Kawasaki disease is an acute form vasculitis (a disorder involving inflammation of one or more blood vessels) that typically affects young children. Most often, patients are age three or younger. After 10 years of age, Kawasaki disease is extremely rare, and any diagnosis of the condition should be treated with skepticism.
The etiology (origin) of Kawasaki disease is unknown. There have been many theories, but there are none that are generally accepted. It is not contagious, although there are a few cases where two or more siblings in a family developed the disease. In rare cases, children have had two episodes of Kawasaki. The disease often occurs in epidemics that occur every few years.
The disease usually begins with a fever that is unresponsive to acetaminophen (Tylenol) or aspirin, and which continues for at least 7-10 days. Many – but not all – children develop a swollen area on the neck which looks like an infection. Doctors usually recognize the disease when they see:
The most important part of Kawasaki disease is its tendency to cause inflammation of the coronary arteries, which supply blood to the heart. Changes can be found on echocardiogram in about 15% of patients. A few of these patients will have aneurysms (balloon-like dilatations) that can be very serious. If one of the aneurysms becomes blocked or bursts, the blood flow to the heart is interrupted and the child can have a heart attack. Fortunately, this is very rare, and deaths due to Kawasaki disease are less than 5/1000.
The treatment for Kawasaki disease is intravenous (IV) gammaglobulin. Large doses of intravenous gammaglobulin are usually very effective in stopping the fever of Kawasaki disease and seem to limit or prevent aneurysm formation as well. It is very rare for a child not to improve with gammaglobulin. Although some children require two treatments, if there is no improvement, the diagnosis should be reconsidered.
Other diseases, which may require different therapies, can be confused with Kawasaki disease Some doctors are reluctant to give gammaglobulin if the symptoms have been present for more than 10 days. In truth, gammaglobulin is still effective after the first 10 days, but the likelihood of preventing aneurysms is lower than if it is given during the first 10 days. Recent studies have shown that corticosteroids are effective for many of the children who fail to respond appropriately to gammaglobulin.
Once the acute inflammation is brought under control, the chronic symptoms of Kawasaki disease are usually controlled with nonsteroidal anti-inflammatory drugs like naproxen or ibuprofen. Many cardiologists and some rheumatologists still use aspirin, but the other nonsteroidal drugs are considered safer, easier to give, and equally effective.
Usually, children recover completely with proper therapy. There is some concern that children with damaged coronary arteries will have problems later in life, but this seems to be very rare. If your child has Kawasaki disease, he or she will need to be treated and monitored by a team that includes a primary care physician, a cardiologist, and perhaps a rheumatologist or other specialist (depending on the symptoms).
The vast majority of children with Kawasaki disease recover and resume normal lives. Your doctor should be able to tell you if there is any reason to be unusually concerned. If your child has not recovered appropriately after an episode of Kawasaki disease, it is important to be sure that the diagnosis was correct and that another disease requiring different therapies has not been missed. A pediatric rheumatologist is the specialist best able to do this.