Eosinophilic gastroenteritis : Current aspects on etiology , pathogenesis , diagnosis and treatment

Idiopathic eosinophilic gastroenteritis is a rare inflammatory disease of unknown origin, characterized by diffuse eosinophilic infiltration of the gastrointestinal tract, accompanied by varying abdominal symptoms related to the location, severity and depth of invasion. Any part of the gastrointestinal tract including the esophagus may be involved, although the stomach and small bowel are the most frequently affected areas. Other sites of involvement include the pancreas, liver and biliary tree and tissues outside gastrointestinal tract. Although the exact etiology is unknown, an allergic disorder is present in almost 1⁄2 of the patients. Increased production of Interleukin-5 and activated eosinophils has been shown to be the rule in all cases. A large proportion of patients demonstrates peripheral eosinophilia. Eosinophil localization to the lamina propria at baseline is critically regulated by eotaxin, a chemokine expressed throughout the gastrointestinal tract. Diagnosis may sometimes be difficult but it can be achieved with the help of endoscopy plus mucosal biopsies, while peripheral and tissue eosinophilia supported by the findings of radiology, ultrasound and computed tomography can establish the diagnosis in the majority of cases. Eosinophilic gastrenteritis should be considered in the differential diagnosis of patients with unexplained gastrointestinal symptoms even in the absence of peripheral eosinophilia. Treatment with corticosteroids and the newer ones such as budezonide produces rapid relief of symptoms and clinical signs of the disease. Other valuable therapeutic modalities include administration of immunosuppressives, chromoglycate and dietary restrictions. Surgery is advocated only for obstructing forms of the disease. The course of the disease is characterized by frequent exacerbations and remissions. The long-term prognosis is relatively benign. Patients suffering from eosinophilic gastroenteritis require regular surveillance and prompt treatment in order to avoid possible complications.