Steroid-Refractory Crohn's Colitis: Add Infliximab
For a patient with Crohn's disease and patchy colitis failing to respond to steroids, add infliximab (5 mg/kg) as the next step. This represents steroid-refractory disease and requires escalation to biologic therapy rather than adding aminosalicylates or switching to ileal-releasing steroids 1.
Defining Steroid-Refractory Disease
Your patient meets criteria for steroid-refractory Crohn's disease, defined as active disease despite adequate steroid dosing (>20 mg/day prednisolone for >2 weeks) 1. This clinical scenario mandates escalation beyond conventional therapy.
Why Infliximab is the Correct Choice
Infliximab (5 mg/kg) is specifically indicated for moderate to severe Crohn's disease that is refractory to steroids 1. The guidelines explicitly state this should be reserved for patients who have failed to respond to corticosteroids, making it the appropriate next step in your case 1.
- Infliximab demonstrates Grade A evidence for efficacy in steroid-refractory Crohn's colitis 1
- The standard induction regimen is 5 mg/kg at weeks 0,2, and 6, followed by maintenance dosing every 8 weeks 1
- Recent network meta-analyses confirm infliximab 5 mg/kg, 10 mg/kg, and 20 mg/kg rank among the highest for disease remission (SUCRA 98.6%, 92%, and 91.8% respectively) 2
Why NOT the Other Options
5-ASA (mesalazine) is ineffective in this scenario. While high-dose mesalazine (4 g/daily) may be sufficient for mild ileocolonic Crohn's disease, it explicitly fails in patients who require steroids or have moderate-to-severe disease 1. Your patient has already progressed beyond the point where aminosalicylates would be beneficial. Additionally, mesalazine has limited benefit for maintenance and is ineffective for those who needed steroids to induce remission 1.
Ileal-releasing steroids (budesonide) are inappropriate here. Budesonide 9 mg daily is specifically indicated for isolated ileo-caecal disease with moderate activity, not for colonic disease 1. Your patient has patchy colitis, making budesonide the wrong anatomic target. Furthermore, budesonide is marginally less effective than prednisolone and would represent a step down rather than escalation 1.
Treatment Algorithm for Steroid-Refractory Crohn's Colitis
- Confirm steroid failure: Active disease despite >20 mg/day prednisolone for >2 weeks 1
- Exclude complications: Rule out abscess, stricture, or infection before starting biologics 1
- Initiate infliximab: 5 mg/kg IV at weeks 0,2, and 6 1
- Add immunomodulator: Consider concurrent azathioprine (1.5-2.5 mg/kg/day) as steroid-sparing agent and to reduce antibody formation 1
- Taper steroids: Gradually reduce prednisolone over 8 weeks as infliximab takes effect 1
Alternative Considerations
If infliximab is contraindicated or unavailable, second-line options include 1:
- Azathioprine/mercaptopurine: First-line immunomodulators for steroid-dependent disease, but slow onset (3-6 months) precludes use as sole therapy in active disease 1
- Methotrexate: 25 mg IM weekly effective for chronic active disease, but also slower onset 1
Critical Pitfalls to Avoid
- Do not continue steroids long-term: Corticosteroids are ineffective for maintenance and cause significant toxicity 1, 3. Your patient needs definitive escalation, not prolonged steroid exposure.
- Do not add 5-ASA to failing steroids: This adds no benefit in moderate-to-severe disease and delays appropriate biologic therapy 1
- Screen before biologics: Check for latent tuberculosis, hepatitis B, and HIV before initiating infliximab 4
- Monitor for infusion reactions: Most common side effect; may require antihistamine or acetaminophen 5
Newer Biologic Options
While infliximab remains first-line, newer IL-23 inhibitors (guselkumab, mirikizumab) show promising efficacy (SUCRA 82-90%) with favorable safety profiles 2. However, these are typically reserved for anti-TNF failures or specific clinical scenarios where infliximab is contraindicated.