The alliance of genes and environment in asthma and allergy

The diseases of asthma, eczema and hay fever are typified by reactions to c ommon allergens, which are mediated by immunoglobulin E. These allergic dis eases are increasing in prevalence, and are now a major source of disabilit y throughout the developed world. They are the result of complex interactio ns between largely unknown genetic and environmental mechanisms. The identi fication of the environmental factors offers the real possibility of preven tion of disease, and unravelling the genetics of allergic illnesses is like ly to change their classification and treatment. Early life seems particula rly important, when the initiation of allergic disease may result from gene tic and environmental modification of the immune interaction between mother and child.