The effect of brief neonatal exposure to cows' milk on atopic symptoms up to age 5

Consumption of cow's milk formula in the nursery and the development of milk allergy

BACKGROUND

The effect of the amount of transient cow's milk formula (CMF) consumed during the first days of life on IgE-cow's milk allergy (IgE-CMA) is unknown.

METHODS

A cohort of 58 patients with IgE-CMA was identified from a large scale population-based study of 13,019 infants followed from birth. A group of 116 infants matched for sex and breastfeeding only duration (beyond the nursery period), and another random group of 259 healthy infants were used as controls. Parents were interviewed and the infants' medical records were searched to assess CMF consumption in the nursery.

RESULTS

While 96% of the mothers of the 174 infants (58 with Cow's milk allergy and 116 controls) reported on exclusive breastfeeding during the stay in the nursery, CMF consumption was documented in 96 (55%) of the infants. Of those, most (57; 59%) received one to three feedings, 20 (21%) received four to nine feedings, and 19 (20%) received ≥10 feedings. Fewer formula feeds (1-3) were significantly more common in the allergic group than ≥4 feeds (p = 0.0003) and no feeds at all (p = 0.02) compared to controls (n = 116). Of those exclusively breastfed in the nursery, 13/23 allergic infants (57%) introduced CMF at age 105-194 days (the period with highest-risk for IgE-CMA) compared to 33/98 (34%) from the random control group (n = 259) (p = 0.04).

CONCLUSIONS

Most infants end up receiving few CMF feeds in the nursery. Transient CMF in the nursery is associated with increased risk of IgE-CMA.

Relevance of Early Introduction of Cow’s Milk Proteins for Prevention of Cow’s Milk Allergy

Food allergy incidence has increased worldwide over the last 20 years. For prevention of food allergy, current guidelines do not recommend delaying the introduction of allergenic foods. Several groundbreaking studies, such as the Learning Early About Peanut Allergy study, showed that the relatively early introduction of this allergenic food between 4–6 months of age reduces the risk of peanut allergy. However, less is known about the introduction of cow’s milk, as many children already receive cow’s-milk-based formula much earlier in life. This can be regular cow’s milk formula with intact milk proteins or hydrolyzed formulas. Several recent studies have investigated the effects of early introduction of cow’s-milk-based formulas with intact milk proteins on the development of cow’s milk allergy while breastfeeding. These studies suggest that depending on the time of introduction and the duration of administration of cow’s milk, the risk of cow’s milk allergy can be reduced (early introduction) or increased (very early introduction followed by discontinuation). The aim of this narrative review is to summarize these studies and to discuss the impact of early introduction of intact cow’s milk protein—as well as hydrolyzed milk protein formulas—and the development of tolerance versus allergy towards cow’s milk proteins.

Primary Prevention of Allergic Diseases: The Role of Early Exposure to Cow's Milk Formula

The burden of atopic disorders is continuously worsening worldwide, especially in childhood. Therefore, risk factors and preventive measures have been called into question. The age when infants introduce complementary foods, varies greatly according to traditional habits, clinical practice recommendations, and breastfeeding duration. It is still debated the impact of early exposure to cow's milk on the increase of allergic diseases, mainly food allergy, and atopic dermatitis. Many factors may play a role in this potential link, such as genetic variation, parental atopy, infant feeding regimens. Recent evidences suggest that the early introduction of complementary foods (up to 6 months of age), including cow's milk, could prevent the development of food allergies. So, several countries included this new approach into feeding guidelines. Our review will focus on the influence of early exposure to cow's milk formula on the development of allergic diseases. Some trials found that cow's milk supplementation in the first days of life could even increase the development of IgE sensitization and food allergies. Other trials did not show any efficacy on prevention of allergic disorders. Further studies are needed to understand the prospective for allergy prevention related to optimal timing of cow's milk formula introduction.

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.

