Eosinophilic esophagitis (EE) is an allergic inflammatory reaction of the esophagus (the tube that connects the throat and the stomach). Also known as allergic esophagitis, its symptoms can range from severe heartburn, difficulty swallowing, food impaction in the esophagus, nausea, vomiting and weight loss.
Eosinophilic esophagitis is caused by a large build up of eosinophils in the esophagus. Eosinophils are white blood cells (leukocytes) manufactured in the bone marrow and are one of many types of cells that actively promote inflammation caused by allergic reactions. A large number of eosinophils can accumulate in tissues such as the esophagus, the stomach, the small intestine, and sometimes in the blood when individuals are exposed to an allergen. The allergen(s) that causes eosinophilic esophagitis is not known ( it is not even known whether the allergen is inhaled or ingested). Eosinophilic esophagitis is more common among individuals with other allergic conditions such as asthma, hay fever, allergic rhinitis, and atopic dermatitis.
Although the disease occurs in adults most cases of Eosinophilic esophagitis have developed in children,occurring more often in boys than in girls. Most adults affected by the condition are men in their 20's and 30's. There appears to be some age-related differences in symptoms, with younger children having more symptoms of weight loss, and older children and adults having food impaction and difficulty swallowing.
An increasing number of EE cases having been diagnosed within the last five years though it is unclear whether EE is occurring more often or if it is just being diagnosed more frequently.
The major symptom among adults with eosinophilic esophagitis is difficulty swallowing solid food (dysphagia), where often the food gets stuck in the esophagus after it is swallowed. Less common symptoms include heartburn and chest pain.
Eosinophilic esophagitis decreases the ability of the esophagus to stretch and accommodate mouthfuls of swallowed food. As a result, solid foods (most frequently meats like steak or chicken) will have difficulty passing through the esophagus. When solid food sticks in the esophagus, it causes an uncomfortable sensation in the chest, referred to as dysphagia. Sometimes the solid food becomes impacted, that is, it can neither pass into the stomach or be regurgitated. The impacted solid food causes chest pain that can mimic a heart attack and repeated spitting of saliva that cannot be swallowed (because of the obstruction of the esophagus). Individuals with impacted food are unable to eat or drink. To relieve the obstruction, a doctor usually will have to insert a flexible endoscope through the mouth and into the esophagus to remove the impacted food.
Among children, the most common symptoms are abdominal pain, nausea, vomiting, coughing and failure to thrive.
Eosinophilic esophagitis is an allergic reaction, which involves the immune system’s inappropriate response to a protein. The body perceives the protein to be harmful, and produces immunoglobulin E (IgE) antibodies to defend against the "invader." When the IgE antibodies come in contact with the offending protein, chemicals known as histamines and leukotrienes are released, causing the symptoms most people associate with allergies, including itchiness, rashes, hives, swelling, nausea, diarrhea and shortness of breath.
Food allergies such as milk, eggs, nuts, wheat, soy, corn and shellfish are the cause of 80 percent of Eosinophilic esophagitis, according to the American Academy of Allergy, Asthma and Immunology (AAAAI). Environmental allergens, such as pollen and mold, are also related to EE. The allergic reaction creates inflammation in the esophagus which causes vomiting, difficulty swallowing, nausea and abdominal pain in susceptible individuals.
EE may be misdiagnosed as GERD as some of the symptoms are similar, and GERD is common. However, symptoms of EE do not improve with acid blockage medications like those used to treat GERD. EE does appear to improve with an elimination diet to remove the food allergen source or with corticosteroid medications commonly used to treat asthma.
Left untreated, the inflammation related to EE will begin to damage the esophagus, resulting in narrowing of the esophagus (stricture) and in increase in fibrous tissue (fibrosis).
Diagnosis is obtained during an upper GI endoscopy where biopsies are taken of the esophagus. At the time of endoscopy, ridges or furrows may be seen in the esophagus wall. Sometimes, multiple rings may occur in the esophagus, leading to the term "corrugated esophagus" or "feline esophagus" due to the similarity in the rings of the cat esophagus. A high number of eosinophils are seen on microscopic examination of the biopsy specimens.
Physicians can also perform skin testing to narrow the cause of symptoms to a specific allergen. During skin testing the physician will prick or inject allergen extracts into the patient’s skin. The development of a small, raised, reddish area indicates a positive reaction. Common allergens of EE patients are cow's milk, soy, egg, and wheat.
Treatment strategies include dietary modification, drug therapy, and mechanical dilatation of the esophagus. If the skin tests identified food allergies the diet is modified so that these allergens are eliminated.
Drug therapy begins with acid-inhibition medication. Most patients with EE have an acid reflux component to their condition calling for the use of Proton pump inhibitors. Treating acid reflux alone however won't completely alleviate EE symptoms. Treatment that targets the inflammation is required and may include: corticosteroids such as fluticasone, leukotriene modifiers like montelukast, and anti-interleukins such as the anti-IL-5 monoclonal antibody mepolizumab. Other drugs attempt to stop the allergic response; these include antihistamines such as loratidine. Patients with severe symptoms despite these interventions may require oral corticosteroids such as methylprednisolone.
Mechanical dilatation may be considered in severe cases of EE that have progressed to esophageal stricture or severe stenosis. Dilatation is accomplished by passing dilators through the mouth and down the esophagus to gently expand its diameter.
Doctors have used elimination diets (for example, diets without wheat, soy, milk, peanuts, and/or seafood) and elemental diets (for example, liquid diets that contain only amino acids but no proteins to act as allergens) in treating children with eosinophilic esophagitis with some success. Doctors have little experience, however, in treating adults with elimination diets. It would be difficult to identify an individual allergen causing eosinophilic esophagitis and elemental liquid diets are difficult to tolerate for more than a few weeks.
Eosinophilic Esophagitis- References
By Mortin - Copyright 2010
Last modification 05/02/2010