I understand Food Allergy Institute uses patch testing. What is the difference between a patch test and a traditional skin prick test?

Patch Tests are a method of testing used to detect possible food allergies and gastrointestinal sensitivities. The Patch Test measures conserved, innate immune responses to food allergens via the closed (air-tight) application of food allergens to the skin followed by measurement of the immune response 24 hours later. The test allows Food Allergy Institute to assess how the patient’s gastrointestinal tract reacts to various allergens, as the dendritic cells in the skin mimic those in the stomach. This test differs from ImmunoCap blood tests or skin prick tests, which are used to evaluate for immediate reactions that may result in symptoms such as hives or anaphylaxis. 

Combining patch testing and skin prick testing helps better identify foods that are causing allergic symptoms.