Kawasaki Syndrome Treatment

by Food and Drug Administration (FDA)

Toddlers with fevers? Only about as common as sand on the beach. But for toddlers with Kawasaki syndrome, fever is just one of the early signs of a very serious illness.

Kawasaki disease, or Kawasaki syndrome, is an infectious inflammatory disease that affects mainly infants and young children. At first, the symptoms — fever, rash, watery eyes, swollen lymph nodes — look like those seen with many of the bugs kids pick up all the time.

But this is no simple bug. It affects many systems in youngsters' bodies, but damage to the heart and surrounding tissue is of the greatest concern. Left untreated, Kawasaki syndrome can damage the coronary arteries that feed the heart, possibly causing a massive heart attack. Recently, the Food and Drug Administration approved use of a previously licensed biologic, intravenous immune globulin — Immune Globulin Intravenous (Human) — to help minimize the complications of Kawasaki syndrome.

Although there have been rare reports of Kawasaki syndrome in adults, the disease primarily affects children under 5 years old, with most cases affecting 1- to 2-year-olds. The disease affects boys about 50 percent more often than girls, and seems to affect children of Asian descent at a much higher rate than children of African or European descent. "The typical patient would be a 2-year-old boy with high fever," says Stanford Shulman, M.D., Chief of Infectious Diseases at Children's Memorial Hospital in Chicago.

There have been three epidemics of the disease in Japan: in 1979, 1982 and 1986. According to surveys of those epidemics, 1 in 250 Japanese children with the disease died from it, and 15 to 20 percent developed heart aneurysms. These abnormal enlargements of blood vessels cause a weakening of the vessel that could burst at any time, threatening the patient's life.

Kawasaki syndrome is not considered contagious, although outbreaks tend to occur in certain geographic regions. The disease is most common in Asia, particularly in Japan and Korea. In the United States, the incidence in children of Japanese or Korean background is four times greater than in children of European background. This link puzzles researchers. The disease is more prevalent even in Asian children with little or no exposure to the foods or customs of Asian culture.

In Hawaii, the disease is far more common among Japanese-American children. While Japanese-Americans compose one-third of Hawaii's population, Japanese-American children account for 85 to 90 percent of the cases of Kawasaki syndrome in that state. Most of these children are third- or fourth-generation Americans with little or no Japanese cultural influence in their daily lives. These statistics appear to indicate a genetic factor that researchers are not yet able to explain.

The disease was first described by Tomisaku Kawasaki, M.D., a Tokyo pediatrician, in 1967, but wasn't reported in English literature until 1974. Fever develops within the first few days of onset of the disease. Many Kawasaki patients experience abrupt spikes in temperature — several spikes a day for five or more days — as the disease begins. Left untreated, the spiking can continue for as long as four weeks.

A measles-like rash usually accompanies the fever, and lymph nodes in the neck swell. Conjunctivitis, characterized by red eyes and swollen eyelids, may also develop in the first few days. The lips, tongue and throat may become red and swollen. One of the most distinguishing symptoms of Kawasaki disease is the redness and swelling of palms and soles within a few days of onset. After a couple of weeks, the skin of the hands and feet begins to peel.

Diagnosis Critical

Early and accurate diagnosis is critical to successful treatment, as the disease can start to damage the heart after just one week of illness.

But diagnosis is difficult. One problem is that the symptoms don't always appear together. Some patients experience all of the symptoms, and some have only a few. Infants are less likely than toddlers to have all symptoms.

Fever and swollen glands are a source of concern for any parent, but "cardiac involvement is the only long-term issue in Kawasaki disease," says Shulman, "It's the only thing of real importance."

The acute phase of Kawasaki syndrome is followed by a convalescent stage, which can be misleading. Often patients' families see improvement, even without treatment. Fever is reduced — sometimes temperature even returns to normal — skin redness subsides, and skin begins to peel.

"The worrisome thing [during this stage]," says Shulman, "is that in those children who are destined to develop heart involvement, this is the period of time it begins to show up."

According to a study by the Division of Pediatric Cardiology of Columbia University's College of Physicians and Surgeons, 25 percent of Kawasaki patients show some signs of heart inflammation — such as fast or irregular heartbeat — during this stage. Heart inflammation is a warning sign indicating the possibility of damage to the cardiovascular system. Although heart inflammation may subside over time, aneurysms, permanent and sometimes life-threatening dilations of blood vessels, may occur.

"The peak size of an aneurysm is typically reached three to four weeks after the onset of fever," says Jane Newburger, M.D., a pediatric cardiologist with Children's Hospital in Boston. This makes it important to monitor Kawasaki patients carefully. Once an aneurysm has formed, there is no guarantee that the damage can be reversed. However, treatment is aimed at preventing the formation of aneurysms.

The damage from Kawasaki disease is thought to start with an inappropriate immune response. Children with the disease produce an unusually large number of immune cells. The immune cells go haywire and begin to attack artery walls.

Once the artery wall is damaged, it becomes a dam where platelets can form a blood clot. This clot, combined with the damage to the artery wall, further enlarges the artery, causing an aneurysm. Once this happens, blood flow is severely restricted, and a heart attack is possible.

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