Early solid food diet and eczema in childhood: a 10-year longitudinal study

Maternal allergy-preventive diet index, offspring infant diet diversity, and childhood allergic diseases

BACKGROUND

Studies of childhood diet diversity and allergic disease have not examined additional associations with an offspring allergy-linked maternal diet index during pregnancy. We studied both associations in a pre-birth cohort.

METHODS

Offspring allergic disease diagnoses were obtained from electronic medical records. Maternal and infant diet were self-reported. Adjusted parametric Weibull time-to-event models assessed associations between maternal diet index, infant diet diversity and time to development of allergic rhinitis, atopic dermatitis, asthma, wheeze, IgE-mediated food allergy, and a combined outcome of any allergic disease except for wheeze.

RESULTS

Infant diet diversity at 1 year was associated with the risk of the combined outcome between 1 and 4 years of age (p = .002). While both maternal diet index and infant diet diversity at 1 year were associated with the risk of the combined outcome between 1 and 4 years of age (both p < .05), infant diet diversity at 1 year did not modify the association between maternal diet index and the risk of the combined outcome between 1 and 4 years of age (p = .5). The group with the lowest risk of the combined allergy outcome had higher maternal diet index and higher infant diet diversity.

CONCLUSIONS

The novel finding that both maternal diet index during pregnancy and infant diet diversity at 12 months are associated with the risk of a combined allergic disease outcome points to two targets for preventive interventions: maternal diet index scores during pregnancy and offspring diet diversity during infancy.

Associations between diet diversity during infancy and atopic disease in later life: Systematic review

Background

The incidence of allergic disease remains high, and many studies have focused on the association between food diversity in infancy and allergic disease later in life, but their conclusions are still controversial.

Objective

We aimed to synthesize the literature on the association between childhood diet diversity and atopic disease.

Methods

We searched the PubMed, Cochrane Library, Embase, Scopus, VPCS, and Wanfang databases for studies about food diversity and atopic disease. Seventeen high-quality studies, 14 cohort studies, and 1 case-control study were included from 5244 studies with sample sizes ranging from 100 to 5225.

Results

All high-quality cohort studies showed that increasing food diversity in infancy can effectively prevent the occurrence of food allergies (5/5). Moderate evidence showed that increased food diversity reduced the risk of asthma (4/6), food sensitization (3/5), and atopic dermatitis (3/5). However, its effect on eczema (5), allergic rhinitis (4), and other diseases remains controversial.

Conclusions

Increasing food diversity during infancy is a potential method for preventing food allergy, asthma, atopic dermatitis, and food sensitization later in life. There is little or no comparative evidence about the protective effect of food diversity on other atopic diseases.

Immunonutrition: Diet Diversity, Gut Microbiome and Prevention of Allergic Diseases

Allergic diseases are increasing both in morbidity and mortality. Genetic, environmental, and dietary factors may all be involved in this increase. Nutrition during pregnancy, breastfeeding, and early life may play a particularly important role in preventing allergic diseases. Based on current systematic reviews, the intake of specific nutrients has failed to prevent allergic disease. Prevention strategies have shifted their focus to the overall diet which can be described using diet diversity. Infant and maternal diet diversity in pregnancy has been associated with reduced allergy outcomes in childhood. Overall, diet also seems to have a marked effect on the microbiome compared to single foods. Factors that may negate the allergy-preventative effect of overall diet diversity include the addition of emulsifiers, advanced glycation end-product content, and overuse of commercial baby foods. There is a need to perform randomized controlled trials using overall dietary intake to support international food allergy guidelines. These studies should ideally be conducted by multi-professional teams.

Does the severity of atopic dermatitis change with allergic sensitization? Is it real or a myth?

OBJECTIVE

Atopic dermatitis (AD) is a chronic inflammatory skin disease that can occur at any age. This study aimed to evaluate the impact of food allergy on disease severity as well as clinical/laboratory findings in children with AD.

METHODS

Clinical and laboratory data of AD patients evaluated for food allergy between January 2021 and December 2022 were examined retrospectively.