Association between Caesarean Delivery and Isolated Doses of Formula Feeding in Cow Milk Allergy

BACKGROUND

Cow milk allergy (CMA) is the most common food allergy in breastfed infants. The aim of this study is to verify whether certain perinatal factors may influence the development of CMA immunoglobulin E (IgE)+.

METHODS

A retrospective, observational study of case and control groups was carried out. Information was collected of patients with CMA IgE+ from our department during the years 1990-2013. Patients of the same age and sex were recruited for the control group. Information on the following variables was collected: sex, age, pregnancy tolerance, duration of pregnancy, type of delivery, isolated doses of formula feeding in hospital (FFH), duration of breastfeeding, and family history of allergy (defined as ≥1 first-degree family member with allergic disease). Statistical analysis was performed using multivariate logistic regression techniques.

RESULTS

A total of 211 cases were included in this study. Multivariate analysis showed an influence of duration of breastfeeding, FFH to be a risk factor (OR 4.94; 95% CI 2.68-9.08), especially in caesarean delivery (OR 11.82; 95% CI 2.64-47.50), and prematurity (OR 0.29; 95% CI 0.09-0.92) to be a protective factor.

CONCLUSIONS

Perinatal factors play a key role in the development of CMA IgE+, with an influence of breastfeeding duration, FFH and caesarean delivery as risk factors and prematurity as a protective factor. While family history had no important role, environmental factors were more decisive.

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.

A programme of research to set priorities and reduce uncertainties for the prevention and treatment of skin disease

Background

Skin diseases are very common and can have a large impact on the quality of life of patients and caregivers. This programme addressed four diseases: (1) eczema, (2) vitiligo, (3) squamous cell skin cancer (SCC) and (4) pyoderma gangrenosum (PG).

Objective

To set priorities and reduce uncertainties for the treatment and prevention of skin disease in our four chosen diseases.

Design

Mixed methods including eight systematic reviews, three prioritisation exercises, two pilot randomised controlled trials (RCTs), three feasibility studies, two core outcome initiatives, four funding proposals for national RCTs and one completed national RCT.

Setting

Secondary care, primary care and the general population.

Participants

Patients (and their caregivers) with eczema, vitiligo, SCC and PG, plus health-care professionals with an interest in skin disease.

Interventions

Our three intervention studies included (1) barrier enhancement using emollients from birth to prevent eczema (pilot RCT); (2) handheld narrowband ultraviolet light B therapy for treating vitiligo (pilot RCT); and (3) oral ciclosporin (Neoral®, Novartis Pharmaceuticals) compared with oral prednisolone for managing PG (pragmatic national RCT).

Results

Systematic reviews included two overarching systematic reviews of RCTs of treatments for eczema and vitiligo, an umbrella review of systematic reviews of interventions for the prevention of eczema, two reviews of treatments for SCC (one included RCTs and the second included observational studies), and three reviews of outcome measures and outcome reporting. Three prioritisation partnership exercises identified 26 priority areas for future research in eczema, vitiligo and SCC. Two international consensus initiatives identified four core domains for future eczema trials and seven core domains for vitiligo trials. Two pilot RCTs and three feasibility studies critically informed development of four trial proposals for external funding, three of which are now funded and one is pending consideration by funders. Our pragmatic RCT tested the two commonly used systemic treatments for PG (prednisolone vs. ciclosporin) and found no difference in their clinical effectiveness or cost-effectiveness. Both drugs showed limited benefit. Only half of the participants’ ulcers had healed by 6 months. For those with healed ulcers, recurrence was common (30%). Different side effect profiles were noted for each drug, which can inform clinical decisions on an individual patient basis. Three researchers were trained to PhD level and a dermatology patient panel was established to ensure patient involvement in all aspects of the programme.

