Food allergy and food sensitization in early childhood: results from the DARC cohort

Prevalence of tree nut allergy in Europe: A systematic review and meta-analysis

In 2014, the European Academy of Allergy and Clinical Immunology (EAACI) published the first systematic review that summarized the prevalence of food allergy (FA) and food sensitization in Europe for studies published 2000-2012. However, only summary estimates for tree nut allergy (TNA) were feasible in that work. In the current update of that systematic review, we summarized the prevalence of tree nut allergy/sensitization to individual tree nuts. Six databases were searched for relevant papers published 2012-2021 and 17 eligible studies were added to the 15 studies already identified between 2000 and 2012, giving a total of 32 studies. Of the investigated tree nuts, meta-analysis was possible for hazelnut, walnut, almond, and in few cases, for cashew, and Brazil nut. The lifetime self-reported prevalence was 0.8% (95% CI 0.5-1.1) for hazelnut and 0.4% (0.2-0.9) for walnut. The point self-reported prevalence was 4.0% (2.9-5.2) for hazelnut, 3.4% (2.0-4.9) for Brazil nut, 2.0% (1.1-2.9) for almond, and 1.8% (1.1-2.5) for walnut. Point prevalence of food challenge-confirmed TNA was 0.04% (0.0-0.1) for hazelnut and 0.02% (0.01-0.1) for walnut. Due to paucity of data, we could not identify any meaningful and consistent differences across age groups and European regions.

Gastrointestinal Comorbidities Associated with Atopic Dermatitis-A Narrative Review

The current understanding of atopic dermatitis (AD) seems to be extending beyond a skin-confined condition frequently associated with allergic comorbidities, as in a number of epidemiological studies, the prevalence rate of a range of illnesses has been determined to be greater in patients with AD, or inversely. In most cases, the reasons for this are vague. A subset of these conditions are gastrointestinal disorders, including food sensitization (FS) and food allergy (FA), eosinophilic esophagitis (EoE) (it is of mixed background, both IgE-dependent and independent), food protein-induced enterocolitis syndrome (FPIES) (it exemplifies an IgE-independent food allergy), Crohn's disease (CD), colitis ulcerosa (CU), celiac disease, irritable bowel syndrome (IBS), and gastroesophageal reflux disease (GERD). In this review, we performed a comprehensive search of the literature using the PubMed database. We addressed the epidemiology of the increased co-occurrence of these diseases with AD and discussed potential causes for this subject. Multiple gastroenterological comorbidities appear to be more common in patients with AD, according to our review. The mechanisms that underlie this phenomenon are largely unknown, highlighting the need for further study in this field.

Directed acyclic graph for epidemiological studies in childhood food allergy: Construction, user's guide, and application

Understanding modifiable prenatal and early life causal determinants of food allergy is important for the prevention of the disease. Randomized clinical trials studying environmental and dietary determinants of food allergy may not always be feasible. Identifying risk/protective factors for early-life food allergy often relies on observational studies, which may be affected by confounding bias. The directed acyclic graph (DAG) is a causal diagram useful to guide causal inference from observational epidemiological research. To date, research on food allergy has made little use of this promising method. We performed a literature review of existing evidence with a systematic search, synthesized 32 known risk/protective factors, and constructed a comprehensive DAG for early-life food allergy development. We present an easy-to-use online tool for researchers to re-construct, amend, and modify the DAG along with a user's guide to minimize confounding bias. We estimated that adjustment strategies in 57% of previous observational studies on modifiable factors of childhood food allergy could be improved if the researchers determined their adjustment sets by DAG. Future researchers who are interested in the causal inference of food allergy development in early life can apply the DAG to identify covariates that should and should not be controlled in observational studies.

Defining and Measuring the Scope of Atopic Dermatitis

Atopic dermatitis (AD) has no definitive diagnostic test and has a large range of phenotypes, making it a difficult disease to assess and define. However, an agreed-upon definition of AD is important for clinical trials, population-based studies, and clinical practice. Several diagnostic criteria systems have been proposed to fill these needs, with none considered the gold standard. To further aid in standardized assessment of AD patients, numerous disease severity and quality-of-life measurement tools have been proposed. There is similarly no gold standard and efforts are ongoing to develop a single consensus scale. Finally, assessment of AD-associated comorbidities, including allergic/immunologic conditions, psychiatric disorders, and metabolic/cardiac conditions, is important when evaluating this patient population.

Clinical Approach to Patients with Moderate-to-Severe Atopic Dermatitis: A Spanish Delphi Consensus

Despite emerging evidence and advances in the management of atopic dermatitis there a lack of consensus regarding the diagnostic criteria, therapeutic approach, method to assess severity, and patient follow-up for this condition. An expert consensus study was conducted to provide recommendations on the management of patients with moderate-to-severe atopic dermatitis. The study used Delphi-like methodology based on a literature review, a summary of the scientific evidence, and a 2-round survey. The agreement of 60 panellists on 21 statements was evaluated. Consensus was pre-defined as ≥ 80% agreement of all respondents. In the first round 6 statements reached consensus. Unanimous consensus was achieved regarding therapeutic goals and patient satisfaction (maintained in the long term and periodic goals reassessment recommended every 3-6 months). In the second round, half of the statements reached consensus, all related to patient follow-up, treatment goals, and atopic comorbidities. The statements that did not reach consensus were related to diagnosis (biomarkers, allergy, and food testing) and starting patients on conventional systemic treatment rather than advanced treatment. The study assessed expert opinion regarding a variety of topics related to the clinical approach to patients with moderate-to-severe atopic dermatitis, in order to provide guidance on the diagnosis and management of patients with atopic dermatitis.

Food Sensitivity in Children Diagnosed with Atopic Dermatitis in The First 2 Years: How Many of These Patients Are Truly Allergic?

Objectives

In this study, it was aimed to examine food sensitivity in patients with atopic dermatitis (AD) and to investigate the frequency of food allergy in patients with food sensitivity.

Methods

Patients aged 0-2 years who were followed up with the diagnosis of AD were included in the study. The characteristics of demographic and clinical and laboratory findings of the patients were recorded retrospectively. Patients were classified as mild, moderate, and severe using the SCORing AD index according to the severity of AD. The presence of food sensitivity was evaluated by skin prick test and serum-specific immunoglobulin (Ig)E results. Food allergy was diagnosed by oral food challenge (OFC) test.

Results

Of the 72 patients included in the study, 62.5% (n=45) were male, and the mean age was 9±4.8 months. When the disease severity was evaluated, it was mild in 40 patients (55.6%); moderate/severe AD was present in 32 patients (44.4%). The frequency of moderate/severe AD was higher in patients who were younger (p=0.01), whose symptoms started in the first 6 months (p=0.03), who had a family history of allergic disease (p=0.001), who breastfed for <6 months (p=0.01), who had a higher median serum total IgE level, and a higher percentage of serum eosinophils (p=0.005 and p=0.01, respectively). Food sensitivity in 45.8% of patients; food allergy was detected in 41.7% of them. The most common sensitivities and allergies were eggs white/yolk and cow's milk, respectively. The rate of food sensitivity was found to be higher in male gender (p=0.03) and breastfed patients (p=0.03), whereas it was similar in patients with mild and moderate/severe AD.

