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Food Allergies - What Happens

The first time you eat a food that triggers an allergic reaction, your body's immune system recognizes the food as a foreign substance (allergen). Your body reacts by developing antibodies against the food. When you eat the offending food again, the antibodies attack the allergen, releasing histamine and other chemicals that cause the symptoms of an allergic reaction.

To learn more, see the Symptoms and Treatment Overview sections of this topic.

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    This information is produced and provided by the National Cancer Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National Cancer Institute via the Internet web site at http:// cancer .gov or call 1-800-4-CANCER.

    WebMD Medical Reference from Healthwise

    Last Updated: March 12, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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