based studies to examine the temporal trends of food allergies. The incidence of food allergies increased markedly between 2002 and 2009, with stabilization afterward. Additional longitudinal studies are warranted to assess for epidemiological evidence of changes in food allergy incidence with changing recommendations for allergenic food introduction.

Allergenicity assessment of Buchanania lanzan protein extract in Balb/c mice

Tree nuts are among "Big Eight" and have been reported globally for causing allergy. Buchanania lanzan (Bl) is one of the major tree nuts consumed by Indian population. However, very little is known about B. lanzan's induced allergic manifestation. Therefore, evaluation of it's allergenic potential was undertaken. Bl-crude protein extract sensitized BALB/c mice sera were used to identify the allergic proteins by it's IgE binding capability. The major IgE binding proteins found with molecular weight of 11, 20, 23, 25, 48, 54, and 65 kDa. Specific IgE, specific IgG1, MCPT-1, PGD₂ and histamine were assessed in mice sera. Enormous amount of mast cell infiltration was noted in different organs. The levels of Th1/Th2 transcription factors GATA-3, SOCS3 and STAT-6 were found upregulated, whereas T-bet was downregulated. Furthermore, elevated Th1/Th2 cytokine responses were observed in mice sera. All together, these reactions developed systemic anaphylaxis upon Bl-CPE challenge in sensitized BALB/c mice. In order to confirm the evidences obtained from the studies carried out in BALB/c, the investigation was extended to human subjects as well. Control subjects and allergic patients were subjected to skin prick test (SPT). Later sera collected from those positive to SPT along with controls were used for IgE immunoblotting. The study evaluated the allergic manifestation associated with Bl, and identified it's proteins attributing Bl-mediated allergy. This work may help in managing tree nuts mediated allergies especially due to Buchanania lanzan sensitization.

Food Allergen Epitope Mapping

With the increased global awareness and rise in food allergies, a multifold interest in food allergens is evident. The presence of undeclared food allergens results in expensive food recalls and increased risks of anaphylaxis for the sensitive individuals. Regardless of the allergenic food, the immunogen needs to be identified and detected before making any efforts to inactivate/eliminate it. In type I food allergies, protein immunogen cross-links immunoglobulin E, leading to basophil/mast cell degranulation, resulting in the symptoms that range from mild irritation to anaphylaxis. A portion/part of the protein, known as the epitope, can interact with either antibodies to elicit allergic reactions or T-cell receptors to initiate allergic sensitization. Antibody-recognized epitopes can be either a linear sequence of amino acids (linear epitope) or a three-dimensional motif (conformational epitope), while T-cell-receptor-recognized epitopes are exclusively linear peptides. Identifying and characterizing human-allergy-relevant epitopes are important for allergy diagnosis/prognosis, immunotherapy, and developing food processing methods that can reduce/eliminate immunogencity/immunoreactivity of the allergen.

Non-topical management of recalcitrant paediatric atopic dermatitis

Atopic dermatitis (AD) is a common chronic, pruritic skin disease in children. As the incidence of AD increases, especially in high-income countries, paediatricians may see an increasing number of recalcitrant AD cases in their practice. Although these cases are principally managed by paediatric dermatologists, it is important for paediatricians to be aware of the use and side effects of non-topical treatment like phototherapy and systemic agents as well as the evidence for alternative treatment, which caregivers may ask about. This review presents paediatric evidence for the practical use of phototherapy and certain oral immunosuppressants for paediatric AD including doses, duration of use and monitoring of adverse effects. The use of alternative therapy including traditional medicine, probiotics and the role of nutrition are also discussed. Narrow band ultraviolet B phototherapy is effective in recalcitrant paediatric AD. When phototherapy is ineffective or contraindicated, systemic drugs may be administered cautiously with close surveillance of side effects. The use of azathioprine, ciclosporin, methotrexate and mycophenolate mofetil is generally safe in the short term under close monitoring and can be effective alongside compliance to topical treatment. Alternative complementary treatment is not known to be effective. Holistic management including therapeutic patient education is important. Good quality paediatric studies for non-topical AD treatment are needed for definitive guidelines.

