Kawasaki Disease
Acute Systemic Medium-Vessel Vasculitis
Primary risk age: Children under 5 years (Highest prevalence in children of Asian descent)
- Urgency
- Emergency
- Typical age
- Children under 5 years (Highest prevalence in children of Asian descent)
- Body system
- Cardiovascular System
Typical course: Acute hospital phase lasts 3 to 7 days; full convalescent tissue repair takes 6 to 8 weeks.
Reviewed against AAP · CDC · WHO · NHS guidance Last reviewed 2026-06-13
1. Summary & Pathophysiology
Acute Systemic Medium-Vessel Vasculitis
Pathophysiology (Development Path)
An inflammatory cascade targets the endothelial and smooth muscle cells of medium-sized arteries, particularly the coronary arteries. Neutrophils, followed by T-lymphocytes and macrophages, infiltrate the vascular walls, breaking down elastin and collagen. This weakens the structural integrity of the vessels, leading to aneurysms.
Primary Causes & Etiology
Unknown etiology; believed to be triggered by an unclassified infectious agent that prompts an exaggerated auto-inflammatory immune response in genetically predisposed individuals.
2. Symptom Continuum
- Early Onset Signs
High spikes of unremitting fever (often >39°C) lasting at least 5 days, bilateral non-purulent conjunctival injection, and erythema of the lips and oral mucosa ("strawberry tongue").
- Progressive Phase
Polymorphous macular rash on the trunk, firm induration of the hands and feet with vivid palmar and plantar erythema, and unilateral non-suppurative cervical lymphadenopathy (>1.5 cm).
- Severe Indicators
Desquamation (peeling) of the skin starting under the nails, acute myocarditis marked by tachycardia out of proportion to the fever, gallop rhythms, and signs of congestive heart failure.
3. Clinical Verification
Clinical diagnosis based on the criteria of a 5-day fever plus at least 4 out of 5 classic mucocutaneous signs. Echocardiography is performed immediately to evaluate the coronary arteries.
4. Care & Elements Plan
Primary Care Treatment Plan
Aims to reduce vascular wall inflammation and prevent coronary artery thrombosis. Administer high-dose immunoglobulins and high-dose salicylate therapy early in the illness.
Home Support Elements
This condition requires immediate inpatient hospitalization. Home care is limited to post-discharge tracking for a return of fever or bleeding risks related to therapeutic blood thinners.
Generic Active Ingredients (No Brands)
- Intravenous Immunoglobulin (IVIG - to suppress systemic vascular immune damage)
- Acetylsalicylic acid (Aspirin - given at high anti-inflammatory doses initially, then switched to low anti-platelet doses).
Lists active elements only. Never administer self-designed therapies.
5. Doctor Critical Lines
Critical Thresholds: When to See a Doctor
Any child running an unexplained high fever for more than 4-5 days accompanied by bloodshot eyes, red cracked lips, or a widespread rash requires immediate emergency pediatric evaluation.
6. Vaccine & Prevention
Routine Prophylaxis (Prevention)
No preventative methods or lifestyle modifications exist, as the primary trigger remains unclassified.
Immunization Context
No immunization exists. Note that high-dose IVIG therapy requires delaying live viral vaccines (such as MMR and Varicella) for 11 months.
7. Timelines & Outlook
Active Timeline
Acute hospital phase lasts 3 to 7 days; full convalescent tissue repair takes 6 to 8 weeks.
Expected Prognosis
Excellent if treated within the first 10 days of onset, reducing the risk of coronary aneurysms from 25% to under 5%.
Potential Untreated Complications
Coronary artery aneurysms, myocardial infarction, pericarditis, and sudden cardiac death.
More in Acquired Inflammatory Vascular Pathologies
Severe Acute Rheumatic Fever (ARF)
Post-Streptococcal Autoimmune Inflammatory Connective Tissue Disease
5 to 15 Years (Rarely occurs in children under 3 years)
Emergency Pediatric Myocarditis
Inflammation of the heart muscle, most often following a viral infection.
All ages, including infants and adolescents.
Moderate Henoch-Schönlein Purpura (IgA Vasculitis)
The most common childhood vasculitis, inflaming small blood vessels in the skin, joints, gut, and kidneys.
Most common between 3 and 10 years, often after a respiratory infection.