RESULTS

Of the 52 patients evaluated, 32 (61.5%) were males, with a median age of 6 months (2-118 months). Among them, 26 (50%) had food allergies (FA) and five (9.6%) had inhalant allergen sensitivity. No significant difference in AD severity was observed between patients with and without FA. However, the FA group showed higher serum lactate dehydrogenase (LDH) levels (343.3 ± 81.5 U/L vs 297.7 ± 77.4 U/L; P = 0.011) and lower red cell distribution width (RDW). Inhalant allergen sensitivity was associated with higher AD severity.

CONCLUSION

While guidelines recommend investigating food allergies in moderate to severe AD, this study found no significant difference in the relationship between AD severity and the presence of FA. However, inhalant allergen sensitivity was linked to increased AD severity. Therefore, a comprehensive patient history should include an evaluation of food allergies in children with AD, regardless of disease severity. Elimination and provocation tests related to suspected food items should be performed, and allergenic foods should be removed from the diet if they are found to contribute to the allergy.

Comparing the Diagnostic Accuracy of Measures of Maternal Diet During Pregnancy for Offspring Allergy Outcomes: The Healthy Start Study

BACKGROUND

Allergic diseases in children are increasing. Although maternal diet quality in pregnancy may be protective, it is unclear which measure of maternal diet best predicts offspring diseases.

OBJECTIVE

To examine the associations between multiple diet measures and allergy outcomes, and to compare the diagnostic accuracy of the measures for the prediction of allergy outcomes.

METHODS

Maternal diet during pregnancy was measured using a validated instrument, and scored using 5 measures: the maternal diet index (MDI), Healthy Eating Index, total diet diversity, healthy diet diversity, and unhealthy diet diversity. Unadjusted and adjusted logistic regression models assessed associations between maternal diet measures and offspring allergy outcomes up to age 4 years. The diagnostic accuracy of the diet measures was compared.

RESULTS

There were significant associations between MDI (odds ratio [OR], 0.78; 95% CI, 0.70-0.87), Healthy Eating Index (OR, 0.98; 95% CI, 0.97-0.99), and healthy diet diversity scores (OR, 0.91; 95% CI, 0.85-0.98) during pregnancy and the primary combined outcome "any allergy excluding wheeze" in children up to age 4 years. Neither maternal total diet diversity (OR, 0.99; 95% CI, 0.95-1.03) nor unhealthy diet diversity scores (OR, 1.05; 95% CI, 0.98-1.13) were associated with the "any allergy excluding wheeze" outcome. For all outcomes studied, except for food allergy, there was a significant difference in the diagnostic accuracy between the 5 measures of maternal diet. The area under the curve for MDI was highest for every disease outcome, although not always significantly higher.

CONCLUSIONS

Better quality and higher diversity of a woman's diet during pregnancy, measured in various ways, is associated with offspring allergy outcomes, with healthy foods associated with decreased risk, and unhealthy foods associated with a higher risk. The MDI, which appropriately weighted both healthy and unhealthy foods, best predicted childhood allergic disease.

Early intervention and prevention of allergic diseases

Food allergy (FA) is now one of the most common chronic diseases of childhood often lasting throughout life and leading to significant worldwide healthcare burden. The precise mechanisms responsible for the development of this inflammatory condition are largely unknown; however, a multifactorial aetiology involving both environmental and genetic contributions is well accepted. A precise understanding of the pathogenesis of FA is an essential first step to developing comprehensive prevention strategies that could mitigate this epidemic. As it is frequently preceded by atopic dermatitis and can be prevented by early antigen introduction, the development of FA is likely facilitated by the improper initial presentation of antigen to the developing immune system. Primary oral exposure of antigens allowing for presentation via a well-developed mucosal immune system, rather than through a disrupted skin epidermal barrier, is essential to prevent FA. In this review, we present the data supporting the necessity of (1) an intact epidermal barrier to prevent epicutaneous antigen presentation, (2) the presence of specific commensal bacteria to maintain an intact mucosal immune system and (3) maternal/infant diet diversity, including vitamins and minerals, and appropriately timed allergenic food introduction to prevent FA.

