What is the etiology and treatment of Kawasaki disease?

From the Guidelines

Kawasaki disease is an acute, self-limited vasculitis primarily affecting young children, with unknown exact etiology, and current evidence suggests it results from an abnormal immune response to an infectious trigger in genetically susceptible individuals. The etiology of Kawasaki disease remains unknown, although clinical and epidemiological features strongly suggest an infectious cause 1.

Key Points

• The diagnosis of Kawasaki disease continues to rest on the identification of principal clinical findings and the exclusion of other clinically similar entities with known causes 1.
• Treatment should begin immediately upon diagnosis with intravenous immunoglobulin (IVIG) at 2 g/kg as a single infusion over 10-12 hours, along with high-dose aspirin (80-100 mg/kg/day divided into four doses) during the acute phase 1.
• After fever resolution, aspirin is reduced to a low dose (3-5 mg/kg/day) for 6-8 weeks or until coronary artery abnormalities resolve.
• For IVIG-resistant cases (persistent fever after 36 hours), a second IVIG dose may be administered, or corticosteroids (methylprednisolone 30 mg/kg/day for 1-3 days) or infliximab (5 mg/kg single dose) considered 1.
• Prompt treatment significantly reduces the risk of coronary artery aneurysms, the most serious complication.
• All patients require echocardiography at diagnosis, 1-2 weeks later, and 4-6 weeks after onset, with additional monitoring for those with coronary abnormalities.

Treatment Recommendations

• IVIG at 2 g/kg as a single infusion over 10-12 hours, along with high-dose aspirin, is the recommended initial treatment 1.
• Corticosteroids, such as methylprednisolone, may be considered for IVIG-resistant cases 1.
• Infliximab, a monoclonal antibody against TNF-, may be considered for patients who are resistant to IVIG and steroids 1.

Monitoring and Follow-up

• Echocardiography is essential for monitoring coronary artery abnormalities 1.
• Patients with coronary abnormalities require additional monitoring and follow-up to prevent long-term cardiac complications.

From the Research

Etiology of Kawasaki Disease

• The etiology of Kawasaki disease is largely unknown, but clinical, epidemiologic, immunologic, pathologic, and ultrastructural evidence suggests that an infectious agent triggers the illness 2.
• Epidemiologic investigations and the clinical presentation suggest a microbial agent as the cause of the disease 3.
• Despite extensive research, the infectious agent remains unidentified at present 2.

Treatment of Kawasaki Disease

• The principal treatment for Kawasaki disease includes intravenously administered immunoglobulin (IVIG) and acetylsalicylic acid (ASA) to reduce inflammation of the coronary arteries and myocardium 3.
• Corticosteroids are effective as an adjunctive treatment, particularly in high-risk patients or as rescue therapy for IVIG-resistant patients 4, 5, 6.
• The use of corticosteroids, such as methylprednisolone pulse therapy, may be beneficial in specific populations, including high-risk patients or those who fail to respond to IVIG 4.
• Aspirin is also used in the treatment of Kawasaki disease, although the evidence base is less secure, and high-dose ASA (> 30 mg/kg/day) has no clear benefit over antiplatelet doses in improving coronary outcome 5, 6.