A food allergy is completely different from a food intolerance. A food allergy involves an immune system response to the protein in the food, whereas a food intolerance doesn’t involve your immune system. These conditions are diagnosed differently and dietary management may also vary.
Some other differences between allergies and intolerances include:
• The onset of symptoms (allergies appear shortly after eating the food; intolerances can be delayed)
• The amount of food eaten (an allergy will appear after even the smallest amount of food is eaten; with an intolerance a certain amount of food can be eaten with no adverse reaction)
• Food allergies can be life-threatening whereas intolerances are unpleasant but rarely life-threatening
• The symptoms differ (allergies cause skin, gastrointestinal and respiratory symptoms such as hives, itchiness, swelling of the skin, vomiting, diarrhoea; the main symptoms of food intolerances are intestinal gas, abdominal pain or diarrhoea)