The association of atopic dermatitis in infancy with immunoglobulin E food sensitization

Management of Infant Atopic Eczema to Prevent Severe Eczema and Food Allergy

Early intervention and active management of infant atopic eczema may play a crucial role in limiting eczema severity and preventing the onset of immediate-type food allergy. Eczema management involves education, skincare and medications targeting skin inflammation and barrier repair. Topical corticosteroids are the mainstay of anti-inflammatory therapy, with nonsteroidal options available for some infants. Proactive therapy, addressing subclinical inflammation, is useful for preventing eczema flares, especially in infants with recurrent eczema flares despite reactive therapy. In clinical practice, holistic consideration of overall infant and family health is essential. Providing advice on maternal stress management, nutritional guidance and recommendations for proper sleep and lifestyle is crucial for the well-being of children and their families, not limited to eczema treatment alone.

Prediction of Food Sensitization in Children with Atopic Dermatitis Based on Disease Severity and Epidermal Layer Impairment

INTRODUCTION

Atopic dermatitis (AD) is characterized by an impaired epidermal barrier, which could be associated with sensitization to food allergens (FAs) and/or inhaled allergens and contribute to the severity of AD. However, no clinical guidance has been established for evaluations of food sensitization (FS) in AD patients. This study investigated how AD severity and epidermal barrier impairment are associated with FS and factors that can predict FS in children with AD.

METHODS

This cross-sectional study included 100 children (12-60 months) diagnosed with AD. AD severity was determined using the Scoring Atopic Dermatitis (SCORAD) index. FS was evaluated by measuring serum-specific IgE antibodies against 31 FAs using an immunoblotting method. Epidermal barrier impairment was assessed by measuring transepidermal water loss (TEWL) and stratum corneum hydration (SCH) levels.

RESULTS

90% of participants were sensitized to at least one tested FA, with cow's milk, egg white, beef, almond, egg yolk, and peanut being the most common. Children with moderate-severe AD had lower SCH levels than those with mild AD. Children with AD who were sensitized to >10 FAs had significantly higher TEWL and lower SCH levels, compared with those sensitized to 1-4 FAs and 5-10 FAs. The SCORAD score and SCH level in lesional skin provided moderately predictive value for sensitization to FAs in children with AD.

CONCLUSION

FS is common in children with AD and closely associate with AD severity as well as epidermal barrier impairment. Evaluations of FS should be considered for children with moderate to severe AD and/or low SCH levels.

Environmental Exposure to Foods as a Risk Factor for Food Allergy

PURPOSE OF REVIEW

Many factors have been reported to contribute to the development of food allergy. Here, we summarize the role of environmental exposure to foods as a major risk factor for developing food allergy.

RECENT FINDINGS

Peanut proteins are detectable and biologically active in household environments, where infants spend a majority of their time, providing an environmental source of allergen exposure. Recent evidence from clinical studies and mouse models suggests both the airway and skin are routes of exposure that lead to peanut sensitization. Environmental exposure to peanut has been clearly associated with the development of peanut allergy, although other factors such as genetic predisposition, microbial exposures, and timing of oral feeding of allergens also likely contribute. Future studies should more comprehensively assess the contributions of each of these factors for a variety of food allergens to provide more clear targets for prevention of food allergy.

Atopic Dermatitis Mediates the Association Between an IL4RA Variant and Food Allergy in School-Aged Children

BACKGROUND

Atopic dermatitis (AD) and food allergy (FA) may share genetic risk factors. It is unknown whether genetic factors directly cause FA or are mediated through AD, as the dual-allergen hypothesis suggests.

OBJECTIVE

To test the hypothesis that AD mediates the relationship between an IL-4 receptor alpha chain gene (IL4RA) variant, the human IL-4 receptor alpha chain protein-R576 polymorphism, and FA.

METHODS

A total of 433 children with asthma enrolled in the School Inner-City Asthma Study underwent genotyping for the IL4RA⁵⁷⁶ allele. Surveys were administered to determine FA, AD, and associated allergic responses. Mediation analysis was performed adjusting for race and ethnicity, age, sex, and household income. Multivariate models were used to determine the association between genotype and FA severity.

RESULTS

AD was reported in 193 (45%) and FA in 80 children (19%). Each risk allele increased odds of AD 1.39-fold ([1.03-1.87], P = .03), and AD increased odds of FA 3.67-fold ([2.05- 6.57], P < .01). There was an indirect effect of genotype, mediated by AD, predicting FA; each risk allele increased the odds of FA by 1.13 (odds ratio [95% CI], Q/R = 1.13 [1.02-1.24], R/R = 1.28 [1.04-1.51]; P < .01). Each risk allele increased the odds of severe FA symptoms 2.68-fold ([1.26-5.71], P = .01).

CONCLUSIONS

In a cohort of children with asthma, AD is part of the causal pathway between an IL4RA variant and FA. This variant is associated with increased risk of severe FA reactions. Addressing AD in children with an IL4RA polymorphism may modulate the risk of FA.

Estimating the Risk of Severe Peanut Allergy Using Clinical Background and IgE Sensitization Profiles

Background: It is not well-understood why symptom severity varies between patients with peanut allergy (PA). Objective: To gain insight into the clinical profile of subjects with mild-to-moderate and severe PA, and investigate individual and collective predictive accuracy of clinical background and IgE to peanut extract and components for PA severity. Methods: Data on demographics, patient history and sensitization at extract and component level of 393 patients with probable PA (symptoms ≤ 2 h + IgE sensitization) from 12 EuroPrevall centers were analyzed. Univariable and penalized multivariable regression analyses were used to evaluate risk factors and biomarkers for severity. Results: Female sex, age at onset of PA, symptoms elicited by skin contact with peanut, family atopy, atopic dermatitis, house dust mite and latex allergy were independently associated with severe PA; birch pollen allergy with mild-to-moderate PA. The cross-validated AUC of all clinical background determinants combined (0.74) was significantly larger than the AUC of tests for sensitization to extract (0.63) or peanut components (0.54-0.64). Although larger skin prick test wheal size, and higher IgE to peanut extract, Ara h 1 and Ara h 2/6, were associated with severe PA, and higher IgE to Ara h 8 with mild-to-moderate PA, addition of these measurements of sensitization to the clinical background model did not significantly improve the AUC. Conclusions: Models combining clinical characteristics and IgE sensitization patterns can help establish the risk of severe reactions for peanut allergic patients, but clinical background determinants are most valuable for predicting severity of probable PA in an individual patient.

Establishing subclasses of childhood eczema, their risk factors and prognosis

Background

The heterogeneity of development and progression of eczema suggests multiple underlying subclasses for which aetiology and prognosis may vary. A better understanding may provide a comprehensive overview of eczema development and progression in childhood. Thus, we aimed to determine longitudinal eczema subclasses based on assessments and identify their associations with risk factors and allergic outcomes.

Methods

A total of 619 participants with a family history of allergic disease were assessed at 24 time‐points from birth to 12 years. At each time, eczema was defined as the report of current rash treated with topical steroid‐based preparations. Longitudinal latent class analysis was used to determine eczema subclasses. Subsequent analyses using regression models assessed the associations between eczema subclasses and potential risk factors and allergic outcomes at 18‐ and 25‐year follow‐ups (eczema, allergic rhinitis, asthma and allergic sensitization).

