Kawasaki disease, also known as mucocutaneous lymph node syndrome, is a multisystem vasculitis that occurs in children. Minimally, it presents with mucocutaneous symptoms and fever, but it also may damage the coronary arteries and result in fatal myocardial infarction. Prompt treatment is imperative. Bradley and Glodé reviewed the identification and treatment of this disease.
The incidence of Kawasaki disease in Japan is about 100 per 100,000 children under five years of age — about 10 times of that in the United States. In North America, people of Asian and African descent are more likely to be diagnosed with the disease. Patients are usually under 10 years of age, with the peak age of occurrence at one year. The disease is more common and more commonly fatal in boys. Death occurs in about 0.5 percent of patients, most of whom are under three years of age.
The specific etiology of Kawasaki disease is uncertain. The high fevers and evidence of acute phase reactants on laboratory testing indicate an infectious etiology. No single agent has yet been identified. The clinical aspects of this disease mimic those of a toxin-mediated disease, as does the fact that intravenous immune globulin (IVIG), known to have neutralizing antibodies against several bacterial toxins, has improved symptoms in some patients.
The criteria for diagnosis are noted in the accompanying table. Fever, a blotchy exan-them, desquamation of the palms of the hands and the soles of the feet, ocular involvement and erythema of the oral mucosa are usually present. Adenitis occurs in two thirds of patients, along with a wide variety of systemic complaints and signs. Sinus tachycardia at rest occurs in most children. The three phases in the course of Kawasaki disease include: (1) the acute phase, consisting of approximately 10 days of fever, oral changes and lymphadenitis; (2) the subacute phase, during which fever and skin manifestations have resolved but irritability and conjunctival injection may continue; and (3) the convalescent phase, beginning at the end of clinical signs and concluding with the resolution of all serum abnormalities.
Characteristic laboratory findings include an elevated leukocyte count with a leftward shift, elevated platelet counts and greatly elevated erythrocyte sedimentation rate and C-reactive protein levels. Sterile pyuria and albuminuria may be noted early in the disease. Subtle electrocardiographic abnormalities may occur, including mild prolonged PR interval, T-wave flattening or inversion, and nonspecific ST segment changes.
Patients are generally admitted to the hospital for management. High-dose aspirin therapy reduces the fever and clinical symptoms and is continued, in reduced dosages, until all laboratory evidence of disease has resolved. IVIG is very helpful in reducing disease symptoms but has side effects, including fever, chills, hypotension and rare episodes of hemolytic anemia. All other treatments are considered investigational at present.
The best known complication of Kawasaki disease is formation of coronary artery aneurysm. Treatment with IVIG reduces the incidence of this complication. Myocardial infarction occurs in less than 0.5 percent of affected children. Other reported cardiac lesions include insufficiency of the aortic and mitral valves, myocardial dysfunction, conduction system inflammation and myocardial fibrosis.
The authors conclude that a definitive diagnostic test and a treatment for cases that are refractory to aspirin and IVIG are needed for Kawasaki disease.