What is the treatment for a Crohn's disease flare?

Treatment of Crohn's Disease Flare

For moderate-to-severe Crohn's disease flares, initiate systemic corticosteroids (prednisolone 40-60 mg daily or equivalent) for rapid symptom control, while simultaneously planning early introduction of biologic therapy (anti-TNF agents) with or without immunomodulators for maintenance to prevent relapse and disease progression. 1, 2

Initial Assessment Before Treatment

Before initiating therapy, confirm active inflammation and rule out complications:

• Measure objective inflammatory markers including fecal calprotectin and C-reactive protein (CRP) to confirm active inflammation rather than functional symptoms 1
• Exclude complications such as intra-abdominal abscess, stricture, or superimposed infection that require specific interventions before or instead of immunosuppression 1
• Assess disease location, severity, and behavior (inflammatory vs. stricturing vs. penetrating) as this determines treatment selection 3

Induction Therapy Based on Disease Severity and Location

Mild-to-Moderate Disease Limited to Ileum/Right Colon

Use budesonide 9 mg daily for 8 weeks as first-line therapy for disease confined to the ileum and/or ascending colon 1, 2

• Budesonide has superior safety profile compared to systemic steroids with lower rates of steroid-related adverse effects 1, 2
• This approach is effective for inducing clinical response and remission in localized disease 1

Moderate-to-Severe or Extensive Disease

Initiate systemic corticosteroids (prednisolone 40-60 mg daily or methylprednisolone equivalent) 1, 2

• Systemic corticosteroids are twice as effective as placebo for inducing remission 1
• Evaluate response within 2-4 weeks of initiating corticosteroids 2

Critical caveat: Do NOT use 5-aminosalicylic acid (mesalazine) products for Crohn's disease flares—they are ineffective for both induction and maintenance of remission 3, 1, 2

Maintenance Therapy Strategy

Begin planning maintenance therapy immediately upon starting corticosteroids—do not wait for complete taper. 1, 2

For Steroid-Dependent Patients

Thiopurines (azathioprine or mercaptopurine) are strongly recommended for patients who are steroid-dependent 3, 1

• This prevents repeated steroid exposure and associated complications 3
• Monitor according to BNF/BNFC guidelines including regular blood counts even with normal TPMT activity 3

For High-Risk or Moderate-to-Severe Disease

Early introduction of anti-TNF biologics (infliximab or adalimumab) with or without immunomodulators is recommended while tapering corticosteroids 1, 2

• Combination therapy with infliximab plus thiopurine is more effective than monotherapy for maintaining remission 2
• The REACT trial demonstrated that early combined immunosuppression in high-risk patients reduces complications, hospitalizations, and need for surgery compared to stepwise management 3
• Assess response to anti-TNF therapy between 8-12 weeks; consider discontinuation and alternative treatment if no response by week 14 2

Alternative biologics if anti-TNF fails or is contraindicated:

• Ustekinumab (anti-IL-12/23): 51% clinical remission at 44 weeks vs 35.9% placebo 3
• Vedolizumab (anti-integrin): 39% clinical remission at 52 weeks vs 21.6% placebo 3

Methotrexate as Alternative

Methotrexate (subcutaneous, ≥15 mg weekly with folic acid) can be used for maintenance, particularly in steroid-dependent patients 2

• 65% maintained remission vs 39% placebo in steroid-dependent patients 3
• Requires monitoring per BNF/BNFC guidelines 3

Critical Safety Monitoring

Corticosteroid-Related Complications

Monitor for and counsel patients about:

• Increased risk of intra-abdominal/pelvic abscesses (particularly concerning in Crohn's disease) 1
• Cushing syndrome, hypertension, diabetes, and osteoporosis 1
• Never use corticosteroids for maintenance therapy—they are for induction only 1

Immunosuppression Monitoring

• Establish documented local safety monitoring policies with designated staff to track abnormal results 3
• Monitor for neutropenia with thiopurines regardless of TPMT status 3
• Follow BNF/BNFC guidelines for specific monitoring requirements 3

Treatment Algorithm Summary

1. Confirm inflammation with biomarkers and exclude complications
2. Localized mild-moderate disease → Budesonide 9 mg daily
3. Extensive or severe disease → Systemic corticosteroids (prednisolone 40-60 mg)
4. Simultaneously initiate maintenance planning:
   • Steroid-dependent → Thiopurines
   • High-risk/moderate-severe → Anti-TNF ± immunomodulator
   • Consider early combination therapy to prevent complications
5. Assess response at 2-4 weeks (steroids) or 8-12 weeks (biologics)
6. Taper steroids once remission achieved; continue maintenance therapy long-term

Common pitfall to avoid: Waiting until steroid taper is complete before starting maintenance therapy leads to higher relapse rates. Start maintenance therapy early while tapering steroids. 1, 2