Conclusions

Findings from this programme of work have already informed clinical guidelines and patient information resources. Feasibility studies have ensured that large national pragmatic trials will now be conducted on important areas of treatment uncertainty that address the needs of patients and the NHS. There is scope for considerable improvement in terms of trial design, conduct and reporting for RCTs of skin disease, which can be improved through wider collaboration, registration of trial protocols and complete reporting and international consensus over core outcome sets. Three national trials have now been funded as a result of this work. Two international initiatives to establish how best to measure the core outcome domains for eczema and vitiligo are ongoing.

Trial registration

Current Controlled Trials Barrier Enhancement for Eczema Prevention (BEEP) (ISRCTN84854178 and NCT01142999), Study of Treatments fOr Pyoderma GAngrenosum Patients (STOP GAP) (ISRCTN35898459) and Hand Held NB-UVB for Early or Focal Vitiligo at Home (HI-Light Pilot Trial) (NCT01478945).

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 4, No. 18. See the NIHR Journals Library website for further project information.

Prevention of food and airway allergy: consensus of the Italian Society of Preventive and Social Paediatrics, the Italian Society of Paediatric Allergy and Immunology, and Italian Society of Pediatrics

BACKGROUND

Allergic sensitization in children and allergic diseases arising therefrom are increasing for decades. Several interventions, functional foods, pro- and prebiotics, vitamins are proposed for the prevention of allergies and they can't be uncritically adopted.

OBJECTIVE

This Consensus document was developed by the Italian Society of Preventive and Social Paediatrics and the Italian Society of Paediatric Allergy and Immunology. The aim is to provide updated recommendations regarding allergy prevention in children.

METHODS

The document has been issued by a multidisciplinary expert panel and it is intended to be mainly directed to primary care paediatricians. It includes 19 questions which have been preliminarily considered relevant by the panel. Relatively to each question, a literature search has been performed, according to the Italian National Guideline Program. Methodology, and a brief summary of the available literature data, has been provided. Many topics have been analyzed including the role of mother's diet restriction, use of breast/formula/hydrolyzed milk; timing of introduction of complementary foods, role (if any) of probiotics, prebiotics, vitamins, exposure to dust mites, animals and to tobacco smoke.

RESULTS

Some preventive interventions have a strong level of recommendation. (e.g., the dehumidifier to reduce exposure to mite allergens). With regard to other types of intervention, such as the use of partially and extensively hydrolyzed formulas, the document underlines the lack of evidence of effectiveness. No preventive effect of dietary supplementation with polyunsaturated fatty acids, vitamins or minerals has been demonstrated. There is no preventive effect of probiotics on asthma, rhinitis and allergic diseases. It has demonstrated a modest effect, but steady, in the prevention of atopic dermatitis.

CONCLUSIONS

The recommendations of the Consensus are based on a careful analysis of the evidence available. The lack of evidence of efficacy does not necessarily imply that some interventions may not be effective, but currently they can't be recommended.

Position document: IgE-mediated cow's milk allergy

The present document offers an update on the recommendations for managing patients with cow's milk allergy - a disorder that manifests in the first year of life, with an estimated prevalence of 1.6-3% in this paediatric age group. The main causal allergens are the caseins and proteins in lactoserum (beta-lactoglobulin, alpha-lactoalbumin), and the clinical manifestations are highly variable in terms of their presentation and severity. Most allergic reactions affect the skin, followed by the gastrointestinal and respiratory systems, and severe anaphylaxis may occur. The diagnosis of cow's milk allergy is based on the existence of a suggestive clinical history, a positive allergy study and the subsequent application of controlled exposure testing, which constitutes the gold standard for confirming the diagnosis. The most efficient treatment for cow's milk allergy is an elimination diet and the use of adequate substitution formulas. The elimination diet must include milk from other mammals (e.g., sheep, goat, etc.) due to the risk of cross-reactivity with the proteins of cow's milk. Most infants with IgE-mediated cow's milk allergy become tolerant in the first few years of life. In those cases where cow's milk allergy persists, novel treatment options may include oral immunotherapy, although most authors do not currently recommend this technique in routine clinical practice. Enough evidence is not there to confirm the efficacy of elimination diets in the mother and infant for preventing the appearance of cow's milk allergy. Likewise, no benefits have been observed with prebiotic and probiotic dietetic supplements in infants for preventing food allergy.

