Food allergy can have significant effects on morbidity and quality of life and can be costly in terms of medical visits and treatments. There is therefore considerable interest in generating ...efficient approaches that may reduce the risk of developing food allergy. This guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Taskforce on Prevention and is part of the EAACI Guidelines for Food Allergy and Anaphylaxis. It aims to provide evidence‐based recommendations for primary prevention of food allergy. A wide range of antenatal, perinatal, neonatal, and childhood strategies were identified and their effectiveness assessed and synthesized in a systematic review.
Based on this evidence, families can be provided with evidence‐based advice about preventing food allergy, particularly for infants at high risk for development of allergic disease. The advice for all mothers includes a normal diet without restrictions during pregnancy and lactation. For all infants, exclusive breastfeeding is recommended for at least first 4–6 months of life. If breastfeeding is insufficient or not possible, infants at high‐risk can be recommended a hypoallergenic formula with a documented preventive effect for the first 4 months. There is no need to avoid introducing complementary foods beyond 4 months, and currently, the evidence does not justify recommendations about either withholding or encouraging exposure to potentially allergenic foods after 4 months once weaning has commenced, irrespective of atopic heredity. There is no evidence to support the use of prebiotics or probiotics for food allergy prevention.
Carbon‐nanotube‐reinforced Cu matrix nanocomposites have been fabricated by molecular‐level mixing of functionalized carbon nanotubes (CNTs) with Cu ions, followed by spark plasma sintering. The ...compressive strengths and Young's moduli of CNT‐reinforced nanocomposites are considerably higher than those of the Cu matrix due to the homogeneously dispersed CNTs embedded in the Cu matrix (see Figure).
Summary
Background
The prevalence and time trends of food allergy change during childhood depending on the age of the child and the type of food.
Objective
To study prevalence and longitudinal trends ...in food allergy from birth to 18 years in an unselected birth cohort in the Isle of Wight.
Method
Information on food allergy was collected at ages 1, 2, 4, 10 and 18 years from the Isle of Wight Birth Cohort (n = 1456). Skin prick testing (SPT) was performed at the age of 1 and 2 years in symptomatic children. At 4, 10 and 18 years of age, participants were tested to a panel of food and aeroallergens. Food allergy was diagnosed based on the criteria: symptoms suggestive of a typical IgE‐mediated reaction and reaction <4 hours following exposure to a known food allergen. McNemar's test was used to determine significance of changes in prevalence over time.
Results
The prevalence of food allergy remained relatively constant in early childhood (5.3%, 4.4% and 5.0% at 1, 2 and 4 years, respectively), with significant decline at 10 years (2.3%, P < .001 vs 4 years) followed by significant rise at 18 years (4%, P = .02 vs 10 years). Cow's milk (1.6%‐3.5%) and egg (1.1%‐1.4%) were the most common allergens in the first 10 years with peanut (1%) and tree nuts (0.5%) becoming more prevalent beyond 10 years. Fruit and wheat allergy were less common at 10 years, and shellfish and kiwi emerged during adolescence. The prevalence of food allergy plus positive SPT was 1.3%, 0.8%, 0.8%, 0.9% and 2.2% at 1, 2, 4, 10 and 18 years, respectively.
Conclusion
Food allergy is highly prevalent in infancy with partial resolution during late childhood. However, a number of children acquire new food allergy during adolescence resulting in a relatively higher prevalence at 18 years.
Background: Tumour necrosis factor α (TNFα) is a major therapeutic target in a range of chronic inflammatory disorders characterised by a Th1 type immune response in which TNFα is generated in ...excess. By contrast, asthma is regarded as a Th2 type disorder, especially when associated with atopy. However, as asthma becomes more severe and chronic, it adopts additional characteristics including corticosteroid refractoriness and involvement of neutrophils suggestive of an altered inflammatory profile towards a Th1 type response, incriminating cytokines such as TNFα. Methods: TNFα levels in bronchoalveolar lavage (BAL) fluid of 26 healthy controls, 42 subjects with mild asthma and 20 with severe asthma were measured by immunoassay, and TNFα gene expression was determined in endobronchial biopsy specimens from 14 patients with mild asthma and 14 with severe asthma. The cellular localisation of TNFα was assessed by immunohistochemistry. An open label uncontrolled clinical study was then undertaken in 17 subjects with severe asthma to evaluate the effect of 12 weeks of treatment with the soluble TNFα receptor-IgG1Fc fusion protein, etanercept. Results: TNFα levels in BAL fluid, TNFα gene expression and TNFα immunoreative cells were increased in subjects with severe corticosteroid dependent asthma. Etanercept treatment was associated with improvement in asthma symptoms, lung function, and bronchial hyperresponsiveness. Conclusions: These findings may be of clinical significance in identifying TNFα as a new therapeutic target in subjects with severe asthma. The effects of anti-TNF treatment now require confirmation in placebo controlled studies.
