There are a variety of other tests available on the market that we do not use, apart from occasionally the Immunoglobulin G, some of which are listed below.
Immunoglobulin G is fashionable and has been marketed as "the best test to diagnose food intolerance" on the assumption that food intolerance always involves IgG allergy. Whilst it is reproducible, it tends to identify only reactions to more common foods and its accuracy tends to help more simple problems.
Leuco-cytotoxic Test is based on the observation that the white blood cells of a person with intolerance might dramatically alter in size, getting smaller or larger, once in contact with a reactive food. Degrees of change reflect different degrees of reactivity. Such tests currently available in the UK seem to screen all blood cells, not just white cells. Accuracy and reproducibility varies.
Interleukin Test assesses levels of hormones secreted by a person's immune cells, T-lymphocytes, when in contact with various foods. Raised levels correspond to reactivity. Whilst it makes good theoretical sense, clinical trials so far show variable results.
Applied Kinesiology Test is based on the association of individual substances or foods having an effect on the body electromagnetism. A reactivity is thought to cause changes in a person's muscle tone and the same is believed about nutritional deficiencies and toxic metals.
This measures changes of the bodily low level frequencies, when in contact with a suspected allergen. The available clinical research of some of these methods to date has not substantiated claims made by the practitioners using them. Periodically, we do meet people who have found them helpful and others who have not. The existence of different methods to test food intolerance reflects the fact that there are various mechanisms of immune reactivity and there is no perfect test to assess the entire process. In the absence of a highly accurate test, it is not surprising that food intolerance is not a generally accepted diagnosis and it is not found in medical textbooks. However, when supported by a detailed history, some of the above methods are very helpful to identify most causes of allergy.