How should ulcerative colitis with eosinophilic infiltration be managed?

Management of Ulcerative Colitis with Eosinophilic Infiltration

When ulcerative colitis patients demonstrate significant eosinophilic infiltration in colonic mucosa and are refractory to standard maintenance therapy, short-term corticosteroid therapy should be initiated, as this approach achieves both clinical and endoscopic remission in the majority of cases. 1

Recognition and Clinical Context

Eosinophilic infiltration in UC represents a distinct clinical scenario that requires specific therapeutic consideration:

• Eosinophilic infiltration occurs in a subset of UC patients who fail standard maintenance therapy (5-ASAs, immunomodulators) and may represent a mechanistically distinct inflammatory pattern. 1
• Higher eosinophil levels correlate with increased disease activity and poorer clinical outcomes in 25 of 34 studies examining tissue eosinophils, though this relationship is not universal. 2
• Dense eosinophilic infiltration can precede typical UC histology and may suggest eosinophil-mediated initiation of disease flares in some patients. 3

Therapeutic Algorithm

First-Line: Corticosteroid Therapy

For UC patients with documented high eosinophilic infiltration who are refractory to maintenance therapy, initiate prednisolone at approximately 20-25 mg daily:

• Average effective dosing is 21 mg daily for approximately 100 days, with systematic tapering as clinical response is achieved. 1
• All three validated outcome measures improve significantly: clinical activity index (2.4→1.0), Mayo endoscopic subscore (1.8→0.7), and UC endoscopic index of severity (3.9→1.1). 1
• Steroid discontinuation is achievable in all patients without requiring re-administration when this phenotype is correctly identified and treated. 1

Concurrent Advanced Therapy Considerations

The 2024 AGA guidelines for moderate-to-severe UC recommend early use of advanced therapies rather than gradual step-up, but do not specifically address the eosinophilic infiltration phenotype. 4

When eosinophilic infiltration develops during TNF-antagonist therapy:

• Consider eosinophilic gastroenteritis as a distinct diagnosis, which can occur during golimumab or other TNF-antagonist treatment and requires prednisolone for resolution. 5
• Obtain upper endoscopy with gastric and duodenal biopsies if systemic symptoms (ascites, peripheral eosinophilia >5%) develop, as eosinophilic gastroenteritis may coexist with UC. 5

Maintenance Strategy Post-Corticosteroid Response

After achieving remission with corticosteroids in eosinophil-rich UC:

• Transition to advanced therapies (biologics or JAK inhibitors) rather than returning to failed maintenance therapy, following the AGA recommendation for early advanced therapy use in moderate-to-severe disease. 4
• Discontinue 5-ASAs if the patient has already failed this therapy, as the AGA suggests stopping 5-ASAs in patients who have escalated beyond them. 4
• Monitor for symptomatic response within 3 months, biochemical remission within 3-6 months, and endoscopic improvement within 6-12 months of advanced therapy initiation. 4

Diagnostic Confirmation Requirements

Before attributing treatment refractoriness to eosinophilic infiltration:

• Confirm active inflammation with UC-related symptoms, biomarkers, AND endoscopic evaluation before escalating therapy. 4
• Obtain colonic biopsies during endoscopy to quantify eosinophil density, as endoscopic appearance alone does not predict eosinophil burden. 1
• Measure peripheral blood eosinophil count, though tissue eosinophils are more clinically relevant than peripheral counts for predicting UC outcomes. 6

Critical Pitfalls to Avoid

Do not assume baseline tissue or peripheral blood eosinophil counts predict long-term disease severity in newly diagnosed UC—these markers lack predictive value for time to biologics or colectomy. 6

Do not continue ineffective maintenance therapy in patients with documented high eosinophilic infiltration and clinical refractoriness—this phenotype responds specifically to corticosteroids and requires therapeutic escalation. 1

Do not overlook alternative diagnoses when eosinophilia is prominent:

• Hypereosinophilic syndrome/chronic eosinophilic leukemia can coexist with UC and may require imatinib mesylate at higher doses (400 mg/day) even without FIP1L1-PDGFRA fusion gene. 7
• Eosinophilic gastroenteritis can develop as a complication during biologic therapy and presents with wall thickening, ascites, and peripheral eosinophilia. 5

Monitoring and Follow-Up

After initiating corticosteroid therapy for eosinophil-rich UC:

• Reassess endoscopically with biopsies to document both clinical and histologic response, as symptom improvement does not reliably correlate with mucosal healing. 8
• Taper corticosteroids systematically over the 100-day treatment course based on clinical response. 1
• Transition to maintenance advanced therapy before complete steroid withdrawal to prevent relapse. 4