because often a patient will test positive to a Challenge Testing. This tests your response to consuming a small amount of a food. Skin prick testing did not confirm any of these allergies- more of which later. We would certainly like an accurate test for food allergy. Allergy testing involves having a skin or blood test to determine what substance, or allergen, may Allergies. Hives. Poison Ivy and Other Plant Gemoscan offers food intolerance tests & sensitivity blood testing. Accurate Allergy Testing allows you to take back control over your weight & health. .