Effects of early nutritional interventions on the development of atopic disease in infants and children: the role of maternal dietary restriction, breastfeeding, timing of introduction of complementary foods, and hydrolyzed formulas

Risks for common medical conditions experienced by former preterm infants during toddler years

AIMS

To identify associations between reactive airway disease (RAD), eczema, and gastroesophageal reflux (GERD) and antenatal/neonatal variables.

METHODS

This is a retrospective observational cohort analysis of former preterm (PT) infants evaluated at the Regional Neonatal Follow-up Program in the Lower Hudson Valley Region of New York. Subjects <2 years evaluated between January 2005 and December 2007 were included. Patient demographics, antenatal factors and co-morbidities of prematurity were correlated with each medical condition.

RESULTS

A total of 727 subjects were analyzed: 12.8% had RAD, 10.5% had eczema; and 26.7% had GERD. RAD and GERD correlated inversely with gestational age. RAD was more prevalent in singletons and African Americans; GERD in Caucasians; and eczema in singletons and males. Respiratory disease in the newborn period increased the incidence of RAD and GERD. Toddlers who had RAD were likely to have eczema or GERD; no association between GERD and eczema existed.

CONCLUSIONS

These three medical conditions were strongly associated. Their association may be the result of a common element developing each condition, or due to one condition exacerbating another. Respiratory problems in the newborn were strong predictors of GERD and RAD.

Modified egg as a nutritional supplement during peak brain development: a new target for fortification

BACKGROUND

Though eggs have the unique capacity, like breastmilk, to concentrate essential nutrients required for early growth and brain development of offspring - i.e. n-3 PUFA, increasingly deficient and sources contaminated - cholesterol and allergy concerns often exclude them from perinatal recommendations.

OBJECTIVE

Egg's potential contribution of key nutrients required for peak brain development are re-evaluated vis-à-vis fortification, accessibility, and risks.

METHODS

Contributions of standard (USDA) and fortified (selected market-available) egg compositions to perinatal requirements for critical brain-supporting nutrients were compared to human and cow milks, and risks and recommendations evaluated.

RESULTS

Standard egg has already higher concentrations/kcal of iron, selenium, zinc, choline, vitamins B12 and E, and essential amino acids (plus taurine) than human milk. Fortified egg could further yield significant n-3 PUFA % recommendations for pregnancy-lactation (total n-3 69.6-75.0% [DRI=1400-1300 mg/day]), including DHA (120.1-129.3%, mostly approximately 80% [calculated DRI=140-130 mg/day]), plus antioxidant vitamins A (9.0-15.2%) and E (51.6-65.3%), and minerals iodine (33.6-44.5%) and selenium (33.7-39.3%); % recommendations for children (1-3 y) even more. Cholesterol, important for nerve membranes and learning, may not be generally contraindicated in childbearing-aged women (approximately 10.5% hypercholesterolemia), and early-life egg exposure may increase tolerance. Egg-inclusive perinatal nutrition programs have shown significant contributions.

CONCLUSIONS

Eggs, especially target-fortified, may provide a unique nutritional supplement for peak brain development continously during pregnancy, nursing, and infancy (from 6 months), especially vs. insufficiencies. Missing nutritional opportunities by egg exclusion vs. concerns of hypercholesterolemia or allergy could be addressed individually, rather than as general recommendations, warranting further research and targeted egg design.

Strategies for primary prevention of atopy in children

In recent decades, the prevalence of atopic diseases such as asthma, hayfever, food allergy, and atopic dermatitis has been steadily increasing. Unfortunately, more advances have been made in secondary prevention of symptoms and exacerbations than in primary prevention. One barrier to adopting prevention strategies is uncertainty regarding the cause of atopy. A genetic predisposition has been well documented. However, other factors, including diet, environment, infections, medications, and gastrointestinal flora, all play a role in the development of atopic disease. Modifying these factors holds promise for stopping the atopic march in the future. This paper reviews advances that have been made in the primary prevention of atopic disease.

Pediatric atopic dermatitis: the importance of food allergens

Food allergy and atopic dermatitis often occur in the same patients. Food-induced eczema may be perceived as a controversial topic because the immunologic mechanisms have yet to be fully elucidated. Nevertheless, published clinical studies have clearly demonstrated that foods can induce symptoms in a subset of patients with atopic dermatitis. Those at greatest risk are young children in whom eczematous lesions are severe or recalcitrant to therapy. Allergy testing can be helpful but must be applied judiciously. A medical history obtained by a skilled and knowledgeable health care provider is of paramount importance to interpret test results appropriately. Finally, the implementation of proper dietary avoidance can improve symptoms and provide safety from potentially fatal anaphylaxis. However, if inappropriate prescribed, elimination diets can have significant negative nutritional and social consequences.

