What is component testing and why should I get it tested?
An estimated 32 million Americans (including children) – have food allergies and this number has been on the rise in the last two decades. Allergy component testing is a relatively new form of IgE blood testing that looks at the specific proteins or “components” of an allergen that cause a reaction, rather than the allergen as a whole. For example, 70% of children with egg allergies do not react to baked eggs while 75% of children with milk allergy do not react to baked milk. This may be because those children are specifically allergic to ovalbumin (in eggs), alpha-lactalbumin, or beta-lactoglobulin (in milk), which may become denatured when heated. For a patient suspected to have a peanut allergy, component testing looks at the IgE antibody levels for different peanut proteins. If the patient has high levels for the Ara h 2, studies show that this is a good indicator that the person is peanut-allergic. However, if the person instead has high levels of Ara h 8 or 9, then the symptoms are likely to be linked to a cross-reaction with pollen, a less severe condition known as oral allergy syndrome.