Celiac disease can also occur in asymptomatic individuals who have associated conditions. Recent studies show the prevalence of celiac in children under 15 years in the general population is 3 to 13 per 1,000 children, or approximately 1:300 to 1:80 children. A figure of 1 in 133 people is commonly used as an average for rates of celiac disease in the general population.
Diagnosis of Celiac Disease
Celiac disease can be challenging to diagnose, because its symptoms are often similar to those of other diseases. Celiac disease is easily taken for other diseases such as Crohns disease, chronic fatigue syndrome, diverticulitis, various intestinal infections, irritable bowel syndrome, iron-deficiency anemia caused by menstrual blood loss. Thus, celiac disease is often misdiagnosed, and generally under-diagnosed.
Celiac practice guidelines call for routine screening of anyone with a family history of celiac disease or of disorders such as thyroid disease, anemia of unknown cause, type I diabetes or other immune disorders or Downs syndrome. Otherwise, patients are generally screened case by case according to individual symptoms.
Likely Signs of Celiac Disease
As a general practice, celiac disease should be considered in the earliest stages of differential diagnosis of children with persistent diarrhea, especially with failure to thrive.
Celiac disease should also be considered in the differential diagnosis of children with persistent GI symptoms, including recurrent abdominal pain, constipation and vomiting, and any other GI issues commonly associated with celiac disease.
Testing is recommended for children with celiac-associated non-gastrointestinal symptoms, such as delayed puberty, dental enamel hypoplasia of permanent teeth, dermatitis herpetiformis, iron-deficient anemia resistant to oral iron, osteoporosis, and short stature.
Testing is also recommended for asymptomatic children whose relatives have celiac, and those who have celiac-associated conditions, such as autoimmune thyroiditis, Down syndrome, selective IgA deficiency, Turner syndrome, type 1 diabetes mellitus, or Williams syndrome.
Celiac practice guidelines call for testing asymptomatic children who belong to at-risk groups at around three years of age, as long as they have eaten gluten regularly for at least one year before testing.
Therefore, guidelines call for testing asymptomatic individuals with negative serological tests, and who belong to at-risk groups at regular intervals. Treatment guidelines do not presently call for routinely testing autistic children for celiac disease, as there is currently no peer reviewed scientific evidence that celiac disease is more common in autistic children than in the general population (although more research needs to be done in this area because many parents report a vast improvement in their childrens symptoms by eliminating gluten and casein from their diets).
Testing for Celiac Disease
A blood test, such as anti-tissue transglutaminase and anti-endomysial antibodies, can detect abnormally high antibody levels, and is often used to screen people who are most likely to have the disease, and for those who may need further testing.
Based on the current evidence and practical considerations, including accuracy, reliability, and cost, measurement of IgA antibody to human recombinant tissue transglutaminase (TTG) is recommended for initial testing for celiac disease. Although it is nearly as accurate as TTG, measurement of IgA antibody to endomysium (EMA) is observer dependent and therefore more subject to interpretation error and added cost. Because of the inferior accuracy of the antigliadin antibody tests (AGA), the use of AGA IgA and AGA IgG tests is no longer recommended for detecting celiac disease.
More than 90% of patients with celiac disease have genetic markers HLA DQalpha *0501, and HLA DQbeta *0201. Negative tests for these markers in conjunction with negative serum antibody tests suggest an absence of celiac disease. However, positive tests for the genetic markers do not necessarily mean that the patient has celiac disease. In conclusion, genetic markers can generally be used as a test to exclude celiac disease as a diagnosis, although there have been reported cases of the disease absent these markers--it is a scenario that is rare.
Celiac Disease Biopsy
To confirm a diagnosis of celiac disease, your doctor may need to do a biopsy, that is, microscopically examine a small portion of intestinal tissue, looking for celiac associated damage to the small intestine. To do this, your doctor inserts a thin, flexible tube (endoscope) through your mouth, esophagus and stomach into your small intestine and takes a sample of intestinal tissue to look for damage to the villi (tiny, hair-like projections in the walls the small intestine that absorb vitamins, minerals and other nutrients).
