Makindo Medical Notes

Related Subjects:Acute Cholecystitis |Acute Appendicitis |Chronic Peritonitis |Abdominal Aortic Aneurysm |Ectopic Pregnancy |Acute Cholangitis |Acute Abdominal Pain/Peritonitis |Assessing Abdominal Pain |Penetrating Abdominal Trauma |Acute Pancreatitis |Acute Diverticulitis

🔥 Familial Mediterranean Fever (FMF) is an autosomal recessive autoinflammatory disorder causing recurrent fever, abdominal pain, arthritis, and serositis. ⚠️ The main long-term complication is AA amyloidosis → renal failure.

📖 About

• Hereditary periodic fever syndrome.
• Most common in people of Eastern Mediterranean ancestry:
  • Sephardic Jews 🇮🇱
  • Turks 🇹🇷
  • Armenians 🇦🇲
  • Arabs 🇱🇧
• Onset often in childhood or adolescence.

🧬 Aetiology

• Mutation in MEFV gene (chromosome 16).
• Encodes pyrin (781 amino acids) → regulates neutrophil inflammation.
• Dysfunction → uncontrolled neutrophilic inflammation.
• Chronic inflammation predisposes to AA amyloid deposition.

🩺 Clinical Features

• Attacks triggered by stress, exercise, or menses.
• Febrile episodes last 1–3 days.
• Abdominal pain: peritonitis → rigid, tender abdomen; recurrent episodes cause adhesions, infertility, obstruction.
• Serositis: pleurisy (pleuritic chest pain), pericarditis.
• Arthritis: large joints of lower limbs (hip, knee, ankle).
• Genitourinary: tunica vaginalis inflammation can mimic testicular torsion.
• Associated vasculitides: Henoch–Schönlein purpura, Polyarteritis nodosa.

🔬 Investigations

• FBC: neutrophilia during attacks; Hb usually normal.
• CRP/ESR: markedly raised during attacks.
• Urine: proteinuria → suggests renal amyloidosis.
• Genetic testing: MEFV mutation (confirmation, not always required for diagnosis).

📊 Diagnosis

• Typical attack = recurrent, febrile (≥38 °C), short (12 hrs – 3 days).
• Incomplete attack = painful, recurrent but does not meet all criteria.

💊 Management

• Colchicine 1–2 mg daily (lifelong) → prevents attacks & amyloidosis.
• If colchicine resistant/intolerant:
  • Anakinra (IL-1 receptor antagonist)
  • Canakinumab (monoclonal antibody to IL-1β)
  • Thalidomide (rarely used due to toxicity)
• Monitor renal function & proteinuria regularly.

📌 Revision Pearls

• Think FMF in recurrent fevers + serositis + Mediterranean ethnicity.
• Main danger = renal amyloidosis (proteinuria, renal failure).
• Colchicine lifelong even if asymptomatic → protects kidneys.

📅 Revision Note

• Last updated: 21/07/2017