Kawasaki Disease

Kawasaki disease usually occurs in babies and children who are younger than five years old. The condition was first described in Japan in the late 1960s.

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Symptoms

Signs of Kawasaki disease develop in stages beginning with:

  • A fever of more than 102 degrees, lasting a week or two without treatment
  • Irritability
  • Occasional lethargy or listlessness
  • Stomach pain that comes and goes

A day or two after the fever appears, the membranes that cover the eyes and the eyelids become red, swollen and tender but there is no discharge from the eyes.

Within five days, red, flushed spots appear - usually on the trunk. These spots can resemble hives, measles or scarlet fever. There may be congestion in the throat; the lips become red, dry and cracked and the tongue becomes a strawberry red color. During this time, the palms of the hands and soles of the feet turn purple-red and may swell. The base of the fingernails and toenails may become white spotted or streaked.

Within 10 days, the skin of the palms, the soles of the feet and around the finger and toenails may begin to peel off in sheets that retain the shape of the body after they peel away. Tender, swollen lymph nodes in the neck appear in about half the patients with Kawasaki disease. The illness can last two to more than 12 weeks.

More general symptoms may include:

  • Arthritis or pain in the large joints
  • Diarrhea
  • Swelling and tenderness of the urethra, the tube that carries urine from the bladder outside the body
  • Swelling of the gallbladder from fluid, and
  • Swelling of the membrane that cover the brain without an infection being present

Kawasaki disease can lead to life-threatening complications including:

  • Swelling and tenderness of the middle layer of the heart's muscle (acute myocarditis)
  • Arteries that enlarge and develop weak spots. The pressure of the blood moving through the vessels can cause the weak areas to balloon out (aneurysms)
  • Heart failure
  • Irregular heart rhythms (arrhythmias)
  • Swelling and tenderness of the membrane that covers the heart (pericarditis)
  • Swelling and inflammation of the heart and the arteries of the heart

Causes and Risk Factors

It is not yet known what causes this disease. It may be an infection or an abnormal response by the body to an infection. While it affects many racial and ethnic groups, persons of Japanese descent are most likely to develop this condition. Eight out of 10 children with this disease develop it before the age of five. Slightly more boys than girls develop Kawasaki disease.

Cases of Kawasaki disease can develop at any time of the year, but most often appear in the spring or winter. The disease sometimes appears in clusters in a community, although it is not clear how it might spread from one person to another.

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Diagnosis

A doctor will do a physical examination and tests to rule out other conditions. Because the condition affects different organs, a variety of tests may be needed. The doctor may order:

  • Blood tests to rule out infections, to uncover anemia (iron poor blood) if it exists. A person with Kawasaki disease may have a high white blood cell count, often with many immature white blood cells, especially in the acute stage of the illness
  • Coronary arteriography
  • Echocardiograms
  • Electrocardiograms to check for abnormalities in the electrical system that normally causes the heart to beat in a regular rhythm
  • Stress tests
  • Urine tests

A doctor will seek to rule out scarlet fever or measles, blood poisoning, mercury poison or juvenile rheumatoid arthritis, among others.

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Treatments

A team of doctors including an experienced pediatric cardiologist or pediatric infectious disease specialist should be involved in treating a child with Kawasaki disease as well as a rheumatologist.

Treatment should be started as soon as possible, ideally within 10 days after the first symptoms appear. Aspirin should be given to reduce the fever and high-dose shots of immune globulin. Most patients respond quickly - within 24 hours of treatment.

Aspirin therapy may be continued for at least eight weeks until repeated echocardiograms show that there are no signs of artery aneurysms or inflammation. If there are abnormalities of the coronary arteries, the child may need to take aspirin indefinitely. If a large aneurysm of the coronary arteries is present, more intense therapy to prevent the blood from clotting may be needed. This might include prescribing coumadin or other anticoagulant.

Special care is needed for children who are taking aspirin on a long-term basis. Should they develop symptoms of flu, a pediatrician should be called immediately to avoid the small risk of developing Reye's syndrome.

It may be necessary to use a different drug until the child no longer has the flu symptoms. Children who are on aspirin therapy for Kawasaki disease should receive an influenza vaccination each year.

Because of the high doses of immune globulin given, a child may be less responsive to vaccinations made up of live vaccines. Childhood vaccinations should be delayed until the effects of the immune globulin have worn off.