Food Allergy Testing - Non-IgE Mediated Allergy

Non-IgE mediated food allergies are caused by a reaction involving other components of the immune system apart from IgE antibodies. The reactions do not appear immediately after the ingestion of the food and usually relate to reactions in the gastrointestinal tract such as vomiting, bloating and diarrhoea. The mechanism of non-IgE-mediated food allergy is not well understood. Although the immune system is presumed to be involved, IgE antibodies are not associated with this condition, hence the term “non-IgE-mediated” food allergy. Non-IgE-mediated food allergy is less well understood than IgE-mediated food allergy. Because the symptoms are usually delayed as compared to IgE mediated food allergy it is more difficult to make the association between offending food and the symptoms. The most common causative food for non-IgE-mediated food allergies are cow’s milk in infants. Unlike IgE mediated food allergy non IgE food allergies are very rarely life threatening because they do not result in anaphylaxis. Unlike IgE mediated food allergy there are no blood or skin tests which have proved useful. Therefore the diagnosis may be confirmed by observing that the symptoms improve when the suspected food is removed from the diet and return when the food is reintroduced into the diet. This process can take a number of weeks or months to complete properly. The rechallenge aspect of the test is very important to confirm the link between the offending food and symptoms since symptoms...