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eosinophilic gastroenteritis

Friday 3 October 2003

Definition: Eosinophilic gastroenteritis is a heterogeneous lesionnal syndrome characterized by eosinophilic inflammation of the gastrointestinal tissues.

Eosinophilic gastroenteritis is a rare condition characterized by recurrent eosinophilic infiltration of portions of the GI tract and presenting with nonspecific GI symptoms in association with peripheral eosinophilia. Its etiology and pathogenesis remain unclear and its symptoms overlap with many GI and systemic diseases.

Eosinophilic gastroenteritis (EGE) is a rare condition characterized by recurrent eosinophilic infiltration of portions of the gastrointestinal (GI) tract presenting with nonspecific GI symptoms in association with peripheral eosinophilia.

The etiology and pathogenesis of EGE remain unclear. The role of allergy in recruitment of eosinophils to the GI tract remains controversial.

Eosinophilic gastroenteritis is a rare disease of unknown etiology. It is characterized by eosinophilic infiltration of the bowel wall to a variable depth and symptoms associated with gastrointestinal tract.

Eosinophilic gastroenteritis affects one or more gastrointestinal segments, commonly involving the stomach and small bowel.

It usually presents between the 2nd and 5th decades of life. Seventy-five percent of patients present under age 50.

Some patients havean underlying connective tissue disorder or an infection with Eustoma rotundatum, a parasite of North Sea herring.

Many patients have a history of allergy, peripheral eosinophilia, asthma, eczema, or food sensitivity.

Pathology

Eosinophilic tissue infiltration can affect any of the three layers of the digestive apparatus with symptoms varying according to the affected layer.

The most common classification of EGE based on the involved layer of the GI tract is known as Klein’s classification. Subsequently, there are three subtypes of EGE (mucosal, muscular, and subserosal), with some degree of overlap.

Data are insufficient in regard to the true prevalence of EGE and each of its subtypes. However, the mucosal form is the most common followed by muscular and lastly subserosal [6].

The eosinophilic infiltrates tend to affect specific layers of the bowel wall.

They may involve only the mucosa, the submucosa (the most common location), the muscularis propria, or the serosa.

Symptoms differ depending on the site and extent of involvement.

Patients with predominantly mucosal disease experience post-prandial nausea, vomiting, abdominal pain, and food intolerance.

Disease predominantly affecting the muscular layer results in thickening and rigidity of the muscularis propria and gastric outlet obstruction.

The least common disease pattern predominantly involves the serosa.

Usually, one ofthese patterns predominates; some patients have a mixed disease pattern.

Patients often have a prompt response to steroid treatment.

Mucosal edema, capillary lymphatic dilation, and an intense but patchy eosinophilic infiltrate displace and destroy gastric pits and glands.

The infiltrate typically contains 10 to 50 eosinophils per high-powered field (hpf).

One often sees a concomitant increase in IgE-secreting plasma cells.

Epithelial necrosis and degeneration develop, but ulcers are rare.

Mucosal eosinophilic gastritis can be diagnosed in gastric biopsies, but due to its patchy distribution, multiple biopsies should be evaluated, including deeper biopsies that sample the submucosa, since each biopsy may show striking variations in the intensity of the eosinophilic, lymphocytic, and histiocytic infiltrates.

The muscularis propria may show pronounced hyperplasia with the muscle fibers separated by dense eosinophilic aggregates. Charcot-Leyden crystals are present in areas of eosinophilic infiltrates.

Some patients develop loose granulomas and acute vasculitis affecting small arteries, features characteristic of allergic granulomatosis.

Postinflammatory strictures complicate muscularis propria involvement.

Physiopathology

Several studies have shown that half of the patients with EGE have preexisting history of atopy.

In addition, serum IgE levels are elevated in some patients; yet rarely IgE antibodies are directed against identified food allergens.

Furthermore, hypoallergenic diets have not been shown to be of significant benefit in treating EGE.

Regardless of the initial trigger, activated tissue eosinophils release various chemoattractive cytokines resulting in recruitment of more eosinophils into the affected tissues.

According to the localization in the digestive wall

- mucosal eosinophilic gastroenteritis
- muscular eosinophilic gastroenteritis
- serosal eosinophilic gastroenteritis

Variants

- small bowel obstruction

Pathology

- dense infiltration of eosinophils throughout the entire thickness of ileal wall
- eosinophilic enteritis

See also

- gastric eosinophilic inflammation (gastric eosinophilia)

References

- Eosinophilic gastroenteritis presenting as small bowel obstruction: a case report and review of the literature. Yun MY, Cho YU, Park IS, Choi SK, Kim SJ, Shin SH, Kim KR. World J Gastroenterol. 2007 Mar 21;13(11):1758-60. PMID: 17461485