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Food Allergy Patch Testing

What is allergy patch testing?

Patch tests are used to help diagnose a child’s suspected allergies. Actual food is used to test how a child’s body reacts to its presence.

How is the patch test done?

Foods are chosen based on a patient’s diet, history of previous reactions and prior skin testing results. Typically, food is pureed and placed in small metal chambers that are securely taped to a child’s back so that they are in contact with the skin. The chambers are left in place for 48 hours and must stay dry.

Will my child be uncomfortable while the patches are on their skin?

Some children may experience discomfort from the tape or food in the chambers due to irritant reaction from the tape or from a reaction on the skin from the food.

Antihistamines can be taken for itching and will not affect the results of the patch test.

When can the patches be removed?

After 48 hours, the patches can be removed at home. After 72 hours from the placement of the patches, the patient will return to their allergist’s office to have the results read. The skin is examined for any reaction.

It is important that the child does not bathe or get wet until after the skin has been examined by the child’s doctor.

What does it mean if my child has a skin reaction during an allergy skin patch test?

A reaction doesn’t always mean that a patient is allergic to a specific allergen. It does, however, provide a child’s medical team with a guide as to which foods may be causing a patient’s allergic reactions.

Understanding Food Allergies

A food allergy is an abnormal response of the body to a certain food. This is different from a food intolerance, which does not affect the immune system, although some of the same symptoms may be present. Learn more about food allergies and how they are managed at CHOC.

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