The clinical picture in this age group is less dramatic than in infants. Cow's milk allergy is quite rare after the age of 2. The shift towards tolerating cow's milk protein is progressive and it is quite normal for a child to be free from clinical symptoms, but continue to have IgE antibodies to cow's milk for some time.
It is important that children on an elimination diet receive a normal diet as soon as possible once the reactivity against the offending food has decreased. A challenge test should be considered about every 6 months on children who are following elimination diets. Another option is to follow the decrease of allergen-specific IgE antibodies (ImmunoCAP®), which may help in deciding the time for challenge and when the food could be reintroduced.
The foods which, in addition to cow's milk, are most likely to cause IgE-mediated gastrointestinal problems in toddlers are egg white, wheat, fish, soy, tree nuts and peanuts. The symptoms of an IgE-mediated reaction are acute onset stomach pains, vomiting or diarrhea, urticaria, associated with food intake. The child is symptom-free when the food is eliminated from the diet. Chocolate, citrus fruits and strawberries can cause non-specific reactions.
After 1-2 years of elimination, the child usually tolerates the food again. Cases with delayed onset or chronic symptoms do not respond as well to specific food elimination and IgE antibodies are usually not detected.
Elimination of a specific food sounds simple, but is much more complicated in practice. For example, soy is used as a meat extender or as a flavoring in a wide variety of foods. Eggs are present in almost all baked goods. Cross-reactions are also common, for example between soy, peanuts, peas and licorice.
To avoid malnutrition it is also important that every food eliminated from the diet is replaced by another food of equivalent nutritional value. For example, milk elimination can quickly lead to calcium deficiency. This can be replaced, either by a calcium supplement, or by other foods with high calcium content. If more than one food is eliminated from the child's diet, nutritional advice should be obtained from a qualified dietitian.