If your child is allergic to a food, their immune system responds to an otherwise harmless protein in it. When they consume it, their immune system makes antibodies in an attempt to fight off the offending food. In the process, substances called histamines and other chemicals are released. These cause allergy symptoms that can range from mild to severe.
Because some food allergies can be serious, you should talk with your pediatrician if you suspect your child has one.
How are food allergies diagnosed?
To help diagnose a food allergy, the doctor will review your concerns. They may perform some tests and refer you an allergist for further testing.
Food allergy symptoms in children
Sometimes a food allergy is obvious, like when a child gets hives and lip swelling after eating a walnut. Other symptoms, such as dry skin patches, are less obvious. Tests, including a skin prick test and blood tests, can provide more information and answers.
Skin and blood tests for allergies
Skin prick test
With the skin prick test (or scratch test), the doctor will prick the skin with drops of the suspicious food allergens on your child’s back or forearm. This can result in redness, swelling and itching at the site, which the doctor will measure after 20 minutes.
Blood test
A blood test can measure antibodies to foods as well. These antibodies are called immunoglobulin E, or IgE. A sample of your child’s blood will be drawn and sent to a lab for testing.
Are skin or blood tests results enough to diagnose food allergies?
A positive skin or blood test alone is not enough to diagnose food allergy, however. Your doctor should discuss with you the specifics of your child’s diet, including any possible reactions you’ve seen to certain foods. This helps determine what tests to consider and how to interpret the results.
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