Current understanding of allergic march and the role of eczema in its development

Abstract

An increasing morbidity of atopic diseases (atopic dermatitis, food allergy, asthma and allergic rhinitis) documented in large cohort epidemiological studies is at least partially determined by high hygienic standards of living. Over the last 40 years, the accepted concept of pathogenesis of atopic diseases, the so-called atopic march, was proposed by Fouchard in 1973. It referred to the natural history of atopy manifestation, with a typical sequence of symptoms presented as atopic dermatitis in early childhood for subsequent development of allergic respiratory symptoms in late childhood and adolescence. New data suggests that the leading role of atopic dermatitis in atopic march might be less pronounced than previously expected, indicating coexistence rather than succession of atopic symptoms. The objective of this paper is to present the currently discussed concepts of atopic dermatitis – its pathogenesis, etiology, course and role in the development of other allergic diseases. More widely, we will present: 1. The genetic factors involved in skin barrier disruption with the leading role of loss-of-function gene for filaggrin mutation, 2. Genetic defects and epigenetic regulation of the immune system 3. Epidermal changes with physical barrier dysfunction as well as 4. Skin microbiome disturbances with Staphylococcus aureus colonization leading to abnormalities of the epidermal protective barrier.