Results

We identified five eczema subclasses ‘early‐onset persistent’, ‘early‐onset resolving’, ‘mid‐onset persistent’, ‘mid‐onset resolving’ and ‘minimal eczema’. Filaggrin null mutations were associated with the early‐onset persistent (OR = 2.58 [1.09–6.08]) and mid‐onset persistent class (OR = 2.58 [1.32–5.06]). Compared with ‘minimal eczema’, participants from early‐onset persistent class had higher odds of eczema (OR = 11.8 [5.20–26.6]) and allergic rhinitis (OR = 3.13 [1.43–6.85]) at 18 and at 25 years eczema (OR = 9.37 [3.17–27.65]), allergic rhinitis (OR = 3.26 [1.07–9.93]) and asthma (OR = 2.91 [1.14–7.43]). Likewise, mid‐onset persistent class had higher odds of eczema (OR = 2.59 [1.31–5.14]), allergic rhinitis (OR = 1.70 [1.00–2.89]) and asthma (OR = 2.00 [1.10–3.63]) at 18 and at 25 years eczema (OR = 6.75 [3.11–14–65]), allergic rhinitis (OR = 2.74 [1.28–5.88]) and asthma (OR = 2.50 [1.25–5.00]). Allergic and food sensitization in early life was more common in those in the persistent eczema subclasses.

Conclusion

We identified five distinct eczema subclasses. These classes were differentially associated with risk factors, suggesting differences in aetiology, and also with the development of allergic outcomes, highlighting their potential to identify high‐risk groups for close monitoring and intervention.

Heterogeneous origin of IgE in atopic dermatitis and psoriasis revealed by B cell receptor repertoire analysis

BACKGROUND

Epicutaneous sensitization is an important route for the production of IgE, and skin inflammation-induced IgE has recently been reported having features of natural antibody. Atopic dermatitis (AD) and psoriasis have differentially increased level of serum IgE; however, the production mechanism of IgE in these inflammatory skin diseases remains unknown.

OBJECTIVE

To explore the origin of IgE in AD and psoriasis by analyzing the B cell receptor repertoire.

METHODS

mRNA was prepared from peripheral blood mononuclear cells of AD and psoriasis patients that had elevated serum levels of IgE, and immunoglobulin heavy chain (IGH) repertoires were sequenced after reverse transcription. Clonal lineages of B cells containing members expressing IgE were identified, and somatic hypermutations in IGH inherited from common ancestors within the clonal lineage were used to infer the relationships between B cells.

RESULTS

The proportions of IGHE from AD and psoriasis were higher than that of normal control, which were positively correlated with the levels of serum total IgE. The somatic hypermutation value of IGHE variable region was lower than that of IGHG and IGHA, but higher than IGHM and IGHD, indicating a mixed natural and adaptive origins of IgE; and psoriasis demonstrated lower level of hypermutation than AD. The Shannon indexes of CDR3 in IGHE of AD and psoriasis were higher than that of normal control, also supporting the natural origin. The VH usage of IgE was weakly biased in AD and psoriasis patients with high level of house dust mite-specific IgE. Comparison of the number of shared mutations in multi-isotype lineages containing IgE showed that isotype-switching from IgG-expressing B cells might be the major source of IgE in AD and psoriasis.

CONCLUSION

IgE has heterogeneous origin in AD and psoriasis, and skin inflammation may contribute to the increased production of natural IgE.

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.

Overview of oral tolerance induction for prevention of food allergy-Where are we now?

Oral tolerance induction through early introduction of allergenic food has proven effective in randomized controlled trials. This new approach to weaning has been incorporated into many national and international infants' feeding guidelines. However, there are questions that require further discussion, such as, which foods should be introduced early, should the intervention be targeted to infants at high-risk or to the general population, and what is the ideal timing for early food introduction. This review examines the extent to which recent trials address these critical questions and highlights areas where further research is required.

International Peanut Allergy Prevention, 6 Years After the Learning Early About Peanut Study

Six years ago, the Learning Early About Peanut (LEAP) trial findings helped fundamentally shift the paradigm of peanut allergy prevention. Although the results of LEAP are well accepted, policy-makers, caregivers, and clinicians struggle with how best to implement and apply the study's key findings in clinical practice. Differences in guidelines highlight issues related to peanut allergy prevention implementation, including caregiver acceptability, cost, fidelity, feasibility, appropriateness, and adoption. The goals of this rostrum are to review how the LEAP study has informed international peanut allergy prevention policy, as well as to review the strengths and ongoing controversies in peanut allergy prevention implementation.

Sensitization to peanut, egg or pets is associated with skin barrier dysfunction in children with atopic dermatitis

BACKGROUND

Children with atopic dermatitis (AD) are often sensitized to food and aeroallergens, but sensitization patterns have not been analysed with biologic measures of disease pathogenicity.

OBJECTIVE

We sought to define allergen sensitization grouping(s) using unbiased machine learning and determine their associations with skin filaggrin (FLG) and transepidermal water loss (TEWL) (assesses skin barrier integrity), S100A8 and S100A9 expression (assesses skin inflammation) and AD severity.

METHODS

We studied 400 children with AD in the Mechanisms of Progression from Atopic Dermatitis to Asthma in Children (MPAACH) cohort to identify groupings of food and aeroallergen sensitizations. MPAACH is a paediatric AD cohort, aged 1-2, recruited through hospital/community settings between 2016 and 2018. We analysed these groupings' associations with AD biomarkers: skin FLG, S100A8 and S100A9 expression, total IgE, TEWL and AD severity.

RESULTS

An unbiased machine learning approach revealed five allergen clusters. The most common cluster (N = 131), SPT_PEP, had sensitization to peanut, egg and/or pets. Three low prevalence clusters, which included children with allergen sensitization other than peanut, egg or pets, were combined into SPT_Other . SPT_NEG included children with no sensitization(s). SPT_PEP children had higher median non-lesional TEWL (16.9 g/m² /h) and IgE (90 kU/L) compared with SPT_OTHER (8.8 g/m² /h and 24 kU/L; p = .01 and p < .001) and SPT_NEG (9 g/m² /h and 26 kU/L; p = .003 and p < .001). SPT_PEP children had lower median lesional (0.70) and non-lesional (1.09) FLG expression compared with SPT_OTHER (lesional: 0.9; p = .047, non-lesional: 1.78; p = .01) and SPT_NEG (lesional: 1.47; p < .001, non-lesional: 2.21; p < .001). There were no differences among groupings in S100A8 or S100A9 expression.

CONCLUSIONS AND CLINICAL RELEVANCE

In this largely clinic-based cohort of young children with AD, allergic sensitization to peanut, egg, cat or dog was associated with more severe disease and skin barrier function but not markers of cutaneous inflammation. These data need replicating in a population-based cohort but may have important implications for understanding the interaction between AD and allergic sensitization.

Thaumatin-Like Protein (Pru av 2) Is a Cherry Allergen That Triggers Percutaneous Sensitization in Mice

Numerous recent studies have suggested that food allergens enter the skin and predispose individuals to food allergies through the production of IgE antibodies in the body. Cherries are a popular fruit eaten worldwide. However, cherries are an allergenic food and percutaneous sensitization with cherry allergens through the perioral region may occur while ingesting cherries. The identity of the cherry protein that triggers percutaneous sensitization in humans or animal models remains unknown. In this study, the backs of BALB/c mice were shaved and crude cherry extracts containing sodium dodecyl sulfate were applied to the skin. Thereafter, the cherry-specific IgE and IgG1 antibodies generated and secreted in response to the epidermal application were measured using an enzyme-linked immunosorbent assay or immunoblotting. Skin exposure to cherry extracts elevated cherry-specific IgG1 levels. Application of fractionated and purified cherry proteins (antigen candidates for percutaneous sensitization) that bound to the IgG1 antibodies led to the identification of a thaumatin-like protein (Pru av 2). This molecule is known as the major cherry allergen that affects humans. In conclusion, our study identified Pru av 2 as a cherry allergen that triggers percutaneous sensitization in mice for the first time.

Test-guided dietary management of eczema in children: A randomized controlled feasibility trial (TEST)

BACKGROUND

Parents commonly ask about food allergy tests, to find a cause for their child's eczema, yet the value of routine testing is uncertain.

