Migrants and allergy: a new view of the atopic march.

Atopy is the result of the influence of environmental factors on genetically predisposed individuals. Migration flows represent an interesting model to study the possible reciprocal roles of genes and environment. In this review the following issues influencing the development of allergic sensitization and/or atopic disorders in migrants will be rooted out: 1) ethnicity, genetic polymorphisms and risk of atopy; 2) double faceted effects of parasitic infestations; 3) biodiversity loss and industrial progress. Moreover, an extensive revision of the literature about the relationship between the migratory status and allergy development is provided.