Cow's milk-specific cellular and humoral immune responses and atopy skin symptoms in infants from atopic families fed a partially (pHF) or extensively (eHF) hydrolyzed infant formula

Infant Formulas With Partially or Extensively Hydrolyzed Milk Proteins for the Prevention of Allergic Diseases: A Systematic Review and Meta-Analysis of Clinical Trials

Despite the widely recommended usage of partially hydrolyzed formula (PHF) or extensively hydrolyzed formula (EHF) of milk protein for preventing allergic diseases (ADs), clinical studies have been inconclusive regarding their efficacy compared with that of cow's milk formula (CMF) or breast milk (BM). We aimed to systematically evaluate the effects of PHF or EHF compared with those of CMF or BM on risk of ADs (cow's milk allergy, allergic rhinitis, eczema, asthma, wheeze, food allergy, and sensitization) in children. We searched PubMed, Embase, Cochrane Library, and Web of Science for clinical trials published from inception to 21 October, 2022. We used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to grade the strength of evidence. Overall, 24 trials (10,950 infants) were included, 17 of which specifically included high-risk infants. GRADE was low for the evidence that, compared with CMF, infants early fed with EHF had lower risk of cow's milk allergy at age 0-2 y [relative risk (RR): 0.62; 95% CI: 0.39, 0.99]. Moderate evidence supported that PHF and EHF reduced risk of eczema in children aged younger or older than 2 y, respectively (RR: 0.71; 95% CI: 0.52, 0.96; and RR: 0.79; 95% CI: 0.67, 0.94, respectively). We also identified moderate systematic evidence indicating that PHF reduced risk of wheeze at age 0-2 y compared with CMF (RR: 0.50; 95% CI: 0.29, 0.85), but PHF and EHF increased the risk compared with BM (RR: 1.61; 95% CI: 1.11, 2.31; and RR: 1.64; 95% CI: 1.26, 2.14). Neither PHF nor EHF had significant effects on other ADs in children of any age. In conclusion, compared with CMF, PHF, or EHF had different preventive effect on cow's milk allergy, eczema, and wheeze. Compared with BM, both PHF and EHF may increase risk of wheeze but not other ADs. Given that most trials included only high-risk infants, more research on non-high-risk infants is warranted before any generalization is attempted. This protocol was registered at PROSPERO as CRD42022320787.

Atopic dermatitis and nutrition

Atopic dermatitis, a common chronic and pruritic inflammatory skin disorder, can create significant disruptions in sleep and quality of life. Atopic dermatitis is especially common in infants and children; therefore, safe and natural therapeutic options have considerable appeal. Over the past several decades, there has been an increase in the prevalence of atopic dermatitis in industrialized nations. Also, there is variability in the prevalence of atopic dermatitis in the United States, both across and within states. Environmental factors including diet are believed to be associated with this increased risk. Dietary interventions continue to be an area of keen interest and have been studied extensively, albeit with variable results. Maternal dietary restrictions during pregnancy and lactation, hydrolyzed or partially hydrolyzed formulas, delaying the introduction of solid foods, and omega-3 or omega-6 fatty acids supplementation do not appear to have a beneficial effect on the treatment and prevention of atopic dermatitis. Exclusive breastfeeding for 3 to 4 months, a diet high in fruits and vegetables, and prebiotics might have a beneficial effect. Because environmental triggers, including dietary exposures, are thought to play a role in the pathogenesis of atopic dermatitis, we herein review the current literature on the role of dietary habits, vitamin and mineral supplementation, and probiotics on the treatment and prevention of atopic dermatitis.

