Abstract

PIP: In addition to the potential dangers of feeding cow's milk to the newborn which you list in your editorial on infant feeding (January 2, p.30), other hazards have been proposed. 1 apparent consequence, reported by Johnston and Dutton, is an increased prevalence of allergy later in childhood. We examined this thesis in the course of a study on hearing loss in Vancouver primary school children. A trained interviewer put precoded questions to the children's mothers, 1 of which was whether the child had received any food other than breastmilk in the 1st month of the child's life. Another was whether she or the father or any of the child's siblings had ever had asthma, eczema, or hay fever, i.e., whether there was an immediate family history of allergy. A smear of the child's nasal secretions was made and was subsequently examined for eosinophils by a technician. If there were 10 eosinophils/highpower field in any 2 highpower fields, the child was said to have a nasal secretion eosinophilia. This appears to be a useful sign of allergic rhinitis. In the group with an immediate family history of allergy, the association between early introduction of foreign food and the presence of nasal secretion eosinophilia was significantly positive at the 5% level by the chi square test of association. For those children who received supplemental foods in the 1st month, 22 (32%) showed evidence of nasal secretion eosinophilia; 46 (68%) did not. Only 2 (11%) of those on breastmilk alone displayed this sign and 16 (89%) did not. In the remaining 233 children who did not have an immediate family history of allergy the association was not significantly positive. The sequence of events leading to respiratory allergy may be as follows: a neonate not only drinks his weight in cow's milk in a week, but also absorbs a disproportionately large amount of immunologically intact protein. Thus it would not be surprising to find a relatively high incidence of cow's milk allergy in genetically predisposed infants. There is evidence that, once an individual has become allergic to 1 substance, allergy to other antigens develops more readily, and 1 may therefore expect an infant with a milk allergy to be more liable than usual to develop allergy to housedust, animal danders, and pollens to which he is exposed in childhood. A nasal secretion eosinophilia is usual when these substances cause an allergic rhinitis. If further studies substantiate Johnston and Dutton's and our findings, another reason will have been added for encouraging breastfeeding and delaying the introduction of other foods, especially where there is an immediate family history of allergy.