Eosinophils, a type of white blood cell, are an important part of the immune system. A high number of eosinophils in the blood are commonly seen in eosiniophilic esophagitis, known as EoE, and varying other conditions, such as parasite infection, food allergy and drug allergy, to name but a few. The esophagus is the tube that sends food from the mouth to the stomach. While normally there are no eosinophils in the esophagus, in EoE large numbers of esosinophils are found in the inflamed esophagus tissue.
EoE is an allergic and inflammatory disease. It affects from one to four of every 10,000 people in the United States, and may occur in certain families. An estimated 50 percent of patients with EoE also have food allergies, seasonal allergies, asthma or even eczema. Environmental allergies to allergens such as dust mites, animals, pollen and molds may also play a role in some patients with EoE, therefore, both genetic and environmental factors play a significant role in the development of the disease.
EoE can occur at any age and most commonly occurs in Caucasian males. The symptoms of EoE vary with age. Infants and toddlers may refuse food or fail to grow properly. Other, younger children often have recurring abdominal pain, trouble swallowing or vomiting. Older children and adults most often have difficulty swallowing or suffer food stuck in the esophagus. Proper diagnosis of EoE needs be confirmed by both an allergist and a gastroenterologist, each of whom will take a clinical history. Additionally, skin tests to food or even inhalant allergens will be ordered as will an upper endoscopy with biopsy to examine for eosinophils and inflammation of the esophagus. Gastrointestinal reflux or other inflammatory conditions need to be excluded as well.
The relationship between food allergy and EoE is very complicated. In some patients, a triggering food can cause conventional immediate IgE-mediated reaction (IgE is a type of antibody) or non-IgE mediated delayed reactions. Allergies to these foods often cannot be easily proven by conventional allergy tests (skin tests, or blood tests). Occasionally, food patch testing, done in the research center, is used to determine if the patient has delayed reactions to a food. Eliminating major food allergens from diet including dairy, egg, wheat, peanut, tree nuts and fish have been shown to be very helpful in treating EoE. Amino-acid-based formulas and dietary elimination are very effective therapies for children with EoE. Consultation with a registered dietitian is necessary to ensure adequacy of calories, protein and micro-nutrition.
Glucocorticosteroids, which can reduce eosinophils and inflammation, are the most helpful medications for treating EoE, and proton pump inhibitors, which decrease stomach acid, may also be effective. When indicated, dilation of stricture of esophagus provides relief of dysphagia.
Dr. Yong H. Tsai is board-certified in rheumatology, allergy and clinical immunology and has been practicing in this area since 1993. Send questions to Dr. Tsai in care of features@news-jrnl.com. You can also check his website: arthritis-allergy.net.