Debates in allergy medicine: Specific immunotherapy in children with atopic dermatitis, the "con" view

Atopic dermatitis (AD) is a common chronic skin condition in children that has a proven association with other atopic conditions and allergies. These associations, like the general pathophysiology of AD, are complex and not fully understood. While there is evidence for the efficacy of specific immunotherapy (SIT) in pediatric asthma and allergic rhinitis (AR), there is a lack of strong data to support its use in AD. IgE has been shown to be elevated in many patients with AD, but it is an unreliable biomarker due to variability and great fluctuation over time, poor positive predictive value for clinically relevant allergy, and poor correlation with disease state. In spite of this, almost all studies of SIT use either positive skin prick testing (SPT) or serum specific IgE levels to guide therapy. Allergen avoidance, with some exceptions, is generally not effective at controlling AD in children. The few studies that have investigated the efficacy of SIT in children with AD have produced conflicting results, and a lack of reproducibility with a standard treatment protocol. Limited studies have shown clinical improvement in mild to moderate AD cases, but no effect on more severe patients. Uncontrolled studies are difficult to interpret, due to the natural history of remission or “outgrowing” of AD over time in many patients without specific interventions. Drawbacks to SIT include the length of treatment, poor compliance, cost, and potential side effect profile. The potential for misdirection of time and energy away from skin directed therapy could negatively impact on AD outcomes.

FPIES: Reviewing the Management of Food Protein-Induced Enterocolitis Syndrome

Purpose of Review. The aim of this review is to provide a case driven presentation of the presenting features and diagnostic criteria particularly focusing on the management of FPIES. It also summarises the natural history and resolution of cow's milk induced FPIES. Data Sources. OvidSP Database was used to search for literature using the keywords food protein-induced enterocolitis and FPIES. Recent Findings. The diagnosis of FPIES is often delayed following two or more presentations. Symptoms in the acute form include profuse vomiting usually 2–6 hours following ingestion of food. Vomiting may or may not be accompanied by diarrhoea. Management involves removing the causal food protein from diet. There is some concomitance in cow's milk and soya induced FPIES. Hence extensively hydrolysed formula is the milk of choice unless breast-feeding is carried out in which case that should be continued. Summary. FPIES is a complex form of non-IgE mediated food allergy. More awareness and knowledge of the condition are required to prevent misdiagnosis. Early diagnosis and removal of the culprit food protein improve the outcome. Good nutritional advice and clear management plans are important. More multicentre studies are required to reevaluate and produce consistent oral food challenge criteria and guidelines.

Food Allergy in Atopic Dermatitis

Food allergy in atopic dermatitis (AD) is debatable from decades. Role of diet in the cause and treatment of AD is controversial and is not well-defined. Allergists and pediatricians are convinced about the food allergy in AD whereas many dermatologists are contrary for this. However, there are studies in the Indian and western literature supporting the evidence that elimination diet may improve the severe type of AD. There is increasing awareness and lot of misconception among caregivers about food allergy and hence careful understanding about this concept is necessary to counsel parents. Recent evidence-based literature suggests avoidance of proven food allergens in AD could be beneficial in moderate to severe type of AD.

Development and characterization of an effective food allergy model in Brown Norway rats

BACKGROUND

Food allergy (FA) is an adverse health effect produced by the exposure to a given food. Currently, there is no optimal animal model of FA for the screening of immunotherapies or for testing the allergenicity of new foods.

OBJECTIVE

The aim of the present study was to develop an effective and rapid model of FA in Brown Norway rats. In order to establish biomarkers of FA in rat, we compared the immune response and the anaphylactic shock obtained in this model with those achieved with only intraperitoneal immunization.

METHODS

Rats received an intraperitoneal injection of ovalbumin (OVA) with alum and toxin from Bordetella pertussis, and 14 days later, OVA by oral route daily for three weeks (FA group). A group of rats receiving only the i.p. injection (IP group) were also tested. Serum anti-OVA IgE, IgG1, IgG2a, IgG2b and IgA antibodies were quantified throughout the study. After an oral challenge, body temperature, intestinal permeability, motor activity, and mast cell protease II (RMCP-II) levels were determined. At the end of the study, anti-OVA intestinal IgA, spleen cytokine production, lymphocyte composition of Peyer's patches and mesenteric lymph nodes, and gene expression in the small intestine were quantified.