Nutritional Factors in the Prevention of Atopic Dermatitis in Children

Atopic dermatitis is one of the most frequent chronic skin diseases worldwide and often develops within the first few years of life. Recent advancements in our knowledge of its pathophysiology have brought to light the role of genetic predisposition and environmental triggers. With the increasing prevalence of allergic diseases, there is a strong need for a better understanding of the various modifiable eliciting factors of such conditions. The concomitant rise in food allergy and insights into the skin barrier function has highlighted the role of nutrition and diet in the prevention and modification of allergic disorders. Furthermore, the identification of the skin as an important route of sensitization, and the risk of progression to asthma later in life, stress the significance of optimizing our management of skin inflammation in the prevention of allergies. Many nutritional factors, including the type of maternal diet during pregnancy, the duration of breastfeeding, the epicutaneous exposure of allergenic food proteins in the first few years of life, the timing of the introduction of complementary foods, the supplementation of vitamins and probiotics/prebiotics during prenatal and early life, have been assessed as potential targets for the prevention of atopy and eczema. Here, we review the latest data addressing prenatal and perinatal nutritional and dietary interventions in the primary prevention of atopic dermatitis. Also, we define knowledge gaps and targets for future research in the prevention of atopic dermatitis.

Dietary Interventions and Nutritional Factors in the Prevention of Pediatric Asthma

Asthma is the most frequent chronic disease in children, and its pathogenesis involves genetic, epigenetic, and environmental factors. The rapid rise in the prevalence of asthma registered over the last few decades has stressed the need to identify the environmental and modifiable factors associated with the development of the disease. In particular, there is increasing interest in the role of modifiable nutritional factors specific to both the prenatal and post-natal early life as, during this time, the immune system is particularly vulnerable to exogenous interferences. Several dietary factors, including maternal diet during pregnancy, the duration of breastfeeding, the use of special milk formulas, the timing of the introduction of complementary foods, and prenatal and early life supplementation with vitamins and probiotics/prebiotics, have been addressed as potential targets for the prevention of asthma. In this review, we outline recent findings on the potential role of prenatal and perinatal dietary and nutritional interventions for the primary prevention of pediatric asthma. Moreover, we addressed unmet needs and areas for future research in the prevention of childhood-onset asthma.

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.

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.

Hydrolysed formula and risk of allergic or autoimmune disease: systematic review and meta-analysis

OBJECTIVE

To determine whether feeding infants with hydrolysed formula reduces their risk of allergic or autoimmune disease.

DESIGN

Systematic review and meta-analysis, as part of a series of systematic reviews commissioned by the UK Food Standards Agency to inform guidelines on infant feeding. Two authors selected studies by consensus, independently extracted data, and assessed the quality of included studies using the Cochrane risk of bias tool.

DATA SOURCES

Medline, Embase, Web of Science, CENTRAL, and LILACS searched between January 1946 and April 2015.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Prospective intervention trials of hydrolysed cows' milk formula compared with another hydrolysed formula, human breast milk, or a standard cows' milk formula, which reported on allergic or autoimmune disease or allergic sensitisation.

RESULTS

37 eligible intervention trials of hydrolysed formula were identified, including over 19,000 participants. There was evidence of conflict of interest and high or unclear risk of bias in most studies of allergic outcomes and evidence of publication bias for studies of eczema and wheeze. Overall there was no consistent evidence that partially or extensively hydrolysed formulas reduce risk of allergic or autoimmune outcomes in infants at high pre-existing risk of these outcomes. Odds ratios for eczema at age 0-4, compared with standard cows' milk formula, were 0.84 (95% confidence interval 0.67 to 1.07; I(2)=30%) for partially hydrolysed formula; 0.55 (0.28 to 1.09; I(2)=74%) for extensively hydrolysed casein based formula; and 1.12 (0.88 to 1.42; I(2)=0%) for extensively hydrolysed whey based formula. There was no evidence to support the health claim approved by the US Food and Drug Administration that a partially hydrolysed formula could reduce the risk of eczema nor the conclusion of the Cochrane review that hydrolysed formula could allergy to cows' milk.

CONCLUSION

These findings do not support current guidelines that recommend the use of hydrolysed formula to prevent allergic disease in high risk infants.

REVIEW REGISTRATION

PROSPERO CRD42013004252.

