What is the treatment approach for a patient with Crohn’s (Crohn's disease) disease presenting with an ulcerative skin lesion?

Treatment Approach for Ulcerative Skin Lesions in Crohn's Disease

For patients with Crohn's disease presenting with ulcerative skin lesions, anti-TNF-α biologics, particularly infliximab, should be considered as first-line therapy due to their proven efficacy in treating both intestinal and cutaneous manifestations of the disease. 1

Types of Cutaneous Manifestations in Crohn's Disease

Skin lesions in Crohn's disease can be categorized into four main types:

• Specific lesions - Share the same granulomatous histopathology as intestinal Crohn's disease, including metastatic Crohn's disease (non-contiguous to GI tract) 2, 3
• Reactive lesions - Different histopathology but closely linked pathophysiologically (e.g., pyoderma gangrenosum) 3
• Associated lesions - Common comorbid conditions (e.g., erythema nodosum, psoriasis) 3
• Treatment-induced lesions - Cutaneous reactions to IBD medications 3

Diagnostic Approach

• Skin biopsy is essential for definitive diagnosis of the type of skin lesion 2
• Evaluate disease activity of underlying Crohn's disease, as skin manifestations often correlate with intestinal disease activity 3
• Rule out infection as a potential cause or complication of skin lesions 1

Treatment Algorithm

First-Line Therapy

• Anti-TNF-α agents (particularly infliximab) have the most robust evidence for treating fistulizing and cutaneous manifestations of Crohn's disease 1
  • Recommended induction dosing: IV infliximab with weight-based dosing 1
  • For maintenance: Continue scheduled dosing to prevent recurrence 1

Alternative Biologics (For Anti-TNF Failures or Contraindications)

• Ustekinumab (IL-12/23 inhibitor):

  • FDA-approved for moderate to severe Crohn's disease 4
  • Induction: Single IV infusion based on weight 4
    • Up to 55 kg: 260 mg

    • 55 kg to 85 kg: 390 mg

    • 85 kg: 520 mg 4

  • Maintenance: 90 mg SC every 8 weeks 4

• Vedolizumab (anti-integrin) is suggested as an alternative option for patients with primary non-response to TNF-α inhibitors 1

Adjunctive Therapies

• Topical or intralesional corticosteroids for limited cutaneous lesions 2
• Antibiotics (particularly metronidazole) may be beneficial for specific types of cutaneous lesions, especially those with infectious components 1
• Immunomodulators (azathioprine, 6-mercaptopurine) can be used in combination with biologics for enhanced efficacy 1

Special Considerations

• Perianal lesions (abscesses, fistulas) require surgical drainage if fluctuant 1
• Metastatic Crohn's disease (non-contiguous skin lesions) typically responds best to systemic therapy rather than local treatments 2
• Skin tags associated with Crohn's disease should not be surgically excised due to high risk of complications and poor wound healing 1
• Anal fissures in Crohn's disease are often painless and heal spontaneously in >80% of cases; surgical intervention should be limited 1

Monitoring and Follow-up

• Regular assessment of both cutaneous and intestinal disease activity 1
• Adjust therapy based on clinical response of both skin and intestinal manifestations 1
• Screen for potential complications of therapy, including infections and malignancy 4

Pitfalls to Avoid

• Avoid surgical excision of typical Crohn's disease skin tags due to high risk of complications 1
• Do not delay biologic therapy in patients with moderate-to-severe disease; early introduction of biologics with or without immunomodulators is preferred over delayed use 1
• Avoid relying solely on corticosteroids for maintenance therapy, as they are not effective for long-term disease control 1
• Be cautious with IL-17 inhibitors (secukinumab) which may paradoxically worsen intestinal Crohn's disease 1