Kawasaki disease
Overview
Kawasaki disease (KD) is an acute systemic vasculitis of small and medium vessels that mainly affects children under 5 years. It is a paediatric emergency because coronary artery inflammation can progress to dilation and aneurysm formation, with risk of thrombosis, myocardial ischaemia and long‑term cardiac morbidity.
Early recognition and treatment (ideally within 7-10 days of fever onset) substantially reduce coronary complications (see NICE NG143).
Epidemiology and aetiology
- Most commonly affects children aged 6 months-5 years (peak ~2-3 years).
- Infants <12 months often have fewer classic features but are at higher risk of coronary abnormalities.
- Slight male predominance (~1.5:1).
- Seasonal peaks in winter-spring in temperate regions.
- Cause unknown; an infective trigger is suspected but no single pathogen has been proven.
Clinical features - what to look for
KD evolves over days; features may appear or resolve before assessment. Ask carers about symptoms since fever onset (NICE NG143).
Core diagnostic features
- Fever for ≥5 days (usually high and persistent) - nearly universal.
- Bilateral non‑purulent conjunctival injection.
- Oral mucosal changes: erythema, cracked/fissured lips, "strawberry" tongue, diffuse oropharyngeal erythema.