Background
Food allergies can have serious physical, social, and financial consequences. This systematic review examined ways to prevent the development of food allergy in children and adults.
...Methods
Seven bibliographic databases were searched from their inception to September 30, 2012, for systematic reviews, randomized controlled trials, quasi‐randomized controlled trials, controlled clinical trials, controlled before‐and‐after studies, interrupted time series studies, and prospective cohort studies. Experts were consulted for additional studies. There were no language or geographic restrictions. Two reviewers appraised the studies using appropriate tools. Data were not suitable for meta‐analysis due to heterogeneity, so were narratively synthesized.
Results
Seventy‐four studies were included, one‐third of which were of high quality. There was no good evidence to recommend that pregnant or breastfeeding women should change their diet or take supplements to prevent allergies in infants at high or normal risk. There were mixed findings about the preventive benefits of breastfeeding for infants at high or normal risk, but there was evidence to recommend avoiding cow's milk and substituting with extensively or partially hydrolyzed whey or casein formulas for infants at high risk for the first 4 months. Soy milk and delaying the introduction of solid foods beyond 4 months did not have preventive benefits in those at high or normal risk. There was very little evidence about strategies for preventing food allergy in older children or adults.
Conclusions
There is much to learn about preventing food allergy, and this is a priority given the high societal and healthcare costs involved.
Cite this as: R. J. Kurukulaaratchy, W. Karmaus, A. Raza, S. Matthews, G. Roberts and S. H. Arshad, Clinical & Experimental Allergy, 2011 (41) 851–859.
Summary
Background
Longitudinal studies of the ...natural history of childhood and adolescent rhinitis are lacking.
Objectives
To investigate the natural history of rhinitis up to 18 years of age, and how that is influenced by gender and atopy.
Methods
The Isle of Wight birth cohort was recruited in 1989 (n=1456). Questionnaire data on nasal symptoms (rhinitis) were collected at 1, 2, 4, 10 and 18 years of age. To define atopy, skin prick tests were conducted at 4, 10 and 18 years. The 12‐month period prevalence plus positive and negative transitions (defined as change in disease status in two consecutive study assessments) were stratified by gender and atopic status.
Results
Overall rhinitis prevalence increased from 5.4% at 4 years to 35.8% at 18 years (P<0.001), without gender difference. Atopic rhinitis prevalence increased steadily from 3.4% at 4 years to 27.3% at 18 years (P<0.001), was commoner in boys at 18 years (P=0.02) and associated with greater positive transition in boys from 10 to 18 years (P=0.01). Prevalence of non‐atopic rhinitis also increased from 4 to 18 years (P=0.003) and was greater in girls at 18 years (P<0.001) reflecting higher female positive transition from 10 to 18 years (P<0.001). Non‐atopic rhinitis negative transition (remission) was highest in early life and reduced in later childhood/adolescence.
Conclusion
Atopic rhinitis becomes increasingly common as children grow into adolescents, with stronger associations to male gender. Non‐atopic rhinitis shows a female predominance at 18 years as girls ‘grow into’ it more during adolescence. Our findings suggest differential gender effects on the increasing prevalence of both atopic and non‐atopic rhinitis in adolescence.
Clinical Relevance
A better understanding of how gender and atopic status influence rhinitis during adolescence emerges from this study. Application of such knowledge could help to improve clinical recognition, judge prognosis and ultimately improve management of this common condition.
Background
Season of birth influences allergy risk; however, the biological mechanisms underlying this observation are unclear. The environment affects DNA methylation, with potentially long‐lasting ...effects on gene expression and disease. This study examined whether DNA methylation could underlie the association between season of birth and allergy.
Methods
In a subset of 18‐year‐old participants from the Isle of Wight (IoW) birth cohort (n = 367), the risks of birth season on allergic outcomes were estimated. Whole blood epigenome‐wide DNA methylation was measured, and season‐associated CpGs detected using a training‐and‐testing‐based technique. Validation method examined the 8‐year‐old Prevention and Incidence of Asthma and Mite Allergy (PIAMA) cohort. The relationships between DNA methylation, season of birth and allergy were examined. CpGs were analysed in IoW third‐generation cohort newborns.
Results
Autumn birth increased risk of eczema, relative to spring birth. Methylation at 92 CpGs showed association with season of birth in the epigenome‐wide association study. In validation, significantly more CpGs had the same directionality than expected by chance, and four were statistically significant. Season‐associated methylation was enriched among networks relating to development, the cell cycle and apoptosis. Twenty CpGs were nominally associated with allergic outcomes. Two CpGs were marginally on the causal pathway to allergy. Season‐associated methylation was largely absent in newborns, suggesting it arises post‐natally.
Conclusions
This study demonstrates that DNA methylation in adulthood is associated with season of birth, supporting the hypothesis that DNA methylation could mechanistically underlie the effect of season of birth on allergy, although other mechanisms are also likely to be involved.