A Consensus Approach to the Primary Prevention of Food Allergy Through Nutrition: Guidance from the American Academy of Allergy, Asthma, and Immunology; American College of Allergy, Asthma, and Immunology; and the Canadian Society for Allergy and Clinical Immunology

Recently published data from high-impact randomized controlled trials indicate the strong potential of strategies to prevent the development of food allergy in high-risk individuals, but guidance in the United States at present is limited to a policy for only the prevention of peanut allergy, despite other data being available and several other countries advocating early egg and peanut introduction. Eczema is considered the highest risk factor for developing IgE-mediated food allergy, but children without risk factors still develop food allergy. To prevent peanut and/or egg allergy, both peanut and egg should be introduced around 6 months of life, but not before 4 months. Screening before introduction is not required, but may be preferred by some families. Other allergens should be introduced around this time as well. Upon introducing complementary foods, infants should be fed a diverse diet, because this may help foster prevention of food allergy. There is no protective benefit from the use of hydrolyzed formula in the first year of life against food allergy or food sensitization. Maternal exclusion of common allergens during pregnancy and/or lactation as a means to prevent food allergy is not recommended. Although exclusive breast-feeding is universally recommended for all mothers, there is no specific association between exclusive breast-feeding and the primary prevention of any specific food allergy.

The Role of Diet Diversity and Diet Indices on Allergy Outcomes

Nutrients in foods are not eaten in isolation and food intake interacts in a complex manner, affecting health and disease outcomes. For this reason, focusing on the whole "pattern" of dietary intake instead of the single nutrients or groups of nutrients when studying diseases outcomes is increasingly appealing and growing. Diet diversity refers to the variety of foods being eaten, and the terms, diversity or variety, are often used interchangeably. When the overall diet is characterized by healthy foods, diet diversity will reflect a diversity/variety of healthy foods eaten over a period of time. The introduction of solid foods in the 1st year of life is considered a measure of increased diet diversity. Consuming a diverse range of foods and food allergens in the first year of life may increase intake of important nutrients and positively affect the gut microbiome structure and function. Intake of omega-3 fatty acids and fibers/prebiotics may be particularly important but more information is required about dose and which individuals are most likely to benefit. Increased diet diversity in the first year of life is also associated with reduced food allergy outcomes. In addition to diet diversity, diet indices are considered measures of overall diet quality and can be used as a simple assessment of dietary intake. The focus of this paper is to review and critically address the current knowledge of the association between diet diversity and diet indices and allergy outcomes. Based on the current evidence, we recommend the introduction of solid foods, including common allergenic solids, during the 1st year of life, according to the infant's neuro-developmental abilities and familial or cultural habits. For infants with severe AD and/or FA, medical assessment may be advisable before introducing common food allergens into the diet. Limited evidence exist about the role of diet indices in pregnancy and allergic disease in the offspring, and the most promising results indicate a reduction in childhood wheeze and/or asthma intake.

EAACI position paper on diet diversity in pregnancy, infancy and childhood: Novel concepts and implications for studies in allergy and asthma

To fully understand the role of diet diversity on allergy outcomes and to set standards for conducting research in this field, the European Academy of Allergy and Clinical Immunology Task Force on Diet and Immunomodulation has systematically explored the association between diet diversity and allergy outcomes. In addition, a detailed narrative review of information on diet quality and diet patterns as they pertain to allergic outcomes is presented. Overall, we recommend that infants of any risk category for allergic disease should have a diverse diet, given no evidence of harm and some potential association of benefit in the prevention of particular allergic outcomes. In order to harmonize methods for future data collection and reporting, the task force members propose relevant definitions and important factors for consideration, when measuring diet diversity in the context of allergy. Consensus was achieved on practice points through the Delphi method. It is hoped that the definitions and considerations described herein will also enable better comparison of future studies and improve mechanistic studies and pathway analysis to understand how diet diversity modulates allergic outcomes.

Complementary feeding and food allergy, atopic dermatitis/eczema, asthma, and allergic rhinitis: a systematic review

BACKGROUND

Nutrition during infancy and toddlerhood may influence health and disease prevention across the life span. Complementary feeding (CF) starts when human milk or infant formula is complemented by other foods and beverages, beginning during infancy and continuing to age 24 mo.

OBJECTIVES

The aim of this study was to describe systematic reviews conducted for the USDA and the Department of Health and Human Services Pregnancy and Birth to 24 Months Project to answer the following question: What is the relationship between the timing of the introduction of complementary foods and beverages (CFBs), or types and amounts of CFBs consumed, and the development of food allergy, atopic dermatitis/eczema, asthma, and allergic rhinitis?