Conclusion

In the investigation of food sensitivity in patients with AD, it is important to evaluate other demographic and clinical characteristics such as gender and breastfeeding, apart from the severity of disease. The OFC test should be performed to confirm the food allergy in patients with food sensitivity before the recommendation of an elimination diet.

Prevalence estimates of eight big food allergies in Europe: Updated systematic review and meta-analysis

In 2014, the European Academy of Allergy and Clinical Immunology published prevalence estimates for food allergy (FA) and food sensitization (FS) to the so-called eight big food allergens (i.e. cow's milk, egg, wheat, soy, peanut, tree nuts, fish and shellfish) in Europe for studies published between 2000 and 2012. The current work provides 10-year updated prevalence estimates for these food allergens. A protocol was registered on PROSPERO before starting the research (reference number CRD42021266657). Six databases were searched for studies published 2012-2021, added to studies published up to 2012, resulting in a total of 93 studies. Most studies were graded as at moderate risk of bias. The overall pooled estimates for all age groups of self-reported lifetime prevalence were as follows: cow's milk (5.7%, 95% confidence interval 4.4-6.9), egg (2.4%, 1.8-3.0), wheat (1.6%, 0.9-2.3), soy (0.5%, 0.3-0.7), peanut (1.5%, 1.0-2.1), tree nuts (0.9%, 0.6-1.2), fish (1.4%, 0.8-2.0) and shellfish (0.4%, 0.3-0.6). The point prevalence of food challenge-verified allergy were as follows: cow's milk (0.3%, 0.1-0.5), egg (0.8%, 0.5-1.2), wheat (0.1%, 0.01-0.2), soy (0.3%, 0.1-0.4), peanut (0.1%, 0.0-0.2), tree nuts (0.04%, 0.02-0.1), fish (0.02%, 0.0-0.1) and shellfish (0.1%, 0.0-0.2). With some exceptions, the prevalence of allergy to common foods did not substantially change during the last decade; variations by European regions were observed.

Unique Gut Microbiome Signatures among Adult Patients with Moderate to Severe Atopic Dermatitis in Southern Chinese

Imbalance of the immune system caused by alterations of the gut microbiome is considered to be a critical factor in the pathogenesis of infant eczema, but the exact role of the gut microbiome in adult atopic dermatitis (AD) patients remains to be clarified. To investigate the differences of the gut microbiome between adult AD patients and healthy individuals, stool samples of 234 adults, containing 104 AD patients and 130 healthy subjects, were collected for 16S rRNA gene amplicon. Altered structure and metabolic dysfunctions of the gut microbiome were identified in adult AD patients. Our results illustrated that the adult AD patients were more likely to have allergies, particularly non-food allergies. In addition, the gut microbiome composition of the AD and normal groups were considerably different. Moreover, Romboutsia and Clostridi-um_sensu_stricto_1 was enriched in the normal group, whereas Blautia, Butyricicoccus, Lachnoclostridium, Eubacterium_hallii_group, Erysi-pelatoclostridium, Megasphaera, Oscillibacter, and Flavonifractor dominated in the AD group. Additionally, purine nucleotide degradation pathways were significantly enriched in the AD group, and the enrichment of proteinogenic amino acid biosynthesis pathways was found in the normal group. This study provides insights into new therapeutic strategies targeting the gut microbiome for AD and evidence for the involvement of the gut-skin axis in AD patients.

The Impact of Air Pollution on Atopic Dermatitis

PURPOSE OF REVIEW

Atopic dermatitis (AD) remains a dermatological disease that imposes a significant burden on society. Air pollution has previously been linked to both the onset and severity of atopic dermatitis. As air pollution remains a critical environmental factor impacting human health, this review seeks to provide an overview of the relationship between different air pollutants and AD.

RECENT FINDINGS

AD can develop from multiple causes that can be broadly grouped into epidermal barrier dysfunction and immune dysregulation. Air pollution imposes significant health risks and includes a wide variety of pollutant types. AD has been linked to outdoor air pollutants such as particulate matter (PM), volatile organic compounds (VOC), gaseous compounds, and heavy metals. Exposure to indoor pollutants such as tobacco smoke and fungal molds has also been associated with an increased incidence of AD. While different pollutants impact distinct molecular pathways in the cell, they mostly converge on ROS product, DNA damage, and dysregulated T-cell activity and cytokine production. The presented review suggests a strengthening tie between air pollution and AD. It points to opportunities for further studies to clarify, as well as potential therapeutic opportunities that leverage the mechanistic relationships between air pollution and AD.

Pearls and Pitfalls of Weaning an Infant with Severe Atopic Dermatitis and Sensitization/Allergy to Food

Atopic dermatitis (AD) is a common chronic inflammatory skin disorder in childhood. Skin barrier impairment exposes infants to food allergens, potentially causing sensitization followed by IgE-mediated food allergy. We describe the case of an infant with severe AD in whom several sensitizations to foods are detected, with consequently difficult weaning, and a history of anaphylaxis to cashew nut. Foods for which skin tests were negative were introduced into the infant's diet. Then, when AD control was managed, oral food challenges (OFCs) for foods to which the patient was sensitized, with the exception of cashew nut, were performed. The simultaneous presence of sensitization toward multiple foods made it difficult to introduce them using classic OFC. Therefore, it was decided to perform the low-dose, gradual controlled OFC. This led to an introduction of sensitized foods into the infant's diet, with the exception of cashew nut, avoiding allergic reactions. Absolute recommendations on how, when, and where to perform OFCs with allergenic food to which the child with AD is sensitized are lacking so far. In our opinion, OFCs and the subsequent ntroduction of allergenic foods should be individualized, evaluating some factors such as their social and nutritional importance, the patient's age and clinical phenotype (including the history of anaphylaxis), and the sensitization profile. There is agreement on the fact that the dietary approach in children with moderate-severe AD should no longer include a strict elimination diet. We believe that an early, gradual controlled introduction of all allergenics to identify the amount of food tolerated in the absence of reactions, even if low dose, may improve patients' and families' quality of life. However, even if discussing a vast relevant literature, the limitation of our work is that we describe the management of a single patient. Extensive and high-quality research is needed in this field to improve the available evidence in the area.

Attenuating the atopic march: Meta-analysis of the dupilumab atopic dermatitis database for incident allergic events

BACKGROUND

Atopic march refers to the sequential development of allergic diseases from infancy through adolescence, typically beginning with atopic dermatitis (AD), followed by food allergy and then airway diseases, later evolving to broader or worsened spectrum of allergic diatheses. No intervention has shown to alter its course.

OBJECTIVE

We sought to determine the rate of acquisition of new or worsened allergic events for dupilumab versus placebo in patients with AD.

METHODS

Allergy-associated events from 12 clinical trials were grouped into 17 allergy categories, and IgE changes from baseline were defined. A new/worsened event was considered one step of atopic march. Treatment effect was assessed by incidence rate ratios (IRRs), dupilumab versus placebo, by meta-analysis.