Historic overview of allergy research in the Netherlands

Research in allergy has a long history in the Netherlands, although the relation with immunology has not always been appreciated. In many aspects Dutch researchers have made major contribution in allergy research. This ranges from the first characterization of house dust mite as an important allergen, the first characterization of human Th2 and Th1 T cell clones, to the development of diagnostic test systems. In this overview Aalberse and Knol have made an overview of the major contributions of Dutch immunologists in allergy.

Primary prevention of food allergy in children and adults: systematic review

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.

EAACI food allergy and anaphylaxis guidelines. Primary prevention of food allergy

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.

How should an incident case of atopic dermatitis be defined? A systematic review of primary prevention studies

BACKGROUND

Eczema prevention is now an active area of dermatologic and allergy research. Defining an incident case is therefore a prerequisite for such a study.

OBJECTIVE

We sought to examine how an incident case of atopic dermatitis was defined in previous atopic dermatitis prevention studies in order to make recommendations on a standard definition of new atopic dermatitis cases for use in future prevention trials.

METHODS

We conducted a systematic review of controlled interventional atopic dermatitis prevention studies by using searches of MEDLINE and Cochrane databases for studies published from 1980 to the end of January 2011. Studies that included atopic dermatitis as a secondary outcome, such as asthma prevention trials, were included.

RESULTS

One hundred two studies were included in the final analysis, of which 27 (26.5%) did not describe any criteria for defining an incident case of atopic dermatitis. Of the remaining 75 studies with reported disease criteria, the Hanifin-Rajka criteria were the most commonly used (28 studies). A disease definition unique to that particular study (21 studies) was the second most commonly used disease definition, although the sources for such novel definitions were not cited.

CONCLUSIONS

The results from this systematic review highlight the need for improved reporting and standardization of the definition used for an incident case in atopic dermatitis prevention studies. Most prevention studies have used disease definitions such as the Hanifin-Rajka criteria that include disease chronicity. While acceptable for cumulative incidence outcomes, inclusion of disease chronicity precludes the precise measurement of disease onset. We propose a definition based on existing scientific studies that could be used in future prospective studies.

Can food allergy be prevented? The current evidence

Food allergy is a recognized public health concern, for which preventative strategies are required. Although an intervention that adequately protects against the development of food allergy has still to be identified, limited benefits have been shown for the prevention of related allergic conditions such as eczema, and to a lesser extent asthma and rhinitis; these benefits are usually limited to at-risk populations. Prevention strategies need to be tested using randomized controlled study designs that account for the numerous methodological challenges, safety concerns, and necessary ethical limitations.

Clinical practice: Breastfeeding and the prevention of allergy

The increase in allergic disease prevalence has led to heightened interest in the factors determining allergy risk, fueled by the hope that by influencing these factors one could reduce the prevalence of allergic conditions. The most important modifiable risk factors for allergy are maternal smoking behaviour and the type of feeding. A smoke-free environment for the child (to be), exclusive breastfeeding for 4-6 months and the postponement of supplementary feeding (solids) until 4 months of age are the main measures considered effective. There is no place for restricted diets during pregnancy or lactation. Although meta-analyses suggest that hypoallergenic formula after weaning from breastfeeding grants protection against the development of allergic disease, the evidence is limited and weak. Moreover, all current feeding measures aiming at allergy prevention fail to show effects on allergic manifestations later in life, such as asthma. In conclusion, the allergy preventive effect of dietary interventions in infancy is limited. Counselling of future parents on allergy prevention should pay attention to these limitations.

