The prevention of eczema in infants and children: an overview of Cochrane and non‐Cochrane reviews

Abstract

Background Eczema is the most common inflammatory skin disease of childhood, characterized by an itchy red rash that usually involves the face and skin folds. There is currently no curative treatment for eczema, so the reduction of eczema incidence through disease prevention is a desirable goal. Potential interventions for preventing eczema include exclusive breastfeeding, hydrolysed protein formulas and soy formulas when bottle feeding, maternal antigen avoidance, omega oil supplementation, prebiotics and probiotics. Objectives This overview of reviews aims to present the current body of data from Cochrane and non-Cochrane reviews to provide the most up-to-date evidence on the efficacy and safety of interventions to prevent eczema in infants and children at different risk levels for developing allergic disease. Methods Our pool of Cochrane and non-Cochrane reviews came from the 2010 United Kingdom National Health Service (NHS) Evidence Skin Disorders Annual Evidence Updates Mapping Exercise on Atopic Eczema. This group used a comprehensive search strategy last conducted in August 2010 to identify all systematic reviews on eczema prevention. We identified all reviews that met our pre-specified inclusion criteria, and data were extracted, analysed, compiled into tables and synthesized using quantitative and qualitative methods. Main results Seven systematic reviews containing 39 relevant trials with 11 897 participants were included in this overview. Overall, there was no clear evidence that any of the main interventions reviewed reduced eczema incidence. In subgroup analyses of infants at high risk of allergic disease, an observational study found that exclusive breastfeeding for at least six months compared with introduction of solids at three to six months decreased the incidence of eczema by 60% (risk ratio (RR): 0.40; 95% confidence interval (CI): 0.21, 0.78), and a randomized controlled trial found that prebiotics compared with no prebiotics decreased incidence by 58% (RR: 0.42; 95% CI: 0.21, 0.84). However, each of these findings was based on the results of a single small trial, and no intervention reduced eczema incidence beyond the first two years of life. Although we pre-specified incidence of atopic eczema (i.e. eczema associated with immunoglobulin E (IgE) sensitization) as a primary outcome, data on whether participants diagnosed with eczema were truly atopic were largely lacking from systematic reviews. Similarly, data on atopy, measured using skin prick tests or specific IgE tests to allergens, were not reported in many reviews. No interventions were found to decrease atopy when reported. Adverse events data were generally lacking, but data from a trial of probiotics versus no probiotics showed significantly more spitting up in the first one (RR: 1.88; 95% CI: 1.03, 3.45) and two (RR: 1.69; 95% CI: 1.02, 2.80) months of life, but no overall increase in risk of gastrointestinal symptoms in the first year. Authors’ conclusions Although there is currently no clear evidence showing that any of...

What guidance is available for researchers conducting overviews of reviews of healthcare interventions? A scoping review and qualitative metasummary

“…The first purpose is to present and describe the complete body of SR evidence on a clearly defined topic [26, 27]. The second purpose is to address a question that differs from the question(s) in the underlying SRs and that often relates to a subset of the questions in the SRs (e.g., subpopulations, or subsets of interventions or outcomes) [28, 29]. Distinguishing between these two purposes, and recognizing that different methods may be used for each, can help resolve some discrepancies and challenges likely to be encountered during the latter stages of the overview process.…”

Factors affecting breast milk composition and potential consequences for development of the allergic phenotype

“…Data from studies done on large cohorts have not consistently shown a preventative effect of hydrolysed milk formulas on allergy and eczema development (36,37) but oligosaccharide-enriched formula was found to have an eczema preventive effect in children with low atopy risk in 3 studies (17,38,39).…”

Scoping systematic review of treatments for eczema

“…Prevention of eczema has been covered in 40 systematic reviews 69 and one overview of the reviews 70 (see Chapter 1), which is itself a component of the eczema prevention work programme of this grant.…”

“…Some other non-Cochrane reviews have been well reported and are mapped for further reference on the Centre of Evidence Based Dermatology resource section [see www.nottingham.ac.uk/dermatology (accessed 6 November 2015)]. Overviews of existing single intervention systematic reviews, such as the one conducted for eczema prevention, 70 are also needed, as is the application of mixed-treatment comparisons for understanding more about the crucial missing treatment comparisons that are needed to inform clinical practice.…”