Primary prevention of allergic disease through nutritional interventions

With the rising prevalence of atopic disease, primary prevention may play a role in reducing its burden, especially in high-risk infants. With this in mind, the Adverse Reactions to Foods Committee of the American Academy of Allergy, Asthma & Immunology was charged with the task of developing recommendations for primary care physicians and specialists about the primary prevention of allergic disease through nutritional interventions according to current available literature and expert opinion. Recommendations that are supported by data are as follows. Avoidance diets during pregnancy and lactation are not recommended at this time, but more research is necessary for peanut. Exclusive breast-feeding for at least 4 and up to 6 months is endorsed. For high-risk infants who cannot be exclusively breast-fed, hydrolyzed formula appears to offer advantages to prevent allergic disease and cow's milk allergy. Complementary foods can be introduced between 4 and 6 months of age. Because no formal recommendations have been previously provided about how and when to introduce the main allergenic foods (cow's milk, egg, soy, wheat, peanut, tree nuts, fish, shellfish), these are now provided, and reasons to consider allergy consultation for development of a personalized plan for food introduction are also presented.

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.

Economic evaluation of a 100% whey-based partially hydrolyzed infant formula in the prevention of atopic dermatitis among Danish children

OBJECTIVE

A pharmacoeconomic analysis was undertaken to determine costs, consequences, and cost-effectiveness of a brand of partially hydrolyzed 100%-whey formula manufactured by Nestlé (PHF-W), in the prevention of atopic dermatitis (AD) in 'at risk' Danish children compared to extensively hydrolyzed formula (EHF-Whey or Casein).

METHODS

Given the non-significant differences between PHF-W and EHF, the base case analytic approach amounted to a cost-minimization analysis (CMA) reporting the difference in formula acquisition costs over the period of formula consumption for the population of interest. However, sensitivity analyses (SAs) were undertaken to explore applying the nominal efficacy of PHF-W and EHF, thus leading to a cost-effectiveness analysis (CEA). Hence, an economic model based on a 12-month time horizon was developed synthesizing treatment pathways, resource utilization, and costs associated with the treatment of AD in the population of interest. The final economic outcome of the SAs was the incremental cost per avoided case (ICER) defined as the expected cost per avoided case of AD for PHF-W vs EHF, determined from three perspectives: the Ministry of Health (MOH), the family of the subject, and society (SOC).

RESULTS

In the base case CMA, savings of DKK 9 M, DKK 20 M, and DKK 29 M were generated for PHF-W vs EHF from the MOH, family, and SOC perspectives. In the sensitivity CEA, PHF-W was dominant over EHF-Whey from all perspectives, while EHF-Casein displayed against PHF-W unattractive ICERs of DKK 315,930, DKK 408,407, and DKK 724,337 from the MOH, family, and SOC perspectives. Probabilistic SAs indicated that PHF-W was 86% likely to be dominant over EHF-Whey, whereas EHF-Casein had no likelihood of dominating PHF-W.

CONCLUSION

Under a range of assumptions, this analysis demonstrated the attractiveness of PHF-W vs both types of EHF in the prevention of AD among 'at risk' Danish infants who are not or cannot be exclusively breastfed.

Meta-analysis of a partially hydrolysed 100%-whey infant formula vs. extensively hydrolysed infant formulas in the prevention of atopic dermatitis

OBJECTIVES

This study presents previously unpublished point and cumulative incidence rates and relative risks (RRs) for comparing a partially hydrolysed 100% whey-based infant formula, NAN-HA * (PHF-W) to extensively hydrolysed whey- (EHF-Whey) or casein-based (EHF-Casein) infant formulas in the prevention of atopic dermatitis (AD) in infants who cannot be breastfed exclusively. It also outlines methods to convert the above-mentioned data as well as data comparing PHF-W to cows' milk formula (SF) into inputs to be applied to a pharmacoeconomic model. * NAN-HA is a registered trade name of Nestlé SA, Switzerland.