Practice Guidelines for Treatment of Celiac Disease with an Aggressive Life-long Gluten-free Diet
As there is presently no cure for celiac disease, avoiding gluten is crucial. Practice guidelines call for a life-long diet free of gluten as the standard treatment for celiac disease. To manage the disease and prevent complications, its essential that patients avoid all foods that contain gluten. That means it is crucial for the patient to avoid all foods made with wheat, rye, or barley. This includes types of wheat like durum, farina, graham flour, and semolina. Also, bulgur, kamut, kasha, matzo meal, spelt and triticale. Examples of products that commonly contain these include breads, breading, batter, cereals, cooking and baking mixes, pasta, crackers, cookies, cakes, pies and gravies, among others.
It is also good practice in treating celiac disease for patients to avoid oats, at least during initial treatment stages, as the effects of oats on celiac patients are not fully understood, and contamination with wheat in processing is common. So, its a good practice when first adopting a gluten-free diet to eliminate oats, at least until symptoms subside, and their reintroduction into the diet can be fairly monitored and evaluated.
Another good practice is coaching celiac patients to avoid processed foods that may contain hidden gluten. Wheat flour is commonly used in many processed foods that one might never suspect. A few examples include candy bars, canned soup, canned meat, energy bars, ketchup, ice cream, instant coffee, lunch meat, mustard, pastas, processed meat and sausages.
Also, gluten is also commonly found in many vitamins and cosmetics, such as lipstick, and in the production of many capsules and tablets, where wheat starch is a commonly used binding agent. Obviously, patients must avoid beer (most is made using barely, although there are gluten-free beers on the market), though wine, brandy, whiskey and other distilled and non-wheat or non-barley alcohols are okay.
Celiac patients are encouraged to eat a diet rich in fish, fresh meats, rice, corn, soybean, potato, poultry, fruits and vegetables. Initially celiac patients should also avoid milk and other dairy products, as it is common for patients with celiac disease to be lactose intolerant. Dairy products can often be slowly reintroduced into the diet over time with successful treatment.
It is also important for patients to learn to identify gluten-free foods. Because a gluten-free diet needs to be strictly followed, and because food ingredients may vary from place to place and even over time for a given product, it is important to always read ingredient labels.
For lists of gluten-free foods and products, and for specific advice on adopting, shaping and maintaining the gluten-free diet that is right for them, patients may wish to consult a registered dietitian who is experienced in teaching the gluten-free diet, or purchase a commercial gluten-free product listing.
Most patients who remove gluten from their diets find that their symptoms improve as inflammation of the small intestine begins to subside, usually within several weeks to several months. Many patients who adopt a gluten-free diet report an improvement within 48 hours. Results of a gluten-free diet can be especially dramatic in children with celiac disease. Not only does their diarrhea and abdominal distress usually subside but, frequently, their behavior and growth rate are often markedly improved.
A reappearance of intestinal villi nearly always follows an improvement in symptoms. In younger people, the villi may complete healing and re-growth in several months, while in older people, the process may take as long as two to three years.
In cases where nutritional deficiencies are severe, celiac patients may require vitamin and mineral supplements to help bring about a healthier vitamin profile: folic acid and B12 for patients with anemia due to folate or B12 deficiency; vitamin K for patients with an abnormal ProTime; calcium and vitamin D supplements for patients with low blood calcium levels or with osteoporosis. For all such cases, individuals should consult their health professional.
Skin lesions common in patients with dermatitis herpetiformis often improve with adherence to a gluten-free diet.
The Importance of Follow-up Testing for Celiac Patients on a Gluten-free Diet
Research indicates that only half of those patients who have had celiac disease for at least 20 years were following a strict gluten-free diet. Up to 30% of those patients showed evidence of bone loss and iron deficiency. These are but a few of the long-term consequences for celiac patients failing to follow a gluten-free diet.
Thus, it is important to conduct follow-up testing of celiac patients to determine the success of their gluten-free diets, and the progress of their treatment, and to make any necessary adjustments to each.
Even done properly, with no accidental consumption of gluten, the elimination of gluten antibodies from the blood takes months. To estimate the treatments effectiveness, current guidelines call for a single serological testing after 3-6 months on a gluten-free diet. In addition many doctors recommend an annual serological screening and biopsy to make certain that the disease is properly controlled.
For patients who are free of antibodies, and actively following a gluten-free diet, it is wise to consult a doctor if there is any recurrence of celiac-associated symptoms. First degree relatives of celiac patients should have a repeat blood test every 2-3 years.health writer who lives in San Francisco and is a frequent author of articles for Celiac.com.