OBJECTIVE

To determine whether a clinical trial comparing test-guided dietary advice versus usual care, for the management of eczema, is feasible.

METHODS

Children (>3 months and <5 years) with mild-to-severe eczema, recruited via primary care, were individually randomized (1:1) to intervention or usual care. Intervention participants underwent structured allergy history and skin prick tests (SPT) with dietary advice for cow's milk, hen's egg, wheat, peanut, cashew and codfish. All participants were followed up for 24 weeks. A sample of doctors and parents was interviewed. Registration ISRCTN15397185.

RESULTS

From 1059 invitation letters sent to carers of potentially eligible children, 84 were randomized (42 per group) with mean age of 32.4 months (SD 13.9) and POEM of 8.7 (4.8). Of the 42, 6 (14%) intervention participants were advised to exclude one or more foods, most commonly egg, peanut or milk. By participant, 1/6 had an oral food challenge (negative); 3/6 were told to exclude until review in allergy clinic; and 6/6 advised a home dietary trial (exclusion and reintroduction of food over 4-6 weeks) - with 1/6 partially completing it. Participant retention (four withdrawals) and data completeness (74%-100%) were acceptable and contamination low (two usual care participants had allergy tests). There were three minor SPT-related adverse events. During follow-up, 12 intervention and 8 usual care participants had minor, unrelated adverse events plus one unrelated hospital admission.

CONCLUSIONS

It is possible to recruit, randomize and retain children with eczema from primary care into a trial of food allergy screening and to collect the outcomes of interest. Changes to recruitment and inclusion criteria are needed in a definitive trial, to ensure inclusion of younger children from more diverse backgrounds.

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.

The Microbiome and Food Allergy

The gut-associated lymphoid tissue (GALT) faces a considerable challenge. It encounters antigens derived from an estimated 1014 commensal microbes and greater than 30 kg of food proteins yearly. It must distinguish these harmless antigens from potential pathogens and mount the appropriate host immune response. Local and systemic hyporesponsiveness to dietary antigens, classically referred to as oral tolerance, comprises a distinct complement of adaptive cellular and humoral immune responses. It is increasingly evident that a functional epithelial barrier engaged in intimate interplay with innate immune cells and the resident microbiota is critical to establishing and maintaining oral tolerance. Moreover, innate immune cells serve as a bridge between the microbiota, epithelium, and the adaptive immune system, parlaying tonic microbial stimulation into signals critical for mucosal homeostasis. Dysregulation of gut homeostasis and the subsequent disruption of tolerance therefore have clinically significant consequences for the development of food allergy.

Influences on allergic mechanisms through gut, lung, and skin microbiome exposures

In industrialized societies the incidence of allergic diseases like atopic dermatitis, food allergies, and asthma has risen alarmingly over the last few decades. This increase has been attributed, in part, to lifestyle changes that alter the composition and function of the microbes that colonize the skin and mucosal surfaces. Strategies that reverse these changes to establish and maintain a healthy microbiome show promise for the prevention and treatment of allergic disease. In this Review, we will discuss evidence from preclinical and clinical studies that gives insights into how the microbiota of skin, intestinal tract, and airways influence immune responses in the context of allergic sensitization.

Risk prediction of severe reaction to oral challenge test of cow's milk

Cow's milk is one of the most common food allergens among children. Oral food challenge tests determine the threshold dose of allergens, but have not been standardized. To reduce the severe reactions, we developed a practical model of the test. We studied 111 high-risk patients who underwent a first milk oral food challenge on the risk-stratified dose between 2011 and 2017 for predicting the severe reaction risk. Severe reactions were defined as showing > 3 of Sampson's classification grade. Twenty-eight patients (25%) showed severe reactions without death. Prior to oral food challenge, severe reaction patients experienced milk avoidance (71% vs. 45%, p = 0.02) or bronchial asthma (61% vs. 28%, p = 0.003) more frequently and showed higher milk-specific IgE levels (median 28.3 vs. 7.7 U_A/mL, p < 0.0001) than non-severe reaction patients. Multivariate logistic regression analyses established a formula including severe reaction-associated factors; increased levels of milk-specific IgE (odds ratio 11.61, p = 0.001), milk avoidance (odds ratio 3.88, p = 0.02), and bronchial asthma (odds ratio 3.75, p = 0.02). This model had 86% sensitivity and 56% specificity (cut-off 0.25) for risk. Five patients with < 25% probability developed severe reactions, which started in > 3 grade dyspnea up to 20 mL of challenge.Conclusion: This model could effectively reduce the severe reaction development on the first milk oral food challenge test according to the individual needs. What is Known: •Higher levels of milk-specific IgE values, bronchial asthma, and complete milk avoidance are independent risk factors of severe reactions during the cow's milk oral food challenge. What is New: •Statistical analyses of our milk oral food challenge records for 111 patients helped us develop a model formula predicting severe reactions at the first test with high specificity and sensitivity. •This simple risk-stratified protocol is useful for minimizing the adverse events in the first milk challenge.

Infant formulas containing hydrolysed protein for prevention of allergic disease

BACKGROUND

Infant formulas containing hydrolysed proteins have been widely advocated for preventing allergic disease in infants, in place of standard cow's milk formula (CMF). However, it is unclear whether the clinical trial evidence supports this.

OBJECTIVES

To compare effects on allergic disease when infants are fed a hydrolysed formula versus CMF or human breast milk. If hydrolysed formulas are effective, to determine what type of hydrolysed formula is most effective, including extensively or partially hydrolysed formula (EHF/PHF). To determine whether infants at low or high risk of allergic disease, and whether infants receiving early short-term (first few days after birth) or prolonged formula feeding benefit from hydrolysed formulas.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 11), MEDLINE (1948 to 3 November 2017), and Embase (1974 to 3 November 2017). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles and previous reviews for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We searched for randomised and quasi-randomised trials that compared use of a hydrolysed formula versus human milk or CMF. Outcomes with ≥ 80% follow-up of participants from eligible trials were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed trial quality and extracted data from the included studies. Fixed-effect analyses were performed. The treatment effects were expressed as risk ratio (RR) and risk difference (RD) with 95% confidence intervals and quality of evidence using the GRADE quality of evidence approach. The primary outcome was all allergic disease (including asthma, atopic dermatitis, allergic rhinitis and food allergy).

MAIN RESULTS

A total of 16 studies were included.Two studies assessed the effect of three to four days infant supplementation with an EHF while in hospital after birth versus pasteurised human milk feed. A single study enrolling 90 infants reported no difference in all allergic disease (RR 1.43, 95% CI 0.38 to 5.37) or any specific allergic disease up to childhood including cow's milk allergy (CMA) (RR 7.11, 95% CI 0.35 to 143.84). A single study reported no difference in infant CMA (RR 0.87, 95% CI 0.52 to 1.46; participants = 3559). Quality of evidence was assessed as very low for all outcomes.No eligible trials compared prolonged hydrolysed formula versus human milk feeding.Two studies assessed the effect of three to four days infant supplementation with an EHF versus a CMF. A single study enrolling 90 infants reported no difference in all allergic disease (RR 1.37, 95% CI 0.33 to 5.71; participants = 77) or any specific allergic disease including CMA up to childhood. A single study reported a reduction in infant CMA of borderline significance (RR 0.62, 95% CI 0.38 to 1.00; participants = 3473). Quality of evidence was assessed as very low for all outcomes.Twelve studies assessed the effect of prolonged infant feeding with a hydrolysed formula compared with a CMF. The data showed no difference in all allergic disease in infants (typical RR 0.88, 95% CI 0.76 to 1.01; participants = 2852; studies = 8) and children (typical RR 0.85, 95% CI 0.69 to 1.05; participants = 950; studies = 2), and no difference in any specific allergic disease including infant asthma (typical RR 0.57, 95% CI 0.31 to 1.04; participants = 318; studies = 4), eczema (typical RR 0.93, 95% CI 0.79 to 1.09; participants = 2896; studies = 9), rhinitis (typical RR 0.52, 95% CI 0.14 to 1.85; participants = 256; studies = 3), food allergy (typical RR 1.42, 95% CI 0.87 to 2.33; participants = 479; studies = 2), and CMA (RR 2.31, 95% CI 0.24 to 21.97; participants = 338; studies = 1). Quality of evidence was assessed as very low for all outcomes.

