Food allergen avoidance in the prevention of food allergy

SELECTED ARTICLES FROM THE RECENT LITERATURE 2003

8/11/03

Food allergen avoidance in the prevention of food allergy

Summary
There has been an increasing incidence of food allergy in infants and children with impact on both the patient and the family. This subject was reviewed by Zeiger of the Kaiser-Permanente Medical Center in San Diego, CA. He pointed out that prevention can be classified as 1) primary (decreased immunologic sensitization, particularly IgE); 2) secondary (suppresses disease expression after sensitization); 3) tertiary (averts symptoms after disease expression).

Food allergy prevention strategies must consider the ability to: 1) predict the high-risk infant and child; 2) use acceptable interventions; 3) demonstrate effectiveness of these interventions; 4) minimize adverse effects of these strategies; 5) generate cost- effective outcomes.

Prevention recommendations (which are still works in progress) have been made in the area of food allergy by the American Academy of Pediatrics (AAP) and European societies of pediatric allergology and G-I/nutrition with the understanding that such recommendations are not intended to be "standards of care."

Current findings suggest the utility of certain preventive measures carried out in the early infancy of at risk children with avoidance of: 1) early bottle feeding; 2) early introduction of allergenic foods; 3) environmental tobacco smoke exposure. Avoidance of certain topical medications and allergenic dust may also be helpful although the evidence for such is less established to date.

Such avoidance measures have been shown statistically to be helpful only in children with histories of atopy in the immediate family, particularly if both parents or one parent and > one sibling are atopic. The presence of present/past history of food allergy in a parent or sibling is a particularly strong risk factor for food allergy developing in the index child.

However, the AAP and European guidelines do not recommend exclusion of essential foods with allergenic potential such as cow’s milk or eggs from the maternal diet during pregnancy. However, avoidance of peanuts (a non-essential food) during pregnancy is advisable. Breast feeding as the exclusive feeding for a prolonged (> 4-6 months) period is recommended for at risk infants although debate still exists about the degree to which breast feeding reduces the risk for the development of food allergy in the involved child. Conflicting findings have been obtained in studies to determine whether maternal avoidance of foods such as cow’s milk, eggs and fish during lactation will reduce development of allergy in at risk infants. However, it is generally recommended that peanuts be avoided by breast-feeding mothers. Soy formulas should not be used as a cow’s milk substitute for children in primary food allergy prevention.

Reference
Pediatrics 2003;111:1662-71

Editor’s Comments
This is a very thoughtful, detailed review of a complex subject with often strongly differing opinions rendered based on sometimes conflicting findings. The author, one of the leading investigators of the natural history of food allergy, makes a point worth emphasizing; that for many aspects of primary prevention strategies, one has to individualize recommendations to the particular child, based on the risk for atopy, family circumstances and possibly other factors.