What is the first-line treatment for a 13-year-old female with chronic diarrhea and altered bowel habits, diagnosed with transmural inflammation on colonoscopy, suggestive of Crohn's disease (inflammatory bowel disease)?

First-Line Treatment for Pediatric Crohn's Disease

For this 13-year-old with transmural inflammation consistent with Crohn's disease, exclusive enteral nutrition (EEN) should be the first-line treatment, but if unavailable or not feasible, systemic corticosteroids are the appropriate initial therapy. 1

Pediatric-Specific Treatment Approach

Primary Treatment Option: Exclusive Enteral Nutrition

• EEN is recommended as first-line therapy to induce remission in children and adolescents with mild active Crohn's disease, achieving remission in 73% of pediatric patients on an intention-to-treat basis 1
• EEN has the critical advantage of improving nutritional status and supporting linear growth, which is paramount in pre-pubertal patients 1
• This approach avoids the growth-suppressing effects of corticosteroids, which is particularly important given this patient's age 1

When EEN is Not Feasible: Systemic Corticosteroids

• If EEN cannot be implemented, systemic corticosteroids (prednisolone 40 mg daily tapering by 5 mg weekly) are effective for inducing remission in colonic Crohn's disease 1
• For ileocecal disease specifically, ileal-release budesonide 9 mg once daily for 8 weeks is as effective as prednisolone with significantly fewer side effects (51% vs 52.5% remission rates) 1
• Budesonide is inferior to prednisolone in severe disease (CDAI >300), so disease severity assessment is critical 1

Why NOT the Other Options

Infliximab (Option B) - Reserved for High-Risk Disease

• Biologics like infliximab are not first-line therapy in pediatric Crohn's disease unless the patient has high-risk features 1
• High-risk features requiring first-line anti-TNF therapy include: perianal fistulizing disease, extensive disease, significant growth retardation, deep colonic ulcerations, severe osteoporosis, or stenosis/penetrating disease at diagnosis 1
• This patient's presentation does not indicate these high-risk features 1

Methotrexate (Option C) - Maintenance Therapy Only

• Methotrexate is used for maintenance of remission, not induction 1, 2
• In comparative studies, methotrexate achieved mucosal healing in only 11% (2/18) of patients, compared to 50% with azathioprine and 60% with infliximab 1

Critical Pediatric Considerations

Growth and Development Priority

• Linear growth impairment affects approximately half of children with Crohn's disease and is primarily a consequence of chronic inflammation 1
• Peak bone mass is reached by late adolescence and is decreased in approximately half of children with Crohn's disease, especially those malnourished 1
• Failure to control inflammation and monitor linear growth may result in children not achieving their genetic growth potential 1

Disease Location Matters

• The transmural inflammation pattern suggests Crohn's disease rather than ulcerative colitis 2, 3
• Crohn's disease distribution: 25% colitis only, 25% ileitis only, 50% ileocolitis 2
• Treatment should be tailored to disease location once fully characterized with ileocolonoscopy 1

Common Pitfalls to Avoid

• Do not start with biologics in low-risk pediatric patients - this exposes them to unnecessary immunosuppression and expense when safer alternatives exist 1
• Do not use budesonide for distal colonic disease - it has no evidence of benefit in more distal colonic inflammation 1
• Do not use 5-aminosalicylates (mesalamine) for Crohn's disease - they have no proven role except sulfasalazine for mild colonic disease 4, 5
• Ensure adequate calcium (800-1,000 mg/day) and vitamin D (400-800 units/day) supplementation if corticosteroids are used 1

Answer to Multiple Choice Question

The correct answer is A - Systemic steroid (assuming EEN is not listed as an option, which is the true first-line in pediatrics). 1