The links between allergen exposure and sensitization in children and adolescents: an overview for the clinician

ABSTRACT

Introduction

The links between allergen exposure and sensitization are complex and depend not only on the type of allergen but on various genetic and environmental factors.

Areas covered

This review discusses the link between allergen exposure and atopic sensitization for different types of allergens and the factors that mediate or affect this link. For the purposes of this review search of PubMed was undertaken to identify English language articles using the terms ‘sensitization’ and ‘allergen exposure’ and ‘children/or adolescents.’

Expert opinion

Regarding food sensitization, the available data for peanuts and eggs suggest that there is a window period between 4 and 6 months of age when the introduction of these foods may limit sensitization and clinically overt allergy to the respective foods. As far as it concerns aeroallergens, it seems that there is a complex and variable relationship between mite exposure and specific sensitization especially if the exposure occurs early in life. Early exposure to dog allergens does not seem to be associated with specific sensitization; regarding cats, the results are still inconsistent. Several factors may mediate the relationship between early exposure to allergens and the development of sensitization or clinical allergy.

KEYWORDS:

• Aeroallergen
• air pollution
• allergen
• allergen exposure
• atopy
• endotoxin
• food allergy
• house dust mite
• pets
• sensitization

Article highlights

• It was initially believed that avoiding exposure to food allergens during prenatal life and early infancy may prevent IgE-mediated food sensitization and food allergy.

• More recently, it has been shown that, at least for peanuts and eggs, there is a window period between 4 and 6 months of age when the introduction of these foods may limit sensitization and clinically overt allergy for the respective foods.

• In high-risk children with skin barrier disruption, the epicutaneous exposure route may increase the risk for the development of peanut sensitization and allergy.

• It seems that there is a complex and variable relationship between mite exposure and specific sensitization especially if the exposure occurs early in life.

• Early exposure to dog allergens does not seem to be associated with specific sensitization; regarding cats, the results are still inconsistent. In general, the role of early exposure to pets in the development of atopy remains controversial.

• Several factors may mediate the relationship between early exposure to allergens and the development of sensitization or clinical allergy. Genetic predisposition, environmental factors such as exposure to endotoxin and bacterial load, air pollution, and tobacco smoke seem to play a crucial role.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.