May is Celiac Disease Awareness Month. Physicians and others in the medical community need to be more aware of celiac disease.  Celiac disease is an autoimmune disease triggered by the ingestion of gluten that affects approximately 1 percent of the U.S. population.   However, most physicians didn’t learn much about it in medical school or during training.  As a result, physicians don’t include celiac disease in their differential diagnoses and don’t screen for it often enough.   According to the most recent examination of data from the Centers for Disease Control and Prevention, over 80 percent of individuals with celiac disease in the U.S. are undiagnosed.   And those who are diagnosed typically suffer from symptoms for years before the diagnosis is made.  Researchers often describe a “celiac iceberg”  as patients diagnosed with the disorder make up only a small percentage of those living with celiac disease.  In addition to symptoms, those with celiac disease can develop osteoporosis, other autoimmune diseases, and more rarely, cancers, including lymphomas and small bowel cancers.

Some important facts to know about celiac disease:

1. Celiac disease is common. It is estimated that almost 3 million people in the United States have celiac disease, but it is found worldwide and represents a global health problem.   It is not a disease found only in Caucasians of European ancestry, and doctors need to consider it in all their patients, whatever the patient’s ethnicity.   While more research is needed, the worldwide prevalence of celiac disease varies by location but is estimated to be about 1 percent overall.   In people with a first-degree relative with celiac disease, such as a parent, sibling, or child, the rate of celiac disease is increased to approximately 10 percent.

Celiac disease has become more common.  It is not just that the disease is being diagnosed due to more awareness or testing. In studies looking at both stored serum and epidemiological data, the rates of celiac disease have dramatically increased.  This is likely related to environmental triggers that have yet to be identified.

2. Celiac disease is a multisystem disorder. Physicians will encounter individuals with celiac disease, whatever their specialty. There are many symptoms of celiac disease, and this can be a diagnostic challenge.   Symptoms include both gastrointestinal symptoms and also extraintestinal symptoms.  Classic symptoms of celiac disease include diarrhea and weight loss. However, more individuals currently present with non-classical symptoms, which include abdominal pain, iron deficiency anemia, delayed growth in children, abnormal liver chemistry tests, infertility, neurological symptoms, osteoporosis, bloating, constipation, vitamin deficiencies, headaches, dental enamel defects, and more.  Some individuals also present with dermatitis herpetiformis, an itchy rash. Other people may be asymptomatic.  Celiac disease is also increased in certain conditions, including Type 1 diabetes, Down syndrome, and other autoimmune diseases.

3. Screening for celiac disease can be performed easily. Screening for celiac disease can be performed by a blood test for anti-tissue transglutaminase antibodies (TTG IgA Ab) along with a level of total IgA antibodies to exclude IgA deficiency. It is important that a person is consistently eating gluten before testing, or the blood tests will not be reliable.  Screening should be considered in those with the above symptoms as well as for family members of those with celiac disease. Recently direct-to-consumer celiac disease screening testing kits have also been introduced on the market.

In the United States, the standard for diagnosing celiac disease is a small bowel biopsy. However, guidelines have recently changed in some other countries to facilitate a diagnosis using a combination of genetic testing and antibody testing.   An individual should be referred to a gastroenterologist for endoscopy if they have an abnormal screening blood test or if the suspicion for celiac disease remains high despite a negative blood test.

4. The only treatment for celiac disease is a strict lifelong gluten-free diet. Celiac disease is unique amongst other autoimmune diseases as the trigger is gluten, a protein found in wheat, rye, and barley. While many other individuals without celiac disease may choose to avoid gluten, a gluten-free diet is the only treatment for people with celiac disease. It is not a fad diet and is not easy.  The gluten-free diet is more expensive, socially inconvenient, and can be associated with side effects like constipation and weight gain. As celiac disease is treated only with diet, consultation with a knowledgeable registered dietitian nutritionist is important for assessment, education, and monitoring.  National and local groups and online communities provide support and advocacy for those with celiac disease.

For a food to be labeled “gluten-free,” the FDA has determined that it must contain less than 20 parts per million of gluten and can not contain an ingredient that contains any wheat, rye, or barley. Several organizations conduct testing and certification of gluten-free food. Consumers can look for a seal while shopping. There are several apps and websites that also can assist with shopping for gluten-free food and eating in restaurants.

5. Gluten contamination happens. In patients with celiac disease on a gluten-free diet, contamination still occurs in most patients and can result in debilitating symptoms. Gluten contamination is also the most common cause for continued symptoms in patients with celiac disease and should be excluded.   In addition, there can be psychological consequences associated with maintaining a strict gluten-free diet, and those most vigilant to a gluten-free diet have been found to have a lower quality of life. 

There are several clinical trials underway for therapies to treat celiac disease.  If approved for clinical use, these therapies appear likely to be used alongside a gluten-free diet to minimize the effects of contamination.

Physicians and other health care providers can do a service to our communities by becoming more aware about celiac disease.  This will help improve the diagnosis of celiac disease and improve support for those already living with the disease.

Christina Tennyson is a gastroenterologist.

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