RESULTS

Serum OVA-specific IgG1, IgG2a and IgG2b concentrations rose with the i.p. immunization but were highly augmented after the oral OVA administration. Anti-OVA IgE increased twofold during the first week of oral OVA gavage. The anaphylaxis in both IP and FA groups decreased body temperature and motor activity, whereas intestinal permeability increased. Interestingly, the FA group showed a much higher RMCP II serum protein and intestinal mRNA expression.

CONCLUSIONS

These results show both an effective and relatively rapid model of FA assessed by means of specific antibody titres and the high production of RMCP-II and its intestinal gene expression.

Food-specific IgG Antibody-guided Elimination Diets Followed by Resolution of Asthma Symptoms and Reduction in Pharmacological Interventions in Two Patients: A Case Report

Asthma is one of the most common causes of office visits in the primary care and emergency care settings. Individuals are often able to maintain symptomatic control with long-term pharmacological therapy. Exacerbations of asthma commonly occur due to exposure to triggers such as viruses, pollutants, and allergens. While it is widely accepted that exposure to immunoglobulin E food allergens can exacerbate asthma symptoms, there is little evidence examining delayed immunoglobulin G-mediated reactions to food. Here we present two clinical cases of individuals who experienced a reduction in asthma symptoms, decreased dependence on pharmacological therapies, and increased quality of life by eliminating foods that demonstrated reactivity to immunoglobulin G levels identified through serum testing.

The natural history of cow's milk allergy in north-eastern Poland

PURPOSE

The rate of cow's milk allergy diminishes with age. There is not enough information concerning geographical trends in persistent cow's milk allergy in children. The objective of the study was to evaluate the prevalence of persistent cow's milk allergy in children previously diagnosed with IgE-mediated cow's milk allergy (CMA).

MATERIAL/METHODS

Diagnosis of cow's milk allergy was established by a medical history of symptoms associated with exposure to cow's milk, positive skin prick tests with cow's milk, the presence of milk-specific IgE, and by a positive double- or single-blind placebo-controlled food challenge with milk confirmed by a positive open-controlled milk challenge. A second oral challenge was performed after at least one year of a milk-free diet and children with a positive oral milk rechallenge were diagnosed as having a persistent CMA.

RESULTS

Two hundred ninety-one children, 2-14 years of age (mean 5.30±3.16 years, 95% CI, 5.02-5.62 years) completed the study. Persistent CMA was diagnosed in 79 patients (27.1%). Two hundred twelve children (72.9%) outgrew their allergy to cow's milk at a mean age of 5 years after an average time of 16.4±0.8 months on an elimination diet. Eighty percent of children below 3 years of age became milk tolerant. Milk-specific IgE (p=0.018) and history of paternal bronchial asthma and/or rhinitis (p=0.020) were associated with persistence of cow's milk allergy in regression analysis.

CONCLUSIONS

An age above 3 years, as well as features of atopy, individual and familial, may be associated with a risk of delayed tolerance to milk in children.

Prevalence of food avoidance and food allergy in Chinese patients with chronic urticaria

BACKGROUND

Food avoidance is common among Chinese patients with chronic urticaria because food allergy is considered to be the cause of disease. The benefit of food avoidance and its relationship with food allergy is unknown.

OBJECTIVES

The aims of this study were to examine the prevalence and effect of food avoidance and food allergy in patients with chronic urticaria.

METHODS

Four hundred and ninety-four patients with chronic urticaria, who attended Peking University Third Hospital from January 2009 to December 2010, were studied. Food avoidance and its effect were investigated with a detailed questionnaire. Food allergy was diagnosed by serum food-specific immunoglobulin E (IgE), elimination diet based on food-specific IgE, and open food challenge.

RESULTS

One hundred and fifty-eight patients (32%) avoided fish, shrimp, crab, lamb or beef prior to evaluation and 82·9% of them reported food avoidance ineffective. Out of 341 patients tested for serum food-specific IgE, 75 (22%) were positive, with soy, peanut, beef, lamb, chicken, crab and shrimp as the leading allergens. Chronic urticaria induced by food allergy was found in only 2·8% of patients.

CONCLUSIONS

The prevalence of food avoidance is high and mostly ineffective in Chinese patients with chronic urticaria. Foods avoided do not correspond to serum food-specific IgE. The incidence of IgE-mediated urticaria, as demonstrated by open food challenge, is low. Physicians and patients should be aware of unnecessary dietary avoidance while seeking treatment of chronic urticaria.