What is the best course of treatment for a patient with recent adenovirus infection, eosinophilia, and recurrent abdominal pain?

Clinical Approach to Eosinophilia with Recurrent Abdominal Pain Post-Adenovirus

The most likely diagnosis is eosinophilic gastroenteritis (EGE), and you should proceed with upper and lower endoscopy with multiple biopsies to confirm the diagnosis, followed by corticosteroid therapy if ≥20 eosinophils per high-power field are found in the gastrointestinal mucosa.

Diagnostic Evaluation

Initial Endoscopic Assessment

• Perform upper endoscopy with at least 6 biopsies from multiple sites (esophagus, stomach, duodenum) to evaluate for eosinophilic infiltration 1
• Obtain lower endoscopy with biopsies from terminal ileum and colon, as EGE can affect any portion of the gastrointestinal tract 2
• The diagnostic threshold is ≥20 eosinophils per high-power field in gastrointestinal mucosa for EGE, distinct from the ≥15 eosinophils per 0.3 mm² threshold used for eosinophilic esophagitis 2, 1
• Endoscopic appearance may be completely normal despite significant eosinophilic infiltration, making biopsy essential even with normal-appearing mucosa 2

Key Diagnostic Considerations

• The peripheral eosinophil count of 5% (absolute count matters more than percentage) combined with recurrent abdominal pain strongly suggests EGE 2, 3
• History of recent adenovirus infection may be a trigger in a patient with underlying atopic predisposition 4, 3
• Evaluate for history of atopy, allergic rhinitis, asthma, or food allergies, as these are present in the majority of EGE patients 4, 3

Treatment Algorithm

First-Line Therapy

Initiate oral corticosteroids once diagnosis is confirmed histologically:

• Prednisone is the standard treatment with rapid symptom resolution typically within 2-4 weeks 5, 4, 3
• The typical course is 3-4 weeks of oral prednisone with complete resolution of symptoms expected 4, 3
• Symptoms respond quickly to corticosteroid treatment, often within days to weeks 5, 4

If Eosinophilic Esophagitis is Confirmed

• Topical corticosteroids are first-line for isolated eosinophilic esophagitis 6
• Proton pump inhibitors twice daily for 8-12 weeks are also effective for inducing remission 6
• Elimination diets with dietitian support can achieve clinico-histological remission, particularly six-food elimination diet 6

Critical Pitfalls to Avoid

Diagnostic Errors

• Do not rely on peripheral eosinophil count alone—the diagnosis requires tissue confirmation with ≥20 eosinophils/HPF 2
• Do not assume normal endoscopy excludes EGE—mucosal appearance is often normal despite significant eosinophilic infiltration 2
• Biopsy multiple sites even if endoscopy appears normal, as eosinophilic infiltration can be patchy 2

Management Considerations

• Delay in diagnosis is common (average 4.6 years in some series), leading to unnecessary suffering and potential complications 1
• Ascites with 99% eosinophils can occur in severe cases, indicating serosal involvement 4
• Joint management with allergist is recommended if significant concomitant atopic disease exists 1, 6

Follow-Up Strategy

• Repeat endoscopy with biopsies after treatment to confirm histological remission, as symptoms may not correlate with disease activity 6
• Monitor for symptom recurrence after corticosteroid discontinuation, which may require maintenance therapy 6
• Consider long-term dietary modification or maintenance corticosteroids if symptoms recur 6

The combination of eosinophilia (even mild), recurrent abdominal pain, and recent viral infection in the context of possible atopy creates a high pretest probability for EGE that warrants aggressive diagnostic evaluation 2, 3.