Overview
Definition
An acute, self-limiting systemic vasculitis of unknown etiology that predominantly affects children < 5 years of age.
Epidemiology
Highest incidence in children of Asian descent.
Etiology & Risk Factors
- Unknown. Suspected to be an aberrant immune response to an infectious trigger in genetically predisposed children.
Clinical Symptoms
- CRASH and Burn: Conjunctivitis (bilateral, non-exudative)
- Rash (polymorphous, primarily on the trunk)
- Adenopathy (cervical, >1.5 cm, usually unilateral)
- Strawberry tongue and cracked red lips
- Hands and feet (erythema, edema, subsequent desquamation)
- Burn: Fever lasting ≥ 5 days
Clinical Approach
Diagnosis
- Clinical diagnosis requiring fever for ≥ 5 days plus 4 of the 5 'CRASH' criteria
- Echocardiogram is MANDATORY to evaluate for coronary artery aneurysms
- Labs: Elevated ESR/CRP, Thrombocytosis (often > 500,000) in the subacute phase
Management
- Intravenous Immunoglobulin (IVIG) as a single high dose (reduces risk of aneurysms from 25% to < 5%)
- High-dose Aspirin (for anti-inflammatory and anti-platelet effects, despite the theoretical risk of Reye syndrome)
Complications
- Coronary artery aneurysms (can lead to myocardial infarction in young children)
- Myocarditis
- Macrophage Activation Syndrome (MAS)