A chronic inflammatory disorder, eosinophilic esophagitis (EoE) of the esophagus is immune- or antigen-mediated. It involves symptoms such as heartburn, difficulty swallowing, and food impaction (ingested items such as meat or fish bones getting stuck in the esophagus. With children, the range of common symptoms extends to nausea, vomiting, and abdominal pain. The disorder is linked to esophageal remodeling and abnormal narrowing (stricture formation) when not treated.
EoE diagnosis relies on evaluating symptoms, performing endoscopic biopsy, and obtaining esophageal mucosa tissue samples. Tissue abnormalities, such as high levels of eosinophils (white blood cells) in the esophagus, are associated with EoE. An allergic reaction to the environment and foods occurs as the eosinophils build up in the esophagus. With approximately one in a thousand people affected by EoE, those with allergies such as allergic rhinitis (hay fever) are particularly susceptible. As with allergies in general, the number of EoE sufferers is increasing.
For about a third of patients, proton pump inhibitors (PPIs) provide a first-line therapy that they are responsive to. Other pharmacological approaches include swallowed topical corticosteroids and budesonide for pain and inflammation. Unfortunately, these approaches may not address the immune system-related causes of inflammation.
While EoE is often categorized as a food allergy-driven disease, the reaction differs from the anaphylactic symptoms (tongue swelling, hives, throat tightness) typically associated with food allergies. With EoE, a delayed response results from chronic exposure to problematic foods. An immune reaction is triggered by lymphocytes, which recruit eosinophils into the tissue. Food allergies cause the eosinophils to break down and disintegrate, which releases cytotoxic granules associated with tissue inflammation. Fibrosis, scarring, and a narrowing of the esophagus then follow.
A landmark study published in Gastroenterology 1995 revealed that pediatric patients with elevated eosinophil levels in their esophagus were responsive to a nonallergenic amino acid-based (elemental) formula diet. This pediatric EoE approach was subsequently confirmed at Lurie Children’s Hospital in Chicago, with six food groups: milk, soy, wheat, eggs, nuts, and seafood, which often trigger EoE, empirically eliminated. Since then, adults have also been studied, with around 70 percent responsive to dietary therapy. This makes dietary therapy a first-line approach to treating both children and adults.
There are three basic dietary approaches to combat EoE. For children, the elemental diet involves removing all food allergens and placing them on an amino acid-based formula for six weeks. Once the inflammation is gone and eosinophils eliminated, foods are gradually introduced again, one at a time, until food triggers are identified. Considered the most effective approach, it is also the most time-consuming and expensive, with a feeding tube often required for delivering formula.
For adults, the first-line approach is the empiric, or 6-food elimination diet. This does not require avoiding all normal foods but eliminating the six most common allergens. If EoE has resolved itself after six weeks, it’s clear that one of these foods is the cause. At this point, the six foods are added back to the diet, one at a time, and allergens are assessed each time. The most common trigger is wheat, which impacts 60 percent of patients, followed by milk (50 percent), soy and nuts (10 percent each), and eggs (five percent).
Children seem to have a different immune reactivity than adults. They often respond to a third approach: an allergy-directed diet that relies on blood, patches, or skin-prick testing for the food allergen. Once the triggering food is identified, it is eliminated for six weeks, and results are monitored.