Early consumption of peanuts in infancy is associated with a low prevalence of peanut allergy

BACKGROUND

Despite guidelines recommending avoidance of peanuts during infancy in the United Kingdom (UK), Australia, and, until recently, North America, peanut allergy (PA) continues to increase in these countries.

OBJECTIVE

We sought to determine the prevalence of PA among Israeli and UK Jewish children and evaluate the relationship of PA to infant and maternal peanut consumption.

METHODS

A clinically validated questionnaire determined the prevalence of PA among Jewish schoolchildren (5171 in the UK and 5615 in Israel). A second validated questionnaire assessed peanut consumption and weaning in Jewish infants (77 in the UK and 99 in Israel).

RESULTS

The prevalence of PA in the UK was 1.85%, and the prevalence in Israel was 0.17% (P < .001). Despite accounting for atopy, the adjusted risk ratio for PA between countries was 9.8 (95% CI, 3.1-30.5) in primary school children. Peanut is introduced earlier and is eaten more frequently and in larger quantities in Israel than in the UK. The median monthly consumption of peanut in Israeli infants aged 8 to 14 months is 7.1 g of peanut protein, and it is 0 g in the UK (P < .001). The median number of times peanut is eaten per month was 8 in Israel and 0 in the UK (P < .0001).

CONCLUSIONS

We demonstrate that Jewish children in the UK have a prevalence of PA that is 10-fold higher than that of Jewish children in Israel. This difference is not accounted for by differences in atopy, social class, genetic background, or peanut allergenicity. Israeli infants consume peanut in high quantities in the first year of life, whereas UK infants avoid peanuts. These findings raise the question of whether early introduction of peanut during infancy, rather than avoidance, will prevent the development of PA.

Atopic dermatitis: a review of recent advances in the field

Atopic dermatitis is increasing in prevalence and currently affects 15–30% of children in urban areas. Immune dysregulation and an impaired epidermal barrier are important factors in the pathogenesis of this disease. Pruritus and a chronic relapsing remitting course are hallmarks of the disorder, and sleep disturbance can occur in both the patient and family. Preventive interventions include exclusive breastfeeding in the first 4 months of life and withholding solid foods for 6 months. The avoidance of irritants and the use of emollients decrease flares. Topical corticosteroids remain the mainstay of therapy, and should be judiciously utilized. Excessive and inappropriate use must be avoided, as well as ‘steroid phobia’. The topical calcineurin inhibitors can be useful adjuncts. Systemic therapies are available for severe disease, but carry risks of adverse effects.

American Academy of Pediatrics recommendations on the effects of early nutritional interventions on the development of atopic disease

PURPOSE OF REVIEW

To review the American Academy of Pediatrics statement on the effects of early nutritional interventions on the development of atopic disease in infants and children.

RECENT FINDINGS

Recent findings suggest that restriction of maternal diet during pregnancy and lactation does not play a major role in the development of allergic disease. In high-risk infants, exclusive breastfeeding for at least 4 months prevents or delays atopic dermatitis, cow milk allergy, and wheezing early in life. There is evidence that supplementing breastfeeding with a hydrolyzed formula protects against atopic disease, especially atopic dermatitis in at-risk infants. Finally, there is little evidence that delaying the introduction of complementary foods beyond 4-6 months of age has any protective effect against allergy. There is insufficient data that any dietary intervention beyond 4-6 months of age has any protective effect against developing atopic disease.

SUMMARY

In high-risk infants, there is evidence that exclusive breastfeeding for at least 4 months, and delaying of complementary foods until 4-6 months, prevent the development of allergy. There is some evidence that supplementing hydrolyzed formulas in high-risk infants may delay or prevent allergic disease. There is no convincing evidence that maternal manipulation of diet during pregnancy or lactation, use of soy products, or infant dietary restrictions beyond 4-6 months has any effect on the development of atopic disease.

[What's new in pediatric dermatology?]

The main selected articles in pediatric dermatology covered the following topics: development and maturation of the epidermal barrier in the neonate, iatrogenic events in the neonatal ICU, diagnostic value of minor birthmarks, complications, risk factors and treatment of hemangiomas, coagulopathy in venous malformations, epidemiology and dermoscopy of congenital and acquired melanocytic nevi in childhood, growth of the body surface area, new pathogenic concepts and treatment in atopic dermatitis, the impact of filaggrin deficiency, hereditary factors in Kawasaki disease, severe and drug resistant cases, management of juvenile dermatomyositis, treatment of childhood psoriasis with biologics, the new classification of epidermolysis bullosa and therapeutic approach with cell therapy, neurological impairment in xeroderma pigmentosum, behavioural anomalies in X-linked ichthyosis, guidelines for neurofibromatosis type I, the genetics of an hereditary hypotrichosis, infantile acne, rosacea in childhood, mast cell disease management and, last but not least, treatment of hair lice with silicone.

