[From atopic eczema to respiratory allergy]

The prevalence of atopic eczema in childhood is increasing. This is probably related with a deviation of immune system to Th2 directed to allergen instead of Th2 directed to microorganisms. Atopic eczema is genetically linked, but its expression is principally determined by environmental factors, allergens and infections. In children with atopic eczema, the immune system is altered. The number of Langheran's cells is augmented. Th2 cells infiltrate the skin and produce cytokines which mediate both immediate and late allergic reaction. Most of eczematous children is allergic to food. A IgE-mediated reaction take place at the mucosal intestinal site. The food challenge test is the most reliable mean to identify offending foods. Soy formula can be used in the treatment of cow milk allergy. The tolerance of formulae based on cow milk hydrolysed protein should be tested under medical supervision in children with cow milk allergy. Prevention of atopic disease with dietary interventions has not been successful. To prevent asthma, the administration of immunotherapy in children with allergic rhinitis seems to be promising. In eczematous children with elevated total IgE and specific IgE to inhalant allergens, cetarizine seems to prevent onset of asthmatic symptoms.