First-Line Treatment for Pediatric Crohn's Disease
For this 13-year-old with transmural inflammation consistent with Crohn's disease, systemic corticosteroids (specifically oral prednisolone 40mg daily or budesonide 9mg daily for ileocecal disease) represent the first-line treatment for moderate to severe disease. 1, 2
Rationale for Corticosteroid Selection
The colonoscopy findings of transmural inflamed patches are pathognomonic for Crohn's disease, which is characterized by transmural granulomatous inflammation 1, 3. The 3-4 month duration of chronic diarrhea and altered bowel habits indicates this is not mild disease requiring only observation.
Treatment Algorithm Based on Disease Severity
For moderate to severe Crohn's disease (which this presentation suggests):
- Oral prednisolone 40mg daily is the recommended first-line therapy, with gradual tapering over 8 weeks 1, 2, 4
- Budesonide 9mg daily is preferred if disease is isolated to the ileocecal region with moderate activity, as it has fewer systemic side effects 2, 5, 6
Why not the other options:
Infliximab (Option B) is reserved for moderate-to-severe disease that fails conventional therapy, fistulizing disease, or as part of early "top-down" therapy in high-risk patients 2, 3. It is not standard first-line therapy in treatment-naive pediatric patients, though the FDA label does support its use in pediatric Crohn's disease aged 6-17 years 7
Methotrexate (Option C) is used as a steroid-sparing maintenance agent or for steroid-dependent disease, not as initial induction therapy 2, 3
5-aminosalicylates have limited benefit in Crohn's disease compared to ulcerative colitis, though high-dose mesalazine (4g daily) may be considered for mild ileocolonic disease 2, 3, 5
Pediatric-Specific Considerations
In the pediatric population specifically, the FDA-approved infliximab regimen (5mg/kg at weeks 0,2, and 6, then every 8 weeks) showed 88% clinical response at week 10 and superior outcomes with every-8-week maintenance versus every-12-week dosing 7. However, corticosteroids remain the guideline-recommended first-line approach unless there are high-risk features suggesting need for early biologic therapy 1, 2.
Critical Next Steps After Steroid Induction
- Monitor for steroid response within 2-4 weeks - if inadequate response, escalate to biologics 1, 2
- Plan for maintenance therapy with immunomodulators (azathioprine 1.5-2.5mg/kg/day) or biologics to prevent relapse and achieve steroid-free remission 2, 4, 3
- Assess disease extent and behavior with imaging (MR enterography preferred in pediatrics to avoid radiation) to guide long-term management 1
Common Pitfalls to Avoid
- Do not delay treatment waiting for complete disease characterization - transmural inflammation on colonoscopy is sufficient to initiate therapy 1
- Do not use systemic steroids long-term - they are for induction only, not maintenance 1, 2
- Do not assume mild disease based on age alone - pediatric Crohn's can be aggressive and requires the same treatment intensity as adults 7, 3
Answer: A - Systemic steroid is the correct first-line treatment option for this patient with newly diagnosed moderate-to-severe Crohn's disease.