What is the recommended induction and maintenance therapy for Crohn’s disease, including options for mild ileocecal disease, steroid contraindications, and biologic‑sparing strategies?

Crohn's Disease Treatment

Induction Therapy

Mild-to-Moderate Ileocecal Disease

For mild-to-moderate Crohn's disease limited to the ileum and/or ascending colon, use budesonide 9 mg once daily for 8 weeks as first-line therapy. 1

• Budesonide achieves remission in 51% of patients versus 20% with placebo, with significantly fewer side effects than systemic corticosteroids 1, 2
• This locally-acting steroid is as effective as prednisolone 40 mg (tapering to 5 mg) for ileocecal disease but with superior tolerability 1
• Evaluate response between 4-8 weeks; patients not responding by week 8-14 are unlikely to benefit from continued dosing 1, 3
• Critical pitfall: Budesonide has no efficacy for distal colonic disease—do not use for left-sided or extensive colonic involvement 1, 2

Active Colonic Crohn's Disease

For colonic Crohn's disease, initiate systemic corticosteroids (prednisolone 40 mg daily, tapering by 5 mg weekly over 8 weeks). 1

• Systemic steroids achieve remission in 60-83% of patients with moderate-to-severe disease 2
• Sulfasalazine 4 g daily is an alternative for colonic disease when steroids are contraindicated, though less preferred due to side effects 1
• For hospitalized patients with severe disease, use intravenous methylprednisolone 40-60 mg/day with response assessment within 1 week 2

When Steroids Are Contraindicated

Use exclusive enteral nutrition (EEN) as an alternative induction strategy when corticosteroids are contraindicated or refused by the patient. 1

• EEN is less effective than corticosteroids in adults but represents a reasonable steroid-sparing option 1
• In pediatric patients, EEN achieves remission in 73% and is considered primary therapy 1
• Important caveat: Recent data show EEN achieves only 30% clinical remission and 13% endoscopic remission in moderate-to-severe pediatric disease, suggesting biologics may be needed earlier 4

Moderate-to-Severe Disease

For moderate-to-severe Crohn's disease (CDAI >300), initiate biologic therapy (infliximab 5 mg/kg at weeks 0,2, and 6) rather than relying on corticosteroids alone. 5

• Infliximab is indicated for patients with inadequate response to conventional therapy 5
• Consider biologics at initial diagnosis for moderate-to-severe disease to prevent progression and complications 2
• Critical principle: When prescribing systemic corticosteroids, simultaneously plan for advanced therapy (biologics or immunomodulators) to avoid steroid dependency 2

Maintenance Therapy

Steroid Tapering and Discontinuation

Taper budesonide over 1-2 weeks once remission is achieved; never use any corticosteroid (including budesonide) for maintenance therapy. 1, 3

• Budesonide is no more effective than placebo for maintaining remission at 6 or 12 months 3
• Prolonged corticosteroid use increases mortality risk, particularly above 3000 mg prednisolone equivalent per year 2
• Major pitfall: Corticosteroid dependency indicates treatment failure—escalate to immunomodulators or biologics rather than continuing steroids 2

Biologic-Sparing Maintenance Strategies

For patients requiring maintenance after steroid-induced remission, use thiopurines (azathioprine 1.5-2.5 mg/kg/day or mercaptopurine 0.75-1.5 mg/kg/day) as a biologic-sparing option. 1

• Thiopurines are appropriate for maintenance but ineffective as monotherapy for induction due to slow onset of action 1
• Consider immunomodulators for patients requiring two or more steroid courses within a calendar year 2
• Important limitation: Thiopurines have only low-quality evidence for maintenance and should not delay biologic therapy in moderate-to-severe disease 1

When to Avoid Biologic-Sparing Approaches

Do not attempt biologic-sparing strategies in patients with moderate-to-severe disease, fistulizing disease, or those who have failed conventional therapy. 5

• Infliximab 5 mg/kg every 8 weeks is the standard maintenance regimen for moderate-to-severe disease 5
• For fistulizing disease, use infliximab (three infusions at weeks 0,2, and 6) combined with immunomodulation and surgical drainage as needed 1
• Patients losing response on 5 mg/kg may be escalated to 10 mg/kg, though this increases infection risk 5

5-ASA Has No Role

Do not use 5-aminosalicylic acid (mesalamine) for either induction or maintenance therapy in Crohn's disease. 1

• Meta-analyses consistently show no benefit over placebo for clinical remission (RR 1.28,95% CI 0.97-1.69) 1
• The only exception is sulfasalazine for colonic disease when steroids are contraindicated, though this is not first-line 1

Treatment Algorithm Summary

1. Mild ileocecal disease: Budesonide 9 mg daily × 8 weeks → taper over 1-2 weeks → monitor closely or bridge to thiopurine if relapse risk is high 1, 3

2. Mild colonic disease: Prednisolone 40 mg tapering over 8 weeks (or sulfasalazine if contraindication) → bridge to thiopurine if steroid-dependent 1, 2

3. Moderate-to-severe disease: Initiate biologic therapy (infliximab) at diagnosis; use systemic steroids only as bridge therapy while biologics take effect 2, 5

4. Steroid contraindication: EEN for induction → transition to thiopurine or biologic for maintenance 1

5. Repeated steroid courses: Escalate to biologics immediately; avoid repeated steroid exposure 2