How common is celiac disease?

Celiac disease is the most common genetic disease in Europe. In Italy about 1 in 250 people and in Ireland about 1 in 300 people have celiac disease. Recent studies have shown that it may be more common in Africa, South America, and Asia than previously believed.

Until recently, celiac disease was thought to be uncommon in the United States. However, studies have shown that celiac disease occurs in an estimated 1 in 133 Americans. Among people who have a first-degree relative diagnosed with celiac, as many as 1 in 22 people may have the disease. A recent study in which random blood samples from the Red Cross were tested for celiac disease suggests that as many as 1 in every 250 Americans may have it.

Why is the diagnosis of celiac disease missed so frequently?
Celiac disease was originally considered a rare disease of childhood. However, the availability of more accurate serologic tests used in recent studies led to the realization that the disorder is common, affecting an average of 1 in 133 Americans, and up to 1 in 22 for those with associated risk factors (Fasano, 2003; Fasano, 2001; Johnston, 1998; Catassi, 1996; Not 1998). Unfortunately, the lingering perception is that celiac disease is rare when, in fact, it is actually one of the most common inherited diseases and is considered to be the most under-diagnosed common disease today (Fasano, 2003; Case, 2002). This continuing false perception causes many in the health care field to look elsewhere for a cause when the symptoms of celiac disease present themselves in patients.

The following facts about celiac disease help to explain why its diagnosis is commonly missed, and why there is a lack of appreciation of the magnitude of the problem in the United States:

• Celiac disease was originally considered a rare disease of childhood, and hence the diagnosis may be overlooked in adults. It is now recognized as a condition that can be diagnosed at any age, and research shows that in recent years the age of onset has increased (currently at a median of 46 years of age) (Fasano, 2003; Murray, 2003).
• The onset of diarrhea in adults can be gradual or dramatic. The sudden onset of diarrhea would tend to suggest diseases with an acute onset rather than an inherited disease (such as celiac disease). For example, any type of physiological stress or infectious process, such as pregnancy, traveler’s diarrhea, gastroenteritis, or gastrointestinal surgery may act as a trigger for the development of symptoms in celiac disease, but only the trigger tends to be diagnosed (Farrell, 2002).
• Celiac disease is often misdiagnosed as Irritable Bowel Syndrome (IBS) or lactose intolerance (Voelker, 2000), and up to 1/3 of celiac disease patients have been previously misdiagnosed with IBS (Michael, 2003).
• During the past two decades, the clinical picture has changed to include milder forms of celiac disease with less diarrhea and weight loss at presentation. Thus, clinicians need to keep in mind the changing clinical picture of celiac disease as a possible diagnosis in many clinical situations (Makik 2003; Michael, 2003; Murray, 2003).
• Physicians may use more widely known but less accurate serologic testing that can result in missed diagnoses (Fasano, 2001; Ciclitira, 2001).
• Up to 21% of intestinal biopsies, necessary for confirmation of celiac disease, are rejected by insurance companies, claiming that the cost of the testing isn’t justified by the symptoms (Fasano, 2003).
• Pathologists can often miss early features of celiac disease (Oberhuber, 1999).
• Celiac disease can be symptomatic (patients with gastrointestinal symptoms) or asymptomatic (silent).
  • Most patients with silent celiac disease have occult manifestations of the disease, including reduced bone density, iron or folate deficiency (Green, 2000; Tursi, 2001) and associated autoimmune diseases that are frequently more clinically significant.
  • A failure by physicians to appreciate that many individuals with the disease initially present without gastrointestinal symptoms is another reason why CD testing may not be performed (Fasano, 2003).
  • Approximately 50 % of adult patients can present with atypical symptoms further confusing a diagnosis (Farrell, 2002). These manifestations of celiac disease include ataxia, alopecia, myasthenia gravis, and others (Fasano, 2001).

In summary, celiac symptoms can be attributed to other problems. Many doctors are not knowledgeable about the disease. and only a handful of U.S. laboratories are experienced and skilled in testing for celiac disease.

All of these reasons for a missed diagnosis can be overcome, at least in part, by a greater awareness of celiac disease among health care professionals and patients (Fasano, 2003; Lankisch, 1996). It has been estimated that an increase in clinician awareness could more than double the diagnosis rate of celiac disease (Dickey 1998).

Points To Remember

• People with celiac disease cannot tolerate gluten, a protein in wheat, rye, barley, and possibly oats.
• Celiac disease damages the small intestine and interferes with nutrient absorption.
• Treatment is important because people with celiac disease could develop complications like cancer, osteoporosis, anemia, and seizures.
• A person with celiac disease may or may not have symptoms.
• Diagnosis involves blood tests and biopsy.
• Because celiac disease is hereditary, family members of a person with celiac disease may need to be tested.
• Celiac disease is treated by eliminating all gluten from the diet. The gluten-free diet is a lifetime requirement.

 

Last Updated October 3, 2006