What is the best management for a patient with Crohn's disease on infliximab (chimeric monoclonal antibody against tumor necrosis factor-alpha) presenting with a perianal discharging fistula, induration, and low-grade fever for 3 weeks?

From the Guidelines

The best management for a patient with Crohn's disease on infliximab presenting with a perianal discharging fistula, induration, and low-grade fever for 3 weeks is to continue infliximab therapy, optimize the dose if necessary, and combine it with seton drainage and antibiotic therapy.

Key Considerations

• The patient's current infliximab therapy should be continued, as it remains effective for fistulizing Crohn's disease, with potential dose optimization to achieve target levels >10 μg/mL for better response 1.
• Surgical drainage of any perianal abscess is crucial, followed by antibiotic therapy with ciprofloxacin and metronidazole for 2-4 weeks to address the infectious component.
• Seton placement by a colorectal surgeon may be required for complex or recurrent fistulas to facilitate drainage and prevent abscess formation, as recommended by the ECCO guidelines 1.
• MRI of the pelvis should be performed to assess fistula anatomy and identify any undrained collections.

Management Approach

• Initial management should focus on controlling the infection with antibiotics and drainage.
• Infliximab therapy should be optimized, with consideration of increasing the dose to 10 mg/kg or shortening the interval between infusions, as supported by the British Society of Gastroenterology consensus guidelines 1.
• The patient should be monitored closely for signs of systemic infection, and blood cultures should be obtained if fever persists.
• The combination of surgical intervention, antibiotics, and optimized biologic therapy offers the best chance for fistula healing while preventing septic complications, as suggested by the AGA clinical practice guidelines 1.

Prioritizing Outcomes

• The management approach prioritizes reducing morbidity, mortality, and improving quality of life by addressing both the infectious component and the underlying Crohn's disease.
• The goal is to achieve complete fistula closure, prevent septic complications, and maintain remission, as supported by the highest quality evidence available 1.

From the FDA Drug Label

Fistulizing Crohn's Disease The safety and efficacy of infliximab were assessed in 2 randomized, double-blind, placebo-controlled studies in patients with fistulizing Crohn's disease with fistula(s) that were of at least 3 months duration. Concurrent use of stable doses of corticosteroids, 5-aminosalicylates, antibiotics, MTX, 6-mercaptopurine (6-MP) and/or azathioprine (AZA) was permitted In the first trial, 94 patients received 3 doses of either placebo or infliximab at Weeks 0,2 and 6. Fistula response (≥ 50% reduction in number of enterocutaneous fistulas draining upon gentle compression on at least 2 consecutive visits without an increase in medication or surgery for Crohn's disease) was seen in 68% (21/31) of patients in the 5 mg/kg infliximab group (P = 0. 002) and 56% (18/32) of patients in the 10 mg/kg infliximab group (P = 0.021) vs. 26% (8/31) of patients in the placebo arm.

The best management for a patient with Crohn's disease on infliximab presenting with a perianal discharging fistula, induration, and low-grade fever for 3 weeks is to use antibiotics before assessing the infliximab level, as the concurrent use of antibiotics is permitted in the treatment of fistulizing Crohn's disease.

• Key points:
  • The patient is already on infliximab, which has shown efficacy in treating fistulizing Crohn's disease.
  • The use of antibiotics is allowed in conjunction with infliximab.
  • There is no direct information in the label to suggest increasing the dose of infliximab or using an MRI as the first step in management.
  • The patient's symptoms, such as induration and low-grade fever, may indicate an infection that requires antibiotic treatment.
  • Assessing the infliximab level after antibiotic treatment can help determine the next steps in management, such as adjusting the dose or continuing with the current treatment plan 2.

From the Research

Management of Perianal Discharging Fistula in Crohn's Disease

The patient presents with a perianal discharging fistula, induration, and low-grade fever for 3 weeks while on infliximab. The best management approach would involve:

• Assessing the fistula and the patient's overall condition to determine the most appropriate course of action
• Considering the use of antibiotics to manage any potential infection, as suggested by the presence of a discharging fistula and low-grade fever 3, 4, 5
• Evaluating the patient's response to infliximab and considering adjustments to their treatment regimen as needed, which may include assessing infliximab levels 6
• Using imaging studies such as MRI to accurately diagnose and manage the fistula, as this can help define the anatomy of the fistula and identify any potential complications 7

Diagnostic and Therapeutic Considerations

In managing this patient, it is essential to:

• Obtain a swab from the discharge to identify any potential pathogens and guide antibiotic therapy 3, 4
• Consider the use of antibiotics as part of the treatment regimen, taking into account the need for individualized therapy and the potential risks and benefits of antibiotic use 3, 4, 5
• Monitor the patient's response to treatment and adjust the management plan as needed to ensure optimal outcomes

Treatment Options

The treatment options for this patient include:

• Increasing the dose of infliximab, although this may not be the most appropriate initial step given the patient's current symptoms and the potential need for antibiotic therapy 6
• Using antibiotics to manage any potential infection, followed by an assessment of the patient's response to infliximab and adjustment of their treatment regimen as needed 3, 4, 5
• Obtaining a swab from the discharge to guide antibiotic therapy and using MRI to accurately diagnose and manage the fistula 7, 3, 4