Eosinophilic esophagitis
Overview
Eosinophilic esophagitis (EE) is an allergic inflammatory disease characterized by elevated eosinophils in the esophagus. EE is a newly recognized disease that over the past decade has been increasingly diagnosed in children and adults. Eosinophilic esophagitis is a rare disease, but increasing in prevalence to an estimated 1: 2000. This increase is thought to reflect an increase in diagnosis as well as a true increase in EE cases. Fortunately, the medical community is responding and new scientific information is emerging to guide management of this disorder, which often persists with ongoing or recurrent symptoms.
Eosinophilic esophagitis is characterized by a large number of eosinophils and inflammation in the esophagus lining (the tube connecting the mouth to the stomach). The esoinophils are usually only seen with the aid of microscopes and special diagnositic procedures. These eosinophils persist despite treatment with acid blocking medicines and other standard treatments. People with EE commonly have other allergic diseases such as rhinitis, asthma, and/or eczema. EE affects people of all ages and ethnic backgrounds. Males are more commonly affected than females. In certain families, there may be an inherited (genetic) tendency.
In individuals with EE, the eosinophils cause injury to the tissue in the esophagus. EE can be driven by food allergy or intolerance: most patients who eliminate food proteins from their diet (by drinking only an amino-acid based formula) improve or other environmental factors that researchers are beginning to understand.
Eosinophils are not normally present in the esophagus, although they may be found in other areas of the gastrointestinal tract. Diseases other than EE can cause eosinophils in the esophagus including gastroesophageal reflux diseases (GERD), food allergy, and inflammatory bowel disease. A gastroenterologist can diagnose EoE based on clinical symptoms, number of eosinophils present, and tissue inflammation.
Symptoms
Symptoms vary from one individual to the next and may differ depending on age. Vomiting may occur more commonly in young children and difficulty swallowing in older individuals. Symptoms may vary given the developmental ability and communication skills of the age group affected. It is not unusual for it to take several visits to the physician before eosinophilic esophagitis is diagnosed. Some symptoms are common to all age groups.
Common symptoms include:
• Reflux that does not respond to usual therapy (medicines which stop acid production in the stomach) – infant, child, adult
• Dysphagia (difficulty swallowing) – child, adult
• Food impactions (food gets stuck in the esophagus) – older children, adult
• Nausea and Vomiting – infant, child, adult
• Failure to thrive (poor growth, malnutrition, or weight loss) and poor appetite – infant, child, rarely adult
• Abdominal or chest pain –child, adult
• Feeding refusal/intolerance or poor appetite – infant, child
• Difficulty sleeping due to chest or abdominal pain, reflux, and/or nausea – infant, child, adult
Causes
Eosinophils are white blood cells that regulate inflammation and play a key role in allergic reactions. Eosinophilic esophagitis occurs with a high concentration of these white blood cells in the esophagus, most likely in response to an allergy-causing agent (allergen).
In many cases, people who have this kind of esophagitis are allergic to one or more foods. Possible food allergens that may cause eosinophilic esophagitis include milk, egg, wheat, soy, peanuts, beans, rye and beef. People with eosinophilic esophagitis may have other nonfood allergies. For example, inhaled allergens, such as pollen, may be the cause in some cases.
Source: Mayo Clinic
Prevention
Risk factors for eosinophilic esophagitis, or allergy-related esophagitis, may include:
• A family history of the disorder, suggesting that a gene or genes may increase the risk of eosinophilic esophagitis
• A family history of allergies
Source: Mayo Clinic
Diagnosis
Other diseases, including acid reflux, can cause eosinophils in the esophagus. Therefore, it is useful to exclude acid reflux as the cause with a trial of acid suppressive medications.
Currently, the only way to diagnose eosinophilic esophagitis is with an endoscopy and biopsy of the esophagus. This is typically coordinated between a gastroenterologist and a pathologist.
After the diagnosis of eosinophilic esophagitis has been made, an allergist/immunologist, often referred to as an allergist, is the most qualified physician to determine the role of allergies in the condition. An allergist can provide you, your family and your gastroenterologist with a comprehensive evaluation of the allergic components of eosinophilic esophagitis.
Eosinophilic Esophagitis and Allergies
Allergies are the result of a chain reaction that starts in the immune system. Your immune system controls how your body defends itself. For instance, if you have an allergy to tree nuts, the immune system identifies tree nuts as an invader or allergen. Your immune system overreacts by producing antibodies called Immunoglobulin E (IgE). These antibodies travel to cells that release chemicals, causing an allergic reaction.
Food allergy is a major, yet complex, cause of eosinophilic esophagitis in children, and a probable factor in adult eosinophilic esophagitis.
