Many symptoms and diseases are wrongly attributed to food allergy. Patients unhappy with the responses they receive by conventional health care professionals frequently recur to alternative diagnostic methods. The following are the most frequently used:
Cytotoxic tests: These tests are based on incubating blood cells with a number of food extracts and measuring the change in cellular size or the inflammatory response. The most popular of these tests are AlcatTM and NOVO ImmogenicsTM. There are no scientifically sound trials showing their usefulness in food allergy.
Specific IgG against foods: Some companies commercialize arrays to detect IgG to a great number foodstuffs intended to diagnose food allergy. Positive results only demonstrate contact with the food but have been unable to discriminate allergy from tolerance, and are not recommended by the scientific allergy organizations.
Applied kinesiology, subcutaneous and sublingual provocation and neutralization, DRIA test, bioresonance and electroacupuncture or electrothermal test, are in vivo techniques which have no scientific credibility and have not shown clinical efficacy to diagnose food allergy so far.
The gold standard method for diagnosing food allergy, after an adequate allergological evaluation, is the double blind placebo controlled food challenge, which should be performed under the supervision of experienced healthcare professionals.