Exposure to peanuts in utero and in infancy and the development of sensitization to peanut allergens in young children

Forty-three children between the ages of 0 and 3 yr participated in this study. There were 25 peanut-sensitized subjects and 18 control subjects (children sensitized to milk and/or egg, but not to peanuts). A significant association was found between peanut sensitization and sensitivity to soya (p=0.0002), wheat (p=0.03), and cod fish. The authors found that mothers who consumed peanuts more than once a week during pregnancy were more likely to have a peanut-allergic child than mothers who consumed peanuts less than once a week (odds ratio=3.97, 98% confidence interval 0.73-24). Peanuts or peanut butter was introduced into the child's diet from a significantly younger age in the peanut-allergic subjects (p<0.03). There was a positive correlation in the peanut-allergic subjects between age of introduction of peanuts and age at the onset of symptoms (r=0.63). Exclusive breast feeding did not protect against the development of peanut sensitization. Peanut allergy is associated with an increased risk of sensitization to other foods. It is more likely to occur if mothers eat peanuts more frequently during pregnancy and introduce it early to the infant's diet. These features highlight potentially avoidable factors that might prevent sensitization.