An article in Consumer Reports on myths and facts about the causes of allergies quoted Ravi Viswanathan, MD, assistant professor (CHS), Allergy, Pulmonary and Critical Care Medicine. 

Dr. Viswanathan discussed the differences between food sensitivities and food allergies. True food allergies, he explained, involve production of antibodies against substances in a particular food. 

"Every time you eat it, you get hives, swelling, maybe wheezing, chest or throat tightness, shortness of breath, GI symptoms, or dizziness," he said. 

Food sensitivities can result in gastrointestinal discomfort that may or may not occur each time the food causing the sensitivity is eaten.

Resources:

• "Allergy Causes: The Myths and Facts," Consumer Reports, August 15, 2017