Eosinophilic Gastritis: Diagnostic Workup and Treatment
I must clarify that the provided evidence focuses almost entirely on eosinophilic esophagitis (EoE), not eosinophilic gastritis (EG), which is a distinct and less well-studied entity. However, based on available research evidence, eosinophilic gastritis requires endoscopy with gastric biopsies showing >20 eosinophils per high-power field, and corticosteroids remain the mainstay of therapy 1, 2.
Diagnostic Workup
Clinical Presentation
Eosinophilic gastritis presents with non-specific gastrointestinal symptoms that differ from EoE's characteristic dysphagia. Look for:
- Nausea and vomiting
- Epigastric pain
- Early satiety
- Weight loss
- Peripheral blood eosinophilia (present in many cases)
- Hypoalbuminemia (suggests protein-losing enteropathy)
- Anemia
- History of atopy, food allergies, asthma, or eczema 1, 3
Endoscopic Evaluation
Perform esophagogastroduodenoscopy (EGD) with systematic gastric biopsies from multiple sites (antrum, body, fundus). Endoscopic findings may include:
- Mucosal erythema and edema
- Nodularity
- Erosions or ulcerations
- Normal-appearing mucosa (in up to one-third of cases) 3
Histopathological Diagnosis
The diagnostic threshold is ≥20 eosinophils per high-power field in gastric biopsies 1, 3. Additional histological features include:
- Dense eosinophilic infiltrates expanding the lamina propria
- Eosinophil degranulation
- Eosinophil microabscesses
- Possible involvement of muscular or serosal layers (determines disease subtype) 2, 3
Essential Exclusions
Before confirming EG, you must exclude:
- Parasitic infections (stool studies, serologies)
- Drug reactions (NSAIDs, antibiotics)
- Hypereosinophilic syndrome (check absolute eosinophil count >1,500/μL with organ involvement)
- Inflammatory bowel disease
- Connective tissue disorders
- Malignancy (lymphoma, carcinoma)
- H. pylori infection (though this may inversely correlate with eosinophilic disease) 1, 2, 4
Treatment Approach
First-Line Therapy: Corticosteroids
Systemic corticosteroids are highly effective and represent the mainstay of treatment for eosinophilic gastritis 1, 2. The typical regimen:
- Prednisone 20-40 mg daily (or 1 mg/kg/day in children) for 2-4 weeks
- Taper over 4-6 weeks based on clinical response
- Expect dramatic improvement in symptoms within days to weeks
- Reassess with repeat EGD and biopsies at 8-12 weeks to confirm histological remission 1, 2
Critical caveat: 30-40% of patients experience recurrence during or immediately after steroid withdrawal, requiring maintenance therapy 1.
Dietary Management
Consider empiric elimination diet, particularly in patients with documented food allergies or those preferring to avoid long-term steroids:
- Start with elimination of common triggers: milk, wheat, egg, soy
- Requires experienced dietitian support throughout elimination and reintroduction phases
- Do NOT use allergy testing (skin prick, specific IgE, patch testing) to guide dietary restrictions - these tests are not predictive 5
- Elemental diets show high efficacy but poor compliance; reserve for refractory cases 5, 1
Alternative and Adjunctive Therapies
For steroid-dependent or refractory cases:
- Proton pump inhibitors (twice daily dosing for 8-12 weeks) - may have anti-inflammatory effects beyond acid suppression 5
- Mast cell stabilizers (cromolyn sodium) - limited evidence but may help 1, 2
- Leukotriene antagonists (montelukast) - anecdotal benefit 1
- Immunomodulators (azathioprine, 6-mercaptopurine) - consider for steroid-dependent disease, though evidence is limited 1, 2
Emerging Biologic Therapies
Dupilumab (anti-IL-4/IL-13) shows promise for eosinophilic gastritis and is being studied in clinical trials 5, 6. Other biologics under investigation include anti-IL-5, anti-IL-13, and anti-IL-15 receptor antibodies 6.
Monitoring Strategy
Symptoms do not reliably correlate with histological activity - you cannot rely on clinical improvement alone 5, 7:
- Repeat EGD with biopsies 8-12 weeks after initiating or changing therapy
- Define remission as <20 eosinophils per high-power field
- If symptoms recur on treatment, repeat endoscopy immediately 5
Special Considerations
Eosinophilic gastritis rarely exists in isolation - it frequently coexists with eosinophilic involvement of other GI segments (esophagus, duodenum, colon) 3, 8. Therefore:
- Obtain esophageal and duodenal biopsies during initial EGD even if these areas appear normal
- Consider colonoscopy if lower GI symptoms are present
For refractory or complex cases with significant atopic comorbidities, joint management with an allergist/immunologist is warranted 5, 7.
Common Pitfalls
- Failing to obtain adequate biopsies - take multiple samples from different gastric regions
- Relying on symptoms alone to assess treatment response - always confirm histological remission
- Premature steroid discontinuation - leads to high relapse rates; consider maintenance therapy
- Using allergy tests to guide dietary elimination - these are not validated for EG
- Missing concurrent eosinophilic involvement of other GI segments - always biopsy esophagus and duodenum 3, 4