AUTHORS' CONCLUSIONS

We found no evidence to support short-term or prolonged feeding with a hydrolysed formula compared with exclusive breast feeding for prevention of allergic disease. Very low-quality evidence indicates that short-term use of an EHF compared with a CMF may prevent infant CMA. Further trials are recommended before implementation of this practice.We found no evidence to support prolonged feeding with a hydrolysed formula compared with a CMF for prevention of allergic disease in infants unable to be exclusively breast fed.

Identification of the 7S and 11S globulins as percutaneously sensitizing soybean allergens as demonstrated through epidermal application of crude soybean extract

Cutaneous exposure to food allergens can predispose individuals to food allergies. Soybean, a major allergenic food, is an ingredient in various cosmetic products. However, the types of soybean proteins that are percutaneously sensitizing in humans or animal models remain unknown. In this study, BALB/c mice were dorsally shaved and epicutaneously exposed to a crude soybean extract including sodium dodecyl sulfate or distilled water alone. Specific IgEs secreted in response to 7S globulin (Gly m 5), 11S globulin (Gly m 6), Gly m 3, and Gly m 4 were measured using enzyme-linked immunosorbent assays or immunoblots. Exposure to soybean extract elicited the secretion of soybean-specific IgEs. Of the soybean proteins, 7S and 11S globulins acted as percutaneous sensitizers in 6/9 mice (67%). Additionally, IgE bound specifically and preferentially to the 7S globulin β subunit. In conclusion, this is the first report to identify percutaneously sensitizing soybean allergens in a mouse model.

The role of environmental exposure to peanut in the development of clinical allergy to peanut

The prevalence of peanut allergy has increased over the years and still remains one of the most common causes of food-related anaphylaxis. The way in which peanut sensitization occurs has been explored, such as via maternal consumption in pregnancy, via breastmilk and through a disrupted skin barrier. It has previously been shown that environmental exposure to aeroallergens in household dust can be a risk factor for the development of allergic asthma. There is an increasing body of evidence that the combination of cutaneous sensitization via a disrupted skin barrier (ie children with eczema or with filaggrin mutations) and environmental peanut exposure influences the development of peanut allergy. This review aims to explore routes of peanut sensitization and the current evidence on how environmental exposure to peanut affects the development of peanut allergy.

The skin microbiome: impact of modern environments on skin ecology, barrier integrity, and systemic immune programming

Skin barrier structure and function is essential to human health. Hitherto unrecognized functions of epidermal keratinocytes show that the skin plays an important role in adapting whole-body physiology to changing environments, including the capacity to produce a wide variety of hormones, neurotransmitters and cytokine that can potentially influence whole-body states, and quite possibly, even emotions. Skin microbiota play an integral role in the maturation and homeostatic regulation of keratinocytes and host immune networks with systemic implications. As our primary interface with the external environment, the biodiversity of skin habitats is heavily influenced by the biodiversity of the ecosystems in which we reside. Thus, factors which alter the establishment and health of the skin microbiome have the potential to predispose to not only cutaneous disease, but also other inflammatory non-communicable diseases (NCDs). Indeed, disturbances of the stratum corneum have been noted in allergic diseases (eczema and food allergy), psoriasis, rosacea, acne vulgaris and with the skin aging process. The built environment, global biodiversity losses and declining nature relatedness are contributing to erosion of diversity at a micro-ecological level, including our own microbial habitats. This emphasises the importance of ecological perspectives in overcoming the factors that drive dysbiosis and the risk of inflammatory diseases across the life course.

WITHDRAWN: Infant formulas containing hydrolysed protein for prevention of allergic disease and food allergy

BACKGROUND

Allergy is common and may be associated with foods, including cow's milk formula (CMF). Formulas containing hydrolysed proteins have been used to treat infants with allergy. However, it is unclear whether hydrolysed formulas can be advocated for prevention of allergy in infants.

OBJECTIVES

To compare effects on allergy and food allergy when infants are fed a hydrolysed formula versus CMF or human breast milk. If hydrolysed formulas are effective, to determine what type of hydrolysed formula is most effective, including extensively or partially hydrolysed formula (EHF/PHF). To determine which infants at low or high risk of allergy and which infants receiving early, short-term or prolonged formula feeding may benefit from hydrolysed formulas.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group supplemented by cross referencing of previous reviews and publications (updated August 2016).

SELECTION CRITERIA

We searched for randomised and quasi-randomised trials that compared use of a hydrolysed formula versus human milk or CMF. Trials with ≥ 80% follow-up of participants were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

We independently assessed eligibility of studies for inclusion, methodological quality and data extraction. Primary outcomes included clinical allergy, specific allergy and food allergy. We conducted meta-analysis using a fixed-effect (FE) model.

MAIN RESULTS

Two studies assessed the effect of three to four days' infant supplementation with an EHF whilst in hospital after birth versus pasteurised human milk feed. Results showed no difference in infant allergy or childhood cow's milk allergy (CMA). No eligible trials compared prolonged hydrolysed formula versus human milk feeding.Two studies assessed the effect of three to four days infant supplementation with an EHF versus a CMF. One large quasi-random study reported a reduction in infant CMA of borderline significance among low-risk infants (risk ratio (RR) 0.62, 95% confidence interval (CI) 0.38 to 1.00).Prolonged infant feeding with a hydrolysed formula compared with a CMF was associated with a reduction in infant allergy (eight studies, 2852 infants; FE RR 0.82, 95% CI 0.72 to 0.95; risk difference (RD) -0.04, 95% CI -0.08 to -0.01; number needed to treat for an additional beneficial outcome (NNTB) 25, 95% CI 12.5 to 100) and infant CMA (two studies, 405 infants; FE RR 0.38, 95% CI 0.16 to 0.86). We had substantial methodological concerns regarding studies and concerns regarding publication bias, as substantial numbers of studies including those in high-risk infants have not comprehensively reported allergy outcomes (GRADE quality of evidence 'very low').Prolonged infant feeding with a hydrolysed formula compared with a CMF was not associated with a difference in childhood allergy and led to no differences in specific allergy, including infant and childhood asthma, eczema and rhinitis and infant food allergy. Many of the analyses assessing specific allergy are underpowered.Subroup analyses showed that infant allergy was reduced in studies that enrolled infants at high risk of allergy who used a hydrolysed formula compared with a CMF; used a PHF compared with a CMF; used prolonged and exclusive feeding of a hydrolysed formula compared with a CMF; and used a partially hydrolysed whey formula compared with a CMF. Studies that enrolled infants at high risk of allergy; used a PHF compared with a CMF; used prolonged and exclusive feeding of a hydrolysed formula compared with a CMF; and used a partially hydrolysed whey formula compared with a CMF found a reduction in infant CMA.