Age at first introduction of cow milk products and other food products in relation to infant atopic manifestations in the first 2 years of life: the KOALA Birth Cohort Study

OBJECTIVES

Scientific evidence is scarce about timing of solid-food introduction and its association with the development of atopy. We aimed to evaluate any associations between the introduction of cow milk products/other solid food products and infant atopic manifestations in the second year of life, taking into account reverse causation.

METHODS

Data from 2558 infants in an ongoing prospective birth cohort study in the Netherlands were analyzed. Data on the main determinants (introduction of cow milk products and other food products), outcomes (eczema; atopic dermatitis [United Kingdom Working Party criteria]; recurrent wheeze; any sensitization; sensitization against cow milk, hen egg, peanut, and at least 1 inhalant allergen), and confounders were collected by repeated questionnaires at 34 weeks of gestation and 3, 7, 12, and 24 months postpartum. Information on sensitization was gathered by venous blood collections performed during home visits at age 2. Analyses were performed by multiple logistic regression analyses.

RESULTS

More delay in introduction of cow milk products was associated with a higher risk for eczema. In addition, a delayed introduction of other food products was associated with an increased risk for atopy development at the age of 2 years. Exclusion of infants with early symptoms of eczema and recurrent wheeze (to avoid reverse causation) did not essentially change our results.

DISCUSSION

Delaying the introduction of cow milk or other food products may not be favorable in preventing the development of atopy.

Dietary prevention of allergic disease in children: are current recommendations really based on good evidence?

We provide a critical appraisal of the literature on the effects of dietary prevention of atopic disease in children. In our view, currently available studies suffer from lack of blinding which is a major problem if the primary end point is subjective (such as the diagnosis of eczema). In addition, long-term follow-up suggests that atopic symptoms are delayed rather than truly prevented, and that only the mildest cases are prevented (or delayed). Although it has been reported that cow's milk allergy is truly prevented by dietary interventions in early life, this has never been demonstrated by double-blind placebo-controlled food challenges. No studies to date have shown effects of hypoallergenic formulae on objective markers of atopic sensitization, such as specific IgE levels. Finally, there is no universally accepted pathophysiological mechanism which could explain the usefulness of hypoallergenic formulae in allergy prevention. In conclusion, we feel that the currently available evidence on the allergy preventive effects of hypoallergenic formulae is insufficient to justify blanket advice being given to 'high risk' families. Such advice gives parents the hope that they can actually prevent allergy in their children which may not be justified. A cautious approach in advising interventions with hypoallergenic formulae to prevent allergy in high-risk infants is warranted.

Formulas containing hydrolysed protein for prevention of allergy and food intolerance in infants

BACKGROUND

Allergies and food reactions are common and may be associated with foods including adapted cow's milk formula. Formulas containing hydrolysed proteins have been used to treat infants with allergy or food intolerance. However, it is unclear whether hydrolysed formula can be advocated for prevention of allergy and food intolerance in infants without evidence of allergy or food intolerance.

OBJECTIVES

To determine the effect of feeding hydrolysed formulas on allergy and food intolerance in infants and children compared to adapted cow's milk or human breast milk. If hydrolysed formulas are effective, to determine what type of hydrolysed formula is most effective including extensively and partially hydrolysed formulas. To determine which infants benefit, including infants at low or high risk of allergy and infants receiving early, short term or prolonged formula feeding.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. The review was updated with searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2006), MEDLINE (1966-March 2006), EMBASE (1980-March 2006) and CINAHL (1982-March 2006) and previous reviews including cross references.

SELECTION CRITERIA

Randomised and quasi-randomised trials that compare the use of a hydrolysed infant formula to human milk or cow's milk formula. Trials with >80% follow up of participants were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Eligibility of studies for inclusion, methodological quality and data extraction were assessed independently by each review author. Primary outcomes included clinical allergy, specific allergies and food intolerance. Meta-analysis was conducted using a fixed effects model.

