[Primary prevention of allergic disease].

Allergic diseases are a major public health problem. It is essential to develop prevention strategies applied to it. A number of risk factors have been identified, but some are still under contradictory. Changing the dietary pattern of the at-risk infant may prevent food allergy. Evidence suggests that exclusive breast-feeding for the first 4-months seems to protect against atopic dermatitis in infants and early childhood wheezing. Breast-feeding should be encouraged for all infants because of all its well known benefits. Hydrolyzed formulas cannot substitute breast milk on the prevention of allergic diseases. Extensively hydrolysed formulas should be encouraged as a supplement to breast milk in high-risk infants whenever necessary. Partially hydrolysed formulas may be a reasonable substitute, but more studies are necessary. There is no evidence that avoiding allergenic foods during pregnancy will reduce the incidence of allergenic diseases in child. Avoidance food and aeroallergen seems effective in reducing early childhood wheeze, atopic dermatitis and asthma. Maternal avoidance of allergenic foods during lactation should only be undertaken under medical supervision by highly motivated mothers with a high risk of allergy in the offspring.