Eosinophilic Gastroenteritis

A rare benign gastrointestinal disease characterized by the presence of abnormal and nonspecific gastro-intestinal (GI) manifestations, associated with an eosinophilic infiltration of the GI tract, which can affect several segments and involve several layers within the GI wall.

Epidemiology

Prevalence and incidence are unknown. To date, more than 280 cases have been reported, mainly in Caucasians and with a slight male preponderance.

Clinical description

EGE can occur at any age, but it is most commonly observed between the ages of 30 and 50 years. It can affect any area of the digestive tract, with the stomach and duodenum being the most commonly affected sites. The clinical presentation is variable and depends on the region of the digestive tract involved and the depth of eosinophilic involvement. Three sub-types have been defined according to the digestive tract layer involved. Mucosal EGE (the most common sub-type) is characterized by abdominal pain, diarrhea (with or without hemorrhage), dyspepsia, nausea, vomiting, weight loss and symptoms of protein losing enteropathy (e.g. swelling and edema). In children and adolescents, growth retardation, failure to thrive, and anemia may also be observed. Muscular EGE is often associated with hypertrophy and hyperplasia of the muscular layers, leading to symptoms of intestinal stenosis/obstruction (e.g. vomiting, nausea). Less often, symptoms of intussusception can be observed (severe abdominal pain with cramps). Serosal EGE is characterized by bloating, exudative ascites and peripheral eosinophilia. Other features have also been observed such as cholingitis, pancreatitis, and acute appendicitis.

Etiology

The pathogenesis of EGE is poorly understood but it is thought that EGE is mediated by a hypersensitivity reaction. Various stimuli, including food allergens, drugs (azathioprine, gold salts, trimethoprim-sulphonamide) and immunological disorders, may trigger eosinophilic infiltration of the GI tract, followed by degranulation with cytokine release and cellular damage.

Diagnostic methods

Laboratory examinations demonstrate peripheral blood eosinophilia and elevated serum IgE concentrations (20-80% of cases). Other findings include steatorrhea, hypoalbuminemia, iron deficiency anemia, and prolonged prothrombin time. Endoscopy shows erythematous, friable, sometimes nodular and ulcerated mucosa. Histopathological examination of gastric and duodenal biopsies confirms the diagnosis by usually showing eosinophilic infiltrates (> 20-30 eosinophils per high-power field) in the absence of other known causes of eosinophilia. Eosinophilic degranulation or cryptitis are also diagnostic.

Differential diagnosis

Differential diagnosis includes eosinophilic esophagitis, Crohn disease, periarteritis nodosa, Churg-Strauss syndrome, idiopathic hypereosinophilic syndrome, congenital chronic diarrhea with protein-losing enteropathy, celiac disease, lymphoma (see these terms) and gastric cancer.

Management and treatment

In some early-onset pediatric cases, EGE has resolved by suppressing milk from diet. Complete resolution has also been achieved in children by exclusive feeding with an amino acid-based elemental formula or by following a hypoallergenic diet. In moderate to severe cases, treatment is based on oral corticotherapy. Low dose maintenance corticotherapy is needed in case of relapse and to keep the disease under control. Mast cell stabilizers and antihistamines have been successfully used in some cases.

Prognosis

With treatment, prognosis is good with full resolution of symptoms in spite of a possible relapsing course. Complications have been reported in rare cases, mainly in the serosal sub-type, such as intestinal obstruction and perforation that may require surgery and may affect the quality of life.