AUTHORS' CONCLUSIONS

We found no evidence to support short-term or prolonged feeding with a hydrolysed formula compared with exclusive breast feeding for prevention of allergy. Very low-quality evidence indicates that short-term use of an EHF compared with a CMF may prevent infant CMA.In infants at high risk of allergy not exclusively breast fed, very low-quality evidence suggests that prolonged hydrolysed formula feeding compared with CMF feeding reduces infant allergy and infant CMA. Studies have found no difference in childhood allergy and no difference in specific allergy, including infant and childhood asthma, eczema and rhinitis and infant food allergy.Very low-quality evidence shows that prolonged use of a partially hydrolysed formula compared with a CMF for partial or exclusive feeding was associated with a reduction in infant allergy incidence and CMA incidence, and that prolonged use of an EHF versus a PHF reduces infant food allergy.

Infant formulas containing hydrolysed protein for prevention of allergic disease and food allergy

BACKGROUND

Allergy is common and may be associated with foods, including cow's milk formula (CMF). Formulas containing hydrolysed proteins have been used to treat infants with allergy. However, it is unclear whether hydrolysed formulas can be advocated for prevention of allergy in infants.

OBJECTIVES

To compare effects on allergy and food allergy when infants are fed a hydrolysed formula versus CMF or human breast milk. If hydrolysed formulas are effective, to determine what type of hydrolysed formula is most effective, including extensively or partially hydrolysed formula (EHF/PHF). To determine which infants at low or high risk of allergy and which infants receiving early, short-term or prolonged formula feeding may benefit from hydrolysed formulas.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group supplemented by cross referencing of previous reviews and publications (updated August 2016).

SELECTION CRITERIA

We searched for randomised and quasi-randomised trials that compared use of a hydrolysed formula versus human milk or CMF. Trials with ≥ 80% follow-up of participants were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

We independently assessed eligibility of studies for inclusion, methodological quality and data extraction. Primary outcomes included clinical allergy, specific allergy and food allergy. We conducted meta-analysis using a fixed-effect (FE) model.

MAIN RESULTS

Two studies assessed the effect of three to four days' infant supplementation with an EHF whilst in hospital after birth versus pasteurised human milk feed. Results showed no difference in infant allergy or childhood cow's milk allergy (CMA). No eligible trials compared prolonged hydrolysed formula versus human milk feeding.Two studies assessed the effect of three to four days' infant supplementation with an EHF versus a CMF. One large quasi-random study reported a reduction in infant CMA of borderline significance among low-risk infants (risk ratio (RR) 0.62, 95% confidence interval (CI) 0.38 to 1.00).Prolonged infant feeding with a hydrolysed formula compared with a CMF was associated with a reduction in infant allergy (eight studies, 2852 infants; FE RR 0.82, 95% CI 0.72 to 0.95; risk difference (RD) -0.04, 95% CI -0.08 to -0.01; number needed to treat for an additional beneficial outcome (NNTB) 25, 95% CI 12.5 to 100) and infant CMA (two studies, 405 infants; FE RR 0.38, 95% CI 0.16 to 0.86). We had substantial methodological concerns regarding studies and concerns regarding publication bias, as substantial numbers of studies including those in high-risk infants have not comprehensively reported allergy outcomes (GRADE quality of evidence 'very low').Prolonged infant feeding with a hydrolysed formula compared with a CMF was not associated with a difference in childhood allergy and led to no differences in specific allergy, including infant and childhood asthma, eczema and rhinitis and infant food allergy. Many of the analyses assessing specific allergy are underpowered.Subroup analyses showed that infant allergy was reduced in studies that enrolled infants at high risk of allergy who used a hydrolysed formula compared with a CMF; used a PHF compared with a CMF; used prolonged and exclusive feeding of a hydrolysed formula compared with a CMF; and used a partially hydrolysed whey formula compared with a CMF. Studies that enrolled infants at high risk of allergy; used a PHF compared with a CMF; used prolonged and exclusive feeding of a hydrolysed formula compared with a CMF; and used a partially hydrolysed whey formula compared with a CMF found a reduction in infant CMA.

AUTHORS' CONCLUSIONS

We found no evidence to support short-term or prolonged feeding with a hydrolysed formula compared with exclusive breast feeding for prevention of allergy. Very low-quality evidence indicates that short-term use of an EHF compared with a CMF may prevent infant CMA.In infants at high risk of allergy not exclusively breast fed, very low-quality evidence suggests that prolonged hydrolysed formula feeding compared with CMF feeding reduces infant allergy and infant CMA. Studies have found no difference in childhood allergy and no difference in specific allergy, including infant and childhood asthma, eczema and rhinitis and infant food allergy.Very low-quality evidence shows that prolonged use of a partially hydrolysed formula compared with a CMF for partial or exclusive feeding was associated with a reduction in infant allergy incidence and CMA incidence, and that prolonged use of an EHF versus a PHF reduces infant food allergy.

Is there a march from early food sensitization to later childhood allergic airway disease? Results from two prospective birth cohort studies

BACKGROUND

The march from early aeroallergen sensitization to subsequent respiratory allergy is well established, but it is unclear whether early life food sensitization precedes and further increases risk of allergic airway disease.

OBJECTIVE

To assess the association between food sensitization in the first 2 years of life and subsequent asthma and allergic rhinitis by age 10-12 years.

METHODS

We used data from two independent cohorts: the high-risk Melbourne Atopic Cohort Study (MACS) (n = 620) and the population-based LISAplus (n = 3094). Food sensitization was assessed at 6, 12, and 24 months in MACS and 24 months in LISAplus. Multiple logistic regressions were used to estimate associations between sensitization to food only, aeroallergen only, or both and allergic airway disease.

RESULTS

When compared to non-sensitized children, sensitization to food only at 12 months in MACS and 24 months in LISAplus was associated with increased risk of current asthma (aOR = 2.2; 95% CI 1.1, 4.6 in MACS and aOR = 4.9; 2.4, 10.1 in LISAplus). Similar results were seen for allergic rhinitis. Additionally, cosensitization to food and aeroallergen in both cohorts at any tested point was a stronger predictor of asthma (at 24 months, aOR = 8.3; 3.7, 18.8 in MACS and aOR = 14.4; 5.0, 41.6 in LISAplus) and allergic rhinitis (at 24 months, aOR = 3.9; 1.9, 8.1 in MACS and aOR = 7.6; 3.0, 19.6 in LISAplus).

CONCLUSIONS

In both cohorts, food sensitization (with or without aeroallergen sensitization) in the first two years of life increased the risk of subsequent asthma and allergic rhinitis. These findings support the role of early life food sensitization in the atopic march and suggest trials to prevent early onset have the potential to reduce the development of allergic airways disease.

Early smoke exposure is associated with asthma and lung function deficits in adolescents

OBJECTIVE

Early life tobacco smoke exposure may influence asthma, lung function and lung function growth into adolescence. We aimed to determine the associations between perinatal smoke exposure and asthma and lung function up to 18 years of age.

METHODS

We prospectively recorded perinatal parental smoking and measured respiratory outcomes at 12 and 18 years in the Melbourne Atopy Cohort Study (MACS), a longitudinal birth cohort. Multiple logistic regression was used to analyse the associations between perinatal smoke exposure and asthma at 12 (n = 370) and 18 years (n = 411). Multiple linear regression was used to investigate the relationship between perinatal smoking and: lung function (12 and 18 years) and lung function growth (between 12 and 18 years).

RESULTS

At 18 years, girls exposed to parental smoking during the perinatal period had increased odds of asthma (OR: 3.45, 95%CI: 1.36, 8.77), reduced pre-bronchodilator Forced expiratory volume in one-second (FEV₁) (-272 ml/s; -438, -107); FEV₁/ forced vital capacity (FVC) (-0.038; -0.065, -0.010); mid expiratory flow (MEF_25-75) (-430 ml/s; -798, -61), and reduced post-bronchodilator FEV₁/FVC (-0.028, -0.053, -0.004). No associations were found for boys (pre-bronchodilator FEV₁ 26ml/s; -202, 255; FEV₁/FVC 0.018; -0.013, 0.049).

