By The American Partnership for Eosinophilic Disorders
Adapted from APFED’s Eosinophilic Esophagitis Toolkit: A Patient’s Guide to Resources and Hope. Reprinted with permission from The American Partnership for Eosinophilic Disorders.
Eosinophils are a type of white blood cell that are part of our immune system and involved with several medical conditions, including allergies (food and environmental), certain infections, parasites and other conditions.
Typically, eosinophils make up less than five percent of circulating white blood cells and can vary over time in healthy individuals. People who have too many eosinophils in their digestive system, tissues, organs and/or bloodstream, without a known cause, may have an eosinophil-associated disease.
These rare but emerging diseases are further categorized by where in the body the eosinophils accumulate. The most prevalent of these subsets is eosinophilic esophagitis (EoE).
Eosinophils are not normally found in the esophagus, and for those who have EoE, the elevated number of eosinophils causes injury and inflammation to the esophageal tissue. This damage may make eating difficult or uncomfortable, potentially resulting in poor growth, chronic pain and/or difficulty swallowing.
The exact cause of EoE is not yet known; however, it’s generally believed that it’s triggered by an immune response to specific foods. Many patients with EoE have other allergic conditions, such as environmental allergies, IgE-antibody mediated food allergies, asthma and/or eczema.
Symptoms of EoE may vary from one individual to the next and differ depending on age. Infants and toddlers may refuse food or exhibit poor growth, malnutrition or weight loss. School-age children may have recurring abdominal pain, trouble swallowing and/or vomiting. Adolescents and adults most often have difficult or painful swallowing. Their esophagus may narrow so food becomes stuck (impaction), causing a medical emergency.
To be diagnosed EoE, patients must have an upper endoscopy performed. This involves insertion of a small tube called an endoscope through the mouth. The esophagus, stomach and first part of the small intestine are examined for tissue injury and inflammation, and the esophageal wall is examined for thickening. A patient may have EoE even if the esophagus looks normal during endoscopy.
Small tissue samples are taken (biopsies) during the endoscopy procedure for a pathologist to analyze under a high-powered microscope. If eosinophils are present in the samples, the pathologist will count how many are visible. Increased numbers of eosinophils (usually >15 eosinophils per high-powered microscopic ﬁeld) is highly suggestive of EoE. An endoscopy with the biopsies is the only reliable method of diagnosing EoE at this time, although less-invasive methods are currently under investigation.
Current treatment options for EoE include topical corticosteroid therapy (fluticasone or a budesonide mixture/slurry), proton-pump inhibitors (acid suppressors), an elimination diet therapy or a combination of these therapies. Repeat endoscopies with biopsies are needed to monitor the effectiveness of the treatment plan.
Elimination diet therapy involves removal of suspected or known food triggers. For some patients, elemental nutrition may be recommended. Elemental diets consist of special amino acid–based formulas that do not elicit an allergic response. If a patient has difficulty drinking sufficient amounts of formula and/or the doctor believes it is necessary for other reasons, there may be the need for placement of a temporary feeding tube (called nasogastric) or a more long-term alternative (called a G-tube).
EoE is increasingly being diagnosed in children and adults. Based on a 2014 study, it was estimated that there are fewer than 100,000 EoE cases in the U.S. People of all ages and ethnic backgrounds are diagnosed with EoE, although a higher incidence is seen in males. Left untreated, EoE may cause scar tissue to form in the esophagus and cause problems with swallowing, including food impactions.
For more information about EoE or other eosinophil-associated disorders, and resources to manage the condition, visit APFED’s website. █