(Kawasaki Syndrome · KD)
In this condition factsheet:
The Facts on Kawasaki Disease
Kawasaki disease, also called Kawasaki syndrome, is the leading cause of acquired heart disease in children in the developed world. It usually appears in children under 5 years old. If left untreated, it can result in the formation of a coronary artery aneurysm in up to 25% of cases. With treatment, this complication rate is reduced to about 2%.
Kawasaki disease was first diagnosed in Japan in the 1960s. It can occur in people of any race or ethnic origin, although it is still most common in Japan. It affects mostly children 5 years old and under, although children of any age can get it. Boys are twice as likely to get the disease as girls.
In Canada, about 13 in every 100,000 children under the age of 5 years are diagnosed with Kawasaki disease every year.
Causes of Kawasaki Disease
Doctors don't know what causes the disease. They believe a virus or some other kind of infection may be responsible for causing the body to mount an "overzealous" immune response, leading to the inflammation of a child's blood vessels (vasculitis) and causing the signs and symptoms of Kawasaki disease.
Symptoms and Complications of Kawasaki Disease
The disease starts with a fever, usually over 38.9°C (102°F). A child with Kawasaki disease also gets irritable and feels sleepy. Sometimes, children have abdominal cramps. After a few days, they also get a rash that can appear anywhere. The rash does not have a specific pattern and may only last a short while. The white part of the eyes get red (conjunctivitis), although there's no discharge. They may also have cracked, dry, reddened lips and a red tongue with enlarged bumps (papillae) that can look a bit like a strawberry. Their hands and feet often swell and become red or purplish-red. Peeling may also occur, especially on the fingers and toes (usually at the top of the nail). Often, some lymph nodes (especially in the neck) become swollen.
Kawasaki disease is dangerous because up to 20% of children with the condition develop complications involving the heart, though this very rarely includes heart attack and sudden death. Complications include abnormal widening (dilation) of the coronary arteries, aneurysm (a bulge in a blood vessel), pericarditis (inflammation of the sac around the heart muscle), and myocarditis (inflammation of the heart muscle itself).
Other complications include inflammation of the tissues around the brain (meninges), the joints, and the gallbladder. The interior of the eye can also get inflamed. All of these other complications usually settle and don't leave any permanent damage.