Allergy diagnosis

In the western world allergy affects approximately one in four individuals. Common allergic conditions include hay fever, asthma, eczema, food allergy, insect venom allergy and drug allergy. Most individuals with allergy have mild to moderate disease with a much smaller group of individuals having severe allergy, which may be life threatening. Allergy is caused by an abnormal immune response to a harmless agent in the environment e.g. pollen or food. There is a tendency for allergy to run in families. Food allergy should not be confused with food intolerance. There are some types of food intolerance with a known cause e.g. lactose intolerance where an individual is lacking the enzyme necessary for digesting lactose. However, most types of food intolerance have no known cause.
Allergy diagnosis is based on a careful clinical review and there are some internationally validated tests (e.g. skin prick tests, specific IgE tests) which when properly performed can help in confirming the diagnosis. There is however, no blood or other test, which by itself can diagnose allergy. The only exception to this is allergy challenge testing, performed under medical supervision in a hospital setting. In particular, there is no scientific basis to tests such as Vega, hair tests, IgG tests or kinesiology. Not only do these tests not work, they may be dangerous, as they can result in the commencement of restrictive diets and the loss of valuable nutrients. The Irish Health Products Regulatory Authority issued an advisory in March 2015 concerning the use of these tests and you can see that here. Do not waste your money on them. If you are worried about allergy, talk to your doctor.