Kawasaki Disease

Kawasaki disease is a rare disease that mainly affects children. It is also known as mucocutaneous lymph node syndrome. In developed countries, it is the commonest cause of acquired heart disease in children.

About 85 percent of the people with Kawasaki disease are under age five, most commonly between the ages of 18 and 24 months. The disease occurs more often in boys (60 percent) and among those of Asian descent. However, it can occur in every racial and ethnic group. In the UK, Kawasaki disease affects around 8 out of every 100,000 children under the age of 5 years every year.

What happens to those with Kawasaki disease?

The symptoms of Kawasaki disease include:

  • fever
  • rash
  • swollen hands and feet
  • peeling skin on the fingers and toes
  • red eyes
  • swollen lymph glands in the neck
  • red lips, tongue and throat

What causes the disease?

The cause of Kawasaki disease remains unknown, but it is not thought to be contagious. The evidence suggests it is triggered by an infectious agent such as a bacteria or virus, which then causes ‘over-activation’ of the immune system. There is a possibility that certain genes may increase a child’s chance of developing Kawasaki disease.

How does it affect the heart?

The heart is affected in 15 to 25 percent of children with Kawasaki disease, if left untreated. The coronary arteries (blood vessels) are particularly affected. Part of the blood vessel wall can be weakened and bulge out (aneurysm). A blood clot can form in this weakened area and block the artery, sometimes leading to a heart attack. The aneurysm can also burst, but this rarely happens.

Other changes include inflammation of the heart muscle (myocarditis) or the sac surrounding the heart (pericarditis). Arrhythmias (abnormal heart rhythms) or abnormal functioning of some heart valves can also occur.

What tests for Kawasaki disease?

An electrocardiogram (ECG) is used to detect any heart rhythm abnormalities and an echocardiogram (‘echo’) can identify possible damage to the coronary arteries or heart muscle. Blood tests are also done to monitor the ‘inflammation levels’ and assess the response to treatment.

What are the treatments?

Even though the cause of Kawasaki disease is unknown, certain medicines are known to help. Aspirin is often used to reduce fever, rash, joint inflammation and pain, and to help prevent blood clots from forming. Another medicine, intravenous immunoglobulin (IVIG), can decrease the risk of developing coronary artery abnormalities when given early in the illness. Steroids may also be useful in selected cases that do not respond to initial treatment.

Usually all the heart problems go away in six to eight weeks and there is no lasting damage. Repeat echocardiograms over several weeks will need to be performed to assess the resolution of any coronary artery or heart muscle damage. However, sometimes the coronary artery damage can persist and will requiring longer term follow-up and treatment.