Ask Shelley Case: The Difference Between Celiac Disease, Gluten Sensitivity and a Wheat Allergy
Monday, June 13th, 2011
Question:
I am confused about these 3 conditions. Can you tell me more?
Answer:
What a great question and one that is confusing to many people! The following are some facts and pointers regarding each of these conditions to help you understand the differences in these somewhat similar, yet very unique medical conditions:
Celiac Disease (CD)
This is one of the most common inherited disorders with an estimated prevalence rate of 1:100. Celiac disease is an autoimmune disorder in which the villi of the small intestine are damaged by specific proteins in the grains wheat, rye and barley (collectively called gluten). Symptoms of CD are highly variable, may occur at any age, including the elderly, and involve not only the gastrointestinal system but many other organ systems. Gastrointestinal symptoms range from nausea, reflux, bloating, gas, diarrhea and/or constipation. Other symptoms can include fatigue, weight loss (note CD can also occur in obese individuals), mouth ulcers, dental enamel defects, bone and joint pain, easy bruising of the skin, menstrual irregularities, miscarriage, infertility in both women and men, migraines, depression, ataxia, seizures, neuropathy, lactose intolerance and elevated liver enzymes.
Another presentation of CD is the skin condition dermatitis herpetiformis (DH) that is characterized by an intense burning, itchy rash that is symmetrically distributed.
Untreated celiac disease can result in nutritional deficiencies such as anemia and osteoporosis, as well as development of other autoimmune disorders (e.g., thyroid disease, arthritis, liver disease) and intestinal cancers.
There are specific blood tests (TTG and EMA) that can be used to screen for CD, however the only definitive test for diagnosis is the small intestinal biopsy. Diagnosis of DH is a skin biopsy from unaffected skin adjacent to the blisters or erosions. A gluten-free diet should never be started before the blood tests and biopsy are done as this can interfere with making an accurate diagnosis.
Once a diagnosis of CD is confirmed, the treatment is a strict gluten-free diet for life. For more information on the gluten-free diet see www.glutenfreediet.ca
Gluten Sensitivity (GS)
Recent research has revealed that it is possible to be sensitive to gluten and not have celiac disease or wheat allergy. Although the exact mechanisms and prevalence of GS is not known at this time, Dr. Fasano from the Center for Celiac Research in Baltimore has recently published several papers on this topic. There appears to be differences in gut permeability and the immune system of those with CD compared to individuals with GS. GS is not an autoimmune disease, is not accompanied by elevated tissue transglutaminase antibodies (TTG) and does not result in increased intestinal permeability or severe intestinal damage. However, it is interesting to note that IgA and IgG antigliadin antibodies (AGA) were elevated in almost 50% of the cases in the Fasano study. Elevated AGA levels have also been seen in schizophrenia, ataxia (loss of muscle coordination) and other conditions.
Symptoms of GS can be similar to CD such as abdominal pain, bloating, gas, diarrhea, unexplained anemia, muscle cramps, leg numbness, and bone or joint pain.
Currently there are no specific tests for diagnosing GS. The only way to determine if someone has GS is by ruling out CD and wheat allergy, then seeing the response to a gluten-free diet and a gluten challenge. It is not known whether someone with GS must strictly avoid gluten for life like those with CD.
The Center for Celiac Research estimates that GS may affect 6-7% of the population compared to 1% for those with CD. Dr. Fasano will be speaking at the International celiac disease conference in Oslo, Norway June 19 at a session called Gluten Sensitivity: More Than Celiac Disease. So stay tuned for more information in my upcoming columns.
Wheat Allergy
A food allergy is an abnormal immune reaction to naturally occurring proteins. The most common food allergens are wheat, egg, peanut, tree nuts, fish, shellfish, soy and milk. Food allergies are estimated to affect approximately 5 to 6% of young children and 3 to 4 % of adults in westernized countries.
When someone with wheat allergy consumes foods made with wheat, it triggers the release of a specific antibody called Immunoglobulin E (IgE) from various cells in the body. This IgE circulates throughout the bloodstream and causes other cells to release inflammatory chemicals such as histamine. This immune response or allergic reaction may result in a variety of symptoms that can be mild to life threatening anaphylaxis that can occur within minutes to a few hours. It can affect the skin, gastrointestinal tract, respiratory system and/or cardiovascular system. Symptoms of wheat allergy can include swelling and itching in the mouth, hives, itchy rash, eczema, itchy and watery eyes, nasal congestion, abdominal cramps and pain, diarrhea, tightening of the throat and trouble breathing and swallowing, dizziness and a drop in blood pressure. Unlike CD, wheat allergy does not result in severe intestinal damage.
Wheat allergy is more common in infants and young children, and is frequently accompanied by other food allergies. Adolescents and adults can be allergic to wheat although it is not as common as in children. It is estimated that approximately 0.1% of the population has wheat allergies.
The only treatment for wheat allergy is to follow a strict wheat-free diet. But the good news is that the majority of children will outgrow their wheat allergy over time. Check out this link for more information about food allergies and food intolerances.
Ask Shelley Case is a feature of BeFreeForMe.com. It is published the second Tuesday of each month. Shelley Case, RD is a Consulting Dietitian, Speaker and Author of Gluten-Free Diet: A Comprehensive Resource Guide. Visit Shelley and get more gluten-free tips & info at: GlutenFreeDiet.ca