CONCLUSIONS

Perinatal smoke may affect risk of asthma, reduce lung function and lung function growth in adolescence. Girls appear to be more susceptible than boys.

The march from early life food sensitization to allergic disease: a systematic review and meta-analyses of birth cohort studies

BACKGROUND

There is growing evidence for an increase in food allergies. The question of whether early life food sensitization, a primary step in food allergies, leads to other allergic disease is a controversial but important issue. Birth cohorts are an ideal design to answer this question.

OBJECTIVES

We aimed to systematically investigate and meta-analyse the evidence for associations between early food sensitization and allergic disease in birth cohorts.

METHODS

MEDLINE and SCOPUS databases were searched for birth cohorts that have investigated the association between food sensitization in the first 2 years and subsequent wheeze/asthma, eczema and/or allergic rhinitis. We performed meta-analyses using random-effects models to obtain pooled estimates, stratified by age group.

RESULTS

The search yielded fifteen original articles representing thirteen cohorts. Early life food sensitization was associated with an increased risk of infantile eczema, childhood wheeze/asthma, eczema and allergic rhinitis and young adult asthma. Meta-analyses demonstrated that early life food sensitization is related to an increased risk of wheeze/asthma (pooled OR 2.9; 95% CI 2.0-4.0), eczema (pooled OR 2.7; 95% CI 1.7-4.4) and allergic rhinitis (pooled OR 3.1; 95% CI 1.9-4.9) from 4 to 8 years.

CONCLUSION

Food sensitization in the first 2 years of life can identify children at high risk of subsequent allergic disease who may benefit from early life preventive strategies. However, due to potential residual confounding in the majority of studies combined with lack of follow-up into adolescence and adulthood, further research is needed.

Recent Advances in Management of Pediatric Food Allergy

Many children now suffer with a food allergy, immunoglobulin E (IgE) and/or non-IgE mediated. Food allergies have a significant impact on the child’s quality of life, as well as that of their family, due to the resultant dietary restrictions and the constant threat of a potentially life-threatening reaction. At present, there is no cure for food allergies, but there are exciting advances occurring in the management of IgE mediated allergies, including a more active approach to management with anticipatory screening testing, early introduction of common food allergens, active tolerance induction, use of biologics and active risk management. These areas will be discussed in this review.

Broide DH, Aceves SS. The TGFβ1 Promoter SNP C-509T and Food Sensitization Promote Esophageal Remodeling in Pediatric Eosinophilic Esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic antigen mediated disease associated with substantial esophageal remodeling and fibrosis. The functional TGFβ1 promoter SNP C-509 associates with renal fibrosis and asthma. The effect of TGFβ1 genotype and EoE severity or potential gene-environment interactions have not been previously reported in EoE.

METHODS

Genotype at TGFβ1 C-509T and remodeling was analyzed in 144 subjects with EoE. The severity of remodeling and inflammation was analyzed in the context of IgE sensitization to food antigens and C-509T genotype.

RESULTS

The TGFβ1 promoter C-509 genotypes CC, CT, and TT were 35%, 52%, and 13%, respectively. Sixty-six percent of subjects were sensitized to foods by positive skin prick test (SPT) or serum specific IgE. TT genotype subjects had significantly more TGFβ1 (CC subjects = 1300 per mm2; TT = 2250 per mm2) (p<0.05) and tryptase (CC subjects = 145 per mm2: TT = 307 per mm2) (p<0.05) positive cells and higher epithelial remodeling scores (2.4 vs 3.7, p<0.001) than CC subjects. The differences in TGFβ1 and tryptase positive cells as well as fibrosis were significantly increased when there was concurrent food sensitization. Food sensitization alone did not associate with any parameters of inflammation or remodeling.

CONCLUSIONS

Our data support a gene-environment interaction between food and genotype at C-509 that modulates disease severity in EoE. Since EoE subjects often continue to consume foods to which they are sensitized, these findings may have clinical relevance for disease management.

The rapidly changing world of food allergy in children

Food allergy is a common problem in childhood. The term is used to include both immunoglobulin E (IgE)-mediated and non-IgE-mediated food allergies, which have a significant effect on the quality of life of patients and their families. In this report, we aim to discuss recent advances in the diagnosis, management, and treatment modalities of food allergy in children.

Peanut allergy: effect of environmental peanut exposure in children with filaggrin loss-of-function mutations

BACKGROUND

Filaggrin (FLG) loss-of-function mutations lead to an impaired skin barrier associated with peanut allergy. Household peanut consumption is associated with peanut allergy, and peanut allergen in household dust correlates with household peanut consumption.

OBJECTIVE

We sought to determine whether environmental peanut exposure increases the odds of peanut allergy and whether FLG mutations modulate these odds.

METHODS

Exposure to peanut antigen in dust within the first year of life was measured in a population-based birth cohort. Peanut sensitization and peanut allergy (defined by using oral food challenges or component-resolved diagnostics [CRD]) were assessed at 8 and 11 years. Genotyping was performed for 6 FLG mutations.

RESULTS

After adjustment for infantile atopic dermatitis and preceding egg skin prick test (SPT) sensitization, we found a strong and significant interaction between natural log (ln [loge]) peanut dust levels and FLG mutations on peanut sensitization and peanut allergy. Among children with FLG mutations, for each ln unit increase in the house dust peanut protein level, there was a more than 6-fold increased odds of peanut SPT sensitization, CRD sensitization, or both in children at ages 8 years, 11 years, or both and a greater than 3-fold increased odds of peanut allergy compared with odds seen in children with wild-type FLG. There was no significant effect of exposure in children without FLG mutations. In children carrying an FLG mutation, the threshold level for peanut SPT sensitization was 0.92 μg of peanut protein per gram (95% CI, 0.70-1.22 μg/g), that for CRD sensitization was 1.03 μg/g (95% CI, 0.90-1.82 μg/g), and that for peanut allergy was 1.17 μg/g (95% CI, 0.01-163.83 μg/g).

CONCLUSION

Early-life environmental peanut exposure is associated with an increased risk of peanut sensitization and allergy in children who carry an FLG mutation. These data support the hypothesis that peanut allergy develops through transcutaneous sensitization in children with an impaired skin barrier.

Clinical spectrum of food allergies: a comprehensive review

Food allergy is defined as an adverse immune response towards food proteins or as a form of a food intolerance associated with a hypersensitive immune response. It should also be reproducible by a double-blind placebo-controlled food challenge. Many reported that food reactions are not allergic but are intolerances. Food allergy often presents to clinicians as a symptom complex. This review focuses on the clinical spectrum and manifestations of various forms of food allergies. According to clinical presentations and allergy testing, there are three types of food allergy: IgE mediated, mixed (IgE/Non-IgE), and non-IgE mediated (cellular, delayed type hypersensitivity). Recent advances in food allergy in early childhood have highlighted increasing recognition of a spectrum of delayed-onset non-IgE-mediated manifestation of food allergy. Common presentations of food allergy in infancy including atopic eczema, infantile colic, and gastroesophageal reflux. These clinical observations are frequently associated with food hypersensitivity and respond to dietary elimination. Non-IgE-mediated food allergy includes a wide range of diseases, from atopic dermatitis to food protein-induced enterocolitis and from eosinophilic esophagitis to celiac disease. The most common food allergies in children include milk, egg, soy, wheat, peanut, treenut, fish, and shellfish. Milk and egg allergies are usually outgrown, but peanut and treenut allergy tends to persist. The prevalence of food allergy in infancy is increasing and may affect up to 15-20 % of infants. The alarming rate of increase calls for a public health approach in the prevention and treatment of food allergy in children.

