In Kawasaki disease (mucocutaneous lymph node syndrome), the most dangerous complication is coronary artery aneurysm. The primary mechanism of aneurysm formation involves:
- A Atherosclerotic plaque rupture causing pseudo-aneurysm formation
- B Fibrinoid necrosis of the intima with secondary ectasia
- C Transmural inflammatory destruction of the media by neutrophils and macrophages in the acute phase ✓
- D Cystic medial degeneration from excess TGF-beta signaling
Explanation
In Kawasaki disease, the acute phase (first 2 weeks) involves intense neutrophilic infiltration of all layers of coronary artery walls, with subsequent mononuclear cell dominance. Enzymatic destruction of the internal elastic lamina and smooth muscle media by neutrophil-derived proteases (MMP-8, MMP-9, elastases) weakens the arterial wall, leading to dilatation and aneurysm formation (coronary artery aneurysms in 15-25% of untreated patients). IVIG given within the first 10 days dramatically reduces aneurysm risk. Cystic medial degeneration characterizes Marfan syndrome (FBN1 mutation, TGF-beta excess).
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
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Written and medically reviewed by the StethoPrep medical team.