METHODS

The literature was searched using 4 databases (CINAHL, Cochrane, Embase, PubMed) to identify articles published from January 1980 to February 2017 that met predetermined inclusion criteria. For each study, data were extracted and risk of bias was assessed. The evidence was qualitatively synthesized to develop a conclusion statement, and the strength of the evidence was graded.

RESULTS

Thirty-one included articles addressed the timing of CFB introduction, and 47 articles addressed the types and amounts of CFBs consumed.

CONCLUSIONS

Moderate evidence suggests that there is no relationship between the age at which CF first begins and the risk of developing food allergy, atopic dermatitis/eczema, or childhood asthma. Limited to strong evidence, depending on the specific food, suggests that introducing allergenic foods in the first year of life (after 4 mo) does not increase the risk of food allergy and atopic dermatitis/eczema but may prevent peanut and egg allergy. There is not enough evidence to determine a relationship between diet diversity or dietary patterns and atopic disease. Research is needed to address gaps and limitations in the evidence on CF and atopic disease, including research that uses valid and reliable diagnostic measures and accounts for key confounders and potential reverse causality.

Effect of an Intervention to Promote Breastfeeding on Asthma, Lung Function, and Atopic Eczema at Age 16 Years: Follow-up of the PROBIT Randomized Trial

IMPORTANCE

Atopic diseases, including asthma and atopic eczema, are the most common chronic conditions of childhood.

OBJECTIVE

To investigate whether an intervention to promote prolonged and exclusive breastfeeding protects against asthma, atopic eczema, and low lung function in adolescence.

DESIGN, SETTING, AND PARTICIPANTS

Follow-up of the Promotion of Breastfeeding Intervention Trial (PROBIT), a cluster randomized trial in 30 Belarusian maternity hospitals and affiliated polyclinics; recruitment of 17 046 healthy term infants took place from June 15, 1996, to December 31, 1997. Data analysis was conducted from May 9, 2016, to April 21, 2017. The primary analytic approach was by modified intention-to-treat analysis.

INTERVENTIONS

Randomization to receive a breastfeeding promotion intervention vs usual care.

MAIN OUTCOMES AND MEASURES

Spirometry and flexural eczema on standardized skin examination by study pediatricians were the primary outcomes; secondary outcomes were self-reported asthma diagnosis ever, and wheezing and flexural eczema symptoms in the previous year.

RESULTS

A total of 13 557 (79.5%) participants were followed up from September 15, 2012 to July 15, 2015. The intervention (7064 [79.7%]) and control (6493 [79.4%]) groups were similar at follow-up (3590 [50.8%] and 3391 [52.2%] male; mean [SD] age, 16.2 [0.6] and 16.1 [0.5] years, respectively). In the intervention group, 0.3% (21 of 7064) had flexural eczema on skin examination and mean (SD) forced expiratory volume in the first second of expiration/forced vital capacity (FEV1/FVC) ratio z score was -0.10 (1.82), compared with 0.7% (43 of 6493) and 0.35 (1.34), respectively, in the control group. In modified intention-to-treat analysis, accounting for clustering by polyclinic, a 54% lower risk of flexural eczema on skin examination was observed in the intervention compared with the control group (odds ratio [OR], 0.46; 95% CI, 0.25 to 0.86). Self-reported flexural eczema symptoms in the past year (OR, 0.57; 95% CI, 0.27 to 1.18), asthma (OR, 0.76; 95% CI, 0.47 to 1.23), and wheezing in the past year (OR, 0.66; 95% CI, 0.37 to 1.18) were less frequently reported in the intervention compared with the control group, but 95% CIs were wide and included the null. There was no significant difference in the FEV1/FVC ratio z score (β -0.15; 95% CI, -0.76 to 0.45). All results were similar with additional adjustment for baseline characteristics, on instrumental variable analysis, and with multiple imputation among all 17 046 randomized participants.

CONCLUSIONS AND RELEVANCE

A breastfeeding promotion intervention reduced flexural dermatitis risk but had no detectable effect on lung function or questionnaire-derived measures of atopic eczema or asthma in adolescence in a setting where atopic eczema and allergies are rare.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01561612.