Summary
Background
Trends in the prevalence of eczema in the course of childhood and adolescence are not clear although often a net remission during childhood is assumed.
Objectives
To investigate ...the dynamics of change in eczema from 1 to 18 years in a prospective study and to understand the influence of gender and atopy.
Methods
Detailed information regarding eczema were collected at ages 1, 2, 4, 10 and 18 years from the 1989 Isle of Wight birth cohort (n=1456). Skin prick testing was performed at 4, 10 and 18 years of age. The 12‐month period prevalence, positive and negative transitions (defined as change in disease status in two consecutive study assessments) were stratified by gender and atopic status.
Results
The period prevalence of eczema from birth to 18 years of age remained relatively constant (11.9–14.2%) with minimal remission. Up to 10 years of age, gender did not influence prevalence. From 10 to 18 years, eczema became more prevalent among girls (16.3% for girls vs. 8.3% for boys, P<0.001) as a result of a greater positive transition in girls (9.4% for girls vs. 4.3% for boys, P=0.001) and greater negative transition in boys (65.4% for boys vs. 50% for girls, P=0.04). The higher positive transition of eczema in girls was most pronounced for non‐atopic eczema (5.9% for girls vs. 1.5% for boys, P=0.002).
Conclusions
We found only a minimal reduction in the prevalence of eczema during childhood and adolescence. During adolescence, more girls develop eczema and more boys outgrow it suggesting a role for gender‐specific pubertal factors.
Cite this as: A. H. Ziyab, A. Raza, W. Karmaus, N. Tongue, H. Zhang, S. Matthews, S. H. Arshad and G. Roberts, Clinical & Experimental Allergy, 2010 (40) 1776–1784.
Summary
Background
Skin prick testing (SPT) is fundamental to the practice of clinical allergy identifying relevant allergens and predicting the clinical expression of disease. There are only limited ...data on the natural history of SPT results over childhood and adolescence.
Objective
We aimed to describe the natural history of SPT and patterns of sensitization over childhood and adolescence.
Methods
The 1989 Isle of Wight birth cohort (1456 participants) was followed up at 1, 2, 4, 10 and 18 years. SPT was undertaken from 4 years.
Results
SPT was performed on 980 (80%), 1036 (75%) and 853 (65%) of participants at 4, 10 and 18 years. The prevalence of sensitization to any allergen at these time‐points was 19.7%, 26.9% and 41.3% respectively. At each time‐point, boys were significantly more likely to be sensitized (P < 0.016) and sensitization significantly increased over childhood and adolescence (average annual increase of 7%). Some children outgrew their sensitization. The rate of sensitization to most individual allergens increased over childhood and adolescence. A configural frequency analysis showed that whether an individual was sensitizated was relatively fixed over childhood and adolescence. Cluster analysis at 4 years demonstrated four major groups of individuals with similar co‐sensitization to specific allergens. Children who were sensitized at age 4 years generally went onto become sensitized to additional allergens at 10 and 18 years.
Conclusions and Clinical Relevance
Allergic sensitization continues to increase over childhood into adolescence although the majority of children who were not sensitized at 4 years remain non‐sensitized throughout childhood and adolescence. The presence of sensitization at 4 years predicted later sensitization to additional allergens.
Background
WHO guidelines advocate breastfeeding for 6 months, and EAACI guideline recommends exclusive breastfeeding for 4–6 months. However, evidence for breastfeeding to prevent asthma and ...allergic disease is conflicting. We examined whether following recommended breastfeeding guidelines alters the long‐term risks of asthma, eczema, rhinitis or atopy.
Methods
The effect of nonexclusive (0, >0–6, >6 months) and exclusive breastfeeding (0, >0–4, >4 months) on repeated measures of asthma (10, 18 years), eczema, rhinitis, and atopy (1‐or‐2, 4, 10, 18 years) risks was estimated in the IoW cohort (n = 1456) using log‐linear models with generalized estimating equations. The Food Allergy and Intolerance Research (FAIR) cohort (n = 988), also from the IoW, was examined to replicate results.
Results
Breastfeeding (any or exclusive) had no effect on asthma and allergic disease in the IoW cohort. In the FAIR cohort, any breastfeeding for >0–6 months protected against asthma at 10 years (RR = 0.50, 95% CI = 0.32–0.79, P = 0.003), but not other outcomes, whilst exclusive breastfeeding for >4 months protected against repeated rhinitis (RR = 0.36, 95% CI = 0.18–0.71, P = 0.003). Longer breastfeeding was protective against late‐onset wheeze in the IoW cohort.
Conclusion
The protective effects of nonexclusive and exclusive breastfeeding against long‐term allergic outcomes were inconsistent between these colocated cohorts, agreeing with previous observations of heterogeneous effects. Although breastfeeding should be recommended for other health benefits, following breastfeeding guidelines did not appear to afford a consistent protection against long‐term asthma, eczema, rhinitis or atopy. Further research is needed into the long‐term effects of breastfeeding on allergic disease.
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