Practice Essentials
Kawasaki disease (KD), also known as mucocutaneous lymph node syndrome and Kawasaki syndrome, is an acute febrile illness of early childhood characterized by vasculitis of the medium-sized arteries. Given its predilection for the coronary arteries, there is a potential for the development of coronary artery aneurysms (CAAs) and thus sudden death. CAAs develop in approximately 25% of untreated cases; appropriate treatment decreases this risk to 3-5%.
Echocardiography is the study of choice to evaluate for CAAs. KD is the leading cause of acquired heart disease in developed nations.
The incidence of KD in the continental United States is approximately 25/100,000 children under 5 years of age; in Japan, the incidence has been estimated at approximately 250/100,000 children < 5 years of age.
The etiology of this disorder remains unknown.
Diagnosis of Kawasaki disease
There are two forms of KD: complete and incomplete. Diagnosis of complete KD requires fever of at least 5 days’ duration along with 4 or 5 of the principal clinical features. The principal clinical features are as follows:
Extremity changes
Polymorphous rash
Oropharyngeal changes
Bilateral, nonexudative, limbic sparing, painless bulbar conjunctival injection
Acute unilateral nonpurulent cervical lymphadenopathy with lymph node diameter greater than 1.5 cm
The acronym “FEBRILE” is used to remember the criteria as follows:
Fever
Enanthem (mucous membrane rash)
Bulbar conjunctivitis
Rash
Internal organ involvement (not part of the criteria)
Lymphadenopathy
Extremity changes
Incomplete KD is diagnosed when a patient presents with fever for 5 days or longer, 2 or 3 of the principal clinical features, and laboratory findings suggestive of the disease or echocardiographic abnormalities. Suggestive laboratory findings include elevated erythrocyte sedimentation rate (ESR), elevated C-reactive protein (CRP), hypoalbuminemia, anemia, elevated alanine aminotransferase (ALT), thrombocytosis, leukocytosis, and pyuria. The American Heart Association (AHA) suggests an algorithm for the diagnosis of incomplete KD in the most recent guideline.
Echocardiography is the study of choice to evaluate for CAAs. Serial echocardiograms should be obtained as follows:
At the time of KD diagnosis
1-2 weeks after the onset of the illness
5-6 weeks after the onset of the illness
See Clinical Presentation and Workup for more details.
Management of Kawasaki disease
The principal goal of treatment is to prevent coronary artery disease. Intravenous immunoglobulin (IVIG), a purified preparation of gamma globulin, and aspirin are the mainstays of treatment. Patients should be treated with IVIG within 10 days after the onset of fever to prevent the development of cardiac sequelae.
Other medications that are used variably as adjunctive treatments or for IVIG-resistant KD include corticosteroids, infliximab, cyclophosphamide, methotrexate, and ulinastatin. In addition to aspirin, other anticoagulants are sometimes utilized, including clopidogrel, dipyridamole, warfarin, and heparin.
Guidelines
Clinical guidelines include the following:
See Treatment for more details.
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See Kawasaki Disease: Do You Know the Signs?, a Critical Images slideshow, for more information on the diagnosis and management of KD.
Video overview of Kawasaki disease pathophysiology, symptoms, diagnosis, and treatment.