Kawasaki disease

Kawasaki disease is a rare but serious illness. It usually affects younger children under 5 years of age. 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. Early treatment can prevent heart damage. Kawasaki disease can also cause damage to other parts of the body.

The cause of Kawasaki disease is unknown. It's 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 (immune) system of some children.

Your child can't 'catch' Kawasaki disease – it's not contagious.

If Kawasaki disease isn't treated, it can last for 10 days or more. If the disease affects the heart, then the damage can be permanent.

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

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

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.

If you think your child might have Kawasaki disease, you should take them to your healthcare provider straight away.

You should also see your healthcare provider if you're not sure what's wrong, but your child:

• looks unwell
• isn't improving
• still has a fever after 5 days.

There's no single test that can diagnose Kawasaki disease. Your healthcare provider will consider other possible illnesses as well. The diagnosis can be difficult to make. It's usually confirmed by a children's doctor (paediatrician) in hospital.

Kawasaki disease is usually diagnosed if your child has a fever for at least 5 days and at least 4 of the symptoms listed above (see the symptoms section). 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 may help make the diagnosis.

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's similar to the ultrasound scan people have when they're pregnant. This ultrasound may happen in hospital or after your child has gone home from the hospital.

If your tamariki has Kawasaki disease, their healthcare team will discuss with you what treatment and follow-up your child needs. If you don't understand the plan for your child, it's 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 haven't improved after the first dose.

Aspirin

Your child's healthcare provider will prescribe aspirin in case there has been heart damage. Your child will keep taking aspirin at least until they've had an ultrasound scan of their heart.

If your child needs to keep taking aspirin after going home from hospital, there are some important things to remember:

• Don't give your child anti-inflammatory medicine and aspirin: Your child should not take ibuprofen or other anti-inflammatory medicine while they are taking aspirin.
• If your child gets the flu or chickenpox, they may need to stop taking their aspirin: This is to avoid a condition called Reye syndrome – a rare and serious illness linked to aspirin use in children with fever.

See your healthcare provider immediately if your child gets a fever while they're taking aspirin and ask about this. 

Apps reviewed by Healthify

You may find it useful to look at some Baby care apps.

• If your child gets a fever again within 6 weeks of having Kawasaki disease, take them to see your healthcare provider. They may need to go back to hospital.
• It's very unusual to have Kawasaki disease more than once. This only happens to about 3 in 100 tamariki who've had Kawasaki disease.

Possible complications

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. The treatment for Kawasaki disease described above 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 to their heart.

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