It has been estimated that as many as 80% of western people suffer from some type of food allergy. Food allergy is implicated in a wide spectrum of disorders, especially of the skin, respiratory tract and Gastro-intestinal tract. In most cases these allergic reactions are of the delayed type, making them difficult to detect, while they are typically not noticed by the patient until several hours or days after ingestion of a particular food. To determine these food allergies by the elimination and reintroduction of potentially offending foods can be a very lengthy and difficult proces

The IgG4/ IgE food panel is a simple screening test that determines acute and delayed allergy for a large number of foods. Scientific research suggest that the combination of specific IgE and specific IgG4 correlates better with a positive food challenge than skin testing alone. In patients with a defined history to a particular food, the combination of IgE and IgG4 was found to have a better relationship to the history then the challenge itself.1 For delayed reactions that have a component other than IgE, a longer period of elimination may be necessary than is traditionally employed.