Interest in gluten—and in particular, avoiding it — continues to be on the rise. The gluten-free market has become a billion dollar business as more and more adults and children trial this restrictive diet. Many go gluten-free as a lifestyle choice.
However, many turn to a gluten-free diet for medical reasons and for relief of specific symptoms. It is estimated that roughly 10 percent of the population have gluten-related disorders. Figuring out whether an individual needs to be gluten-free and where she lies on the spectrum of gluten-related disorders can be hard, but is an important endeavor.
A complicated diagnostic picture
Celiac disease (CD) is the classic gluten-related disorder. This chronic immune-mediated enteropathy of the small intestine is triggered by dietary gluten exposure (from wheat, rye or barley) in genetically susceptible individuals with one of two HLA types: DQ2 or DQ8.
Clinically, CD can look very different from patient to patient. Gastrointestinal symptoms can range from very mild to quite severe and can include abdominal pain, diarrhea, constipation or abdominal distention/gassiness.
Some children with CD present with poor growth and suboptimal weight gain, but many patients with celiac disease have no detectable reduction in growth rate. Some patients have no gastrointestinal symptoms, or have extra-intestinal symptoms such as delayed puberty, joint pains, fatigue or a host of others.
CD detection rates have increased significantly since two highly specific and sensitive serologic markers—tissue transglutaminase IgA and endomysial IgA — came into clinical use. These tests, however, should always be ordered with a total IgA measurement as well; patients with celiac disease are actually at risk for IgA deficiency, which can lead to false negative results. In addition, not every child with positive celiac serology has celiac disease, and seronegative celiac disease occurs.
For these reasons, endoscopic small bowel biopsies showing villous blunting, crypt hyperplasia and increased intraepithelial lymphocytes remain the “gold standard” for CD diagnosis.
Further complicating this already complex diagnostic picture is a newly characterized disorder: non-celiac gluten sensitivity (NCGS). Patients with this poorly understood condition experience many of the gastrointestinal and/or extraintestinal symptoms seen in CD, and obtain relief through gluten removal or reduction. However, NCGS lacks two important features characteristic of CD: positive celiac serology and villous blunting on small bowel biopsy.
Endoscopic small bowel biopsies showing villous blunting, crypt hyperplasia and increased intraepithelial lymphocytes remain the “gold standard” for CD diagnosis.
Little is known about the prevalence of NCGS, though it appears to be more common among females and the family members of patients with celiac disease. There are no biomarkers for NCGS yet that could assist in making a diagnosis. Nor do we know whether any long-term associated risks exist.
Children who have a wheat allergy or eosinophillic esophagitis can also feel better on a gluten-free diet. So too can patients with irritable bowel syndrome, because such diets are low in fermentable oligo-, di- and monosaccarides and polyols (FODMAP).
Diagnose first, treat second
If you suspect that a child has a gluten sensitivity, it is important that they be evaluated—ideally in partnership with a pediatric gastroenterologist — before initiating a gluten-free diet to identify the underlying condition if possible.
While clearly some children benefit greatly from a gluten-free diet, it has its downsides and should be reserved for those patients who truly need it. It can complicate social activities and paradoxically reduce quality of life even while improving it from a medical perspective. In addition, the diet is frequently low in fiber, iron and B vitamins, and has been linked to increased BMI in both adults and children. Gluten-free food is also expensive.
A solid diagnosis has other benefits as well. It opens the door to appropriate long-term monitoring for known associated comorbidities and potential complications. And it ensures that children and their families who need it can receive specialized education—and much needed extra support — about how to vigilantly avoid gluten exposure.
Questions about celiac disease and other gluten-related disorders in children? Contact the Celiac Disease Program.
About our expert:
Dascha C. Weir, MD, is the associate director of the Celiac Disease Program in Boston Children’s Hospital’s Division of Gastroenterology, Hepatology and Nutrition.