RESULTS

The duration of pooled AD studies was 4 to 52 weeks (1359 patient-years; n = 2296 dupilumab, n = 1229 placebo, median age 35 years). The median age at AD onset was 2 years. Baseline allergic disease burden was comparable between groups. Dupilumab reduced the risk of new/worsening allergies by 34% (IRR 0.66; 95% confidence interval [CI], 0.52-0.84) and new allergies by 37% (IRR 0.63; 95% CI, 0.48-0.83) versus placebo. Including IgE category shift, the IRR for combined new/worsening allergies was reduced by 54% (IRR 0.46; 95% CI, 0.36-0.57). These treatment benefits did not reverse on treatment discontinuation in off-treatment follow-up.

CONCLUSIONS

The acquisition/worsening of allergic conditions suggestive of atopic march was observed in a pooled adult/adolescent AD study population with inadequately controlled AD. Treatment with dupilumab reduced new/worsened allergy events versus placebo; inclusion of IgE category change increased the apparent benefit.

Epicutaneous Sensitization and Food Allergy: Preventive Strategies Targeting Skin Barrier Repair-Facts and Challenges

Food allergy represents a growing public health and socio-economic problem with an increasing prevalence over the last two decades. Despite its substantial impact on the quality of life, current treatment options for food allergy are limited to strict allergen avoidance and emergency management, creating an urgent need for effective preventive strategies. Advances in the understanding of the food allergy pathogenesis allow to develop more precise approaches targeting specific pathophysiological pathways. Recently, the skin has become an important target for food allergy prevention strategies, as it has been hypothesized that allergen exposure through the impaired skin barrier might induce an immune response resulting in subsequent development of food allergy. This review aims to discuss current evidence supporting this complex interplay between the skin barrier dysfunction and food allergy by highlighting the crucial role of epicutaneous sensitization in the causality pathway leading to food allergen sensitization and progression to clinical food allergy. We also summarize recently studied prophylactic and therapeutic interventions targeting the skin barrier repair as an emerging food allergy prevention strategy and discuss current evidence controversies and future challenges. Further studies are needed before these promising strategies can be routinely implemented as prevention advice for the general population.

Frequency of food allergy in Europe: An updated systematic review and meta-analysis

Food allergy (FA) is increasingly reported in Europe, however, the latest prevalence estimates were based on studies published a decade ago. The present work provides the most updated estimates of the prevalence and trends of FA in Europe. Databases were searched for studies published between 2012 and 2021, added to studies published up to 2012. In total, 110 studies were included in this update. Most studies were graded as moderate risk of bias. Pooled lifetime and point prevalence of self-reported FA were 19.9% (95% CI 16.6-23.3) and 13.1% (95% CI 11.3-14.8), respectively. The point prevalence of sensitization based on specific IgE (slgE) was 16.6% (95% CI 12.3-20.8), skin prick test (SPT) 5.7% (95% CI 3.9-7.4), and positive food challenge 0.8% (95% CI 0.5-0.9). While lifetime prevalence of self-reported FA and food challenge positivity only slightly changed, the point prevalence of self-reported FA, sIgE and SPT positivity increased from previous estimates. This may reflect a real increase, increased awareness, increased number of foods assessed, or increased number of studies from countries with less data in the first review. Future studies require rigorous designs and implementation of standardized methodology in diagnosing FA, including use of double-blinded placebo-controlled food challenge to minimize potential biases.

The prevalence of sensitization to food allergens in children with atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) has a complex pathophysiology. The course of the disease is affected by both environmental factors and allergen hypersensitivities. Food and aeroallergens have a significant role in the pathogenesis and disease control.

OBJECTIVE

In this study, it was aimed to determine the prevalence of food and aeroallergen sensitivity of children with AD.

METHODS

Children under 18 years with AD who applied to pediatric allergy and immunology outpatient clinics were evaluated. All patients had a skin prick test (SPT) within most common food and aeroallergens.

RESULTS

One hundred seventy three patients were studied. Most of the moderate and severe AD patients were boys (boys 64% vs. girls 47%). Symptoms started earlier and positive results in SPTs with food allergens were more common in patients with SCORAD (SCORing Atopic Dermatitis) >25 (p < 0.0001). Egg white (39%), egg yolk (31%), cow's milk (13%) and wheat flour (5%), were the most common allergens, respectively. The SCORAD scores were higher in multiple food sensitized patients' groups (p < 0.001). Although, food sensitizations were prevalent in patients who had higher SCORAD scores (p = 0.001), there was no significant difference in sensitization with aeroallergens. (p = 0.392).

CONCLUSION

Sensitizations to both food and aeroallergens are common in patients with AD. In addition, sensitization to these allergens and SCORAD severity in patients with AD have positive correlation.

Narcolepsy-Like Sleepiness: A Symptom of Immediate-Type Reactions in Food-Allergic Children

BACKGROUND

It has been reported that sometimes children fall asleep and can barely be woken up during allergic reactions on food ingestion. Nevertheless, to date, there is scarce data on narcolepsy-like sleepiness as a symptom of allergic reactions.

OBJECTIVE

To investigate the frequency of narcolepsy-like sleepiness during oral food challenges and characterize this symptom regarding comorbidities, eliciting allergens, and severity of reactions.

METHODS

Children with immediate-type allergic reactions during oral food challenges (89% were double-blind, placebo-controlled) have been analyzed in this study. Narcolepsy-like sleepiness was defined as a somnolent condition during which patients could barely be woken up again, occurring within 2 hours of food intake and which was not due to drug side effects. Logistic generalized estimating equations were used to explore the effect of age, severity of reactions, and eliciting allergens on the occurrence of narcolepsy-like sleepiness.

RESULTS

In 106 (12.5%) of all 848 food-allergic children, narcolepsy-like sleepiness was observed during oral food challenges. Children with eczema had a higher risk of developing narcolepsy-like sleepiness (P = .006). Narcolepsy-like sleepiness occurred most often due to an allergic reaction to hazelnut (P = .009) or other tree nuts (P = .003). Moderate to severe reactions occurred more often than mild reactions (P = .026; odds ratio, 1.521; 95% CI, 1.051-2.202) in children with narcolepsy-like sleepiness.

CONCLUSIONS

We were able to show for the first time that narcolepsy-like sleepiness is a frequently occurring clinical manifestation of immediate-type allergic reactions on food ingestion in childhood. Further research is needed to unravel the underlying mechanisms to gain a deeper insight into this underestimated symptom.

Multi-Perspective Observation on the Prevalence of Food Allergy in the General Chinese Population: A Meta-Analysis

Reliable estimates of the prevalence of food allergy (FA) among the general Chinese population have remained unclear. This meta-analysis aims to provide an accurate estimate of FA prevalence in China with comprehensive data. A systematic literature search was conducted in eight electronic databases, i.e., China National Knowledge Infrastructure, Wanfang, Weipu, China Biology Medicine, Web of Science, PubMed, Cochrane, and Embase. A random-effects model was used to analyze the pooled prevalence of FA for four different assessment methods. A total of 46 eligible articles were included in the narrative synthesis, and 41 articles were ultimately included in the meta-analysis. Overall, the pooled prevalence of self-reported FA, self-reported physician-diagnosed FA, SPT (specific skin prick test)-positive FA, and OFC (open food challenge)-positive FA were 11.5% (95% CI: 9.8-13.5%), 5.3% (95% CI: 4.2-6.5%), 11.6% (95% CI: 9.6-14.1%), and 6.2% (95% CI: 4.4-8.7%), respectively. Subgroup analyses suggested that the prevalence of FA was affected by age, year of data collection, region, and sample size, but not by gender. This meta-analysis indicated that FA is common among Chinese people, with an increasing trend in prevalence during the past two decades. Given the high heterogenicity between these studies, a national survey with a large sample size based on standardized diagnosis is urgently needed to gain a more scientific understanding of the actual situation of food allergy in China.

