Kawasaki Disease

Kawasaki Disease General Information

Kawasaki Disease is a vasculitis (defined as a presence of inflammation in the lining of the blood vessels). This is an acute systemic disorder, which can develop into dilatations (aneurysms) that mainly affect the individual’s coronary arteries (the vessels that carry blood to the heart). However, all children with this disease do not develop aneurysms. The majority of affected children will have symptoms that will not evolve to acute complications. This disease is almost exclusively a disorder of young children. About 80 out of 100 patients are under the age of 5 years. The disease is slightly more common among boys than girls. Although cases of Kawasaki Disease can be diagnosed throughout the year, there are some seasonal variations, with an increase in the number of cases at the end of the winter and spring. It is a much more common disease among Japanese children, but cases have been reported around the world.

The cause of this disease remains unclear even if physicians suspect that it is triggered by an infection. Hypersensitivity or an abnormal immune response, probably spurred by an infectious agent (bacteria or viruses) could easily initiate an inflammatory process that might lead to inflammation and damage to blood vessels. Scientists have proven that some individuals are genetically predisposed to this disorder, even if the Kawasaki Disease is not a hereditary medical condition. It is very rare to see more than one family member who is affected by this disease. In addition, the disorder is not contagious and can not be prevented. It is possible, but very rare, to experience a second episode of this disease.

Kawasaki Disease Symptoms

Kawasaki Disease Treatment

A child with a suspected or confirmed diagnosis of Kawasaki Disease should be hospitalized for observation and evaluation of a possible heart attack. To reduce cardiac complications, treatment should be started as soon as the diagnosis has been made. The treatment consists in the intake of aspirin and the administration of intravenous immunoglobulin, both in high doses. Both therapies will reduce systemic inflammation, obliterating acute symptoms. The high doses of immunoglobulin are an essential part of the treatment because they are able to prevent the development of coronary abnormalities in a high proportion of patients. Some corticosteroids may also be indicated, but less frequently. The immunoglobulin treatment is generally well tolerated. As it is well known, a treatment with aspirin may lead to an intolerance of the stomach, and to a temporary increase in liver enzymes. The high-dose immunoglobulin is normally given only once, but sometimes a second dose is needed.

A high dose of aspirin is given at the beginning, as the fever persists, and then the dosage may be reduced. Low doses of aspirin are prescribed in the future as such a therapy can also trigger unpleasant reactions due to the drug’s anticoagulant effect – it affects the platelets that do not stick together as they should any more. Thus, a therapy with aspirin is helpful to prevent the formation of clots in the aneurysms, since the formation of clots in aneurysms can lead to cardiac infarction, the most dangerous complication of Kawasaki Disease. A child without coronary attack will receive aspirin for a few weeks, but a child with aneurysms should receive this drug for a longer period. There is no place for non-conventional treatments for this disease. Patients with Kawasaki Disease should undergo periodic evaluations of the blood and the speed of sedimentation until the values returning to normal.

Repeated cardiac ultrasounds are needed to evaluate the presence of coronary artery aneurysms, and to follow their evolution; the frequency with which these examinations must be carried on depends on the presence and size of these aneurysms. Most of these aneurysms have a regress spontaneously. The pediatrician, pediatric cardiologist and pediatrician rheumatologist can handle the monitoring of these children. In places where there are no pediatric cardiologists available, the pediatrician will have to send these patients with the adult cardiologist, especially if they present a heart attack. Kawasaki Disease takes place in 3 stages: 1) acute, which includes the first 2 weeks when the fever and other symptoms are present, 2) sub-acute, the 2nd to the 4th week, during which the platelet increases and aneurysms can occur, 3) the recovery phase, that last from the 1st month until the 3rd month, when all laboratory tests return normal. For the majority of patients, the prognosis is excellent, and they will have a normal life with normal growth and development. The prognosis of patients with an abnormality of the coronary arteries depends mainly on the development of stenosis (narrowing) and occlusions (decrease in the size of the vessel due to clot formation within the vessel). It is recommended not to immunize these patients for at least 3 to 6 months, since the disease and the immunoglobulin treatment affects the immune system, and this effect can last up to 6 months. Children who have not developed cardiac disorders have no restriction for sports, or any other activity of daily life. However, children with coronary aneurysms should consult a pediatric cardiologist before participating in competitive activity during adolescence.