Kawasaki disease is an acquired heart disease affecting children mostly in the United States and other developed countries. Also known as lymph node syndrome, this disease strikes 80% of children below five years old. It can cause heart abnormalities such as aneurysms and may lead to thrombosis and stenosis and even death. The major cause of death from this disease is heart attack (myocardial infarction). It is still unknown, though, what causes Kawasaki disease but medical experts are pointing to a microbial agent.
Kawasaki disease was first discovered in 1967 and was identified as “mucocutaneous lymph node syndrome.” It first appeared in 50 Japanese children who developed an unusual illness with fever, rashes, conjunctival injection, cervical lymphadenitis, inflammation of the lips and oral cavity as well as redness and swelling of the hands and feet. This disease was later found to have caused the death of several Japanese children mostly under two years old.
An article by Doctors Kathryn Taubert and Stanford Shulman, in collaboration with the American Heart Association, said that Kawasaki disease has been reported worldwide with boys more often affected. It revealed that although the disease occurs anytime of the year, more cases are reported during winter and spring. In North America, children of Asian blood, notably Japanese and Korean, are those mostly affected. In Japan, 116,848 children have contracted the disease based on 12 surveys conducted from 1970 to 1992.
The initial symptom of Kawasaki disease is high fever persisting for five days or longer. Apart from this, major features of this disease that parents should look out for include changes in extremities, skin eruptions or rashes following fever, changes in lips and oral cavity (red tongue, red and cracking lips), blood shot eyes (conjunctival injection) and enlargement of the lymph nodes.
Changes in the extremities include redness and swelling of the hands and feet. When the fever subsides after one to three weeks, there’s desquamation of the fingers and toes while white lines across the fingernails called Beau’s lines may appear after one to two months.
Skin eruptions or rashes on the trunk and extremities appear usually five days after the start of fever. These may come in the form of urticarial exanthema, a morbilliform maculopapular eruption or a diffuse scarlatiniform rash.
The Japanese Disease Research Committee and the American Heart Association have come up with a clinical criteria in diagnosing Kawasaki disease. This was done due to the absence of a specific diagnostic test for this particular childhood disease. The criteria is divided into the principal clinical findings as well as other significant clinical and laboratory findings.
The principal clinical findings include fever and at least four of the five major features. The course of this disease is further divided into three clinical phases – acute, subacute and convalescent. During the acute phase, which lasts from one to two weeks, the patient experiences fever, very red eyes (conjunctival injection), mouth and lip changes, swelling of extremities, rash and enlargement of cervical lymph nodes. In the subacute phase, covering the time the fever ended until day 25, patients may develop arthritis, arthralgia and thrombocytosis. The convalescent phase starts normally six to eight weeks after the onset of Kawasaki disease when clinical symptoms have disappeared. The chronic phase, on the other hand, is significant only in patients who have developed heart problems. The duration may be lifetime because those who experienced heart aneurysm in childhood may also experience it in adulthood.
Meanwhile, findings not found in the major clinical criteria are classified into the cardiac, non-cardiac and laboratory categories. The cardiac findings refer to the heart problems that may occur during the acute phase. These heart manifestations include artery abnormalities, inflammation, a gallop heart rhythm, aneurysms, thrombosis, stenosis or even congestive heart failure. Non-cardiac symptoms that appear during the first two to three weeks of the disease include irritability among infants and children, arthritis and arthralgia affecting the knees, ankles and hips, diarrhea, vomiting, stomach pain and pneumonitis. On the other hand, the laboratory findings do not necessarily point to Kawasaki disease but may only help in establishing the diagnosis. These are usually seen during the first two weeks of the illness but normalize within six to eight weeks. They include mild anemia, high neutrophil, albumin and serum immunoglobulin E levels, thrombocytosis and proteinuria
Tests and treatment
An echocardiogram (ECHO) is normally done to check the patient’s heart condition and for possible aneurysm. A baseline ECHO is necessary during the acute stage and must be repeated in the second and third week and after one month when all other laboratory results have returned to normal. A chest radiograph should also be made to check baseline findings and to determine suspicions of congestive heart failure. If liver or gallbladder dysfunctions are seen, an ultrasound will be prescribed. Other tests that may be done include electrocardiogram (ECG), spiral computed tomography (CT) and electron beam computed tomography (EBCT).
In treating Kawasaki disease, the doctor may prescribe aspirin for the child patient usually in higher doses for a high fever. A lower dose might be given for several more weeks to lessen the risk of heart problems. But apart from lowering fever, aspirin may also help lessen the rash and joint pain as well as in making blood clots. The American Heart Association recommends that aspirin therapy be discontinued only after six to eight weeks if echocardiograms show no evidence of heart problems. However, if the patient develops a flu or chicken pox during the illness, the aspirin should be stopped to reduce the chance of getting another disease like the Reye’s syndrome.
A very important medication given within the first ten days of the start of the illness is the immunoglobulin. Administered intravenously for several hours in the hospital, the immunoglobulin helps prevent heart abnormalities.