METHODS

The incidence rates and RRs were obtained from a meta-analysis which analysed efficacy for PHF-W vs. EHF but did not present those. It took into consideration any relevant randomized controlled trial which compared the use of PHF-W with SF or EHF for the prevention of allergies. The primary outcomes of interest were the incidence, cumulative incidence and period prevalence of allergic manifestations and of AD in particular. Fifteen studies had been included for analysis of which six studies explored PHF-W vs. EHF. These results and PHF-W vs. SF data were adapted for inputs into a pharmacoeconomic model which used a spreadsheet decision-analytic economic model based on 3-month cycles to explore the cost-effectiveness of PHF-W vs. SF and EHF. Weights were applied to the incidence rates and RRs for each reported time period which were then adapted into 3-month indicators.

RESULTS

This meta-analysis for PHF-W (557 patients) vs. EHF-Whey (559 patients) yielded RR of 0.75 (0.54, 1.05) and 0.80 (0.63, 1.02) at 0-12 months and at 0-36 months, respectively. Corresponding RRs for PHF-W vs. EHF-Casein (580 patients) were 1.06 (0.74, 1.53) at 0-12 months and 1.13 (0.87, 1.47) at 0-36 months.

CONCLUSION

It appears that the efficacy of PHF-W falls within the range of that of both EHF formulas (whey and casein) and allows the application of these results in a pharmacoeconomic model.

Meta-analysis of the evidence for a partially hydrolyzed 100% whey formula for the prevention of allergic diseases

OBJECTIVE

Infants with a documented hereditary risk of atopy (i.e., an affected parent and/or sibling) who cannot be breastfed exclusively are recommended to receive a formula with confirmed reduced allergenicity, i.e., a partially or extensively hydrolyzed formula (pHF and eHF, respectively), as a means of preventing allergic reactions. The efficacy of each hydrolyzed formula for the prevention of allergic diseases should be established separately, as factors such as the protein source, hydrolysis method and degree of hydrolysis that often depend on the manufacturer contribute to differences among hydrolysates. The aim was to systematically review data on the efficacy of a partially hydrolyzed 100% whey formula (pHF) in reducing the risk of allergy in healthy infants at high risk for allergy.

METHODS

The Cochrane Library, MEDLINE, EMBASE, and CINAHL databases were searched in September 2009 (from inception to September 2009) for randomized and quasi-randomized controlled trials (RCTs); additional references were obtained from reviewed articles. The company that manufactures the pHF used was contacted for unpublished data.

RESULTS

The search yielded 84 citations. Fifteen RCTs were included, some of which had potential methodological limitations such as unclear or inadequate allocation concealment, no intention-to-treat analysis, and no true blinding. For primary outcomes, i.e., all allergic diseases and atopic eczema/atopic dermatitis, use of the pHF compared with standard formula (SF) was associated with reduced risks (incidence, cumulative incidence, period prevalence) that were statistically significant for most, albeit not all, time points. Comparison of groups who received the pHF versus extensively hydrolyzed (eH) whey formula revealed no significant differences in outcomes except for reductions in the cumulative incidences of all allergic diseases at 0 to 36 months of age. Comparison of groups who received the pHF versus eH casein formula revealed no significant difference in outcomes between groups.

CONCLUSIONS

The use of the pHF compared to SF is effective in allergy prevention in children at high risk for allergy at most time points. These results should be interpreted with caution due to a lack of methodological rigor in many trials. Reassuringly, the strongest evidence comes from a well-designed and conducted, independently funded RCT.

