Makindo Medical Notes

🔥 TRAPS (TNF receptor-associated periodic syndrome) patients show exaggerated innate immune responses. They present with recurrent prolonged fever, migratory rash, peritonitis, myalgia, and arthralgia, and carry a risk of systemic amyloidosis.

📖 About

• Also known as familial Hibernian fever (FHF).
• Shares features with familial Mediterranean fever (FMF) but FHF is autosomal dominant, whereas FMF is recessive.

🧬 Aetiology

• Caused by mutations in TNFRSF1A gene.
• Autosomal dominant inheritance.
• Encodes TNF receptor 1 (TNFR1), which binds TNF and drives inflammatory responses.
• Defective signalling causes uncontrolled inflammation ± apoptosis dysregulation.

🩺 Clinical Features

• ♨️ Recurrent fevers lasting ~3 weeks.
• ⏳ Variable frequency (weeks to years apart).
• ⚡ Triggers: injury, infection, stress, exercise, hormonal changes.
• 🤕 Abdominal pain, myalgia, spreading erythematous rash.
• 👁️ Periorbital oedema (characteristic).
• 🦴 Arthralgia and stiffness.
• 🔥 Serositis: eyes, heart, joints, throat, mucosa (mouth, gut).
• ⚠️ Secondary amyloidosis → chronic kidney disease / renal failure.

🔬 Investigations

• 📊 FBC, U&E – assess systemic/renal disease.
• ⬆️ ESR / CRP – inflammatory markers elevated.
• 🧬 Genetic testing for TNFRSF1A mutations.
• 🧾 Exclude FMF in differential diagnosis.
• 🧪 High serum IL-6 levels – inflammatory marker.

🧾 Differential

• Familial Mediterranean fever (FMF).
• Systemic vasculitis.

💊 Management

• 🌡️ Symptomatic relief: NSAIDs or corticosteroids for acute flares.

🧪 Antibody / Biologic Therapy

• 🛑 TNF inhibitors: Etanercept (useful but may lose efficacy).
• 🧩 IL-1 inhibitors: Anakinra, Canakinumab (Ilaris) – highly effective, even in TNF-resistant cases.
• 🧪 IL-6 inhibitors: Tocilizumab – benefits some patients.

💡 UK Clinical Pearls

• 👁️ Periorbital oedema + recurrent fever is a diagnostic clue for TRAPS.
• 🧬 Think of TRAPS when there is a dominant inheritance pattern (FMF is recessive).
• ⚠️ Always assess for amyloidosis and renal function in long-standing cases.
• 📚 In exams, TRAPS is often contrasted with FMF: note longer fever duration (weeks vs. days) and dominant inheritance.
• 💉 IL-1 blockade (e.g. canakinumab) is now standard therapy in resistant disease in UK/EU practice.

🔗 Links

• ScienceDirect – Review Article on TRAPS