Comparing Coeliac Disease, Food Allergy & Food Intolerance

    In order to explain why they are on a special diet, many people with Coeliac Disease understandably (and perfectly reasonably) try to make things easier for their friends, co workers, and restaurant staff by just saying they are "allergic to wheat" rather than describing in detail what their condition is all about. Although saying you are allergic to wheat is perfectly fine, the statement is not perfectly accurate.

    Coeliac disease is an autoimmune disease, meaning that your immune system has turned against - and is attacking - your own, health tissues. Autoimmune diseases, including CD, typically cause chronic problems, not sudden, life-threatening crises. Food allergies are caused by a different problem with the immune system and can indeed lead to immediate catastrophic situations. A food intolerance (such as lactose intolerance) on the other hand is not related to the immune system and although it leads at times to unpleasant symptoms, is not life-threatening in nature. We illustrate  the key differences between these three conditions..
                            Coeliac Disease        Food Allergy            Food Intolerance
Time to Onset        Days, months to       Seconds to             Minutes to hours
after consuming     years!                      minutes
the Triggering
Food

Common                Variable but             Shortness of           Abdominal cramps
Symptoms              often abdominal       breath, swelling      diarrhea
                             cramping diarrhea    of the lips and
                                                            tongue, hives
                                                                                                                                

Immune                T Cell mediated         Immediate              None
Problem                 disease                    hypersensitivity
                                                            reaction


Technically speaking, a food allergy is a special type of immune reaction (called an immediate hypersensitivity reaction) that involves immune system cells called basophils and mast cells (these are special types of white blood cells involved with the body's allergic response and certain other conditions). An immediate hypersensitivity reaction results, upon exposure to a certain stimulus, in the immediate release into the bloodstream of a substance called histamine, which causes instantaneous - and sometimes life-threatening - symptoms such as shortness of breath, a swollen tongue, and skin rash (hives). Perhaps you know people who are allergic to peanuts. They have this type of food allergy. people can also be allergic to wheat, which is different from Coeliac Disease because the reactions to wheat are immediate and cause problems with breathing, hives and swelling of the mouth and lips. Unlike in Coeliac Disease, wheat does not cause intestinal damage in people with wheat allergy.

   As you know from your own experiences living with CD (or living with someone who has CD) this is entirely different from what happens if a person with Coeliac Disease consumes a gluten-containing food (such as wheat) in which case, such instantaneous, life-threatening symptoms don't occur. Although, the immune system plays a role in CD, it is of an entirely different nature.

   The one exception to Coeliac Disease and food intolerance being unrelated is if you have newly diagnosed and therefore untreated Coeliac Disease in which case you may have temporary lactose intolerance.

Taken from Coeliac Disease for Dummies Part I: Dealing with the Diagnosis of Coeliac Disease