Kawasaki Disease: Complications & Prognosis

Complications:

• Macrophage Activation Syndrome (MAS):
  • Life-threatening hyperinflammation
  • Labs: hyperferritinemia, coagulopathy, thrombocytopenia
  • May mimic MIS-C → needs aggressive immunosuppression
• Coronary Artery Abnormalities (CAA):
  • Giant aneurysms → myocardial infarction, angina, sudden death
  • Moderate aneurysms → may use dual antiplatelet therapy (aspirin + clopidogrel)
  • Large/giant aneurysms → anticoagulation (warfarin, LMWH) + aspirin
  • Acute thrombosis → thrombolytic therapy
  • Rarely: aneurysm rupture
• Long-term sequelae of CAA:
  • Coronary stenosis, inducible ischemia → may require CABG or catheter interventions
  • Regressed aneurysms → myointimal thickening, abnormal vascular function

Prognosis:

• Majority recover fully; timely treatment reduces CAA risk to <5%
• Recurrence of acute KD: 1–3%
• Fatality: <1%
• CAA outcomes:
  • ~50% regress to normal diameter within 1–2 years
  • Giant aneurysms less likely to regress → higher risk thrombosis/stenosis
  • Revascularization or rarely heart transplant may be needed
  • Adult survival with history of giant aneurysms: ~90% at 30 years
• Children without CAA have normal long-term outcomes
• Lifestyle & preventive counseling recommended for all KD patients