Food allergy in infants and children
In Malaysia about 15 percent of the young children develop allergy symptoms often during their early life. In Western countries up to 40% of the children may manifest allergy symptoms. The most common symptoms of food allergies are: diarrhea, eczema, asthma and allergic rhinitis. Less common manifestations of food allergy include infantile colic, reflux of stomach contents, chronic diarrhoea and failure to thrive.

Allergy prevention in children is an active area of research. Although effective treatments are available, it makes sense to try to prevent allergies in infants and children, if possible, before the development of symptoms. Recent studies show that high risk children who were not exposed to milk, soya bean, egg, peanut, fish or beef for the first 7 years of life (either through the breast milk or when solids were introduced) were less likely to develop food allergies and eczema. However, restricting the mother’s diet during pregnancy or lactation for all allergenic foods in general is not recommended. Delayed introduction of allergenic foods during weaning to about 6 months may reduce the risk of food allergies and eczema. The best choice of food during infancy is breast milk. However, if breast feeding is not possible then the best alternative is partially hydrolyzed milk formula (Nan HA1 for infants less than 6 months and Nan HA2 for infants older than 6 months). The use of hypoallergenic formulas instead of conventional formula preparations in high risk infants has been shown in many studies to reduce eczema and the development of sensitivity to cow’s milk in infancy and early childhood.

Foods (particularly cow’s milk, soy, egg, nuts, banana and wheat) are the most common cause of severe allergy in young children. Nuts, legume seeds, fish and crustaceans (e.g. crabs, prawns) are more common allergens in older children and adults, although other triggers such as fruit and vegetables, spices, herbal medicines have been described. Most children allergic to cow’s milk and soy will be able to tolerate these foods by the age of 3 years. However, in recent studies there is a suggestion that milk allergy may last into late childhood in some communities. Allergy to eggs persists into childhood with 80 % growing out of it by age 5 years. Unfortunately, the vast majority of those allergic to tree and ground nuts or seafood (particularly shellfish) rarely seem to grow out of their problem, leading to the need for life-long avoidance strategies. Reducing the intake of peanuts and tree nuts or bird nest soup for the first 3 years and soy products for the first year in infants may down-regulate the development of allergy to these foods.

At present the optimal approach to reduce the risk for the development of allergy is:
(1) To identify through blood tests (raised IgE level) newborn infants who have an increased risk of developing allergies; and (2) To encourage mothers to breast-feed for at least 4 to 6 months or if unable to breast-feed place the infants on partially hydrolyzed milk formula (Nan HA1)