A 28-year-old man from Delhi presents with a 6-month history of bloody diarrhoea, abdominal pain, and weight loss. Colonoscopy reveals continuous mucosal inflammation limited to the colon with crypt abscesses and surface ulceration. Biopsy shows inflammation confined to the mucosa and submucosa without transmural involvement. Laboratory tests show elevated CRP (8.2 mg/dL) and faecal calprotectin 320 µg/g. He is currently on oral mesalamine 2.4 g/day with partial response. What is the most appropriate next step in management?

Explanation

## Clinical Context This patient has **ulcerative colitis (UC)** confirmed by: - Continuous mucosal inflammation limited to the colon - Crypt abscesses and surface ulceration (hallmark histology) - Inflammation confined to mucosa and submucosa (NOT transmural) - Elevated inflammatory markers (CRP, faecal calprotectin) ## Management Strategy for Mild-to-Moderate UC **Key Point:** The patient has inadequate response to mesalamine monotherapy (5-ASA), indicating need for step-up therapy. **High-Yield:** For mild-to-moderate UC with mesalamine failure, the next step is **corticosteroid induction**, not immunosuppression or biologics. ### Rationale for Corticosteroids 1. **Induction therapy role**: Oral corticosteroids (prednisolone 40 mg/day) are first-line for patients failing 5-ASA monotherapy 2. **Rapid anti-inflammatory effect**: Suppress acute inflammation within days–weeks 3. **Avoid premature biologics**: Infliximab is reserved for: - Moderate-to-severe disease (Truelove & Witts criteria) - Steroid-dependent or steroid-refractory disease - This patient has not yet failed steroids 4. **Avoid premature immunosuppression**: Azathioprine is a maintenance agent, not an induction agent; used after steroid response is established ## Treatment Ladder for UC | Severity | First-Line | Second-Line | Third-Line | |----------|-----------|------------|----------| | Mild | 5-ASA (oral ± topical) | Topical corticosteroids | Oral corticosteroids | | Mild-Moderate | 5-ASA + oral corticosteroids | — | — | | Moderate-Severe | Oral corticosteroids ± 5-ASA | IV corticosteroids | Infliximab, vedolizumab | | Steroid-dependent | Azathioprine, 6-MP, infliximab | — | — | **Clinical Pearl:** Prednisolone 40 mg/day is tapered over 8 weeks (reduce by 5 mg every 1–2 weeks) to avoid adrenal insufficiency and rebound flare. ## Why Not the Other Options? **Option 1 (Azathioprine):** Azathioprine is a **maintenance agent** for steroid-dependent disease, not an induction agent. It takes 8–12 weeks to work and is added after steroid response is demonstrated. **Option 3 (Infliximab):** TNF-α inhibitors are reserved for: - Moderate-to-severe disease (not mild-moderate) - Steroid-refractory or steroid-dependent disease - This patient has not failed steroids yet **Option 4 (Surgery):** Total proctocolectomy is curative but reserved for: - Intractable disease despite medical therapy - Toxic megacolon - Dysplasia or cancer - Not indicated as next step in a newly diagnosed patient