What is the diagnostic approach for eosinophilia gastropathy?

Diagnostic Approach for Eosinophilic Gastropathy

Eosinophilic gastropathy requires upper endoscopy with multiple gastric and duodenal biopsies showing ≥20 eosinophils per high-power field (0.3 mm²), combined with compatible clinical symptoms and exclusion of secondary causes of eosinophilia. 1, 2

Clinical Presentation to Recognize

Adults typically present with:

• Abdominal pain, nausea, and vomiting 3, 2
• Symptoms may occur without any history of allergic reactions 3

Children present with age-dependent symptoms:

• Younger children: feeding difficulties, failure to thrive, vomiting, diarrhea 4
• Older children: abdominal pain and dysphagia 4

Laboratory Testing Strategy

Order these specific tests:

• Complete blood count with differential to assess peripheral eosinophilia (≥500 eos/µL increases diagnostic probability significantly) 2, 5
• Serum albumin level (hypoalbuminemia <3.5 g/dL increases diagnostic yield) 5
• The combination of peripheral eosinophilia AND hypoalbuminemia increases biopsy diagnostic yield to 25% 5

Critical caveat: Normal peripheral eosinophil counts do NOT exclude the diagnosis—tissue eosinophilia can occur with normal blood counts 3, 2

Endoscopic Approach

Proceed with upper endoscopy even if mucosa appears grossly normal:

• Endoscopic appearance is frequently normal and unreliable for diagnosis 3, 5
• Ultrasound or CT may show thickened intestinal walls and ascites before endoscopic changes appear 3

Biopsy protocol (this is essential):

• Obtain biopsies from BOTH stomach and duodenum regardless of endoscopic appearance 1, 5
• Take multiple biopsies from different anatomical sites to account for patchy distribution 1, 6
• Include both targeted biopsies (from any visible abnormalities) and random biopsies 3
• In pediatric patients, biopsy all patients undergoing endoscopy for GI symptoms, as appearance is particularly unreliable 4, 5

Histopathologic Diagnostic Criteria

The definitive diagnosis requires:

• ≥20 eosinophils per high-power field (0.3 mm²) in gastric and/or duodenal mucosa 1, 2
• Additional supportive histologic features: eosinophil microabscesses, degranulation, surface layering 1
• Count eosinophils in the most densely infiltrated area (peak count) 1

Important pitfall: If initial biopsies are negative but clinical suspicion remains high, obtain ascitic fluid for cytology if present, and repeat endoscopy with more extensive multisite sampling 3

Exclusion of Secondary Causes

Must rule out these conditions before confirming diagnosis:

• Parasitic infections (obtain stool studies for ova and parasites) 2, 6
• Drug hypersensitivity reactions 6
• Inflammatory bowel disease 6
• Connective tissue disorders 6
• Malignancy 6

Diagnostic Algorithm Summary

1. High clinical suspicion if patient presents with chronic abdominal pain, nausea, vomiting, or diarrhea 3, 2
2. Check CBC with differential and serum albumin - if peripheral eosinophilia (≥500 eos/µL) and/or hypoalbuminemia (<3.5 g/dL) present, diagnostic yield increases substantially 5
3. Perform upper endoscopy with multiple biopsies from stomach and duodenum regardless of mucosal appearance 1, 5
4. Confirm histologically with ≥20 eosinophils/HPF 1, 2
5. Exclude secondary causes through appropriate testing 6
6. If negative but suspicion high: obtain ascitic fluid if present, repeat endoscopy with more extensive sampling 3

The diagnostic yield increases from 1.2% overall to 7.7% with peripheral eosinophilia alone, 9.1% with hypoalbuminemia alone, and 25% when both are present. 5