MAIN RESULTS

Two trials compared early, short term hydrolysed formula to human milk feeding. No significant difference in infant allergy or childhood cow's milk allergy (CMA) were reported. No eligible trial compared prolonged hydrolysed formula to human milk feeding. Two trials compared early, short term hydrolysed formula to cow's milk formula feeding. No significant benefits were reported. One large quasi-random study reported a reduction in infant CMA of borderline significance in low risk infants (RR 0.62, 95% CI 0.38, 1.00). Ten eligible studies compared prolonged feeding with hydrolysed formula versus cow's milk formula in high risk infants. Meta-analysis found a significant reduction in infant allergy (seven studies, 2514 infants; typical RR 0.79, 95% CI 0.66, 0.94), but not in the incidence of childhood allergy (two studies, 950 infants; typical RR 0.85, 95% CI 0.69, 1.05). There was no significant difference in infant eczema (eight studies, 2558 infants, typical RR 0.84, 95% CI 0.68, 1.04), childhood eczema incidence (two studies, 950 infants, typical RR 0.83, 95% CI 0.63, 1.10), childhood eczema prevalence (one study, 872 infants; RR 0.66, 95% CI 0.43, 1.02), or infant or childhood asthma, rhinitis and food allergy. One study reported a significant reduction in infants with CMA with confirmed atopy (RR 0.36, 95% CI 0.15, 0.89). Subgroup analysis of trials blinded to formula found no significant difference in infant allergy (four studies, 2156 infants; typical RR 0.87, 95% CI 0.69, 1.08) or childhood allergy incidence (one study, 872 infants; RR 0.91, 95% CI 0.73, 1.14). No eligible trial examined the effect of prolonged hydrolysed formula feeding on allergy beyond early childhood. There is evidence that preterm or low birthweight infants fed a hydrolysed preterm formula have significantly reduced weight gain, but not in other growth parameters (head circumference or length). Studies in term infants report no adverse effects on growth. Subgroup analysis of trials of partially hydrolysed versus cow's milk formula found a significant reduction in infant allergy (six studies, 1391 infants; typical RR 0.79, 95% CI 0.65, 0.97) but not childhood allergy, or infant or childhood asthma, eczema or rhinitis. Methodological concerns were the same as for the overall analysis. Analysis of trials of extensively hydrolysed formula versus cow's milk formula found no significant differences in allergy or food intolerance. Infants fed extensively hydrolysed formula compared with partially hydrolysed formula had a significant reduction in food allergy (two studies, 341 infants; typical RR 0.43, 95% CI 0.19, 0.99), but there was no significant difference in all allergy or any other specific allergy incidence. Comparing extensively hydrolysed casein containing formula with cow's milk formula, one study (431 infants) reported a significant reduction in childhood allergy incidence (RR 0.72, 95% CI 0.53, 0.97). Meta-analysis found a significant reduction in infant eczema (three studies, 1237 infants; typical RR 0.71, 95% CI 0.51, 0.97). One study reported a significant reduction in childhood eczema incidence (RR 0.66, 95% CI 0.44, 0.98) and prevalence (RR 0.50, 95% CI 0.27, 0.92).

AUTHORS' CONCLUSIONS

There is no evidence to support feeding with a hydrolysed formula for the prevention of allergy compared to exclusive breast feeding. In high risk infants who are unable to be completely breast fed, there is limited evidence that prolonged feeding with a hydrolysed formula compared to a cow's milk formula reduces infant and childhood allergy and infant CMA. In view of methodological concerns and inconsistency of findings, further large, well designed trials comparing formulas containing partially hydrolysed whey, or extensively hydrolysed casein to cow's milk formulas are needed.

Clinical course and prognosis of cow's milk allergy are dependent on milk-specific IgE status

BACKGROUND

Large, prospective population-based studies on clinical course, development of tolerance, and risk for other atopy in children with cow's milk allergy (CMA) are lacking.

