ABSTRACT: For every recognized case of celiac disease, 8 more remain undiagnosed. The reason for this disparity is contingent on the varying presentations of the disease. What was once considered solely a GI disorder, uniformly presenting with diarrhea and malabsorption, has evolved into a multisystem autoimmune disorder with myriad symptoms and signs. In addition, celiac disease is no longer a disorder limited to childhood and adolescence; it has even been diagnosed for the first time in elderly patients. Atypical celiac disease can be found in patients who present primarily with hypothyroidism, liver enzyme elevations, Addison disease, type 1 diabetes mellitus, and other disorders with major pathology outside the GI tract. Studies have demonstrated that an active casefinding strategy in primary care practice can increase the diagnostic yield for celiac disease.
Key words: celiac disease, tissue transglutaminase, gluten
If you were to ask other primary care practitioners which subspecialty niche celiac disease should occupy, most would probably respond, "Gastroenterology, of course." Until recently, we would have agreed. However, celiac disease or, better yet, celiac syndrome needs to be "reframed" for contemporary clinicians.
For example, "atypical" celiac disease—which presents with few or even no GI symptoms or signs—is largely responsible for the increased prevalence of celiac disease today.1 Extraintestinal manifestations of celiac disease are rapidly becoming the rule rather than the exception. One example is thyroid disease, which occurs 4.4 times more frequently in patients with celiac disease than it does in control populations.2 In some of these persons, the thyroid disorder may be diagnosed and treated appropriately, but celiac disease may be either overlooked or only diagnosed later.
Celiac disease can be associated with a variety of autoimmune diseases including type 1 diabetes mellitus, autoimmune liver disease, Graves disease, and Addison disease.3 Thus, celiac disease has become one of our generation's great "masqueraders," similar to the role syphilis played in William Osler's day.
Figure 1 – Duodenal biopsy reveals severe villous atrophy–the classic pathology in celiac disease.
Because of the myriad and frequently enigmatic presentations of celiac disease, the challenge of diagnosis falls squarely on the shoulders of primary care practitioners. Most cases are currently undiagnosed; however, one study demonstrated that an active case-finding strategy in primary care practices improves the detection rate.3
The study included 737 women and 239 men older than 40 years. Any participant with a family history of celiac disease or unexplained anemia or iron deficiency, recurrent abdominal pain or bloating, irritable bowel syndrome (IBS), chronic fatigue, unexplained liver enzyme abnormalities, or an autoimmune disease was offered serological screening for celiac disease. Those with a positive result were referred to a gastroenterologist for duodenal biopsy. The result of this approach was a 32- to 43-fold increase in the case finding of celiac disease.3
This study demonstrated that reframing celiac disease as a systemic autoimmune disorder is the key to earlier diagnosis. Here we will discuss how this approach can be used in primary care practice to augment case finding and appropriate consultation. We will present 3 case studies that illustrate atypical presentations of the disease, and we will also describe high-yield screening studies.
