• Powering Food Allergy Insights With Component Testing

    Information provided by Quest Diagnostics


    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

    The difference between IgE-sensitized and allergic

    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.

    The benefits of component 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.

    Get the component testing you need

    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.


    1. Gupta RS, et al. The public health impact of parent-reported childhood food allergies in the United States. Pediatrics. 2018;142:e20181235.
    2. Sampson HA, et al. Food allergy: A practice parameter update—2014. J Allergy Clin Immunol. 2014;134:1016-1025.e43.
    3. van Veen WJ, et al. Predictive value of specific IgE for clinical peanut allergy in children: relationship with eczema, asthma, and setting (primary or secondary care). Clin Transl Allergy. 2013;3:34.
    4. Yanagida N, et al. Risk of anaphylaxis during an oral food challenge increases with increasing specific IgE levels. J Allergy Clin Immunol. 2018;141:AB151.
    5. Kattan JD, Sicherer SH. Optimizing the diagnosis of food allergy. Immunol Allergy Clin North Am. 2015;35:61-76.
    6. Canonica GW, et al. A WAO - ARIA - GA(2)LEN consensus document on molecular-based allergy diagnostics. World Allergy Organ Journal. 2013;6:1-17.
    7. Kleine-Tebbe J, Jakob T. Molecular allergy diagnostics: Innovation for a better patient management. 2017.
    8. Matricardi PM, et al. EAACI Molecular Allergology User’s Guide. Pediatr Allergy Immunol. 2016;27 Suppl 23:1-250.
    9. Sastre J. Molecular diagnosis in allergy. Clin Exp Allergy. 2010;40:1442-1460.
    10. Treudler R, Simon JC. Overview of component resolved diagnostics. Curr Allergy Asthma Rep. 2013;13:110-117


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