Gluten Allergy, Gluten Hypersensitivity and Celiac Disease: Are They All the Same?
"Doc I think I am allergic to gluten. I stopped eating wheat and dairy products last month. Now I feel much better. Can you test me to gluten?"
More than a few times a year a patient or parent asks about gluten allergy and whether I can do skin testing to diagnose it. Actually, "gluten allergy" is a misnomer (the wrong name for this disorder).
Gluten hypersensitivity is an auto-immune disease that results from eating foods that contain wheat, rye barley and in some cases, oat. People who have this disease make antibodies called IgA which attack the inner surface of the small intestines disrupting its normal function.
Gluten hypersensitivity is also referred to as Celiac Sprue or** Celiac disease** (CD). It is** not** a true food allergy because instead of IgE antibody being produced (as is the case in peanut, egg, milk and shellfish allergy), it is IgA antibody that's formed (as a result of gluten ingestion). It is not known why this happens but the number of people diagnosed with CD has been on the rise.
How does Celiac Disease differ from food allergy?
** IgA** antibodies are produced by white blood cells called lymphocytes. These antibodies do not signal certain cells (mast cells) to release histamine and other allergy related substances as do** IgE** antibody. For this reason, most people with CD don't present to their doctors with complaints of hives and full body itching and swelling. Furthermore, there is not a high risk of throat swelling or allergic shock (dangerous drop in blood pressure), as with food allergy.
Why is it Important to know if you have gluten hypersensitivity (Celiac Disease)?
Celiac disease may cause such intense inflammation of the small intestines that it is unable to adequately absorb fats, vitamins, minerals and other nutrients. Malnutrition resulting from poor small intestinal function may cause anemia, fatigue, weight loss, osteoporosis, failure to thrive (in young children), skin and neurological problems.
What are symptoms of Celiac Disease?
Unfortunately the array of symptoms associated with this disorder overlap many other diseases (including food allergy). People with CD may complain of: stomach upset, diarrhea, constipation, abdominal pain, bloating, mouth sores, intensely itchy rash on the elbows and/or knees, tingling of the legs and feet, joint and muscle pains, irritability or depression.
In addition, because of the poor absorption of fats and other food components CD is associated with foul-smelling or pale stool that may appear oily.
Is Gluten Intolerance the same as Celiac disease?
Intolerance to gluten is not thought to be immune mediated and doesn't have the risks associated with CD. Similar to lactose intolerance, gluten intolerance goes away once gluten has passed through the small intestines. People with gluten intolerance may have gassy abdominal pain, bloating and diarrhea but do not have the severe intestinal inflammation and risks that are associated with CD or the allergic risks associated with food allergy.
Why is it important to confirm the diagnosis?
People with CD are at risk of having permanent bowel damage (not the case in food allergy or gluten intolerance). There is increased risk of intestinal cancer, lymphoma and the development of other autoimmune diseases (for example autoimmune thyroiditis). Family members of people with CD are at higher risk of getting this disease (but it is not contagious). Early diagnosis may help to reduce complications associated with poor intestinal function (osteoporosis, nerve damage, anemia, cancer).
How is Celiac Disease diagnosed?
After a comprehensive interview and physical exam by your primary doctor he/she will decide whether screening blood tests should be ordered. Your doctor may refer you to a gastroenterologist for a small bowel biopsy.
What do you do if you suspect you have Celiac Disease?
- Talk to your doctor and be certain to reveal all your symptoms and any family history of stomach or intestinal diseases.
- Do not go on a diet free of wheat, rye, barley and oat (gluten free diet) until after discussing it with your doctor. You see, avoiding gluten prior to testing may ruin being able to make the diagnosis. Screening blood tests and bowel biopsy may correct and appear falsely normal, despite having the disease.
- Once CD is confirmed, avoidance of gluten is essential to treat it. There is no cure but avoidance of gluten is the next best thing. But this is not easy to do. Working with a certified dietician, skilled in dietary management of CD is most desirable. Carefully read labels of all processed foods before eating them.
- Realize that many people with CD also have milk intolerance (unable to digest lactose sugars) which may contribute to abdominal bloating, gas and stomach pains. After a period of successful CD management, cow's milk may become more tolerable.
- Ask your doctor about follow up appointments and blood tests.