The evolution of food immune reactivity testing: why immunoglobulin G or immunoglobulin A antibody for food may not be reproducible from one lab to another.

The gold standard for identifying food reactions is the elimination-provocation diet. Embarking on this long, tedious journey takes an expert practitioner and a completely dedicated patient, with a whole lot of patience from both. In the contemporary fast lane, microwave, "give me a pill" popping, I-want-satisfaction-now society, many clinicians have turned to laboratory assessments for quick answers to food reactivity. From the introduction of cytotoxic testing for food allergies in 1947 until today, food reactivity testing has evolved and branched; it has been both pseudoimproved and scientifically improved. With multiple available options for methodology, specimen types, and clinical lab, how is a clinician expected to find the one that fits the requirements of a particular practice? How, indeed, when one self-promoting paper supports a particular methodology, while another criticizes it? In this article, with the benefit of his years of training and experience as a research scientist and test development expert, the author, who is trained in both microbiology and immunology, discusses the history of food testing, analyzes the criticisms of it, reviews the scientific literature, and tours the methodologies.