What is "high risk?" a systematic review of atopy risk and implications for primary prevention

Atopic diseases are common and becoming more prevalent. Efforts have focused on primary disease prevention by identifying high-risk children and applying preventative strategies. Our aim was to evaluate methods used to identify high-risk children in atopy prevention studies. A literature search for relevant articles published between 1986 and 2006 was conducted, and all abstracts were reviewed. The search yielded 1,535 publications, 133 were reviewed in detail, and 57 met inclusion criteria. High risk was defined by 30 different methods. First-degree relatives with an atopic disorder were included in all methods, but only three publications used referenced questionnaires to determine this. Less frequently included were cord blood immunoglobulin E measurements and skin prick or radioallergosorbent testing, and 16 methods relied on history alone. Family history was the most common method used to predict high risk of atopic disease in a child, but a minority of studies used a tested questionnaire to determine the presence of atopy in family members. The methods used to identify high-risk children are variable, and the development and widespread use of a validated, practical screening tool is needed.

Hypoallergenic formulas: optimal choices for treatment versus prevention

OBJECTIVES

To provide information on certain formulas that are relevant to allergy practice, focusing on their protein source and allergenicity, and to provide recommendations for selecting an optimal formula, taking into consideration efficacy, safety, palatability, and cost.

DATA SOURCES

A literature search using the PubMed database for the following keywords: hypoallergenic formulas, infant formulas, hydrolysate formulas, elemental formulas, and amino acids formulas.

STUDY SELECTION

Information was derived from pertinent original studies and selected reviews, including recent Cochrane Database Systematic Reviews, published in the English-language literature.

RESULTS

For a formula to be considered hypoallergenic, it should be well tolerated by at least 90% of individuals who are allergic to the parent protein from which that formula has been derived. Extensively hydrolyzed formulas (EHFs), derived from bovine casein or whey, are tolerated by approximately 95% of cow's milk allergic individuals. Elemental formulas are prepared from synthesized free amino acids and are well tolerated practically by all individuals, including those who are allergic to EHFs. Partially hydrolyzed whey formula (PHWFs) cause allergy in one-third to half of milk allergic individuals and are not considered hypoallergenic. Both EHFs and PHWFs seem to be equally effective in reducing the risk of development of allergy in infants of atopic families.

CONCLUSION

The EHFs and amino acids formulas, but not the partially hydrolyzed formulas, are optimal for milk allergic individuals. All 3 types of formulas are useful for prevention. The cost and palatability should be considered in deciding which formula to use.

[Cow milk protein allergies: primary prevention. Nutritional aspects]

In 2001 the Nutrition Committee of the Spanish Association of Pediatrics, published a position paper on "Recommendations on the use of formulae for the treatment and prevention of adverse reactions to cow milk proteins" (An Esp Pediatr. 2001;54:372-9). Since most of the recommendations given in this report still remain effective, the Nutrition Committee of the Spanish Association of Pediatrics reaffirms its support of the data expressed in it. In the present publication we only approach the aspects that have changed due to new knowledge and the accumulated clinical experience, especially on the primary prevention of allergy to cow milk proteins, and on the basis of it, the present recommendations for this prevention are set out. In addition, the importance of the nutritional aspects in all infants and small children receiving special nutritional formulae and exclusion diets are reviewed.

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

This clinical report reviews the nutritional options during pregnancy, lactation, and the first year of life that may affect the development of atopic disease (atopic dermatitis, asthma, food allergy) in early life. It replaces an earlier policy statement from the American Academy of Pediatrics that addressed the use of hypoallergenic infant formulas and included provisional recommendations for dietary management for the prevention of atopic disease. The documented benefits of nutritional intervention that may prevent or delay the onset of atopic disease are largely limited to infants at high risk of developing allergy (ie, infants with at least 1 first-degree relative [parent or sibling] with allergic disease). Current evidence does not support a major role for maternal dietary restrictions during pregnancy or lactation. There is evidence that breastfeeding for at least 4 months, compared with feeding formula made with intact cow milk protein, prevents or delays the occurrence of atopic dermatitis, cow milk allergy, and wheezing in early childhood. In studies of infants at high risk of atopy and who are not exclusively breastfed for 4 to 6 months, there is modest evidence that the onset of atopic disease may be delayed or prevented by the use of hydrolyzed formulas compared with formula made with intact cow milk protein, particularly for atopic dermatitis. Comparative studies of the various hydrolyzed formulas also indicate that not all formulas have the same protective benefit. There is also little evidence that delaying the timing of the introduction of complementary foods beyond 4 to 6 months of age prevents the occurrence of atopic disease. At present, there are insufficient data to document a protective effect of any dietary intervention beyond 4 to 6 months of age for the development of atopic disease.

