Can Tumor Necrosis Factor Receptor-Associated Periodic Syndrome (TRAPS) autoinflammatory syndrome mimic Crohn's disease?

TRAPS Autoinflammatory Syndrome Can Mimic Crohn's Disease

Yes, Tumor Necrosis Factor Receptor-Associated Periodic Syndrome (TRAPS) can mimic Crohn's disease and should be considered in the differential diagnosis when evaluating patients with recurrent abdominal pain and inflammatory symptoms.

Clinical Features of TRAPS That Can Mimic Crohn's Disease

TRAPS is an autosomal dominant autoinflammatory disorder characterized by recurrent episodes of systemic inflammation that can present with symptoms similar to Crohn's disease:

• Abdominal pain: Prominent feature in both conditions
• Fever: Prolonged fever episodes (>7 days) in TRAPS vs. intermittent fever in Crohn's
• Elevated inflammatory markers: Both conditions show elevated CRP, ESR
• Gastrointestinal symptoms: Abdominal pain in TRAPS can mimic intestinal inflammation in Crohn's
• Extraintestinal manifestations: Both can present with:
  • Arthralgia/arthritis
  • Skin manifestations (though different patterns)
  • Ocular involvement

Key Distinguishing Features

TRAPS-Specific Features

• Duration of fever attacks: Typically longer (21 days on average) 1
• Distinctive rash pattern: Centrifugal, erythematous patch 1
• Ocular involvement: Periorbital edema, conjunctivitis 1
• Family history: Strong familial distribution 1
• Response to treatment: Dramatic response to IL-1 inhibitors or etanercept 2, 3

Diagnostic Approach

When suspecting TRAPS in a patient with Crohn's-like symptoms:

1. Genetic testing: NGS platform to detect mutations in TNFRSF1A gene 1

   • Some patients may have somatic mutations requiring deep sequencing 1

2. Inflammatory markers:

   • Elevated CRP, ESR during attacks
   • Consider IL-18 levels (highly sensitive and specific for autoinflammatory conditions) 1

3. Clinical pattern assessment:

   • Recurrent episodes with complete resolution between flares
   • Longer duration of fever episodes (>7 days) compared to other periodic fever syndromes 1
   • Presence of migratory myalgia and characteristic rash

Management Considerations

For patients with confirmed TRAPS:

• First-line therapy: IL-1 receptor antagonists (anakinra) 3
• Alternative therapy: TNF inhibitors (etanercept) 2, 3
• Monitoring: Regular assessment of inflammatory markers to evaluate disease activity 1
• Complication surveillance: Monitor for development of amyloidosis, a serious long-term complication 4

Common Pitfalls to Avoid

1. Misdiagnosis leading to inappropriate treatment: TRAPS patients may not respond to conventional Crohn's disease therapies

2. Overlooking genetic testing: Failure to consider autoinflammatory syndromes in the differential diagnosis of recurrent abdominal pain with systemic inflammation

3. Relying solely on clinical features: Genetic confirmation is essential for definitive diagnosis

4. Inadequate monitoring: Patients with TRAPS require long-term follow-up for disease activity and complications, particularly amyloidosis

5. Delayed diagnosis: The average time to diagnosis can be prolonged due to overlap with more common conditions like Crohn's disease

Conclusion

When evaluating patients with suspected Crohn's disease who have atypical features such as prolonged fever episodes, distinctive rash patterns, periorbital edema, or strong family history of similar symptoms, TRAPS should be considered in the differential diagnosis. Genetic testing for TNFRSF1A mutations is crucial for definitive diagnosis and appropriate management.