OBJECTIVE

We investigated the development of tolerance and the risk for asthma, rhinoconjunctivitis, atopic dermatitis, and sensitization in children with CMA followed to school age.

METHODS

We followed 118 children with CMA until recovery and repeatedly measured their sensitization to cow's milk (CM). At age 8.6 years, 94 allergic subjects and 80 control subjects from the same cohort were studied for atopic diseases and sensitization. In addition, the parents of 12 allergic subjects and 26 control children returned a questionnaire on atopy, respectively.

RESULTS

IgE-mediated CMA was detected in 86 (73%) children; at age 8.6 years, 13 (15%) had persistent CMA. All children with IgE-negative CMA were tolerant by age 5.0 years (P < .0001). Risk factors for persistent CMA at age 2.0 years were sensitization to CM at age 1.6 years (odds ratio, 6.3; 95% CI, 2.6-15.2), urticaria at diagnostic challenge (odds ratio, 3.3; 95% CI, 1.4-7.8), CM exposure at the maternity hospital (odds ratio, 3.2; 95% CI, 1.4-7.8), and early sensitization to egg (odds ratio, 2.8; 95% CI, 1.2-6.6). By age 8.6 years, children with IgE-positive CMA more frequently had asthma (31% vs 13%, P < or = .01), rhinoconjunctivitis (66% vs 21%, P < or = .001), atopic eczema (81% vs 26%, P < or = .001), and sensitization to any allergen (88% vs 39%, P < or = .001) than control subjects. CMA and family history of atopy were independent risk factors for atopic diseases, and CMA was also a risk factor for sensitization to inhalant allergens.

CONCLUSION

IgE-mediated CMA often persists to school age and is a risk factor for other atopy; non-IgE-mediated CMA, by contrast, is a benign infantile condition.

Transient environmental exposures on the developing immune system: implications for allergy and asthma

PURPOSE OF REVIEW

Early environmental exposures have been extensively studied as potential causes of the observed increase in allergic disease over time. Transient fetal or neonatal exposures in particular are of interest in that they may occur during critical windows of immune system development. Due to the tremendous complexity of variables in early life, as well as the difficulty in randomizing many interventions, it is very difficult to properly study these exposures. Some progress, however, has been made and some more candidates for study may be emerging. Of particular interest are micronutrients, whose ever-changing use and immunomodulatory capabilities make them prime targets for study.

RECENT FINDINGS

New risk factors for atopic disease have emerged from the pool of early life interventions, such as caesarian section, prolonged labor and infant multivitamin supplementation. Data are emerging regarding micronutrient status and supplementation and their effects on the developing immune system and risk for allergic disease. Clinical trials have yet to demonstrate much causality but, in some cases, it is too early to make any judgments.

SUMMARY

The gold standard of randomized clinical trials has not borne out a number of proposed early-life allergic risk factors, while other trials are too incomplete to draw any conclusions so far. Properly designed studies for other risk factor interventions may still be achievable, provided that there is a proper understanding of the interventions, populations and outcomes.

Dietary prevention of allergic diseases in infants and small children. Part III: Critical review of published peer-reviewed observational and interventional studies and final recommendations

The role of primary prevention of allergic diseases has been a matter of debate for the last 40 years. In order to shed some light on this issue, a group of experts of the Section of Pediatrics EAACI reviewed critically the existing literature on the subject. An analysis of published peer-reviewed observational and interventional studies was performed following the statements of evidence as defined by WHO. The results of the analysis indicate that breastfeeding is highly recommended for all infants irrespective of atopic heredity. A dietary regimen is unequivocally effective in the prevention of allergic diseases in high-risk children. In these patients breastfeeding combined with avoidance of solid food and cow's milk for at least 4-6 months is the most effective preventive regimen. In the absence of breast milk, formulas with documented reduced allergenicity for at least 4-6 months should be used.