When the food is eaten again there is no accumulation of antigen from the previous time and consequently there is not enough antigen to invoke a response. If your child has a food intolerance and you opt for this approach be aware that it is not necessarily individual foods that precipitate the reaction but food groups. In other words it is necessary to avoid all foods in a group for four days. In practice it is often possible to eat other foods in the group in two days as cross reactions do not occur. Many good books on allergy have details of a four-day exclusion diet for food intolerance.
Good nutrition is the key to preventing or controlling allergies.
The best sources of omega-6 fatty acids are unrefined sunflower, safflower, walnut and flax oil. Nuts and seeds are also a good source. Zinc is found in nuts, seeds, liver and eggs. Vitamin C is found in citrus fruits, red peppers, broccoli and peas. Limit the nasties At the same time as you ensure that your child eats the foods which contain adequate quantities of the essential nutrients it is important to limit the nasties.