An Australian Consensus on Infant Feeding Guidelines to Prevent Food Allergy: Outcomes From the Australian Infant Feeding Summit

BACKGROUND

Infant feeding in the first postnatal year of life has an important role in an infant's risk of developing food allergy. Consumer infant feeding advice is diverse and lacks consistency.

AIM

The Australian Infant Feeding Summit was held with the aim of achieving national consensus on the wording of guidelines for infant feeding and allergy prevention.

METHODS

Two meetings were hosted by the Centre for Food and Allergy Research, the Australasian Society of Clinical Immunology and Allergy, and the Australian National Allergy Strategy. The first meeting of 30 allergy researchers, clinicians, and consumers assessed the evidence. The second consensus meeting involved 46 expert stakeholders including state and federal health care agencies, consumers, and experts in allergy, infant feeding, and population health.

RESULTS

Partner stakeholders agreed on consensus wording for infant feeding advice: CONCLUSIONS: Consensus was achieved in a context in which there is a high prevalence of food allergy. Guidelines for other countries are being updated. Provision of consistent wording related to infant feeding to reduce food allergy risk will ensure clear consumer advice.

Incidence and risk factors for food hypersensitivity in UK infants: results from a birth cohort study

BACKGROUND

The prevalence of food hypersensitivity in the UK is still largely open to debate. Additionally its pathogenesis is also unclear although it is known that there are differing phenotypes. Determining its prevalence, along with identifying those factors associated with its development will help to assess its clinical importance within the national setting and also add to the debate on appropriate prevention strategies.

METHODS

A population based birth cohort study conducted in Hampshire, UK as part of the EuroPrevall birth cohort study. 1140 infants were recruited with 823 being followed up until 2 years of age. Infants with suspected food reactions were assessed including specific IgE measurement and skin prick testing. Diagnosis of food hypersensitivity was by positive double-blind, placebo-controlled food challenge (DBPCFC) where symptoms up to 48 h after the end of the food challenge were considered indicative of a food hypersensitivity. Factors associated with food hypersensitivity and its two phenotypes of IgE-mediated and non-IgE-mediated disease were modelled in a multivariable logistic regression analysis.

RESULTS

Cumulative incidence of food hypersensitivity by 2 years of age was 5.0 %. The cumulative incidence for individual food allergens were hens' egg 2.7 % (1.6-3.8); cows' milk 2.4 % (1.4-3.5); peanut 0.7 % (0.1-1.3); soy 0.4 % (0.0-0.8); wheat 0.2 % (0.0-0.5) and 0.1 % (0.0-0.32) for fish. The cumulative incidence of IgE-mediated food allergy was 2.6 % with 2.1 % reacting to hens' egg. For non-IgE-mediated food allergy the cumulative incidence was 2.4 % (cows' milk 1.7 %). Predictors for any food hypersensitivity were wheeze, maternal atopy, increasing gestational age, age at first solid food introduction and mean healthy dietary pattern score. Predictors for IgE mediated allergy were eczema, rhinitis and healthy dietary pattern score whereas for non-IgE-mediated food allergy the predictors were dog in the home, healthy dietary pattern score, maternal consumption of probiotics during breastfeeding and age at first solid food introduction.

CONCLUSIONS

Just under half the infants with confirmed food hypersensitivity had no demonstrable IgE. In an exploratory analysis, risk factors for this phenotype of food hypersensitivity differed from those for IgE-mediated food allergy except for a healthy infant diet which was associated with less risk for both phenotypes.

Lack of evidence for a protective effect of prolonged breastfeeding on childhood eczema: lessons from the International Study of Asthma and Allergies in Childhood (ISAAC) Phase Two

BACKGROUND

Exclusive breastfeeding for at least 4 months is recommended by many governments and allergy organizations to prevent allergic disease.

OBJECTIVES

To investigate whether exclusive breastfeeding protects against childhood eczema.

METHODS

Study subjects comprised 51,119 randomly selected 8- to 12-year-old schoolchildren in 21 countries. Information on eczema and breastfeeding was gathered by parental questionnaire. Children were also examined for flexural eczema and underwent skin prick testing. Odds ratios (ORs) were calculated for each study centre and then pooled across populations.