Immunological basis and management of food allergy

One of the most common allergies in children involves cow's milk, which contains approximately 20 different proteins that can cause allergic reactions. It is well known that children exhibiting signs of cow's milk allergy early in life often go on to develop allergy-related respiratory diseases; thus, management of early sensitisations and symptoms of food allergies is crucial to preventing subsequent allergic complications. Constant allergen exposure and other environmental factors determine whether a sensitised individual will become chronically allergic and experience persistent symptoms. Management of food allergies in children focuses on minimising sensitisation and encouraging immune system maturation through the exposure of children to exogenous stimuli known to prime the immune system. Hypoallergenic molecules or allergen avoidance can also be used to induce tolerance in allergy-prone children. Available evidence suggests that the onset of the sensitisation phase and the degree of inflammation can be modulated by external factors such as nutrition, and guidelines outlining the most effective dietary regimen for the prevention of allergic disease have been published. The underlying mechanisms of tolerance induction and the potential benefits of prophylactic treatment for food allergies remain to be determined.

Towards a cure for food allergy

Over the past two decades, food allergies have become both more prevalent and long lasting. This burgeoning problem has not been met with any therapeutic options to date, and patients must attempt to avoid known allergenic foods and treat any allergic reactions with 'as-needed' medications. There are a number of promising emerging therapeutic modalities for food allergy, including allergen-specific and allergen non-specific immunotherapeutic approaches. Although the allergen-specific approaches have some distinct differences, they all attempt to induce tolerance by exposing the patient to an allergen via the mucosal route (oral tolerance induction). Allergen non-specific approaches include biologics to suppress free total IgE levels (e.g. anti-IgE antibody) or to induce more general immune suppression (Chinese herbal medication).

Management of atopic dermatitis in the pediatric population

Atopic dermatitis, one of the most common skin disorders in young children, has a prevalence of 10% to 20% in the first decade of life. It is a chronic illness that requires a multifaceted treatment strategy in the setting of limited therapeutic options. Balancing safety concerns with efficacious treatment is of particular importance in the pediatric population. Parents of patients with atopic dermatitis turn to their primary caregivers for guidance regarding this physically demanding and psychologically stressful condition. In addition to serving as a review of atopic dermatitis, this article delves into the state-of-the-art therapeutic options and includes a detailed review of the differences between topical corticosteroids and topical calcineurin inhibitors. We also discuss new treatment strategies that are being used by atopic dermatitis specialists, such as comprehensive "education-as-intervention" models, wet wraps, bleach baths, and systemic immunomodulatory therapies.

Update on the pathogenesis and management of childhood asthma

PURPOSE OF REVIEW

To review and summarize trends in the current literature in childhood asthma with implications for current management and future research.

RECENT FINDINGS

There have been several articles in the last year that address the pathogenesis and pharmacogenomics of asthma. Recent consensus guidelines have been published that emphasize a stepwise approach to management, which will be briefly reviewed here. Several publications have proposed novel treatments to attempt to attenuate asthmatic lower airway inflammation. In terms of measuring this inflammation, a portable exhaled nitric oxide analyzer has been developed.

SUMMARY

Evidence shows that various early life exposures (high house dust mite levels, early antibiotic use) may predispose susceptible individuals to the development of asthma, but the early introduction of solid foods, even so-called allergenic foods, does not appear to be one of these factors. Newly identified pharmacogenomic markers may be the first step in tailoring each asthmatic patient's therapy on the basis of genotype, and management tailored specifically toward each patient's level of airway inflammation is already coming into wider clinical use. Several novel treatments for asthma have shown promise in early studies. On the basis of the most recent evidence, the National Education and Prevention Program's Guidelines for the Diagnosis and Management of Asthma is a comprehensive, stepwise management guide for asthma.

Food allergy knowledge, attitudes and beliefs: focus groups of parents, physicians and the general public

BACKGROUND

Food allergy prevalence is increasing in US children. Presently, the primary means of preventing potentially fatal reactions are avoidance of allergens, prompt recognition of food allergy reactions, and knowledge about food allergy reaction treatments. Focus groups were held as a preliminary step in the development of validated survey instruments to assess food allergy knowledge, attitudes, and beliefs of parents, physicians, and the general public.

METHODS

Eight focus groups were conducted between January and July of 2006 in the Chicago area with parents of children with food allergy (3 groups), physicians (3 groups), and the general public (2 groups). A constant comparative method was used to identify the emerging themes which were then grouped into key domains of food allergy knowledge, attitudes, and beliefs.

