The development of allergy in infants of allergic parents: a prospective study concerning the role of heredity.

Ninety-four infants of allergic mothers were studied from birth to age 24 months. If the father was also allergic, the family history was termed bilateral (36 infants); if the father was not allergic, the family history was termed unilateral (58 infants). Data concerning family history, methods of feeding (bottle versus breast) and allergic skin reactivity were obtained. Significantly, more infants developed allergy if they were from a bilateral allergic parentage (P = less than 0.044). When skin test negative, bottle-fed infants with a bilateral family history were compared to breast-fed infants with a unilateral family history, there was significantly less asthma in the latter group (P = less than 0.047). During the first three months of life there was significantly less atopic dermatitis in the breast-fed infants with an unilateral family history than in the breast-fed infants with a bilateral family history (P = less than 0.027). In this study it remained unclear why infants with positive allergy skin tests demonstrated a different incidence of allergic disease from those who were skin-test negative when the variables of family history were the same.