A lot of people think food allergy and food intolerance are the same. It can be difficult to determine whether the person has a food allergy or food intolerance because the signs and symptoms often overlap.
What is a Food Allergy?
A food allergy occurs when the immune system mistakes an ingredient in food as harmful and creates an immune response to fight it.
IgE antibodies are created, causing histamine release, which if elevated can potentially create a wide range of symptoms which are usually acute, rarely chronic.
Food Allergy is developed most of the time from infancy. If you have a food allergy, even a tiny amount of the offending food can cause an immediate reaction within 1 to 2 hours of exposure and sometimes less, by eating the food, inhaling the food, and even touching the food.
Symptoms can be very severe, from digestive signs and symptoms that may include nausea, vomiting, cramping and diarrhea. Other signs and symptoms can include a tingling mouth, itching, hives, and swelling of the lips, face, tongue, and throat. It is severe life threatening which can cause anaphylaxis with symptoms like difficulty in swallowing, fever, shortness of breath and dangerously low blood pressure.
If you have a food allergy, you’ll need to avoid the offending food entirely.
How to avoid triggers? By using Antihistamines and EpiPen (epinephrine).
How to Diagnose it? By skin pricks test, IgE blood test and/or food challenge.
How many foods? Rarely more than 1 or 2 foods.
Food Allergies persist and are lifelong.
What is a Food Intolerance?
While the symptoms are similar to food allergy, a food intolerance does not involve an immune reaction. Rather, intolerances occur when an ingredient/compound in a food irritates a person’s digestive system or when a person is unable to properly digest and breakdown the food, it is mediated by IgG.
Food intolerance can be developed in any age, it is not life threatening. It is a delayed reaction, occur gradually, up to 72 hours after eating the offending food.
Symptoms of an intolerance are primarily gastrointestinal, usually chronic, rarely acute.
They include stomach pain, nausea, vomiting, headaches, weight gain, bloating, heartburn, constipation, diarrhea, even fatigue and skin rash.
How to Diagnose it? Food Intolerance Test.
How many foods? It can be multiple.
Symptoms can clear after avoidance of offending foods.
Do I have to avoid elevated food for the rest of my life?
No. After avoiding those foods for at least three months and noticing an improvement in your symptoms, you can begin to gradually introduce them back into your diet. You should introduce one food at a time and wait four days before trying another.
Do I need to have a re-test after a few months?
Most people do not need to have a re-test, but if you would like to take another test, I advise a period of 6 months between tests. If symptoms have improved and you have successfully reintroduced offending foods, a re-test is unnecessary.
Both, food allergy and food intolerance need nutrition education on food additives, hidden ingredients, food label, cross contamination.