Allergology has come a long way since Johansson and Ishizaka discovered IgE in 1967 to be the antibody that mediated acute serious allergic reactions. Phadia, and then Thermo Fisher developed multiple specific allergy tests using individual IgE antigens that revolutionised allergy diagnosis and treatment. More recent developments include testing sensitivity to the various component allergenic determinants in a food or environmental protein. This gives us a better indiction of anaphylaxis risk and how to manage the allergy. For example a peanut contains 9 different potentially allergenic proteins, some cause minor oral itching only (Ara h8), whilst others cause anaphylaxis (Ara h2).
Very often a person will have an acute anaphylaxis reaction and one isn’t sure what the trigger or triggers were. Now we can economically test for over 280 different allergens and their components in one test panel and this includes a quantitative result which identifies exactly which allergens may be involved. Enter the ISAC component test which measures over 100 allergens and now the ALEX “Allergy Explorer” which only requires a small amount of blood to test for hundreds of different allergenic components. IGEVIA requires 0.5ml clotted blood sample.