What is the treatment for a patient experiencing a flare-up of Crohn's disease?

Treatment of Crohn's Disease Flare

For moderate to severe Crohn's disease flares, initiate anti-TNF biologic therapy (infliximab or adalimumab) combined with an immunomodulator as first-line treatment, with corticosteroids used only as a bridge while awaiting biologic effect—never for maintenance. 1, 2

Disease Severity Assessment and Initial Treatment Selection

The treatment approach depends critically on disease severity, location, and whether the patient has high-risk features for disease progression:

Mild to Moderate Disease (Ileal/Right Colonic)

• Start oral budesonide 9 mg daily for 8 weeks as first-line therapy for disease limited to the ileum and/or right colon 3, 1
• Budesonide achieves similar remission rates to prednisone (51% vs 52.5%) but with significantly fewer side effects 1
• Evaluate symptomatic response between 4-8 weeks to determine if therapy modification is needed 3
• If no response to budesonide, escalate to prednisone 40-60 mg daily 3

Mild Disease Limited to Colon Only

• Sulfasalazine 4-6 g/day can be considered for mild colonic disease, though efficacy is modest 3
• Evaluate response between 2-4 months 3
• Do not use oral 5-ASA (mesalamine) for induction or maintenance—it is ineffective for Crohn's disease 3, 1, 4

Moderate to Severe Disease

This is where treatment strategy fundamentally changes:

• Initiate anti-TNF therapy (infliximab or adalimumab) immediately in patients with moderate to severe disease, especially those with risk factors for poor prognosis 3, 1, 2
• Combine anti-TNF with thiopurine (azathioprine 2-2.5 mg/kg/day or 6-mercaptopurine 1-1.5 mg/kg/day) or methotrexate—combination therapy is superior to monotherapy 3, 1, 2
• The landmark evidence shows "top-down" combination therapy achieves sustained steroid- and surgery-free remission in 79% versus only 15% with traditional step-up care 2
• Use systemic corticosteroids (prednisone 40-60 mg/day orally) only as a bridge while awaiting biologic effect 3, 1

Severe Disease Requiring Hospitalization

• Administer IV methylprednisolone 40-60 mg/day for patients requiring hospitalization 3
• Evaluate symptomatic response within 1 week to determine need for therapy modification 3
• Simultaneously initiate anti-TNF therapy planning 1

Critical Timing and Monitoring

Response Assessment Timeline

• Evaluate anti-TNF response between 8-12 weeks after induction 3, 1
• If no response by week 14, discontinue anti-TNF and switch to alternative biologic (ustekinumab or vedolizumab) 3, 1, 5
• For patients on corticosteroids alone, assess response at 2-4 weeks 3
• For budesonide, assess at 4-8 weeks 3

Corticosteroid Management

• Taper prednisone rapidly (10 mg/week) once remission achieved to minimize exposure 3
• Never use corticosteroids for maintenance therapy—this leads to steroid dependency without preventing disease progression 3, 1
• Patients on ≥20 mg prednisolone daily should observe strict infection precautions due to increased risk of serious infections 3, 1

Maintenance Therapy Strategy

Once remission is achieved:

• Continue anti-TNF therapy for maintenance in patients who respond to induction 3, 1
• Maintain combination therapy with immunomodulator (thiopurine or methotrexate) to reduce immunogenicity and improve long-term outcomes 3, 1, 2
• For patients who achieved remission on corticosteroids but are not candidates for biologics, consider thiopurine monotherapy for maintenance 3
• Parenteral methotrexate can maintain remission in steroid-dependent/resistant patients 3

Dose Optimization and Loss of Response

• Use therapeutic drug monitoring to guide dose optimization in patients losing response to anti-TNF therapy 3, 1
• For suboptimal response or loss of response, consider dose intensification before switching agents 3
• If patients fail to achieve corticosteroid-free remission within 12-16 weeks on thiopurine or methotrexate, modify therapy 3

Alternative Biologics

For patients who fail or are contraindicated to anti-TNF therapy:

• Ustekinumab (anti-IL-12/23) is particularly effective in anti-TNF naive patients 3, 1
• Vedolizumab (anti-α4β7 integrin) offers gut-selective action with potentially better safety profile but slower onset 3, 1

Critical Pitfalls to Avoid

The most important clinical errors that worsen outcomes:

1. Delaying biologic therapy in moderate-to-severe disease leads to irreversible complications including strictures, fistulas, and need for surgery 1, 2
2. Using corticosteroids for maintenance creates steroid dependency without preventing disease progression 3, 1
3. Continuing ineffective therapy beyond appropriate assessment windows (14 weeks for anti-TNF, 2-4 months for sulfasalazine) 3, 1
4. Using 5-ASA products which are ineffective for Crohn's disease and delay appropriate treatment 3, 1, 4
5. Inadequate dose optimization when patients lose response—check drug levels before abandoning therapy 3, 1
6. Stopping corticosteroids abruptly without appropriate taper or maintenance therapy in place 3

Safety Monitoring

• Screen for latent tuberculosis before initiating anti-TNF therapy 5
• Monitor for serious infections during treatment—discontinue if serious infection or sepsis develops 5
• Be aware that combination therapy with thiopurines increases risk of hepatosplenic T-cell lymphoma, particularly in young males 5
• High-dose corticosteroids increase risk of opportunistic infections, abscesses, and metabolic complications 3, 1