Environmental allergies such as dust mites, animals, pollens and molds may also play a role.
Testing
Allergy skin tests are useful in determining which allergens are triggering your symptoms. With this painless test, a small amount of allergen is put on your skin by making a small scratch or prick on the surface of the skin through a drop of the allergen extract.
If a raised bump or small hive develops within 20 minutes, it indicates a possible allergy. If this does not develop, the test is negative.
In certain cases, such as severe eczema, an allergy skin test cannot be done and your allergist may recommend a blood test. Another method for testing for food allergies is a challenge. This is done by feeding the food to find if it causes a reaction.
Food patch testing is in another type of allergy test that may be used in the evaluation of EE. This test is used to determine whether an individual has delayed reactions to a food. The patch test is done by placing a small amount of fresh food in an aluminum chamber. The food stays in contact with the skin for 48 hours, is removed and the allergist reads the results at 72 hours. Areas of the skin in contact with the food that have become inflamed indicate a delayed reaction to the food.
Prognosis
Eosinophilic Esophagitis does not appear to limit life expectancy and there is currently no strong data suggesting EE causes cancer of the esophagus. In some patients, EE is complicated by the development of esophageal narrowing (strictures) which may cause food to lodge in the esophagus (impaction). It can also make eating very difficult and uncomfortable for children and adults. It is not clear how long EE has to exist before strictures form. Typically, patients present with strictures in the older ages >6 years of age. However, since the natural history of EE is only emerging, careful monitoring and long-term follow-up is advised. The initial diagnosis of EE can be overwhelming and often affects the entire family. A positive attitude and a focus on non-food activities go a long way in learning to live with EE. With proper treatment, individuals with EE can lead a normal life.
Treatment
At present, the two main treatments recommended for eosinophilic esophagitis are dietary management and topical corticosteroids.
Dietary management
Many children and adults with EE respond favorably to dietary treatments, but the response may be less predictable for those with other Eosinophilic Gastrointestinal Disorders (EGIDs) such as eosinophilic gastritis, gastroenteritis, enteritis and colitis. The dietary restrictions are guided by food allergy testing, a detailed medical history, and ‘fine-tuned’ with food trials once the symptoms have resolved.
Targeted Elimination diets, in which "positive" foods on allergy testing or history are removed from the diet, are one type of dietary treatment. An elimination diet may be the only treatment needed for some individuals with eosinophilic esophagitis.
Empiric Six-food elimination diet is another type of elimination diet that has shown success in some EE patients. Instead of basing dietary elimination on skin testing, patch testing, or immunoglobuline E (IgE) testing, patients eliminate 6 common allergenic foods (milk, eggs, wheat, soy, peanuts/other nuts, fish/shellfish) regardless of the results of the allergy testing. These foods must be restricted in all forms, leading to a strict elimination diet including food antigens in small amounts.
Elemental diets, in which all sources of protein are removed from the diet, are another dietary therapy. An elemental diet includes only an amino acid formula (building blocks of protein), with no whole or partial proteins. Simple sugars, salt and oils are permitted on an elemental diet. Because these formulas are not palatable, the use of a strict elemental diet may require a feeding tube. Amino-acid based formulas are very expensive and are only sometimes covered by health insurance. Elemental diets are effective in treating most people with EE. In children and young adults, consideration of developmental issues are paramount in deciding if these diets are appropriate and close follow up is always warranted.
Children and adults who rely in part, or completely, on an elemental amino acid based formula may have a difficult time drinking enough of the formula. To maintain proper nutrition, some may require tube feedings directly into the stomach (enteral feeds). Tube feedings may be temporary i.e. weeks to months or in severe cases more permanent with placement of different types of medical feeding devices.
Food trials involve adding back one ingredient at a time to one’s diet to determine specific foods causing a reaction. Food trials begin after symptoms resolve and eosinophils have cleared. Food trials are handled differently by different professionals, but may involve repeat endoscopies with biopsies as foods are introduced to determine which foods are ‘safe’ for an individual.
Medications
Medications for Eosinophilic esophagitis most commonly include steroids to control inflammation and suppress the eosinophils. Steroids can be taken orally or topically (swallowed medicines traditionally used for asthma). For many patients, swallowed topical corticosteroids (fluticasone or budesonide) have led to EE remission (improvement while on treatment), though their long-term use for maintenance treatment has not been studied. For some people on swallowed steroids, Candida (yeast infections of the mouth and esophagus) can be a side effect. Acid suppressors may also help symptoms in some patients with reflux. Oral viscous budesonide is currently in clinical trials for the treatment of eosinophilic esophagitis.