Atopic dermatitis increases the effect of exposure to peanut antigen in dust on peanut sensitization and likely peanut allergy

BACKGROUND

History and severity of atopic dermatitis (AD) are risk factors for peanut allergy. Recent evidence suggests that children can become sensitized to food allergens through an impaired skin barrier. Household peanut consumption, which correlates strongly with peanut protein levels in household dust, is a risk factor for peanut allergy.

OBJECTIVE

We sought to assess whether environmental peanut exposure (EPE) is a risk for peanut sensitization and allergy and whether markers of an impaired skin barrier modify this risk.

METHODS

Peanut protein in household dust (in micrograms per gram) was assessed in highly atopic children (age, 3-15 months) recruited to the Consortium of Food Allergy Research Observational Study. History and severity of AD, peanut sensitization, and likely allergy (peanut-specific IgE, ≥5 kUA/mL) were assessed at recruitment into the Consortium of Food Allergy Research study.

RESULTS

There was an exposure-response relationship between peanut protein levels in household dust and peanut skin prick test (SPT) sensitization and likely allergy. In the final multivariate model an increase in 4 log2 EPE units increased the odds of peanut SPT sensitization (1.71-fold; 95% CI, 1.13- to 2.59-fold; P = .01) and likely peanut allergy (PA; 2.10-fold; 95% CI, 1.20- to 3.67-fold; P < .01). The effect of EPE on peanut SPT sensitization was augmented in children with a history of AD (OR, 1.97; 95% CI, 1.26-3.09; P < .01) and augmented even further in children with a history of severe AD (OR, 2.41; 95% CI, 1.30-4.47; P < .01); the effect of EPE on PA was also augmented in children with a history of AD (OR, 2.34; 95% CI, 1.31-4.18; P < .01).

CONCLUSION

Exposure to peanut antigen in dust through an impaired skin barrier in atopically inflamed skin is a plausible route for peanut SPT sensitization and PA.

Childhood wheeze phenotypes show less than expected growth in FEV1 across adolescence

RATIONALE

Better characterization of childhood wheeze phenotypes using newer statistical methods provides a basis for addressing the heterogeneity of childhood asthma. Outcomes of these phenotypes beyond childhood are unknown.

OBJECTIVES

To determine if adolescent respiratory symptoms, lung function, and changes in lung function over adolescence differ by childhood wheeze phenotypes defined through latent class analysis.

METHODS

A prospective birth cohort (Melbourne Atopy Cohort Study) followed 620 high allergy-risk children, recording respiratory symptoms and spirometry at 12 and 18 years. Regression analyses identified relationships between wheeze phenotypes (never/infrequent, early transient, early persistent, intermediate onset, and late onset) and lung function, change in lung function (12-18 yr), respiratory symptoms, and asthma. The baseline classification was never/infrequent wheeze.

MEASUREMENTS AND MAIN RESULTS

Deficits in expected growth of lung function, measured by change in prebronchodilator FEV1 between 12 and 18 years, were found for early persistent (reduced 290 ml; 95% confidence interval [CI], 82-498), intermediate-onset (reduced 210 ml; 95% CI, 62-359), and late-onset wheeze (reduced 255 ml; 95% CI, 69-442). Intermediate-onset wheezers had persistent FEV1 deficit after bronchodilator at 18 years (reduced 198 ml; 46,350). Current asthma risk was increased for all phenotypes except early transient, which was also not associated with lung function deficits at 12 or 18 years.

CONCLUSIONS

Persistent wheeze phenotypes in childhood were associated with reduced growth in prebronchodilator FEV1 over adolescence. Intermediate-onset wheezers showed irreversible airflow limitation by 18 years. Conversely, early transient wheeze was a benign condition with no sequelae for respiratory health by age 18.

Correlation of ovalbumin of egg white components with allergic diseases in children

BACKGROUND

Immunoglobulin E (IgE)-mediated food allergy, such as egg white allergy, is common in young children (<3 years old), but not all young children sensitive to egg white present with allergic symptoms. This study investigated the relationship between sensitization to egg white component allergens and clinical manifestations of allergic diseases in young children.

METHODS

From March to December 2010, 2256 children with physician-diagnosed allergic diseases were tested for serum levels of egg white, ovalbumin, and ovomucoid-specific IgE in the Pediatric Allergy and Asthma Center of Chang Gung Memorial Hospital. Serum was analyzed for specific IgE antibodies to egg white, ovalbumin, and ovomucoid by ImmunoCAP (Phadia, Uppsala, Sweden). Allergen-specific IgE levels ≥0.35 kUA/L were defined as positive.

RESULTS

There was a significantly higher sensitization rate to egg white and its components in children aged 2-4 years old. The sensitization rate to egg white, ovalbumin, and ovomucoid in this age group was 53.5%, 48.3%, and 37.2%, respectively, and the trend of the sensitization decreased with age (p < 0.001). After adjusting for age, sensitization to egg white and ovalbumin was associated with children with dermatitis [egg white: odds ratio (OR) = 1.28, 95% confidence intervals (CI) = 1.03-1.58, p < 0.05; ovalbumin: OR = 1.30, 95% CI = 1.04-1.62, p < 0.05]. Children with ovomucoid sensitization had no statistically significant risk among different groups in the current study.

CONCLUSION

Children aged 2-4 years old have higher sensitivity to egg white, ovalbumin, and ovomucoid. Children with egg white and ovalbumin sensitization have a higher risk for atopic dermatitis, and ovalbumin has a more important contribution. Furthermore, we suggested that in children with atopic dermatitis, if they are aged 2-4 years old and are having egg white and ovalbumin sensitization, avoiding eating raw or slightly heated eggs might have a beneficial effect.

Early-life risk factors for childhood wheeze phenotypes in a high-risk birth cohort

OBJECTIVE

To define longitudinal childhood wheeze phenotypes and identify their early-life risk factors.

STUDY DESIGN

Current wheeze was recorded 23 times up to age 7 years in a birth cohort at high risk for allergy (n = 620). Latent class analysis of wheeze responses identified 5 classes. Multinomial logistic regression estimated associations of probability-weighted wheezing classes with early-life factors. All phenotypes were compared with never/infrequent wheezers.

RESULTS

Lower respiratory tract infection (LRTI) by 1 year (relative risk [RR], 3.00; 95% CI, 1.58-5.70), childcare by 1 year (RR, 1.51; 95% CI, 1.02-2.22), and higher body mass index (RR, 2.51; 95% CI, 1.09-5.81) were associated with increased risk of early transient wheeze, whereas breastfeeding was protective (RR, 0.54; 95% CI, 0.32-0.90). LRTI (RR, 6.54; 95% CI, 2.55-16.76) and aeroallergen sensitization (RR, 4.95; 95% CI, 1.74-14.02) increased the risk of early persistent wheeze. LRTI (RR, 5.31; 95% CI, 2.71-10.41), eczema (RR, 2.77; 95% CI, 1.78-4.31), aeroallergen sensitization (RR, 5.60; 95% CI, 2.86-10.9), and food sensitization (RR, 2.77; 95% CI, 1.56-4.94) increased the risk of intermediate-onset wheeze, whereas dog exposure at baseline (RR, 0.52; 95% CI, 0.32-0.84) and first-born status (RR, 0.49; 95% CI, 0.32-0.76) were protective. Heavy parental smoking at birth (RR, 3.18; 95% CI, 1.02-9.88) increased the risk of late-onset wheeze, whereas breastfeeding reduced it (RR, 0.34; 95% CI, 0.12-0.96). All wheeze classes except early transient had greater risk of wheeze at age 12 years compared with never/infrequent wheezers.

CONCLUSION

We found distinct early-life risk factor profiles for each wheeze phenotype. These findings provide insight into possible wheeze mechanisms and have implications for identifying preventive strategies and addressing clinical management of early-life wheeze.

