Kawasaki disease is a rare childhood disease. It's a form of a condition called vasculitis. This condition involves inflammation of the blood vessels.
In Kawasaki disease, the walls of the blood vessels throughout the body become inflamed. The disease can affect any type of blood vessel in the body, including the arteries, veins, and capillaries.
Sometimes Kawasaki disease affects the coronary arteries, which carry oxygen-rich blood to the heart. As a result, some children who have Kawasaki disease may develop serious heart problems.
Like all autoimmune diseases, the cause of Kawasaki disease is presumably the interaction of genetic and environmental factors, possibly including an infection. The specific cause is unknown, but current theories center primarily on immunologicalcauses for the disease. Evidence increasingly points to an infectious etiology but debate continues on whether the cause is a conventional antigenic substance or a superantigen. Superantigen (An antigen of viral or bacterial origin? an unconventional protein leads to massive T cell activation leads to cytokines production, Ab against endothelial cell ligands.
An association has been identified with a SNP in the ITPKC gene, which codes an enzyme that negatively regulatesT-cell activation. An additional factor that suggests genetic susceptibility is the fact that regardless of where they are living, Japanese children are more likely than other children to contract the disease. The HLA-B51 serotype has been found to be associated with endemic instances of the disease.
The following may be considered as risk factors for Kawasaki disease:
Age - children aged from 2 to 5 years have a higher risk of developing the disease compared to humans of other ages.
Boys - boys are more likely than girls to develop Kawasaki disease.
Ethnic background - people of Asian ancestry, specifically Japanese or Chinese, are more likely to develop Kawasaki disease compared to other people.
Kawasaki disease symptoms appear in phases.
First phase Signs and symptoms of the first phase may include:
Fever, which often is higher than 101.3 F (38.5 C) and lasts one to two weeks
Extremely red eyes (conjunctivitis) without a thick discharge
A rash on the main part of the body (trunk) and in the genital area
Red, dry, cracked lips and an extremely red, swollen tongue ("strawberry" tongue)
Swollen, red skin on the palms of the hands and the soles of the feet
Swollen lymph nodes in the neck and perhaps elsewhere
In the second phase of the disease, your child may develop:
Peeling of the skin on the hands and feet, especially the tips of the fingers and toes, often in large sheets
Third phase In the third phase of the disease, signs and symptoms slowly go away unless complications develop. It may be as long as eight weeks before energy levels seem normal again.
No tests specifically diagnose Kawasaki disease. The diagnosis is usually made based on the patient having most of the classic symptoms.
However, some children may have a fever lasting more than 5 days, but not all of the classic symptoms of the disease. These children may be diagnosed with atypical Kawasaki disease. Therefore, all children with fever lasting more than 5 days should be evaluated, with Kawasaki disease considered as a possibility. Early treatment is essential for those who do have the disease.
The following tests may be performed:
Complete blood count
C-reactive protein (CRP)
Urinalysis - may show pus in the urine or protein in the urine
Procedures such as ECG and echocardiography may reveal signs of myocarditis, pericarditis, arthritis, aseptic meningitis, and inflammation of the coronary arteries.
Kawasaki disease is frequently treated in the hospital, with a stay from a few days to a few weeks. Some children may receive care at home without hospitalization.
Even though the cause of Kawasaki disease is unknown, specific medications are known to be beneficial. Aspirin is used to reduce fever, rash, joint inflammation, and pain, and to prevent formation of blood clots. Recent studies indicate that another medication, intravenous gamma globulin, decreases the risk of developing heart disease when given early in the illness. A major goal of treatment both in the hospital and at home is to make a child as comfortable as possible while the illness runs its course.
If tests reveal an aneurysm or other heart or blood vessel abnormality, repeated echocardiograms or other tests may be necessary for several years following recovery from Kawasaki disease. Almost all children return to completely normal activity after the acute phase of the illness.
Even if there is no evidence of a heart abnormality when your child recovers from the acute phase of Kawasaki disease, it is important to bring your child in for a follow-up visit with your doctor to be sure that there aren't heart problems that did not show up right away.
Without treatment, about 1 in 5 children who have Kawasaki disease develops inflammation of the blood vessels to the heart (coronary arteries). This can cause a swelling of a section of an artery which is called an aneurysm.
A coronary artery aneurysm usually causes no symptoms. Over time it often goes away and the artery returns to normal. However, the wall of an aneurysm is weakened and abnormal. Serious problems may develop in some children with an aneurysm. The most serious is that a thrombosis (clot) may develop in the aneurysm and damage the heart (a heart attack). About 1 in 100 children with Kawasaki disease die of heart problems.
An aneurysm can be detected by a heart scan (an echocardiogram). If an aneurysm does occur, it starts to develop a week or more after the fever and other acute symptoms begin. Treatment within 10 days of symptoms starting often prevents this complication. This is why it is important to diagnose and treat Kawasaki disease in the early stages of the illness.
The aneurysm of a coronary artery is caused by inflammation of the artery (a 'vasculitis'). This can occur in other arteries in various parts of the body - but is very rare. Various other rare problems have also been reported in some children with Kawasaki disease.
Kawasaki disease cannot be prevented but if it is diagnosed and treated promptly, most children will make a full recovery within six-to-eight weeks. If your child has a fever that lasts more than four days, contact your child's doctor. Or, see your child's doctor if your child has a fever along with four or more of the following signs and symptoms:
Redness in both eyes
A very red, swollen tongue
Redness of the palms or soles
Swollen lymph nodes
Treating Kawasaki disease within 10 days of its onset may greatly reduce the chances of lasting damage.Patients who have had Kawasaki disease should have an echocardiogram every 1 - 2 years to screen for heart problems.