AKT · Child health/Infection & rash

Kawasaki disease

Medium-vessel vasculitis (unknown trigger)

Overview

A medium-vessel vasculitis of young children and the leading cause of acquired paediatric heart disease — coronary artery aneurysms. Diagnosed clinically: fever ≥5 days plus ≥4 of five features. Crucially it does NOT respond to antibiotics.

Recognise

Fever ≥5 days PLUS ≥4 of: bilateral non-purulent CONJUNCTIVITIS; cracked lips/STRAWBERRY tongue; cervical lymphadenopathy; polymorphous rash; erythema/oedema of hands & feet then peeling
Very irritable child
Later: peeling of fingertips/toes

Red flags

Coronary artery aneurysms — the feared complication; incomplete Kawasaki in infants

Differentials & how to tell them apart

Scarlet feverresponds to penicillin; sandpaper rash; GAS positive — Kawasaki does NOT respond to antibiotics

MeaslesKoplik spots, 3 Cs, self-limiting

Staphylococcal scalded skin / TSStoxin, skin/shock features

Juvenile idiopathic arthritis (systemic)quotidian fever, arthritis, salmon rash

Investigations

Clinical diagnosis. Bloods: raised CRP/ESR, thrombocytosis (2nd week), anaemia. ECHOCARDIOGRAM at diagnosis and follow-up for coronary aneurysms.

Management

IV immunoglobulin + aspirin

1IV immunoglobulin (single dose) PLUS aspirin. Echocardiogram for coronary aneurysms.Gate: Aspirin is normally avoided in children (Reye syndrome) — Kawasaki is a specific EXCEPTION
2Refractory: second IVIG dose, corticosteroids or infliximab. Long-term aspirin ± anticoagulation if aneurysms.

IV immunoglobulin (IVIG) — first-line, reduces aneurysm risk

Aspirin — high-dose then low-dose — a rare paediatric indication for aspirin

Key points

Two exam traps: (1) it mimics scarlet fever/measles but does NOT respond to antibiotics; (2) aspirin is used despite the usual Reye-syndrome caution.

Monitor & prognosis

Serial echocardiography for coronary aneurysms; inflammatory markers.

Good with early IVIG; aneurysms cause long-term cardiac risk.

Source: NICE; RCPCH