Background: Kawasaki is an uncommon febrile illness in young children. The cause is unknown. It is considered a generalized vasculitis (inflammation of the blood vessels). Blood vessel function is usually impaired and arteries may become swollen (aneurysm). This can be particularly dangerous because it can involve the coronary arteries, which supply oxygenated blood to the heart muscle. Coronary aneurysms are reported in up to 25% of untreated children and only 3-5% of those who receive treatment. Kawasaki is the leading cause of acquired heart disease in children. It occurs in about 20 out of every 100,000 children in the United States. It is most common among children of Asian descent. The first manifestation of the disease is a fever of at least five days duration together with three or four of the following findings:
Skin Rash. The rash is usually raised and bright red. In most patients the rash is on the trunk of the body and may involve the genitalia. It may be confused with scarlet fever.
Swelling of lymph nodes in the neck Swollen tongue with a white coating and big red bumps (“strawberry tongue”) or red, dry, cracked lips.
Swelling of the hands and/or feet.
Many patients are irritable and may complain of a headache.
The second phase usually begins 10-14 days after the onset of fever. The skin on the fingers, hands and feet may begin to peel off in large pieces.
The child may experience joint pain, diarrhea, vomiting or abdominal pain. In addition, to the coronary arteries, the heart muscle, valves and outer sac can become inflamed. Some patients may develop arrhythmias and even heart failure.
Heart involvement is usually the most serious complication resulting in coronary aneurysm, heart infarction, arrhythmia and leaky and/or stenotic heart valves. Other complications include aseptic meningitis, pneumonia, urethritis, liver dysfunction, gangrene, otitis, hepatitis or inflammation of the gallbladder.
The outlook of the affected child is primarily determined by the seriousness of the heart involvement.
The more severe cases of Kawasaki may end up requiring cardiac catheterization, stress testing and nuclear imaging. Several blood and urine tests are indicated. Patients with abdominal pain may require an ultrasound. A spinal tap is usually not performed.
Kawasaki disease is treated with gamma-globulin (IVIG) and aspirin. Patients with persistent joint pains are treated with anti-inflammatory drugs. Plasmapheresis has been used in some centers. Steroids are rarely used. Patients with large coronary aneurysms will require anticoagulation.
What is the outlook for affected children?
The acute findings are usually resolved in 4-8 weeks unless there is damage to the coronary arteries or any other serious complications. Rarely Kawasaki can cause a heart attack, heart failure, blood clots and even death. It has been found that patients who had inflammation of the coronary arteries may have chronic impairment of coronary function (abnormal relaxation).
Many patients who had Kawasaki disease are being followed for several years. Those children with permanent heart damage usually require lifetime follow-up and cardiology care.