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

This study attempted to determine the underlying factors that may influence the development of peanut sensitization in young children in South Africa. One of our objectives was to ascertain whether the consumption of peanuts or peanut-containing foods during pregnancy and lactation by mothers from a topic families impacted upon the development of an allergic response to pea nuts in the child. Forty-three children between the ages of 0 and 3 yr part icipated in this study. There were 25 peanut-sensitized subjects and 18 con trol subjects (children sensitized to milk and/or egg, but not to peanuts). A significant association was found between peanut sensitization and sensi tivity to soya (p=0.0002), wheat (p=0.03), and cod fish. We found that moth ers who consumed peanuts more than once a week during pregnancy were more l ikely to have a peanut-allergic child than mothers who consumed peanuts les s than once a week (odds ratio=3.97, 98% confidence interval 0.73-24). Pean uts or peanut butter was introduced into the child's diet from a significan tly younger age in the peanut-allergic subjects (p<0.03). There was a posit ive correlation in the peanut-allergic subjects between age of introduction of peanuts and age at the onset of symptoms (r=0.63). Exclusive breast fee ding did not protect against the development of peanut sensitization. Peanu t allergy is associated with an increased risk of sensitization to other fo ods. It is more likely to occur if mothers eat peanuts more frequently duri ng pregnancy and introduce it early to the infant's diet. These features hi ghlight potentially avoidable factors that might prevent sensitization.