Phenotype of Atopic Dermatitis With Food Allergy Predicts Development of Childhood Asthma via Gut Wnt Signaling

PURPOSE

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by a wide spectrum of clinical phenotype. However, specific description of phenotypes of AD depending on the comorbidities in early childhood is lacking. This study aimed to investigate whether the AD phenotype in early childhood is related to childhood asthma and to elucidate the mechanisms involved.

METHODS

Data on the first 3 years of life were collected prospectively from 1,699 children in the COhort for Childhood Origin of Asthma and allergic diseases (COCOA). We applied an unsupervised latent class analysis to the following five factors: food sensitization, inhalant sensitization, food allergy (FA), AD, and recurrent wheezing. The risks of developing FA, AD, allergic rhinitis (AR), and asthma in children aged 5-7 years were evaluated. Colonocyte transcriptome and ingenuity pathway analysis were performed.

RESULTS

Four phenotypes were identified; no allergic diseases (78.4%), AD without sensitization (16.4%), FA with AD (2.9%), and AD with sensitization (7.8%). The FA with AD had the highest risk for FA, AR, and asthma and the highest cord blood immunoglobulin E (IgE) levels. In AD without sensitization and with sensitization, scoring of AD (SCORAD) in early childhood was higher than in FA with AD. Canonical pathway analysis with the colonocyte transcriptome revealed that the key pathway in FA with AD was 'Wnt/β-catenin Signaling.' The relative abundance of Wnt6 mRNA was positively correlated with food-specific IgE levels at 1 and 3 years.

CONCLUSIONS

When FA is present in various phenotypes of AD at early life, regardless of severity of eczema, it may be associated with gut Wnt signaling and later development of asthma.

Dietary Elimination for the Treatment of Atopic Dermatitis: A Systematic Review and Meta-Analysis

BACKGROUND

The influence of diet on atopic dermatitis (AD) is complex, and the use of dietary elimination as a treatment has conflicting views.

OBJECTIVE

To systematically review the benefits and harms of dietary elimination for the treatment of AD.

METHODS

We searched MEDLINE, Embase, AMED, PsycINFO, and the Cochrane Central Register of Controlled Trials from inception to January 18, 2022, without language restrictions, for randomized controlled trials (RCTs) and observational studies comparing dietary elimination and no dietary elimination for the treatment of AD. We conducted random-effects meta-analyses of eczema outcomes. We used the grading of recommendations, assessment, development, and evaluation approach to assess certainty of evidence (CRD42021237953).

RESULTS

Ten RCT (n = 599; baseline median of study mean age, 1.5 years; median of study mean SCOring Atopic Dermatitis index, 20.7, range, 3.5-37.6) were included in the meta-analysis. Compared with no dietary elimination, low-certainty evidence showed that dietary elimination may slightly improve eczema severity (50% with vs 41% without dietary elimination improved the SCOring Atopic Dermatitis index by a minimally important difference of 8.7 points, risk difference of 9% [95% CI, 0-17]), pruritus (daytime itch score [range, 0-3] mean difference, -0.21 [95% CI, -0.57 to 0.15]), and sleeplessness (sleeplessness score [range, 0-3] mean difference, -0.47 [95% CI, -0.80 to -0.13]). There were no credible subgroup differences based on elimination strategy (empiric vs guided by testing) or food-specific sensitization. Insufficient data addressed harms of elimination diets among included RCTs, although indirect evidence suggests that elimination diets may increase the risk for developing IgE-mediated food allergy.

CONCLUSIONS

Dietary elimination may lead to a slight, potentially unimportant improvement in eczema severity, pruritus, and sleeplessness in patients with mild to moderate AD. This must be balanced against potential risks for indiscriminate elimination diets including developing IgE-mediated food allergy and withholding more effective treatment options for AD.

Atopic Dermatitis With Coexisting Food Allergy in Early Life Is Associated With Childhood Asthma

PURPOSE

Atopic dermatitis (AD) and food allergy (FA) are associated with respiratory comorbidities, in the concept of 'atopic march.' However, children with AD and a coexisting FA have various disease courses, and the mechanism of atopic march remains unclear. In this study, we investigated whether the phenotype of AD with coexisting FA in early life affected asthma or allergic rhinitis (AR) in school children.

METHODS

A total of 1,579 children from the Panel Study on Korean Children (PSKC) cohort were followed-up in 2013. The participants diagnosed with AD in this cohort were classified by the age of AD onset and persistence as well as FA history. We compared the presence of comorbidities-asthma and rhinitis-among different AD phenotypes.

RESULTS

Asthma and AR with current symptoms within 12 months at age 6-8 years were associated with early-onset persistent AD phenotype, regardless of coexisting FA. AD with FA conferred a higher risk of recent wheezing at 8 years of age than AD without FA (adjusted odds ratio, 8.09; 95% confidence interval, 2.54-25.76). Children with early-onset persistent AD with FA manifested a distinctive trajectory with a higher prevalence of wheezing and AR at age 5-8 years than those without AD.

CONCLUSIONS

AD with FA in early life is strongly associated with asthma and AR in school children, and the early-onset persistent AD with FA had a strong additive effect on the risk of asthma at school age. Classifying AD phenotypes regarding FA in early life will help predict and prevent asthma and AR in school children.

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.

Blocking the inhibitory receptor programmed cell death 1 prevents allergic immune response and anaphylaxis in mice

BACKGROUND

Food allergy and acute anaphylaxis can be life-threatening. While T follicular helper (Tfh) cells play a pivotal role in the allergic immune responses, the immunologic mechanisms that regulate the production of antibodies (Abs) that mediate anaphylaxis are not fully understood.

OBJECTIVE

The aim of this study was to investigate the role of the inhibitory receptor programmed cell death protein 1 (PD-1), which is highly expressed on Tfh cells, in allergic immune responses using an animal model of peanut allergy and anaphylaxis.

METHODS

Naive wild-type mice were exposed to peanut flour intranasally and then challenged with peanut extract to induce systemic anaphylaxis. The roles of PD-1 were examined by blocking Abs and using gene-deficient animals. A hapten model and passive cutaneous anaphylaxis were used to characterize allergen-specific Abs.

RESULTS

Treatment with anti-PD-1 enhanced development of Tfh cells and germinal center B cells in mice exposed to peanut flour. Nonetheless, anti-PD-1 or its ligand fully protected mice from developing anaphylaxis. Anti-PD-1 treatment or genetic deficiency of PD-1 in CD4⁺ T cells inhibited production of peanut-specific IgE and increased the levels of IgG. The passive cutaneous anaphylaxis showed that peanut-specific Abs generated in anti-PD-1-treated animals prevented, rather than provoked, anaphylaxis when transferred to naive animals. Anti-PD-1 promoted production of Abs with low affinity for an antigen in the hapten model.

CONCLUSION

Blockade of the pathway between PD-1 and its ligand is protective against allergic immune responses. The direct interaction between Tfh cells and B cells may play a pivotal role in controlling Ab quality and clinical manifestation of allergic diseases.

