Prevention of allergies inchildhood - whereare we now?

B Ahrens,D Posa

doi:10.5414/alx01807e

Abstract

Allergic diseases represent an increasing health problem for children worldwide. Along with allergic airway diseases, food allergy comes to the fore and herewith closely intertwined the hypothesis that an early allergic sensitization might occur via skin barrier defect(s). The importance of the skin barrier has been documented by several studies meanwhile. Not only genetic studies screen the associations between Filaggrin loss-of-function mutations, atopic dermatitis, allergic sensitization, food allergy and even airway diseases, but also epidemiological studies cast new light on the hypothesis of the atopic march. As another focus in context of the development of an allergic phenotype, the specific microbial exposure with all its diversities has been crystallized as it shapes the immune system in (early) infancy. Studies explored both, the role of human intestinal microbiota as well as the external microbial diversity. Unfortunately suitable markers for atopic predictors are still rare. New studies point out that specific IgE antibodies (e.g., IgE to Phl p 1) in children without allergic symptoms so far, might function as a pre-clinical biomarker, which may help to identify candidates for primary (allergen non-specific) or secondary (allergen-specific) prevention in terms of specific immunoprophylaxis. These manifold research activities document a complex increase in knowledge. Nevertheless new assumptions need to be substantively confirmed in order to finally generate the urgently needed preventive strategies for allergic diseases in childhood.

Highlights

Allergische Erkrankungen stellen ein weltweit steigendes Gesundheitsproblem für Kinder dar
In Ireland, where in the 1990s the 12-month prevalence of asthma among adolescents was fourth highest in the world [5], a recent report shows that the prevalence of asthma of Irish school children aged 6 – 9 years remained stable at a high level between 2002 – 2007 [5]; by contrast, both, the prevalence of allergic rhinoconjunctivitis (AR) and that of atopic dermatitis (AD) continued to increase
The Tucson Epidemiological Study of Airway Obstructive Disease (TESAOD) showed that exposure to parental tobacco smoke in childhood leads to an increased risk of persistent respiratory symptoms into young adult life [49]

Summary

Tobacco smoke and other environmental factors

The Tucson Epidemiological Study of Airway Obstructive Disease (TESAOD) showed that exposure to parental tobacco smoke in childhood leads to an increased risk of persistent respiratory symptoms into young adult life [49]. A Cochrane meta-analysis concluded that the allergen-restrictive diet of a pregnant highrisk woman is not likely to reduce the risk for AD in the child, while a special diet during lactation may influence the development of AD, sufficient data is missing [55] It has been shown, that after maternal consumption of, e.g., peanut, Ara h 6 is measurable in human breast milk as soon as 10 minutes later. Two publications from the PASTURE study group, postulated, that a low-grade inflammation due to infectious agents in early childhood might protect from allergic diseases later in life They observed that elevated levels of high-sensitivity CRP at the age of 1 year were associated with decreased allergic sensitization [77], whereas al1807Ahrens_ENG / 5. Low β-lactoglobulin-specific serum IgG4 levels in the serum of children with eczema and allergy to cow’s milk were lower than in children with eczema who did not have an allergy to cow’s milk [82]

Primary prevention

Secondary prevention

Findings

Conclusion