What is Kawasaki disease?

Kawasaki disease is a syndrome characterized by inflammation of blood vessels throughout the body. It usually affects infants and young children under 5 years of age.

Kawasaki disease is the leading cause of acquired heart disease in children. The disease was first described by a Japanese paediatrician, Dr. Tomisaku Kawasaki in 1967.

What causes Kawasaki disease?

The exact cause is unknown. It is believed that some sort of infection triggers the immune response of genetically susceptible individuals, but no causative agent has been identified to date.

Is Kawasaki disease contagious?

No. If a child gets Kawasaki disease, it is very unlikely for the siblings to get the illness.

What are symptoms and signs of Kawasaki disease?

The disease usually begins with a high fever which lasts for five days or more.

The other usual symptoms and signs of Kawasaki disease include:

• Red eyes (conjunctivitis) without discharge.
• Red, swollen, cracked lips.
• Red tongue or “strawberry” tongue.
• Red hands and feet with swelling followed by peeling.
• Rash all over the body.
• Swollen glands (lymph nodes) in the neck.

In addition to the above, some children especially younger ones may exhibit extreme irritability. Other diseases like measles, scarlet fever and viral infection may have similar symptoms and signs of Kawasaki disease.

What are the complications?

The most important complication of Kawasaki disease is inflammation of the arteries that supply blood to the heart leading to weakened blood vessels wall and widening (coronary aneurysms). Coronary aneurysms occur up to 25% of those with untreated Kawasaki disease.

Less common complications include inflammation of the lining of the heart (pericarditis), heart valve (valvulitis), joints (arthritis) and covering of the brain and spinal cord (meningitis).

Can the complication be prevented?

The risk of heart complications can be reduced significantly by early treatment.

What tests will a child with Kawasaki disease undergo?

There is no specific test to confirm Kawasaki disease. However, some tests are required to assist in diagnosis and to look for complications.

• Blood tests-to look for signs of anaemia (low red blood cell), raised markers of inflammation and raised platelet count (cell which helps in blood clot formation in blood vessels).
• ECG (electrocardiogram) –to look for any heart rhythm abnormalities.
• Echocardiogram (ultrasound scan of the heart)- to look for heart function and for widening or swelling in the blood vessels in the heart (coronary aneurysms).

What is the treatment for Kawasaki disease?

The treatment for Kawasaki disease is intravenous (given via a drip into a vein) immunoglobulin. It is extracted from pooled human blood and contains concentrated amounts of antibodies. This treatment has been shown to reduce the risk of developing coronary aneurysms, especially when given within 10 days of fever. A respond to treatment is often shown by resolution of fever. Some children with this illness may require more than one dose of immunoglobulin.

Kawasaki disease is also treated with high doses of aspirin (salicylic acid) to reduce inflammation. The dose of aspirin will be reduced once the fever or inflammation has subsided to prevent blood clot formation.

Some parents worry about the side-effects of immunoglobulin which is derived from blood products. It is important to understand that the risks of this are very low, yet the risks from untreated Kawasaki disease are high.

Live-attenuated vaccines such as measles-mumps-rubella (MMR) should be deferred for at least 6 months after a child has received intravenous immunoglobulin.

What is the outlook or long term outcome for children with Kawasaki disease?

Most children with Kawasaki disease resolves on its own after four to eight weeks. The outlook is excellent for those without coronary aneurysms. Most small coronary aneurysms can resolve spontaneously.

However, those children with larger aneurysms have less favourable long term outcome because of risks of blood clots forming in the dilated coronary arteries causing heart attack and death.

Can a child have the disease again?

It is very rare for a child with Kawasaki disease to have the disease again after recovery.

Can Kawasaki disease be prevented?

No. There is no vaccine or other prevention method available for Kawasaki disease at the moment.

Kawasaki Disease Key Points

• Kawasaki disease is a syndrome of unknown cause that mainly affects children under 5 years of age.
• The usual findings of the disease include fever lasting five days or more, redness of the eyes, hands, feet, mouth, and tongue, rash and swollen glands in the neck.
• The disease can be treated with intravenous immunoglobulin and high doses of aspirin (salicylic acid).
• Kawasaki disease generally resolves on its own after four to eight weeks.
• Most children with Kawasaki disease recover completely with some suffering damage to the coronary arteries.