RESULTS

There was a small increase in the risk of reported 'eczema ever' in association with 'breastfeeding ever' and breastfeeding < 6 months [pooled adjusted OR 1·11, 95% confidence interval (CI) 1·00-1·22 and OR 1·10, 95% CI 1·02-1·20, respectively]. There was no significant association between reported 'eczema ever' and breastfeeding > 6 months (pooled adjusted OR 1·09, 95% CI 0·94-1·26). Risk estimates were very similar for exclusive breastfeeding < 2 months, 2-4 months and > 4 months and for eczema symptoms in the past 12 months and eczema on skin examination. As for more severe eczema, breastfeeding per se conveyed a risk reduction on sleep disturbed eczema (pooled adjusted OR 0·71, 95% CI 0·53-0·96), but this effect was lost where children had been exclusively breastfed for > 4 months (pooled adjusted OR 1·02, 95% CI 0·67-1·54). Allergic sensitization and a history of maternal allergic disease did not modify any of these findings.

CONCLUSIONS

Although there was a protective effect of ever having been breastfed on more severe disease, we found no evidence that exclusive breastfeeding for 4 months or longer protects against eczema. Our results are consistent with findings from a recent systematic review of prospective studies. The U.K. breastfeeding guidelines with regard to eczema should be reviewed. Intervention studies are now required to explore how and when solids should be introduced alongside breastfeeding to aid protection against eczema and other allergic diseases.

Recent perspectives on the global epidemiology of childhood eczema

The International Study of Asthma and Allergies in Childhood (ISAAC) is the largest epidemiological study ever performed and the only truly global allergy study. This review summarises the childhood eczema-related findings from ISAAC and discusses how these fit into our current understanding of eczema aetiology, with particular emphasis on worldwide time trends in eczema prevalence, climatic and dietary risk factors, breastfeeding, the role of skin barrier impairment and allergic sensitisation.

Maternal immunization to modulate the development of allergic response and pathogen infections

This article reviews recent experimental approaches of preventive strategies regarding allergy and infections by pathogens, particularly in early childhood, by targeting maternal immunomodulation. Basic research is essential to understand maternal vaccination as a strategy to control allergic disease and bacterial and viral infections; thus, providing support for future translational research. The environmental stimuli and host genetic factors, along with maternal influences in early life when immune systems are developing and during postnatal life, are essential for the decision between tolerance induction or allergen sensitization. Maternal immunomodulation strategies should serve as a challenge when attempting to halt the spread of allergy responses and viral infections, until the innate and adaptive arms of the immune system of the neonates are competent.

Prevalence and factors linked to atopic eczema in 10- and 11-year-old schoolchildren. Isaac 2 in Almeria, Spain

BACKGROUND

Atopic eczema affects 5-10% of the Spanish paediatric population, and has increased in frequency over the last few decades, probably due to changes in the environment and lifestyle. Phase II of the ISAAC (International Study of Asthma and Allergies in Childhood) uses a standardised methodology to establish the prevalence of allergic disorders and factors linked to them in each centre.

OBJECTIVES

To assess the prevalence and severity of atopic eczema, and to establish factors linked to atopic eczema in 10-11 year-old school children in the city of Almeria (South-East coast of Spain).

MATERIAL AND METHODS

An ecological study was carried out as part of ISAAC II, using homologated questionnaires and allergic tests in 1143 schoolchildren. Statistic association was assessed by means of chi(2) test, and then logistic regression analysis was performed with the most significant variables from the univariant analysis.

RESULTS

The prevalence of atopic eczema was 11.4%. The risk factors found in the multiple logistic regression analysis were: personal antecedents of severe asthma (OR 19 CI 95% 1.35-266) and severe rhinitis (OR 7.7 CI 95% 1.79-33), fungi in bedroom during the first year of life (OR 4.2 CI 95% 1.17-15.1) and atopic eczema in one parent (OR 5.2 CI 95% 2.69-10.1).

CONCLUSIONS

The prevalence of atopic eczema is similar to that found in other studies within ISAAC Phase I. The most important risk factors for atopic eczema are family and personal history of other atopic diseases and the presence of fungi in the home.

