The Health Gazette

Kawasaki Disease

Karl Hempel, M.D.

Introduction

Kawasaki disease was first described in Japan in 1967. It is a distinctive clinical illness that is characterized by fever, redness of the eyes, diffuse red rash, redness and swelling of the hands and feet, as well as enlarged non-tender lymph nodes in the neck. Kawasaki disease is now the leading cause of acquired heart disease in children in the United States. Rheumatic fever used to be the leading cause of acquired heart disease in children.

Epidemiology

Kawasaki disease occurs most frequently in children under five years of age. Twenty percent of cases involve children five years of age and older. The peak age is 18 to 24 months of age. Approximately 3,000 patients are hospitalized in the United States every year with Kawasaki disease. The incidence is higher in the late winter and spring.

Etiology

The cause of Kawasaki disease is unknown. Several clinical features suggest an infectious agent. An association between exposure to rug shampooing and Kawasaki disease has not been confirmed in recent studies. Another theory suggests that Kawasaki disease is a variant of toxic shock syndrome, but this has not been confirmed.

Symptoms

There are three phases of Kawasaki disease. The first phase is characterized by fever, pus in the urine, red eyes, intensely red tongue, dry fissured lips, rash, swollen hands and feet, enlarged lymph nodes and abnormal liver test.

The second phase is characterized by resolution of the fever, rash and enlarged lymph nodes, but the irritability and poor appetite may persist. The skin of the fingers and toes may begin to peel. Arthritis and heart problems may develop during this phase which lasts from day 10 until day 21. The heart problems are characterized by the development of weak areas in the coronary arteries. These weak areas may eventually lead to a heart attack.

The third phase is called the convalescent phase because the clinical signs begin to disappear and the laboratory values return to normal.

Diagnosis

There is no specific lab test that definitively diagnoses Kawasaki disease. The diagnosis is established by meeting certain criteria. The criteria are as follows:

The fever should have been present for at least five days.

Four of the following five conditions should also be met.

In addition, the illness cannot be explained by any known disease process. The strep screen should be negative. The liver tests may be abnormal.

The WBCs are frequently elevated with an increase in the ESR (sedimentation rate). Liver tests may be elevated. The urine may have pus in it but the culture will not grow bacteria. This is called sterile puree an occurs in 30% of patients.

Treatment

Antibiotics are given until a bacterial infection is excluded. Aspirin is started at a dose of 80-100 milligrams per kilogram per day. Intravenous immune globulin is given over a 12-hour period at two grams per kilogram. Preferably, the immune globulin should be given within the first 10 days of illness. This lowers the risk of cardiac complications. Since aspirin therapy is associated with Reyes syndrome, flu vaccine and chicken pox vaccine should be given if the child is placed on aspirin indefinitely. This is because chicken pox and the flu frequently proceed Reyes syndrome and are thought to contribute to the development of this illness. Corticosteroids should not be given because they may increase the incidence of aneurysm.

Complications

Twenty percent of untreated patients develop weak coronary arteries in the convalescent phase. Treatment with steroids is contraindicated because they increase the incidence of cardiac complications. The mortality rate is 0.5 percent. Twenty percent of untreated patients develop coronary artery aneurysms.

References