Risk factors for the development of food allergy

Both genetic and environmental factors seem to predispose to the development of food allergy. A most notable factor is diet, particularly during infancy. Possible other factors include maternal diet during pregnancy and lactation, birth by cesarean section, exposure to tobacco smoke, multivitamin supplementation, and intake of antacids. It is important to identify and control such risk factors to reduce the development of food allergy.

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.

Hypoallergenic formulas--when, to whom and how long: after more than 15 years we know the right indication!

Hypoallergenic formulas are processed by enzymatic hydrolysis of different protein sources such as bovine casein/whey and soy followed by further processing such as heat treatment and/or ultrafiltration, or they are based on amino acid mixtures. The products have been classified according to the degree of protein hydrolysis as 'extensively' or 'partially' hydrolysed protein products. Product properties may be characterized by biochemical techniques, and reduction of allergenicity may be assessed in vitro with various immunological methods, and in vivo with skin prick tests, patch tests and challenge tests. In vitro tests do not predict the allergenic effects in humans, and at present there is no evidence of a specific threshold of immunogenic protein. Only pure amino acid mixtures are considered to be nonallergenic. Other 'hypoallergenic' products contain residual allergenicity. At present, the potential of a product for treatment and prevention of food allergy can only be determined by clinical trials using scientifically appropriate standards. It has been recommended that dietary products for treatment of cow's milk protein allergy in infants should be tolerated by at least 90% (with 95% confidence) of infants with documented cow's milk protein allergy. Some extensively hydrolysed products and amino-acid-based products have met these criteria. Formulas intended for prevention should have a very low, if any, allergenic activity until otherwise proven. So far there are no firm criteria available for the design of hypoallergenic foods for prevention. Newborns included in prevention studies should be from high-risk families; they should be randomized at birth and fed the formula when supplements are needed for at least the first 4-6 months of life. Follow-up should be at least 18 months, and children should be investigated when symptoms appear. Validated clinical criteria, including controlled food challenges, should be used for diagnosis. Infants fed formulas that claim to prevent or delay allergy should have a statistically significant lower prevalence of allergy when compared with infants fed a standard cow's milk formula. Feeding high-risk infants a documented hypoallergenic formula combined with avoidance of solid foods during the first 4-6 months reduces the cumulative incidence of cow's milk protein allergy and atopic dermatitis as compared with a standard cow's-milk-based formula. Partially hydrolysed formulas may have an effect, though it seems to be less than that of extensively hydrolysed formulas at present. Thus, if exclusive breast-feeding for 4-6 months is not possible in high-risk infants, a documented hypoallergenic formula and avoidance of solid foods are recommended for the first 4 months of life.

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.

Cow's milk allergy in infancy

Cow's milk allergy affects approximately 2% of infants under 2 years of age. This review summarizes the recent advances in understanding its pathophysiology and immunological mechanisms. Apart from IgE-mediated atopic manifestations, T cell-mediated reactions have been demonstrated in infants with cow's milk allergy. The clinical spectrum ranges from immediate-type reactions, presenting with urticaria and angioedema to intermediate and late-onset reactions, including atopic dermatitis, infantile colic, gastro-oesophageal reflux, oesophagitis, infantile proctocolitis, food-associated enterocolitis and constipation. The exact mechanisms of these disorders are still poorly understood. Double-blind, placebo controlled food challenge, the definitive diagnostic test for cow's milk allergy, is increasingly being replaced by the measurement of food-specific antibodies, in combination with skin-prick or atopy patch testing. The treatment of cow's milk allergy relies on allergen avoidance and hypoallergenic formulae, or maternal elimination diets in breast-fed infants.