Granzyme B in Epithelial Barrier Dysfunction and Related Skin Diseases

The predominant function of the skin is to serve as a barrier - to protect against external insults and to prevent water loss. Junctional and structural proteins in the stratum corneum, the outermost layer of the epidermis, are critical to the integrity of the epidermal barrier as it balances ongoing outward migration, differentiation, and desquamation of keratinocytes in the epidermis. As such, epidermal barrier function is highly susceptible to upsurges of proteolytic activity in the stratum corneum and epidermis. Granzyme B is a serine protease scarce in healthy tissues but present at high levels in tissues encumbered by chronic inflammation. Discovered in the 1980s, Granzyme B is currently recognized for its intracellular roles in immune cell-mediated targeted apoptosis as well as extracellular roles in inflammation, chronic injuries, tissue remodeling, and processing of cytokines, matrix proteins, and autoantigens. Increasing evidence has emerged in recent years supporting a role for Granzyme B in promoting barrier dysfunction in the epidermis by direct cleavage of barrier proteins and eliciting immunoreactivity. Likewise, Granzyme B contributes to impaired epithelial function of the airways, retina, gut and vessels. In the present review, the role of Granzyme B in cutaneous epithelial dysfunction is discussed in the context of specific conditions with an overview of underlying mechanisms as well as utility of current experimental and therapeutic inhibitors.

The role of genetics in food allergy

INTRODUCTION

As the prevalence of food allergies (FA) increases worldwide, our understanding of its pathophysiology and risk factors is markedly expanding. In the past decades, an increasing number of genes have been linked to FA. Identification of such genes may help in predicting the genetic risk for FA development, age of onset, clinical manifestation, causative allergen(s), and possibly the optimal treatment strategies. Furthermore, identification of these genetic factors can help to understand the complex interactions between genes and the environment in predisposition to FA.

AREAS COVERED

We outline the recent important progress in determining genetic variants and disease-associated genes in IgE-mediated FA. We focused on the monogenic inborn errors of immunity (IEI) where FA is one of the clinical manifestations, emphasizing the genes and gene variants which were linked to FA with some of the most robust evidence.

EXPERT OPINION

Genetics play a significant role, either directly or along with environmental factors, in the development of FA. Since FA is a multifactorial disease, it is expected that multiple genes and genetic loci contribute to the risk for its development. Identification of the involved genes should contribute to the area of FA regarding pathogenesis, prediction, recognition, prognosis, prevention, and possibly therapeutic interventions.

The Role of Diet Modification in Atopic Dermatitis: Navigating the Complexity

Diet has long been understood to have an intricate association with atopic dermatitis, although much remains unelucidated. Skin barrier dysfunction with dysbiosis and consequent impairment of immune tolerance likely underly the pathogenesis of coincident atopic dermatitis and food allergy. There is a wide range of possible skin reactions to food, complicating the diagnosis and understanding of food allergies. Many patients, parents, and providers incorrectly suspect diet as causative of atopic dermatitis symptoms and many have tried elimination diets. This frequently leads to inaccurate labeling of food allergies, contributing to a dangerous spiral of inappropriate testing, referrals, and dietary changes, while neglecting established atopic dermatitis treatment essentials. Alternatively, certain dietary supplements or the introduction of certain foods may be beneficial for atopic dermatitis management or prevention. Greater consensus on the role of diet among providers of patients with atopic dermatitis is strongly encouraged to improve the management of atopic dermatitis.

Thymic stromal lymphopoietin, skin barrier dysfunction, and the atopic march

OBJECTIVE

Atopic dermatitis often precedes the development of other atopic diseases, and the atopic march describes this temporal relationship in the natural history of these diseases. Although the pathophysiological mechanisms that underlie this relationship are poorly understood, epidemiologic and genetic data have suggested that the skin might be an important route of sensitization to allergens.

DATA SOURCES

Review of recent studies on the role of skin barrier defects in systemic allergen sensitization.

STUDY SELECTIONS

Recent publications on the relationship between skin barrier defects and expression of epithelial cell-derived cytokines.

RESULTS

Animal models have begun to elucidate on how skin barrier defects can lead to systemic allergen sensitization. Emerging data now suggest that epithelial cell-derived cytokines, such as thymic stromal lymphopoietin, drive the progression from atopic dermatitis to asthma and food allergy. Skin barrier defects can lead to induction of epithelial cell-derived cytokines, which in turn leads to the initiation and maintenance of allergic inflammation and the atopic march.

CONCLUSION

Development of new biologic drug targeting type 2 cytokines provides novel therapeutic interventions for atopic dermatitis.

Provider recommendations and maternal practices when providing breast milk to children with immunoglobulin E-mediated food allergy

BACKGROUND

There is limited research investigating maternal dietary practices and health care provider recommendations when providing breast milk (BM) to children with immunoglobulin (Ig) E-mediated food allergy.

OBJECTIVE

To explore health care provider recommendations and maternal practices when providing BM to children with IgE-mediated food allergy and to assess for possible IgE-mediated reactions to BM while the mother consumed the food to which her child has allergy.

METHODS

A web-based survey was distributed to breastfeeding (BF) mothers of children with IgE-mediated food allergies. Reported reactions to BM were scored by an allergist, provided only with the details of the possible reaction and not the suspect allergen or route of exposure, as to the likelihood that the reaction was IgE mediated.

RESULTS

A total of 133 mothers completed the survey. After food allergy diagnosis, 47.4% (n = 63) of the mothers reported that they were advised by their health care provider to continue BF without dietary restriction, 17.3% (n = 23) were advised to avoid eating the food(s) their child has allergy to while BF, and in 28.6% (n = 38), this concern was not addressed. A few of the mothers (12%, 16/133) reported that their child experienced an allergic reaction to BM. An allergist evaluated most of these reactions (75%, 12/16) as not likely IgE mediated.

CONCLUSION

This study exposed inconsistent recommendations for mothers providing BM to children with IgE-mediated food allergies. Most mothers were able to consume the food their child has allergy to without adverse sequelae. Standardized, evidence-based recommendations would enhance the well-being of these mother-infant dyads.

Cow's milk allergy prevention

OBJECTIVE

Scoping review on IgE-mediated cow's milk allergy prevention.

DATA SOURCES

Literature search of PubMed database and gray literature.

STUDY SELECTIONS

Peer-reviewed relevant observational and randomized controlled studies in the pediatric population in the English language were selected and reviewed.

RESULTS

There is increasing literature supporting the role of early and ongoing cow's milk ingestion in the prevention of cow's milk allergy. The studies supporting a preventive role with early cow's milk ingestion suggest cow's milk introduction at a very early age (most within the first month of life), suggesting the possibility of a different mechanism of sensitization than other common allergens. It is possible that gut colonization and the diversity and intensity of microbial exposure may play a role in inducing cow's milk tolerance. It is also possible that vitamin D may have a role in modulating those immune functions.

CONCLUSION

Further research regarding the role that early cow's milk ingestion plays in the prevention of cow's milk allergy is required, and questions remain. The absolute amount required for tolerance is unclear. Studies in higher risk populations are required. However, there is an intriguing and increasingly more pervasive association between early ongoing cow's milk ingestion and cow's milk allergy prevention.

