Kawasaki Disease Program

Acute phase: The acute phase (rapid onset followed by a short, severe course) usually lasts five to 11 days, during which children have high fever and an array of other symptoms, which may include:

• swelling/redness of the hands and feet
• red cracked lips/strawberry tongue
• redness in the eyes
• a rash
• an enlarged lymph node

• irritability
• inflammation of the joints (arthritis)
• elevated white blood cell count
• elevated liver function tests
• signs of inflammation in the blood

Subacute phase: During the subacute phase (between acute and chronic), the fever goes down but the disease continues to affect other systems. A child may experience continued arthritis in the small or large joints, elevated platelet counts (a clotting factor), anemia and continued irritability.

Convalescent phase: In the convalescent phase (the gradual return to health and strength), most findings on physical examination have returned to normal, but blood work shows lingering inflammation.

Affected blood vessels reach their largest size approximately four to six weeks after the onset of fever. Blood flow through enlarged coronary arteries is sluggish, producing a tendency to form blood clots, which in turn can deprive the heart muscle of necessary oxygen. Over time, the body's response to injury of the blood vessel wall is for the cells lining the blood vessel to multiply (myointimal proliferation).

Sometimes such a "healing process" allows the inside dimension of the artery to return to normal, but very large or so-called giant aneurysms rarely shrink back to normal size. Instead, the process of myointimal proliferation may result in areas that are stiff and tight (stenoses), especially at the ends of the aneurysm(s).

Coronary artery stenoses or blockages place the child at risk for insufficient blood flow to the heart (myocardial ischemia) or a heart attack (myocardial infarction).

Although less common, aneurysms (so-called peripheral aneurysms) may also occur in other arteries, such as those supplying the arms, legs or kidneys. Peripheral aneurysms rarely cause symptoms and are generally seen only in those individuals who also have giant coronary aneurysms.