Eosinophilic Gastroenteritis (EG)
Discuss the diagnosis of EG?
A definite diagnosis must fulfil the following criteria:
- Presence of GI symptoms
- Demonstration of eosinophilic infiltration of one or more areas of the GI tract on biopsy
- Absence of eosinophilic involvement of multiple organs outside the GI tract and
- Absence of parasitic infestation
Discuss the aetiology of EG?
Unknown, but possibly allergic in aetiology. Eosinophils may directly damage the GI tract wall. Approximately 50% have allergic disease, such as asthma, defined food sensitivities, eczema, or rhinitis. Any part of the GIT may be involved.
Discuss the epidemiology of EG?
Any age can be affected, but typically present in the third through fifth decades of life. An equal gender distribution or slight male preponderance has been reported.
Discuss the clinical features of EG?
- Symptoms are typically intermittent but often long standing. Upto 1/3 of pts have self limited disease (4 weeks or less) and do not require treatment
- Symptoms vary depending on the layer involved-
- Predominantly mucosal layer disease (most common) – pain, nausea, vomiting, diarrhoea, weight loss, iron deficiency anaemia, malabsorption, protein loosing enteropathy
- Muscle layer disease- Obstruction
- Subserosal (least common) – eosinophilic ascites
- Clinical features generally overlap as multiple layers of the gut wall can be affected.
Discuss the investigations of EG?
- Peripheral blood eosinophilia (1000-2000 cells/ul) is found in about 80% of patients
- ESR may be modestly elevated
- Radiographic changes are variable and non specific
- Histologic- is the best way to make a diagnosis. Histology is characterised by an inflammatory cell infiltrate that is almost entirely composed of eosinophils.
Discuss the differential diagnosis of EG?
- Parasitic infections- Need stool tests
- Cancers such as lymphoma, gastric cancer, and colon cancer, can present with intestinal obstruction, masses on imaging and eosinophilia.
- Crohn’s disease- Lacks eosinophilic infiltration
- Polyarteritis nodosa- may be associated with eosinophilic infiltration of the bowel
- Hypereosinophilic syndrome- other organ systems are involved
Discuss the treatment of EG?
Treat patients who are symptomatic or have evidence of malabsorption.
- Skin prick and/or patch testing for allergies to food and other environmental agents should be considered and treated appropriately with elimination diet.
- Patients who fail or do not consider diet therapy should be treated with prednisolone (20-40mg/day). 90% of pts respond quickly within 2 weeks. The dose can be tapered subsequently over the next 2 weeks. Patients who relapse immediately after steroid cessation may need chronic low dose steroids (5-10 mg/day). This low dose maintenance therapy may be needed in upto 50% of pts. Azathioprine may be added if high dose steroids are required to maintain remission.
- Oral cromolyn (800 mg/day in four divided doses) has been effective for short- and long-term management in some case reports.
- Surgery should be avoided. Bowel obstruction usually responds to conservative measures and steroids
- Exclude bacterial overgrowth in pts with malabsorption
- Empirical antiparasitic therapy (mebendazole 00mg Bd for 3 days) may be justified, because frequently the parasites cannot be detected despite careful stool examinations. This may be particularly true in pts who have travelled to or live in areas that put them at high risk fro parasitic infestations.