Filaggrin Loss-of-Function Mutations Are Risk Factors for Severe Food Allergy in Children with Atopic Dermatitis

Atopic dermatitis is frequently associated with the onset of other allergic conditions, such as asthma, rhino-conjunctivitis and food allergy. The etiology of atopic dermatitis is marginally understood in spite of the number of predisposing factors, above all, mutations in the Filaggrin gene (FLG). In this study, the association between loss-of-function variants in the FLG gene and other allergic manifestations, in particular food allergy, was evaluated in an Italian pediatric population affected by atopic dermatitis. The 10 more frequently mutated loci in the FLG gene were genotyped in 238 children affected by atopic dermatitis and tested for association with clinical features of allergic disorders by a multivariate logistic regression model. R501X and 2282del4 were the only two mutations identified; 12.2% of children carry one of these variants, corresponding to an allelic frequency of 6.5%. According to multivariate statistical analysis, loss-of-function variants in the FLG gene represent a risk factor for the onset of severe manifestations of food allergy (OR = 8.9; CI: 3.1–28.3). Peanut and hazelnut were identified as high-risk foods in patients with FLG mutations. This study demonstrates that atopic children carrying FLG mutations represent a high-risk population due to their predisposition to develop severe food allergy reactions, such as anaphylaxis.

IgE-dependent sensitization to tropho- and aeroallergens with regard to age, sex and birth season of children and adolescents living in the north-eastern region of Poland

Introduction

A small number of studies concern trophoallergens and aeroallergens sensitization in the developmental age population in Poland. Only a few studies describe the role of selected factors determining the frequency and type of IgE-dependent sensitization in this population.

Aim

To assess the rate of sensitization to chosen tropho- and aeroallergens in the group of sensitized patients living in the north-eastern region of Poland with regard to age, sex and birth season.

Material and methods

Skin prick testing (SPT) with selected food allergens (trophoallergens) and airborne allergens was used to evaluate the sensitization process of patients recruited to this study between 1998 and 2012. A positive result of sensitization was defined when the patient had at least one positive skin prick test with the allergen studied. The skin prick tests were done after written consent had been obtained from the parents.

Results

Significant results were as follows: sensitization was more common in boys (41.9%) than in girls (35.7%); the highest percentage of sensitized patients was observed in the group of children aged 13–18 years (45.0%) as compared to the group of children up to 3 years old (the lowest 33.1%). The highest percentage of sensitized patients was observed among children born during winter (41.3%), the lowest among children born in autumn (36.8%).

Conclusions

The assessment of sensitization to chosen trophoallergens and airborne allergens should include the role of age, sex and birth season of the diagnosed patient.

Longitudinal analysis of total serum IgE levels with allergen sensitization and atopic diseases in early childhood

There are few studies addressing the longitudinal analysis of serum IgE levels and its impact to the development of atopic diseases in early childhood. We investigated 170 children who regularly followed up at our clinic for 4 years in a birth cohort study with at least 3 time-points of serum samples. The pattern of total serum IgE levels from 6 months to 4 years of age was clustered using K-means method in R software. Specific immunoglobulin E antibodies against food (egg white and milk) and inhalant allergens (D. pteronyssinus and D. farinae) were measured at 0.5, 1, 1.5, 2, 3 and 4 years of age. By using K-means clustering, the dynamic changes in serum IgE levels was significantly stratified into 3 clusters (cluster A, < 100 kU/L, n = 106; cluster B, 100–200 kU/L, n = 35; cluster C, ≥ 200 kU/L, n = 29). A persistent total IgE levels higher than 100 kU/L appeared to be associated with higher prevalence of sensitization to food but not mite. However, a persistent IgE levels higher than 200 kU/L was not only remarkably related to increased prevalence of mite sensitization, but also risk of eczema at age 1 and allergic rhinitis and asthma at age 2, 3 and 4. In conclusion, a persistent total serum IgE level ≥ 200 kU/L since infancy is strongly associated with the presence of food and mite sensitization, as well as the development of eczema in infants, and rhinitis and asthma later in early childhood.

Atopic dermatitis: Correlation of severity with allergic sensitization and eosinophilia

Background: It is widely acknowledged that food sensitization is related to atopic dermatitis in infants and young children. Objective: To investigate the association of aeroallergen sensitization with increased rates and severity of atopic dermatitis in school children. Methods: We enrolled 576 children (mean age, 9.4 ± 1.8 years) from six elementary schools. Atopic dermatitis was diagnosed by questionnaires, and severity was rated by physical examinations graded by using the Scoring Atopic Dermatitis (SCORAD) index. Skin-prick tests to 22 common allergens (6 aeroallergens and 16 food allergens) were conducted. Logistic and linear regression analyses were performed by using two models: model I adjusted for age, sex, and body mass index z score; and model II adjusted for all model I factors plus asthma and allergic rhinitis. Results: We diagnosed atopic dermatitis in 22.4% (n = 129) of the children, sensitization to foods in 48.3% (n = 278), and sensitization to aeroallergens in 11.3% (n = 65). A total of 26.2% of the children (n = 149) had mild and 6.5% had moderate-to-severe symptoms and signs of atopic dermatitis (n = 37). Atopic dermatitis was associated with sensitization to aeroallergens and eosinophilia (model I), but this risk was no longer significant after additional adjustment for current allergic status (model II). However, the relationship of the total SCORAD score with aeroallergen sensitization and eosinophilia was significant in model I and model II. Conclusion: The severity of atopic dermatitis correlated with the extent of allergic sensitization and eosinophilia. Analysis of our results suggests that more sensitization to dust mites and eosinophilia are related to increased rates and high severity scores of atopic dermatitis.

Development of a screening questionnaire for the study of food allergy in adults

Background & aims

As far as we know, no screening questionnaire has been developed and validated for identification of adverse food reactions in Portuguese-speaking adults, as an initial approach towards the investigation of cases of possible food allergy. Thus, the objective of this study was to develop and validate a screening questionnaire of food allergy in adult Portuguese-speaking patients.

Methods

This was a multicentre, cross-sectional study using a simple random sample of 186 adults between 18 and 82 years old from various parts of the centre of Portugal. Intelligibility of the questionnaire was first assessed in 24 patients with confirmed IgE- or non-IgE-mediated food allergy, and in 24 volunteers without food allergies. The 17-item questionnaire was subsequently applied by phone to 78 food allergic patients (66 IgE-mediated and 12 non-IgE mediated) and to 60 non-food allergic volunteers, with subsequent reassessment (re-test). Face and content validity, intelligibility, construct validity, and test-retest reliability (temporal stability) were analysed.

Results

Face and content validity allowed item reduction from 30 to 17 items with adequate content validity index >0.78. Construct validity was confirmed in the 66 confirmed IgE-mediated food allergic patients, 12 non-IgE-mediated food allergic patients, and 60 non-allergic patients. Test-Retest Reliability (general temporal stability) of the test had a Spearman correlation coefficient value of 0.845 for the retest. Cohen's Kappa values for the relevant questions were greater than 0.890 for almost all items. No differences were found when sex, age, and volunteers' recruitment origin were analysed. An inverse relationship was found between reliability and retest time interval.