Infant feeding and allergy prevention: a review of current knowledge and recommendations. A EuroPrevall state of the art paper

The relationship between infant feeding patterns and the later development of food allergies has been the focus of much debate and research over the last decade. National recommendations have been made by many countries on how to feed infants to reduce the risk of food allergy but due to the lack of firm evidence the recommendations differ widely. This review has been developed as part of EuroPrevall, a European multicentre research project funded by the European Union, to document the differing feeding recommendations made across Europe, to investigate the current evidence base for any allergy prevention feeding recommendations and to identify areas where further research is needed. This review will also provide information which, when combined with the infant feeding data collected as part of EuroPrevall, will give an indication of compliance to national feeding guidelines which can be utilised to assess the effectiveness of current dissemination and implementation strategies.

Do early infant feeding practices vary by maternal ethnic group?

Objective

To examine UK country and ethnic variations in infant feeding practices.

Design

Cohort study.

Setting

Infants enrolled in the Millennium Cohort Study, born between September 2000 and January 2002.

Subjects

A total of 18 150 natural mothers (11 286 (8207 white) living in England) of singleton infants.

Outcome measures

Breast-feeding initiation, breast-feeding discontinuation and introduction of solid foods before 4 months.

Explanatory variables

Maternal ethnic group, education and social class.

Results

Seventy per cent of UK mothers started to breast-feed, of whom 62% stopped before 4 months. Median age at discontinuing breast-feeding was 14, 13, 10 and 6 weeks in Scotland, England, Wales and Northern Ireland, respectively. Thirty-six per cent of UK mothers (34% in England) introduced solids before 4 months. White mothers were more likely to discontinue breast-feeding (62%) and introduce solids early (37%) than most other ethnic minority groups; those stopping before 4 months were more likely to introduce solids early compared with those continuing to breast-feed beyond this age (adjusted rate ratio (95% confidence interval): 1.3 (1.1–1.2)). Educated mothers were less likely to stop breast-feeding before 4 months (white mothers, 0.8 (0.8–0.9); non-white mothers, 0.9 (0.8–1.0)) than those with no/minimal qualifications but, among ethnic minorities, were more likely to introduce solids early (1.3 (1.0–1.6)). Socio-economic status was positively associated with breast-feeding continuation among white women, and with age at introduction of solids among non-white women.

Conclusions

We have identified important geographic, ethnic and social inequalities in breast-feeding continuation and introduction of solids within the UK, many of which have not been reported previously. The factors mediating these associations are complex and merit further study to ensure that interventions proposed to promote maternal adherence to current infant feeding recommendations are appropriate and effective.

Exclusive breastfeeding and risk of atopic dermatitis in some 8300 infants

Earlier studies on breastfeeding and atopy in infants have yielded contradictory results. We examined the relationship between exclusive breastfeeding and atopic dermatitis (AD) in a cohort of infants born between 1 October 1997 and 1 October 1999 in south-east Sweden. We evaluated the risk of AD 'at least once' or 'at least three times' during the first year of life in relation to duration of exclusive breastfeeding: <4 months (short exclusive breastfeeding; SEBF) vs. > or = 4 months. All data were obtained through questionnaires. Of 8346 infants with breastfeeding data, 1943 (23.3%) had suffered from AD during the first year of life. Duration of exclusive breastfeeding was not associated with lower risk of AD (p = 0.868). SEBF did not influence the risk of any AD (OR = 1.03; 95% CI OR = 0.91-1.17; p = 0.614) or AD at least three times (OR = 0.97; 95% CI OR = 0.81-1.16; p = 0.755) during the first year of life. Adjustment for confounders did not change these point estimates. Neither was there any link between SEBF and risk of AD among infants with a family history of atopy [adjusted odds ratio (AOR) = 1.16; 95% CI AOR = 0.90-1.48; p = 0.254]. Furred pets at home were linked to a lower risk of AD both among infants with a family history of atopy (AOR = 0.76; 95% CI AOR = 0.60-0.96; p = 0.021) and among infants with no such history (AOR = 0.79; 95% CI AOR = 0.69-0.90; p < 0.001). Infants with no family history of atopy were less prone to develop AD if parents smoked (AOR = 0.76; 95% CI AOR = 0.61-0.95; p = 0.016). This study indicates that exclusive breastfeeding does not influence the risk of AD during the first year of life, while presence of furred pets at home seems to be negatively associated with AD.