RESULTS

Parents of children with food allergy had solid fundamental knowledge but had concerns about primary care physicians' knowledge of food allergy, diagnostic approaches, and treatment practices. The considerable impact of children's food allergies on familial quality of life was articulated. Physicians had good basic knowledge of food allergy but differed in their approach to diagnosis and advice about starting solids and breastfeeding. The general public had wide variation in knowledge about food allergy with many misconceptions of key concepts related to prevalence, definition, and triggers of food allergy.

CONCLUSION

Appreciable food allergy knowledge gaps exist, especially among physicians and the general public. The quality of life for children with food allergy and their families is significantly affected.

Food allergy: diagnosis, treatment, prognosis, and prevention

Primary care providers are advised to refer to an allergist those children in whom they suspect a food allergic reaction. Approximately 6% of U.S. children have food allergy, although many more parents will present with concerns of a food-induced condition. At higher risk are young children with atopic dermatitis. Generally, the stronger the test response (wheal size or sIgE concentration), the more likely there is to be clinical allergy. However, testing must be applied judiciously. Most importantly, the medical history must be considered in order to interpret test results appropriately. Avoidance of the offending food allergen is currently the only way to prevent reactions. Because exposures and reactions can occur unexpectedly, patients and their families must be prepared to treat symptoms quickly with intramuscular epinephrine in the lateral thigh. Hopefully, additional treatment options will become available in the near future to ease the anxiety and fearfulness that parents and patients face on a daily basis. Until then, healthcare providers are urged to demonstrate the correct administration of autoinjectable epinephrine using a placebo device and review the technique with families on an ongoing basis.

Epidemiologic risks for food allergy

This article reviews possible risk factors and theories for the development of food allergy. It is noted that previous strategies to prevent food allergy through allergen avoidance during pregnancy, breast-feeding, and infancy have more recently been called into question. Alternative hypotheses are examined with respect to food allergy, namely the hygiene hypothesis, the dietary fat hypothesis, the antioxidant hypothesis, and the vitamin D hypotheses. An alternative hypothesis is proposed, suggesting that sensitization to allergen occurs through environmental exposure to allergen through the skin and that consumption of food allergen induces oral tolerance. This hypothesis provides a possible explanation for the close link between eczema and the development of food allergies. It also suggests novel interventional strategies to prevent the development of food allergies.

Food allergy-lessons from Asia

OBJECTIVE

: This is a review on published data available on food allergy in East Asia and a discussion on the insights that it offers.

METHODS

: PubMed searches were made for terms food allergy and anaphylaxis, in combination with Asia.

RESULTS

: There is a paucity of population-based prevalence studies on food allergy in Asia. Certain unique food allergens, such as buckwheat, chestnuts, chickpeas, bird's nest, and royal jelly, which are consumed extensively by certain Asian populations have resulted in clinical food allergy of little importance in other populations. Crustacean shellfish is of importance in this region relative to other common food allergens. The high consumption of these foods and possibly coupled with cross-reactive tropomyosins from dominant inhalant dust mite and cockroach allergens in this region may explain this phenomenon. In contrast, the prevalence of peanut allergy is relatively low in this region. The reasons for this difference are not apparent. However, this may be a reflection of the general reduced propensity in this region to allergic diseases as seen with asthma.

CONCLUSIONS

: Further research on food allergy in Asia is warranted because it offers unique opportunities to further our understanding on the influence of population and environment.

Dietary approaches to the prevention of food allergy

PURPOSE OF REVIEW

The primary prevention of food allergy and atopy has become a public health priority in developed countries. Although some preventive dietary interventions have entered common practice, the level of evidence underpinning these strategies varies.

RECENT FINDINGS

Exclusive breast-feeding and delayed introduction of complementary foods from the age of 4-6 months are key strategies in primary food allergy and atopy prevention. Maternal elimination diets during pregnancy and lactation are currently not recommended. Partially and extensively hydrolyzed formulae may confer a small preventive effect in high-risk infants. Amino acid-based formula is, however, considered a treatment formula and not recommended for primary allergy prevention. The effect of prebiotic oligosaccharides and probiotic bacteria in prevention of food allergy remains unclear and requires further investigation. Maternal fish oil supplementation during pregnancy shows promise in reducing the risk of allergic sensitization in the infant, but prospective long-term data are required. Fish oil supplementation in young infants was not effective.

SUMMARY

Although there is evidence for the primary dietary prevention of eczema and possible respiratory allergies, data on food allergy prevention have, so far, remained less convincing. Further prospective research is needed to clarify the effectiveness of dietary interventions in primary food allergy prevention.