What is the initial treatment approach for a pediatric patient with colitis?

Initial Treatment Approach for Pediatric Colitis

Distinguish Between Crohn's Disease and Ulcerative Colitis First

The initial treatment for pediatric colitis depends critically on whether the patient has Crohn's disease (CD) or ulcerative colitis (UC), as these require fundamentally different first-line approaches. 1, 2, 3

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For Pediatric Ulcerative Colitis

Mild to Moderate Disease (PUCAI <65)

Start with combination therapy of oral mesalamine ≥2.4 g/day plus topical mesalamine (suppositories for proctitis, enemas for left-sided or extensive disease), which is more effective than either treatment alone. 2, 4, 5

Specific Dosing by Disease Location:

• Proctitis: Mesalamine 1 g suppository once daily plus oral mesalamine 2.4 g/day 2, 4
• Left-sided colitis: Mesalamine enema ≥1 g/day plus oral mesalamine 2.4-3 g/day 4, 5
• Extensive colitis: Oral mesalamine 2.4-3 g/day plus topical mesalamine enemas 5

Pediatric Weight-Based Dosing:

For pediatric patients weighing ≥24 kg who can swallow tablets whole 6:

• 24-35 kg: 2.4 g daily (weeks 0-8), then 1.2 g daily maintenance
• >35-50 kg: 3.6 g daily (weeks 0-8), then 2.4 g daily maintenance
• >50 kg: 4.8 g daily (weeks 0-8), then 2.4 g daily maintenance

Treatment Escalation Algorithm:

• Day 10-14: If no improvement, increase oral mesalamine to 4.8 g/day while continuing topical therapy 4, 5
• Day 40: If inadequate response after optimized mesalamine, add oral prednisolone 40 mg once daily with tapering over 6-8 weeks 2, 4, 5
• Alternative: Consider budesonide MMX 9 mg/day for left-sided disease (fewer systemic side effects) 4

Moderate to Severe Disease

Start with oral prednisolone 1 mg/kg once daily (maximum 40 mg) with tapering over 8-10 weeks, combined with mesalamine therapy. 3, 7

Severe/Fulminant Disease (PUCAI >65)

Hospitalize and initiate intravenous hydrocortisone 100 mg three to four times daily (or equivalent methylprednisolone). 1

Assessment on Day 3:

• Oxford criteria: >8 stools/day OR 3-8 stools/day with CRP >45 mg/L predicts 85% colectomy rate 1
• Pediatric criteria: PUCAI >45 on day 3 indicates need to plan rescue therapy; PUCAI >65 on day 5 should prompt rescue therapy 1

Rescue Therapy Options:

• Medical rescue: Infliximab or calcineurin inhibitors for corticosteroid non-responders 3, 8
• Surgical: Colectomy for medical rescue failures or complications 3, 7

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For Pediatric Crohn's Disease

First-Line Therapy: Exclusive Enteral Nutrition (EEN)

EEN with polymeric formula for 6-8 weeks is the preferred first-line treatment for inducing remission in pediatric Crohn's disease, as it achieves remission rates of approximately 80% and superior mucosal healing (74% vs 33% with corticosteroids). 1

EEN Implementation:

• Route: Offer oral polymeric formula first; use nasogastric tube only if unable to achieve 120% of daily caloric needs orally 1
• Duration: 6-8 weeks (range 2-12 weeks in studies) 1
• Formula type: Polymeric formulas are as effective as elemental, better tolerated, more cost-effective, and less often require NG tube 1
• Disease location: Effective for all luminal disease locations including isolated colonic disease 1

When EEN is Especially Preferred:

• Poor growth or low weight 1
• Catabolic state (hypoalbuminemia) 1
• Desire to avoid corticosteroid side effects 1

Alternative: Corticosteroids (if EEN not feasible)

If EEN is not an option, use oral prednisone/prednisolone 1 mg/kg once daily (maximum 40 mg) for moderate to severe active luminal CD. 1

Corticosteroid Dosing Details:

• Standard dose: 1 mg/kg/day (max 40 mg) once daily 1
• If inadequate response: Increase to 1.5 mg/kg/day (max 60 mg) 1
• Tapering: Over approximately 10 weeks per pediatric UC guidelines 1
• IV corticosteroids: May be efficacious if oral corticosteroids fail 1

Mild to Moderate Ileocecal Disease

Budesonide 9 mg daily (up to 12 mg for first 4 weeks) may be used as alternative to systemic corticosteroids, tapered within 10-12 weeks. 1

Adjunctive Therapy Considerations

5-ASA is controversial in Crohn's disease and generally not recommended, but may be considered in selected mild cases (50-80 mg/kg/day up to 4 g daily) especially with colonic disease. 1

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Critical Monitoring and Safety

Before Starting Treatment:

• Exclude infections: C. difficile, CMV, bacterial pathogens 5
• Check baseline renal function (eGFR) before mesalamine 2, 5, 6
• Verify immunization status before immunomodulators 1

During Treatment:

• Renal monitoring: Check eGFR after 2-3 months, then annually on mesalamine 2, 4, 6
• Adequate hydration: Ensure sufficient fluid intake on mesalamine 6
• VTE prophylaxis: Subcutaneous heparin and compression stockings for hospitalized severe UC patients 1
• Nutritional assessment: Trained dietitian evaluation; enteral feeding preferred over parenteral 1

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Common Pitfalls to Avoid

• Never use corticosteroids for maintenance therapy in either CD or UC 1
• Do not tolerate repeated steroid courses or steroid dependency - escalate to immunomodulators or biologics 1
• Avoid topical corticosteroids as first-line for UC - topical mesalamine is more effective 2, 4, 5
• Do not delay treatment escalation - patients requiring ≥2 steroid courses in past year need escalation to thiopurines, anti-TNF, vedolizumab, or tofacitinib 4, 5
• Do not use EEN for extraintestinal manifestations or penetrating CD - no supporting data 1