By Dr. Harold Kim, Allergist, Kitchener, Ontario
Over the last 5 to 10 years, a “new” medical condition has come to light in both children and adults in the world of allergy. This condition has been coined with the term “eosinophilic esophagitis (EE)”. This diagnosis has been sometimes called “allergy of the gut” or “asthma of the gut”. Although the esophagus or feeding tube has been the part of the gastrointestinal tract that has been focused on, this allergic gut condition could affect different parts of the stomach and bowel. The incidence of this condition has been estimated at one in 10,000 children per year, but it is felt to be increasing.
A good method of introducing this topic is with a case report. An eleven-year-old boy was referred to our clinic with a history of recurrent vomiting and severe abdominal pain. These episodes seemed to occur in the spring. He had some symptoms of hayfever or allergic rhinitis in the spring as well as mild asthma. The abdominal symptoms could be so severe that he required hospitalization on 3 occasions. He had positive skin tests to trees, grass and dust mites. There were no food allergies. He was referred to a gastroenterologist and with an endoscope, a biopsy of his esophagus was taken. He had eosinophils (allergy white blood cells) on the biopsy of the esophagus. He was treated with an asthma inhaled steroid that he was instructed to swallow, rather than inhale. His symptoms have been well controlled over the last 3 years.
This case illustrates a number of important points regarding this condition. First of all, it can be very debilitating and it can often be well controlled with the treatments that we have available already. In this article, we will review the clinical presentation, diagnosis and treatment of EE.
This condition can occur in both children and adults. The symptoms can be mild to very severe. Often it is diagnosed incidentally on an endoscopy procedure. The symptoms can include pain on swallowing, food sticking and heartburn in adults. In children the symptoms can be more subtle. They can have feeding aversion, vomiting/regurgitation, heartburn (often not better with medical or even surgical therapy), food sticking, pain with swallowing or even failure to thrive. This disorder can be confused with a number of other gut conditions such as acid reflux, Crohn’s disease, food allergy or bowel infection. Also, the majority of patients with EE are allergic. Between 50-80% of EE patients have coexisting atopic dermatitis, allergic rhinitis and/or asthma. There have been rodent studies confirming that if one places allergen in the airway of mice with EE, the allergic inflammation of the esophagus will worsen. This is an intriguing finding and gives us more evidence that allergy is a truly systemic disease. Some researchers feel that food allergy could cause the inflammation in the esophagus as well.
To diagnose EE, one must have a high degree of suspicion. If a person has the symptoms that can occur in EE and they do not respond to the normal therapies for acid reflux or if they have significant vomiting or swallowing difficulties, a referral to a gastroenterologist should be considered. This is particularly true for a patient with existing allergic conditions such as asthma or rhinitis. The diagnosis can only be made with an endoscopic viewing of the esophagus and with a biopsy of that area. The pathologist will review the biopsy to confirm that there are a significant number of eosinophils in the tissue. Some researchers have advocated extensive allergy testing for foods and aeroallergens in patients with confirmed EE.
After EE is diagnosed, the treatment options could include all of the treatments that we use for both allergic rhinitis and asthma. Because this condition is new, there have not been many properly completed studies on the best treatments for this condition. As with all disorders with a potentially allergic cause, any suspected allergen triggers including foods and aeroallergens should be avoided. There have been some studies to show that avoidance of common food allergens or even severely restricting the diet to an elemental formula can be helpful particularly in children. Although antihistamines and leukotriene antagonists may be helpful, the most effective therapy is felt to be the use of high dose asthma inhaled steroid medications that are sprayed into the mouth and swallowed instead of being inhaled into the lungs. This technique of swallowing the steroid should lead to the delivery of the medication directly to the esophagus. In patients with severe symptoms oral or systemic steroids should be considered, but this should be tapered if possible. EE patients should be followed by their allergist and/or gastroenterologist.
In summary, EE is a condition that can be severe yet still difficult to diagnose. Although the incidence is felt to be increasing, physicians must have a high degree of suspicion so we can identify and treat these patients. Once this condition is diagnosed, there are treatments available that often significantly improve symptoms and the disease process. In the allergy and immunology field, we all look forward to seeing more research into this interesting and new area of “allergy of the gut”.
from Allergy & Asthma News, Issue 1 2008