Kawasaki Disease

Key points to remember about Kawasaki disease

• Kawasaki disease is a rare illness that affects young children
• it causes high fevers for at least 5 days
• it makes children very miserable
• Kawasaki disease can cause heart damage
• early treatment can prevent heart damage

What is Kawasaki disease?

Kawasaki disease is a rare but serious illness. It usually affects younger children under the age of 5 years. The name of the disease comes from Tomisaku Kawasaki, the Japanese doctor who first described it in 1967.

Kawasaki disease causes high fevers that last at least 5 days. If left untreated, about 1 in 5 children with Kawasaki disease will suffer damage to their heart. It can also cause damage to other parts of the body.

What causes Kawasaki disease?

The cause of Kawasaki disease is unknown. It is more common in Japan than most other countries.

One theory is that a common virus or other common infection causes an over-reaction in the infection-fighting system (immune system) of some children.

Your child cannot 'catch' Kawasaki disease - it is not contagious.

How long could Kawasaki disease last?

Without treatment, Kawasaki disease can last for 10 days or more.

If the disease affects the heart, then the damage can be permanent.

What puts my child at risk of getting Kawasaki disease?

Children of Asian and Pacific Island descent are at greater risk. Most children who get Kawasaki disease are under the age of 5 years.

If a child has had Kawasaki disease, there is a slightly higher chance that their brothers or sisters will get it. The risk is higher again for twins - a 1 in 10 chance.

What are the signs and symptoms of Kawasaki disease?

The most striking feature of Kawasaki disease is a high fever that comes and goes for at least 5 days. Children are usually very irritable and easily upset.

Other symptoms of Kawasaki disease include:

• a rash on the body which is often worse in the groin area
• irritated red eyes
• an enlarged reddened tongue (sometimes called 'strawberry' tongue)
• reddened or dry, cracked lips
• redness and/or swelling of the hands and feet
• swollen lymph nodes in the neck
• peeling of the hands and feet (usually later in the illness)

There are many other possible signs and symptoms including tummy pain, vomiting, diarrhoea, and joint pain and swelling.

When should I seek help for Kawasaki disease?

If you think your child might have Kawasaki disease you should take them to your doctor straightaway.

You should also see your doctor if you are not sure what's wrong but your child:

• looks unwell
• is not improving
• still has a fever after 5 days

How is Kawasaki disease diagnosed?

There is no single test that can diagnose Kawasaki disease. Your doctor will consider other possible illnesses as well. The diagnosis can be difficult to make. A children's doctor (paediatrician) in hospital will usually confirm a diagnosis of Kawasaki disease.

For your child to have a diagnosis of Kawasaki disease, they will usually have a fever for at least 5 days and at least 4 of the symptoms listed above. Babies with Kawasaki disease may not have as many of the symptoms as older children. The symptoms may not all be present at the same time.

Blood tests

Blood tests may help make the diagnosis.

Ultrasound scan of the heart (echocardiogram)

Once diagnosed with Kawasaki disease, your child will need an ultrasound scan of the heart (an echocardiogram) to check whether the disease has affected their heart. This is a safe and painless scan. It is similar to the ultrasound scan women have when pregnant. This ultrasound may happen in hospital or after your child has gone home from hospital. 

What treatments are available for Kawasaki disease?

If your child has Kawasaki disease,  the doctors taking care of them will discuss with you what treatment and follow-up your child needs. If you don't understand the plan for your child, it is OK to ask.

Immunoglobulin

Immunoglobulin is a blood product made of concentrated antibodies from donated blood. Your child will receive it through a vein (intravenously).

Immunoglobulin is very effective at reducing the risk of heart damage. It works best when given within 10 days of the start of the illness. With treatment within 10 days, immunoglobulin reduces the chance of heart damage to 1 in 50. Without treatment, the chance of heart damage is about 1 in 5.

After your child has had immunoglobulin treatment, they shouldn't have the measles, mumps, rubella (MMR) or chickenpox (varicella) vaccines for 11 months. That's because these vaccines may not work properly after immunoglobulin.   Your child can have all the other vaccines, including the influenza vaccine, at the normal time. Immunoglobulin won't affect how these vaccines work.

Some children may need a second dose of immunoglobulin if their symptoms have not improved after the first dose. 

Aspirin

Your child's doctor will prescribe aspirin in case there has been heart damage. Your child will keep taking aspirin at least until the ultrasound scan of the heart.

If your child needs to keep taking aspirin after going home from hospital, it is important to remember that:

• they should not take ibuprofen or other anti-inflammatory medicine at the same time
• if they get influenza or chickenpox (varicella), they may need to stop taking their aspirin to avoid a condition called Reye syndrome (a rare and serious illness linked to aspirin use in children with fever)

See your doctor immediately if your child gets a fever while on aspirin and ask about this. 

What should I look out for after my child with Kawasaki disease has left hospital?

If your child gets a fever again within 6 weeks of having Kawasaki disease, take them to see your family doctor (GP). Your child may need to go back to hospital.

Can my child get Kawasaki disease more than once?

It is very unusual to have Kawasaki disease more than once. This only happens to about 3 in 100 children who have had Kawasaki disease. 

How can Kawasaki disease be prevented?

There is no way to prevent Kawasaki disease. Appropriate treatment given early enough in the illness will help prevent complications.

Are there likely to be any complications from Kawasaki disease?

The major complication of Kawasaki disease is heart damage. The most common type of heart damage is caused by irritation or inflammation of the vessels that carry blood to the muscle of the heart. Immunoglobulin works by reducing the inflammation and preventing the damage.

If damage does occur, your child needs regular health checks by a doctor. After a few years, the heart damage heals in about half of all affected children.

There are other treatments available for children with severe damage.