What are the clinical characteristics, diagnosis, and treatment of Kawasaki disease?

From the Guidelines

Kawasaki disease is an acute, self-limited vasculitis primarily affecting young children under 5 years of age, characterized by fever, rash, conjunctival injection, changes in extremities, oral mucosal changes, and cervical lymphadenopathy. Diagnosis requires fever for at least 5 days plus at least four of these five principal clinical features, or fewer features with coronary artery abnormalities detected by echocardiography, as stated in the 2017 American Heart Association guidelines 1. The clinical characteristics of Kawasaki disease include:

• Fever for at least 5 days
• Bilateral nonexudative conjunctivitis
• Erythema of the lips and oral mucosa
• Changes in the extremities
• Rash
• Cervical lymphadenopathy Laboratory findings typically include elevated inflammatory markers (ESR, CRP), thrombocytosis, anemia, hypoalbuminemia, and elevated liver enzymes. The standard treatment consists of high-dose intravenous immunoglobulin (IVIG) at 2g/kg as a single infusion, administered within 10 days of fever onset to reduce the risk of coronary artery aneurysms, as recommended by the American Heart Association 1. Aspirin is also given, initially at high doses (80-100mg/kg/day divided into four doses) during the acute phase for anti-inflammatory effects, then reduced to low-dose (3-5mg/kg/day) for antiplatelet effects once fever resolves. For IVIG-resistant cases (10-20% of patients), a second IVIG dose, corticosteroids (typically methylprednisolone 30mg/kg/day for 1-3 days), or biologics like infliximab (5mg/kg) may be used, as suggested by the 2004 American Heart Association statement 1. Cardiac monitoring with echocardiography is essential at diagnosis, 1-2 weeks later, and 4-6 weeks after treatment. Long-term management depends on the degree of coronary involvement, with some patients requiring extended antiplatelet therapy and cardiac follow-up, as outlined in the 2017 American Heart Association guidelines 1. Early diagnosis and prompt treatment significantly reduce the risk of coronary complications, which are the major cause of morbidity and mortality in this disease, as emphasized by the American Heart Association 1.

From the Research

Clinical Characteristics of Kawasaki Disease

• Kawasaki disease is an acute, systemic vasculitis that predominantly affects patients younger than five years 2
• The disease is characterized by fever, bilateral nonexudative conjunctivitis, erythema of the lips and oral mucosa, changes in the extremities, rash, and cervical lymphadenopathy 3, 4
• Classic (typical) Kawasaki disease is diagnosed based on the presence of a fever lasting five or more days, accompanied by four out of five findings: bilateral conjunctival injection, oral changes, cervical lymphadenopathy, extremity changes, and polymorphous rash 2
• Incomplete (atypical) Kawasaki disease occurs in persons with fever lasting five or more days and with two or three of these findings 2

Diagnosis of Kawasaki Disease

• Kawasaki disease is a clinical diagnosis, with diagnosis based on clinical criteria that include fever, exanthema, conjunctivitis, changes in the extremities, erythema of oral mucosa and lips and cervical lymphadenopathy 5
• Transthoracic echocardiography is the diagnostic imaging modality of choice to screen for coronary aneurysms 2
• Other clinical and laboratory features may be helpful in establishing the diagnosis, especially for cases of atypical or incomplete Kawasaki disease 5

Treatment of Kawasaki Disease

• Treatment for acute disease is intravenous immunoglobulin and aspirin 2
• If there is no response to treatment, patients are given a second dose of intravenous immunoglobulin with or without corticosteroids or other adjunctive treatments 2
• The development of a diagnostic test, a more specific therapy, and ultimately the prevention of this potentially fatal illness in children are all dependent upon the continued advances in determining the etiopathogenesis of this fascinating disorder 4

Complications of Kawasaki Disease

• Coronary artery aneurysms or ectasia develop in approximately 15 to 25% of untreated children with the disease and may lead to myocardial infarction, sudden death, or ischemic heart disease 3, 4
• The presence and severity of coronary aneurysms and obstruction at diagnosis determine treatment options and the need, periodicity, and intensity of long-term cardiovascular monitoring for potential atherosclerosis 2