Comprehensive Food Allergy Clinic of Michigan

Because many diagnostic tests can return a false positives result a food challenge may be necessary to confirm the results.  A strong history of a reaction to a food may confirm the positive food allergy test.  A positive result on a food challenge is considered proof of a food allergy.

Most food challenges are done in a controlled setting under direct doctor supervision.  If the past historical food reaction was mild (i.e.- increased eczema) than the challenge may take place at home.  If an oral food challenge has a risk of causing anything but the mildest of reactions, it will take place at the office.  Rarely a patient with a history of a significant reaction will be challenged while in the hospital.  

The suspected food is given in incrementally increasing doses until the total volume is equal to a normal serving.  Each dose is given every 20-30 min and is usually split into 3-6 doses total.  A Challenge is positive at the first clear sign of a reaction and no further doses will be given.

 

Differences Between Food Challenges and Elimination Diets:

While elimination diets are better suited for narrowing down potential food allergies, or as a diagnostic tool for food intolerances, food challenges have a few advantages over elimination diets for confirming food allergies:

1. The challenged food is administered in increasing dosages, to allow doctors to pinpoint at which dosage a reaction may be triggered.
2. It is far easier to administer a food challenge in a medical setting, thereby allowing doctors to assist in the event of a complication.
3. There is less potential for cross-contamination in a food challenge, leading to less ambiguous results.