From peanuts and tree nuts to milk and eggs, the number of reported food allergies among children in the US has grown over the past two decades.1
Food allergen sensitization develops as a consequence of food-specific immunoglobulin E (IgE) production after a food of concern is eaten. A subset of food IgE-sensitized individuals will develop symptoms immediately, while some develop symptoms after eating this food weeks, months, or even years later. These patients are considered to have a true food allergy. Some allergic patients can even develop a reaction if their IgE antibodies cross-react with similar component proteins found in related foods (tree nuts, fish, shellfish). Food allergy reactions can occur within seconds of exposure. They can be severe and, on occasion, even fatal.
So how do you effectively distinguish between food IgE sensitization and allergy? With food component IgE testing.
For patients with suspected food allergies, guidelines recommend serum IgE tests or skin prick tests with whole foods.2 While these skin prick tests have a long history of use, they do not reliably distinguish IgE sensitization from true allergy.3
The oral food challenge (OFC), considered the gold standard in diagnostic testing for food allergies, can help diagnose food allergies if a clinical history or test results are insufficient to establish a diagnosis. However, OFC is expensive and puts the patient at risk for an anaphylactic reaction.4
Serum IgE component testing, on the other hand, can distinguish patients with a true food allergy from those who are only IgE-sensitized, without the risk of anaphylactic shock associated with OFC.2,5 This approach measures IgE levels to individual food component proteins. Depending on the specific component target(s) of IgE reactivity,6-10 a patient may be at low, variable, or high risk of a true allergy to the food. Component testing can also help determine the likelihood that a patient who is allergic to one food will also react to other potentially cross-reactive foods.
Learn more about the benefits of food component testing in the Quest Diagnostics white paper, “Component Testing for Food Allergy.” Quest offers whole-food IgE testing with reflex to components for certain foods. To learn more about Quest Diagnostic allergy testing, visit KnowingAllergies.com.
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