[Epidemiology of food allergies]

Difficulties resulting from diagnosis of food allergies show an impact on the validity of epidemiological data, which are mainly based on questionnaire data or results from allergy tests for evidence of specific IgE antibodies. The frequency of self-reported adverse food reactions in population based studies ranges between 5% and 33% with women reporting a higher frequency of such reactions. Only two epidemiological studies have performed double blind, placebo-controlled oral food challenge tests. Extrapolating these results, the prevalence of food allergies is estimated at 2% within the general population. An epidemiological questionnaire-based study in France reports on 3.5% of the general population suffering from food allergies. According to studies of the Allergy Ward in Zürich, in 46-60% of all cases skin and mucosa are predominantly affected, with oral allergy syndrome and urticaria being the most frequent manifestations. A food allergy is significantly associated with different manifestations of atopy and predominantly to hay fever, atopic eczema, urticaria and asthma.

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

OBJECTIVE

To prospectively investigate the association of high levels of immunoglobulin E (IgE) sensitization to foods and the presence of atopic dermatitis (judged by reported topical steroid use during the first 16 months of life) in a birth cohort of 620 Australian children "at risk" of allergic disease because of family history.

RESULTS

A total of 559 of the children in the cohort were fully evaluated, and the cumulative prevalence of atopic dermatitis was 24%. More children in the cohort who had atopic dermatitis had strongly positive skin test results (> or = 4+, histamine equivalent units, > or = approximately 6-mm wheal), consistent with IgE food sensitization to either cow's milk, egg, or peanut at 6 months (22% vs 5%, chi(2) = 35; P < 10(-6)) and at 12 months (36% vs 11%, chi(2) = 41; P < 10(-6)) than those without atopic dermatitis. The calculated attributable risk percent for IgE food sensitization as a cause of atopic dermatitis was 65% and 64% at these times. In a separate group of infants with severe atopic dermatitis, the equivalent rates of IgE food sensitization at 6 months was 83% and at 12 months, 65%.

CONCLUSION

IgE food sensitization is a major risk factor for the presence of atopic dermatitis in infancy.

Infant feeding practices in Ottawa-Carleton: the introduction of solid foods

Infant feeding guidelines regarding the introduction of solid foods are generally not well known in Canada. The guidelines recommend that solid foods be introduced between four to six months of age, depending on the developmental readiness of the infant. In order to understand the underlying factors and patterns which contribute to the introduction of solid foods in infants, data were analyzed from three cross-sectional surveys of parents of six-month-old infants from the Ottawa-Carleton region (n = 373, 1988; n = 330, 1992; n = 338, 1996) conducted by the Ottawa-Carleton Health Department. Multivariable analysis showed that mothers who: did not breastfeed, were younger, had lower education, smoked or had partners that smoked, and lacked support after birth, were more likely to introduce solid foods before four months of age. These data support the need for nutrition education programs to increase adherence to the new Nutrition for Healthy Term Infants guidelines.

The descriptive epidemiology of atopic dermatitis in the community

Atopic dermatitis (AD) is a common condition in the community, particularly amongst children. Although comparison of prevalence data between surveys is made difficult by differences in methodology, the available data suggest that there has been a substantial rise in the prevalence of AD, and that social, geographical and racial variation in disease frequency exists. There is a lack of quality data relating to the prognosis of AD. Recently a reliable set of diagnostic criteria has been developed and a number of severity scoring systems have been proposed for use in epidemiological studies.

Is allergy prevention realistic and beneficial?

Allergic diseases among children have shown a marked increase during the last two or three decades, despite increased awareness of possible preventive measures. Preventive efforts have focused on new-borns and infants with a biparental history of allergy as they are at particularly high risk of developing allergic disease (40-60%). No good intervention studies have been performed in the general population, only in high-risk families. Unfortunately, so far known risk factors can only explain a small part of the recent increase in allergic diseases. The most important recommendation for everyone is not to smoke during pregnancy and when living/working with young children. Breast milk is the best for every baby, even from an immunologic aspect. Humidity problems should be reduced in homes, day-care centres and schools. It is probably wise not to keep furred pets indoors in homes when babies have a family history of allergy. However, the effect of such advice should be assessed, including the acceptability, compliance, costs and effectiveness. There is no doubt that we should go on with preventive measures both in babies at high risk of allergy and also in the general population. At the same time, research should try to find even more efficient ways to reduce the current "allergy epidemic".