Conclusions

Due to the quick and easy implementation, confirmation of face, content and construct validity as well as high temporal reproducibility, this screening questionnaire may be a useful study tool for an initial approach to detection of food allergies in adults.

Pros and cons of pre-emptive screening programmes before peanut introduction in infancy

Peanut allergy is an important public health concern and causes substantial psychosocial comorbidity. Although fatal anaphylaxis is rare (occurring at 0·03-0·3 per million person-years in the general population), peanuts are one of the most frequent causes of food allergy mortality. The Learning Early About Peanut study transformed prevention of peanut allergy by showing that early introduction of peanut into the diet of children at high risk (ie, those with an egg allergy or severe eczema) reduced the relative risk of peanut allergy at age 5 years by 81%. Following publication of this study, the US National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, convened an expert panel, which recommended that, for infants with severe eczema or egg allergy, health professionals should strongly consider evaluation with peanut-specific serological IgE or skin prick test (or both) and, if necessary, an oral food challenge before peanut introduction. In the USA, depending on test results, peanut-containing foods are recommended to be introduced from age 4-6 months in infants with severe eczema or egg allergy. Early introduction to peanuts is also advocated for children with either mild to moderate or no eczema, and in children who are not allergic to egg, but without screening before peanut introduction. However, the NIAID addendum guidelines contrast with other international approaches that do not advocate for allergy screening at a population level before introducing peanuts into infants' diets. In this Review, we evaluate the advantages and disadvantages of a pre-emptive screening approach before the early introduction of peanuts in infants at high risk of peanut allergy.

High Frequency of Concomitant Food Allergy Development and Autoantibody Formation in Children Who Have Undergone Liver Transplantation

BACKGROUND

Allergy and other immune-mediated diseases are more frequently reported in children who have undergone liver transplantation. Furthermore, autoantibodies are also prevalent, suggesting a state of immune dysregulation in these patients. Whether or not these processes occur simultaneously in the same individual has not been studied previously.

METHODS

A cohort of 43 children who had undergone liver transplantation for nonautoimmune liver disease at median age of 1.3 years was investigated for allergy and autoimmune disease. Sensitization to food and inhalant allergens was assessed, and autoantibodies were measured.

RESULTS

The prevalence of food allergy was 26% and that of respiratory allergy was 23%, whereas 33% and 26% of the subjects were sensitized to food and inhalant allergens, respectively. Autoimmune disease (ie, autoimmune hepatitis) occurred in a single individual (2%), whereas autoantibodies were present in 44% of the children. Food allergy and autoantibodies occurred concomitantly in 19% of the children, which was almost twice the frequency expected by chance (11%, P = 0.04). Respiratory allergy and the presence of autoantibodies were unrelated (12% concurrence versus the expected 10%, P = 0.73). In the logistic regression analysis, autoantibody formation was associated with discontinued immunosuppression and food allergy, with odds ratios of 13 (P = 0.01) and 7.1 (P = 0.03), respectively.

CONCLUSIONS

In contrast to respiratory allergy, food allergy and autoantibody formation occurred together in the same children who underwent liver transplantation at a frequency higher than would be expected by chance. This may reflect an underlying immune dysregulation that impairs immune tolerance to both food allergens and autoantigens.

Late introduction of solids into infants' diets may increase the risk of food allergy development

Background

This study investigated risk factors associated with food allergy or food intolerance among school children in two Swedish towns.

Methods

Questionnaires were used to collect data on self-reported food allergy or intolerance (SRFA) in children aged 7–8 years from Mölndal in southwestern Sweden and Kiruna in northern Sweden. It included questions about specific food allergy or intolerance to cows’ milk, hens’ eggs, fish, peanuts, tree nuts, and cereals and also age of onset, type of symptoms and age of cessation. Information was also gathered on family allergy history, dietary habits, and certain lifestyle aspects.

Results

Of 1838 questionnaires distributed, 1029 were returned: 717/1354 (53%) from Mölndal and 312/484 (64%) from Kiruna. The cumulative incidence of SRFA was 19.6% with a significantly higher cumulative incidence in Kiruna (28.5%) than in Mölndal (15.7%), P < .001. Solids were introduced at a later age in Kiruna. Introduction of solids into a child’s diet from the age of 7 months or later, and maternal history of allergic disease, were both risk factors associated with a higher risk of food allergy or intolerance.

Conclusion

Late introduction of solids into an infant’s diet may be one risk factor for developing food allergy or intolerance. Later introduction of solids in Kiruna may be one explanation for the higher cumulative incidence of SRFA in that region.

Design, quality, safety and efficacy of extensively hydrolyzed formula for management of cow's milk protein allergy: What are the challenges?

Cow's milk protein allergy (CMPA) is one of the most common food allergies in infancy. Clinical food allergy guidelines recommend an extensively hydrolyzed formula (EHF) as the first-line treatment in nonbreastfed infants with CMPA. Designing and commercializing EHF poses both technical and regulatory challenges. Each manufacturing step, from sourcing of raw materials to release of the final product, needs to be managed in accordance with comprehensive quality systems. To avoid cross-contamination via externally sourced ingredients, suppliers should be carefully selected based on quality requirements. Strict zoning of the manufacturing areas according to contamination risk and air flow control are effective strategies to prevent accidental allergen contamination. Furthermore, dedicated manufacturing lines for hypoallergenic products are used to prevent potential cross-contamination from other products produced on the same line. The enzymatic hydrolysis, heat treatment and ultrafiltration used are specific to each manufacturer. Consequently, EHF are a heterogenous group of products with differences in the molecular weight profile of peptides, content of residual immunogenic cow's milk allergens, and residual in-vitro allergenicity. These differences are likely to affect clinical efficacy and safety. As not all commercialized EHF products have undergone formal testing in the laboratory and clinical trials, there is a need to develop guidelines for minimum technical and regulatory requirements for EHF products, including validated assays for ongoing quality control. Clinical trials assessing new EHF products for their hypoallergenicity and ability to support normal growth remain the definitive proof of efficacy and safety in infants and young children with CMPA.

Peanut Allergy: New Advances and Ongoing Controversies

Peanut allergy is one of the most common food allergies in children, with increasing prevalence over time. The dual-allergen exposure hypothesis now supports transcutaneous sensitization to peanut as a likely pathophysiologic mechanism for peanut allergy development. As a result, there is emerging evidence that early peanut introduction has a role in peanut allergy prevention. Current first-line diagnostic tests for peanut allergy have limited specificity, which may be enhanced with emerging tools such as component-resolved diagnostics. Although management of peanut allergy includes avoidance and carrying an epinephrine autoinjector, risk of fatal anaphylaxis is extremely low, and there is minimal risk related to cutaneous or inhalational exposure. Quality of life in children with peanut allergy requires significant focus. Moving forward, oral and epicutaneous immunotherapy are emerging and exciting tools that may have a role to play in desensitization to peanut.

Epidemiological Study of Hospital Admissions for Food-Induced Anaphylaxis Using the Japanese Diagnosis Procedure Combination Database

Background

Food allergies are common among children, and food-induced anaphylaxis (FIA) is a serious disease with a risk of death; however, there is yet to be a large-scale epidemiological study on causative foods in Japan. The purpose of this study was to identify foods that cause FIA in Japan.

