Three main factors are needed for an infant to develop allergy: allergen exposure, a genetic predisposition, and contributory factors. Recent literature suggests that the incidence of in utero sensitization might have been underestimated up to now. A number of papers provide evidence that atopic dermatitis should be regarded as a manifestation of food allergy. The case for an immunologic mechanism of food allergy has been indirectly strengthened because of the apparent association between increased levels of antibodies to cow's milk proteins and insulin-dependent diabetes mellitus. The vast majority of recent papers deal with the prevention, and thus indirectly with the pathogenesis, of cow's milk protein allergy. In general, studies focusing on the prevention of cow's milk protein allergy in at-risk infants report “satisfactory” results, suggesting that in a majority of infants the decreased or reduced exposure to native cow's milk proteins not only delays but also eliminates cow's milk allergy. Experience with hypoallergenic formulas in therapeutic situations is disappointing. Skin-prick tests with hypoallergenic formulas are recommended before such a formula can be considered in allergic infants.