EOSINOPHILIC GASTROENTERITIS
Eosinophilic gastroenteritis is a rare primary eosinophilic gastrointestinal disorder of unknown cause characterized by the presence of an intense eosinophilic infiltrate in one or more gastrointestinal layers.
It
can occur at any age but appears to be more common between the third and fifth
decades, with a slight male preponderance. The worldwide prevalence is not
known, but more than 300 cases have been reported in the literature.
The
cause of eosinophilic gastroenteritis is not well understood. Several factors
point to a hypersensitivity reaction triggered, perhaps, by a food or an
environmental allergen. More than half of patients have a history of asthma,
eczema, or rhinitis, and peripheral eosinophilia and elevated IgE levels are
seen in a significant proportion. Moreover, the improvement seen with steroid
therapy and with elemental diet supports the allergic component.
Eosinophilic
gastroenteritis can affect any part of the gastrointestinal tract; the stomach,
followed by the small intestine, is commonly involved. Based on the depth of
involvement, the disease is classified as a mucosal, muscular, or subserosal
type. The clinical presentation may vary, depending on the site of disease as
well as the depth and extent of bowel wall involvement. The most common variety
is mucosal disease, which presents with abdominal pain, nausea, vomiting, and
diarrhea. Weight loss and anemia may be present with diffuse disease. Muscular
infiltration presents with bowel wall thickening and impaired motility, whereas
subserosal disease invariably causes ascites.
Peripheral
eosinophilia is present in up to 80% of patients, more commonly associated with
muscular or subserosal disease. Other laboratory features reflect fat and
protein malabsorption that can develop and iron deficiency anemia with or
without evidence of gastro- intestinal bleeding.
Imaging
of the gastrointestinal tract may allow detection of bowel thickening with
muscular disease and confirm the presence of ascites; the findings are
nonspecific, however, and serve to exclude other diseases rather than make a
diagnosis of eosinophilic gastroenteritis.
The
diagnosis is confirmed by the demonstration of an abnormal eosinophilic
infiltrate in an endoscopically guided biopsy of the intestinal mucosa or in a
laparoscopically guided full-thickness biopsy of muscular or serosal tissue.
Eosinophilia is also encountered in the ascitic fluid and can be a clue to the
diagnosis in cases of new onset
unexplained ascites.
The
diagnosis of primary eosinophilic gastroenteritis also requires a lack of
involvement of other organs and an absence of other causes of intestinal
eosinophilia.
Treatment of eosinophilic gastroenteritis is limited and involves dietary and immunosuppressive therapy. A trial of a diet in which six foods are eliminated (soy, dairy, nuts, wheat, eggs, and shellfish) or an elemental diet for at least 6 weeks is recommended for the initial treatment, but patient compliance is an issue. In individuals who do not respond or who cannot tolerate the dietary therapy, corticosteroid therapy is initiated. Improvement in symptoms usually occurs within a few weeks and then the dosage can be tapered; recurrence is common, however, and some patients require longterm treatment. Eosinophilic gastroenteritis has a chronic waxing and waning course, and most patients require close follow-up and long-term maintenance treatment of some kind.
