kawasaki disease
Overview
Kawasaki disease is a rare but serious inflammatory condition that primarily affects children under the age of 5. It causes inflammation in the walls of medium-sized blood vessels, particularly those supplying the heart (coronary arteries). The exact cause is unknown, but it’s thought to be triggered by an abnormal immune response to an infection in genetically susceptible children. Early recognition and treatment are crucial to prevent heart complications.
Why It’s Important
Kawasaki disease is one of the leading causes of acquired heart disease in children in developed countries. If left untreated, it can cause coronary artery aneurysms, which may lead to heart attacks or sudden cardiac death later in life. However, when diagnosed early and treated promptly, most children recover fully without long-term effects.
Quick Facts
Most common in children under 5 years old
Affects boys more often than girls
Unknown cause, but may involve immune system overreaction
Most cases occur in winter and spring
Early treatment significantly reduces risk of heart damage
What Happens in the Body
Kawasaki disease triggers widespread inflammation in blood vessels (vasculitis) throughout the body. The immune system attacks healthy tissue, particularly the coronary arteries, causing them to swell. This inflammation can weaken the artery walls, leading to aneurysms or narrowing, which can impair blood flow to the heart. The condition typically progresses through three stages:
Acute phase (1–2 weeks): Fever and initial symptoms appear.
Subacute phase (weeks 2–4): Risk of heart complications peaks.
Convalescent phase (weeks 4–8): Recovery begins, but lingering inflammation may persist.
Common Signs and Symptoms
Fever lasting more than 5 days (usually high and unresponsive to medication)
Rash (especially on the torso and groin)
Red eyes (conjunctivitis) without discharge
Red, cracked lips and “strawberry” tongue
Swollen hands and feet with redness or peeling skin
Swollen lymph nodes, usually in the neck
Irritability and fatigue
Diagnosis
There is no single test for Kawasaki disease; diagnosis is based on clinical criteria and exclusion of other illnesses.
Blood tests may show inflammation (elevated CRP, ESR, WBC).
Echocardiogram (heart ultrasound) is used to check for coronary artery abnormalities.
Electrocardiogram (ECG) may detect heart rhythm changes.
Urinalysis and liver function tests may show secondary effects of inflammation.
Treatment and Management
Intravenous immunoglobulin (IVIG): The main treatment; reduces inflammation and risk of heart damage if given within the first 10 days.
High-dose aspirin: Used to reduce fever, inflammation, and blood clot risk.
Corticosteroids or biologic drugs (like infliximab) may be used in resistant cases.
Cardiac monitoring: Ongoing follow-up with echocardiograms to detect late complications.
Most children recover completely within 6–8 weeks of treatment.
Risks and Complications
Coronary artery aneurysms or narrowing
Myocarditis (heart muscle inflammation)
Arrhythmias (irregular heartbeat)
Pericarditis (inflammation of heart lining)
Heart attack or sudden death (in severe, untreated cases)
Who Is at Risk
Children under 5 years old, especially boys
Children of Asian descent, particularly Japanese or Korean
Those with a family history of Kawasaki disease
Seasonal risk: late winter to early spring
Related Conditions
Multisystem Inflammatory Syndrome in Children (MIS-C)
Scarlet fever
Toxic shock syndrome
Juvenile idiopathic arthritis
When to See a Doctor
If your child has a fever lasting more than 5 days, especially with a rash, red eyes, or swollen extremities
If your child is unusually irritable or lethargic
Seek emergency care if your child has chest pain, shortness of breath, or fainting after a recent fever illness
Early medical evaluation is key, and treatment within the first 10 days greatly reduces heart risk
Last Updated: October 20, 2025