Atopy as a risk factor for thyroid autoimmunity in children affected with atopic dermatitis

BACKGROUND

As a result of several clinical reports addressing coincidence or coprevalence of atopy and autoimmune disease such as multiple sclerosis and type I diabetes mellitus, there has been considerable interest in defining the relationship between the expression of allergic and autoimmune disease in populations of patients. Although thyroid autoimmunity has been regularly associated with chronic urticaria in children, the cofrequency of thyroid autoimmunity and atopic dermatitis has not yet been investigated. The aim of the study was to describe our experience with children affected by atopic dermatitis and associated thyroid autoimmunity.

METHODS

From January 2010 to December 2012, 147 children affected by atopic dermatitis were consecutively referred to the Pediatric Clinic of the Pediatric Department at the Second University of Naples. Seventy healthy children of comparable ages, unaffected by atopic dermatitis, atopy or thyroid disease, served as a control group.

RESULTS

On the basis of skin prick test results we selected 54 IgE-mediated (36.7%) and 93 non-IgE-mediated AD (63.3%) children. Fourteen of 147 patients (9.52%) showed increased levels of antithyroid antibodies.

CONCLUSIONS

Our results therefore suggest that atopy, especially food allergy, and autoimmunity are two potential outcomes of dysregulated immunity.

Oral food challenge to wheat: a near-fatal anaphylaxis and review of 93 food challenges in children

Background

Wheat allergy is among the most common food allergy in children, but few publications are available assessing the risk of anaphylaxis due to wheat.

Methods

In this study, we report the case of near-fatal anaphylaxis to wheat in a patient undergoing an oral food challenge (OFC) after the ingestion of a low dose (256 mg) of wheat. Moreover, for the first time, we analyzed the risk of anaphylaxis during an OFC to wheat in 93 children, compared to other more commonly challenged foods such as milk, egg, peanuts, and soy in more than 1000 patients.

Results

This study, which includes a large number of OFCs to wheat, shows that wheat is an independent risk factor that is associated with anaphylaxis requiring epinephrine administration (Odds Ratio [OR] = 2.4) and anaphylaxis requiring epinephrine administration to low dose antigen (OR = 8.02). Other risk factors for anaphylaxis, anaphylaxis requiring epinephrine administration, and anaphylaxis to low dose antigen was a history of a prior reaction not involving only the skin (OR = 1.8, 1.9 and 1.8 respectively). None of the clinical variables available prior to performing the OFC could predict which children among those undergoing OFCs to wheat would develop anaphylaxis or anaphylaxis for low dose antigen.

Conclusion

This study shows that wheat is an independent risk factor that is associated with anaphylaxis requiring epinephrine administration and anaphylaxis requiring epinephrine administration to low dose antigen.

The HealthNuts population-based study of paediatric food allergy: validity, safety and acceptability

BACKGROUND

The incidence of hospital admissions for food allergy-related anaphylaxis in Australia has increased, in line with world-wide trends. However, a valid measure of food allergy prevalence and risk factor data from a population-based study is still lacking.

OBJECTIVE

To describe the study design and methods used to recruit infants from a population for skin prick testing and oral food challenges, and the use of preliminary data to investigate the extent to which the study sample is representative of the target population.

METHODS

The study sampling frame design comprises 12-month-old infants presenting for routine scheduled vaccination at immunization clinics in Melbourne, Australia. We compared demographic features of participating families to population summary statistics from the Victorian Perinatal census database, and administered a survey to those non-responders who chose not to participate in the study.

RESULTS

Study design proved acceptable to the community with good uptake (response rate 73.4%), with 2171 participants recruited. Demographic information on the study population mirrored the Victorian population with most the population parameters measured falling within our confidence intervals (CI). Use of a non-responder questionnaire revealed that a higher proportion of infants who declined to participate (non-responders) were already eating and tolerating peanuts, than those agreeing to participate (54.4%; 95% CI 50.8, 58.0 vs. 27.4%; 95% CI 25.5, 29.3 among participants).

CONCLUSION

A high proportion of individuals approached in a community setting participated in a food allergy study. The study population differed from the eligible sample in relation to family history of allergy and prior consumption and peanut tolerance, providing some insights into the internal validity of the sample. The study exhibited external validity on general demographics to all births in Victoria.

Anti-IgE in the treatment of allergic disorders in pediatrics

PURPOSE OF REVIEW

Neutralization of IgE antibodies is a conceptually new approach for the treatment of allergic diseases. This article reviews current concepts of anti-IgE therapy, with a focus on recent studies that provide insights into underlying mechanisms. Findings of the most recent clinical trials of anti-IgE in the treatment of allergic disorders are discussed.

RECENT FINDINGS

Anti-IgE therapy in allergic asthma has been evaluated mostly in adults, but some studies have documented potential clinical efficacy in children and adolescent patients with moderate to severe uncontrolled asthma despite maximal conventional therapy. Pilot investigations have revealed some promising results regarding the use of anti-IgE in the treatment of other atopic diseases and as an adjunctive therapy in conjunction with allergen-specific immunotherapy. Recent work has provided novel insights into the kinetics of cellular responses to anti-IgE treatment and has identified significant anti-IgE effects on both basophils and dendritic cells, suggesting significant roles for these cells as effectors of IgE-mediated disease.

SUMMARY

Studies of anti-IgE therapy have significantly advanced our understanding of IgE-mediated disease mechanisms and have demonstrated clinical efficacy in the treatment of allergic asthma in adults and children. Further studies are needed in children to evaluate long-term safety and to better define its potential use in allergic diseases other than asthma.

Sensitization and allergy to turnip rape: a comparison between the Finnish and French children with atopic dermatitis

AIM

Finnish children with atopic dermatitis (AD) are frequently sensitized and show positive food challenge to turnip rape. We examined whether French children are also allergic to this oilseed plant and whether mustard could be the cross-reacting allergen.

METHODS

Turnip rape and mustard challenge was performed to 14 Finnish and 14 French children with atopic dermatitis and positive skin prick test to turnip rape. Specific IgE antibodies were measured by ImmunoCAP and enzyme-linked immunosorbent assay (ELISA).

RESULTS

Open labial or oral challenge to turnip rape was positive in 14 (100%) Finnish and five (36%) French children and mustard challenge in five Finnish and five French children. IgE antibodies to oilseed rape and mustard were slightly more frequent in the Finnish (100% and 93%) than in the French (93% and 71%) children but rare (4%) in the 28 matched controls. The same findings were true for IgE antibodies to purified 2S albumin allergens, which showed similar cross-wise IgE inhibition patterns.

CONCLUSION

French children with atopic dermatitis show IgE antibodies to turnip rape, oilseed rape and mustard similarly to the Finnish children. 2S albumin allergens in the seeds of these plants are highly cross-reactive and therefore, they all could be important sensitizers in children with atopic dermatitis.

Association of staphylococcal superantigen-specific immunoglobulin e with mild and moderate atopic dermatitis

OBJECTIVE

To examine the frequency of allergic sensitization to staphylococcal superantigens in young children with mild to moderate atopic dermatitis (AD).

STUDY DESIGN

AD severity was assessed with objective Scoring AD. Serum IgE to staphylococcal enterotoxin (SE) A, SEB, SEC, SED, and toxic shock syndrome toxin-1 were measured with ImmunoCAP. Comparisons between mild AD and moderate AD were performed by using logistic regressions.

RESULTS

The prevalence of allergic sensitization to staphylococcal superantigens in patients with mild and moderate AD was 38% and 63%, respectively. Allergic sensitization to staphylococcal superantigens, particularly SEA and SED, was found to be associated with moderate AD, compared with mild AD.

CONCLUSIONS

Our results suggest that allergic sensitization to staphylococcal superantigens is common even in young children with mild to moderate AD, and such sensitization may contribute to the disease severity of these patients.