Signs of Kawasaki disease develop in stages beginning with:
- A fever of more than 102 degrees, lasting a week or two without treatment
- 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
- 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.