Methods

We identified 9,079 patients from the Japanese Diagnosis Procedure Combination Database who were admitted for treatment for FIA from April 1, 2014 through March 31, 2017. We extracted data on patient sex, age, use of epinephrine injections on the first day, prescription for epinephrine self-injection on the day of discharge, length of stay, readmission, and causative foods.

Results

The most common causative food was eggs, followed by wheat, milk, peanuts, and buckwheat. The most common causative food in each age group was eggs among 0–3-year-olds, milk among 4–6-year-olds, peanuts among 7–19-year-olds, and wheat among those aged 20 years and older. Epinephrine was used at admission among about 40%, 50%, and over 60% of cases in which the causative food was eggs; wheat, milk and peanuts; and buckwheat, respectively. The proportion of cases with a prescription for epinephrine self-injection at discharge was highest among those in which the causative food was wheat, followed by peanuts, buckwheat, milk, and eggs.

Conclusions

FIA due to peanuts has become as common in Japan as it is in the West. These results suggest the importance of taking measures to prevent peanut allergies because children cannot make adequate decisions regarding food.

Relationship Between Atopic Dermatitis and Food Allergy

Consistent evidence has been found on the relationship between food allergy (FA) and atopic dermatitis (AD) in some children. Food sensitization can be often found in these patients. Allergy should be confirmed, though, with a food challenge test (FC) before advising a restrictive diet which could be harmful for the patient. Younger children with AD frequently show sensitization to egg, milk or peanut, while older ones and adults are more often sensitized to environmental allergens such as house dust mites, moulds, animal dander or pollens. It is well known that a barrier disturbance plays a main role in the development of sensitization and allergy. Therefore, due to the early appearance of AD, preventive newborn skincare with emollients and early introduction of food appear to be very important to determine food tolerance.

Maternal anxiety and internet-based food elimination in suspected food allergy

BACKGROUND

Food allergy is associated with stress, anxiety, and impairment in quality of life in both children and families. This study aimed to assess the anxiety of mothers in the case of suspected food allergy in their children and the influence of Internet usage on their levels of anxiety and food elimination.

METHODS

Ninety-two patients aged 0-2 years presented at a pediatric allergy department following either a physicians' presumptive diagnosis or family's suspicion of food allergy (Group 1) and 99 healthy controls (Group 2) were evaluated. The clinical diagnosis of food allergy was confirmed or excluded by oral food challenge (OFC). The validated Turkish version of Spielberger State-Trait Anxiety Inventory (STAI) was applied to the mothers of both groups on admission and to Group 1 3 months after OFC.

RESULTS

The state and trait anxiety (STAI-S and STAI-T) scores were significantly higher in Group 1 than Group 2 (P < 0.001, z = 5.410, and P = 0.021, z = 2.304, respectively). Seventy-nine mothers (85.9%) had been eliminating foods on admission. Thirty-seven (40.2%) mothers had eliminated foods on their own. The performance of food allergy-related Web searches was significantly higher among mothers who eliminated foods by themselves than those who did not (P = 0.004, χ²  = 8.391, df = 1). The second STAI-S score was significantly lower among mothers whose children's food allergy diagnosis was excluded than confirmed (effect size = 1.06 (95% CI: 0.56-1.57), P = 0.001, z = 3.442).

CONCLUSION

It is important to make a correct food allergy diagnosis with a detailed allergy work-up, including OFC, to avoid anxiety and not cause unnecessary food elimination.

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.

The impact of pediatric atopic dermatitis on families: A review

BACKGROUND

Atopic dermatitis (AD) is an extremely common childhood disease, with considerable impact on the quality of life of affected children and their families. While pruritus is the hallmark symptom of this disease, AD has been well-documented to impact patients beyond physical symptoms, resulting in behavior problems, mood disorders, and sleep disturbance.

OBJECTIVE

This literature review outlines how atopic dermatitis impacts the quality of life of families of children affected by AD.

METHODS

A total of 3436 articles were identified via an online search of the MEDLINE health literature database and were screened for relevance to quality of life impacts on families with children affected by AD.

RESULTS

Caring for children affected by AD can be an extremely time-consuming task that can impair personal relationships, decrease psychosocial functioning, and cause sleep loss among family members of affected patients. Additionally, AD may result in work absence or decreased work productivity for caregivers. Special diets, irritant and allergen avoidance strategies, and alternative therapies are commonly used by patients to manage their disease and require large amounts of family involvement.

CONCLUSIONS

Atopic dermatitis can greatly decrease quality of life of families of affected children in various domains, including sleep, finances, and relationships. Early intervention and psychotherapy may be needed in some patients to address these quality of life impairments.

The Epidemiology of Food Allergy in the Global Context

There is a lack of high-quality evidence based on the gold standard of oral food challenges to determine food allergy prevalence. Nevertheless, studies using surrogate measures of food allergy, such as health service utilization and clinical history, together with allergen-specific immunoglobulin E (sIgE), provide compelling data that the prevalence of food allergy is increasing in both Western and developing countries. In Western countries, challenge-diagnosed food allergy has been reported to be as high as 10%, with the greatest prevalence noted among younger children. There is also growing evidence of increasing prevalence in developing countries, with rates of challenge-diagnosed food allergy in China and Africa reported to be similar to that in Western countries. An interesting observation is that children of East Asian or African descent born in a Western environment are at higher risk of food allergy compared to Caucasian children; this intriguing finding emphasizes the importance of genome-environment interactions and forecasts future increases in food allergy in Asia and Africa as economic growth continues in these regions. While cow’s milk and egg allergy are two of the most common food allergies in most countries, diverse patterns of food allergy can be observed in individual geographic regions determined by each country’s feeding patterns. More robust studies investigating food allergy prevalence, particularly in Asia and the developing world, are necessary to understand the extent of the food allergy problem and identify preventive strategies to cope with the potential increase in these regions.

New insights into the phenotypes of atopic dermatitis linked with allergies and asthma in children: An overview

Atopic dermatitis (AD) is a complex disease with multiple causes and complex mechanistic pathways according to age of onset, severity of the illness, ethnic modifiers, response to therapy and triggers. A group of difficult-to-manage patients characterized by early-onset AD and severe lifelong disease associated with allergic asthma and/or food allergy (FA) has been identified. In this study, we focus on these severe phenotypes, analysing their links with other atopic comorbidities, and taking into account the results from recent cohort studies and meta-analyses. The main hypothesis that is currently proposed to explain the onset of allergic diseases is an epithelial barrier defect. Thus, the atopic march could correspond to an epithelial dysfunction, self-sustained by a secondary allergenic sensitization, explaining the transition from AD to allergic asthma. Furthermore, AD severity seems to be a risk factor for associated FA. Results from population-based, birth and patient cohorts show that early-onset and severe AD, male gender, parental history of asthma, and early and multiple sensitizations are risk factors leading to the atopic march and the development of asthma. The importance of environmental factors should be recognized in these high-risk children and prevention programs adapted accordingly. Effective targeted therapies to restore both barrier function and to control inflammation are necessary; early emollient therapy is an important approach to prevent AD in high-risk children. Clinicians should also keep in mind the specific risk of atopic comorbidities in case of filaggrin loss-of-function mutations and the rare phenotypes of orphan syndromes due to heritable mutations in skin barrier components.