What is Kawasaki disease?
Kawasaki disease causes inflammation or swelling of the blood vessels. Kawasaki disease can affect any medium-sized artery in the body but primarily affects the coronary arteries. The coronary arteries are special blood vessels that carry blood and oxygen into the heart muscle. If there is a problem with the coronary arteries, the heart will not get enough blood and oxygen, making it unable to work properly.
Signs and symptoms of Kawasaki disease
Signs and symptoms of Kawasaki disease include:
- Five or more consecutive days of fever
- Red or bloodshot eyes
- Red lips, mouth or tongue
- Puffy or red hands and feet
- A swollen gland in the neck
Causes of Kawasaki disease
The exact causes of Kawasaki disease are unknown. It is also not known why some children get the disease and others do not. It is possible that genetics play a role in the development of Kawasaki disease.
It is also possible a viral or bacterial infection may trigger the disease in children. Infections and Kawasaki disease often occur at the same time.
Kawasaki disease is not contagious
Kawasaki disease not spread from child to child, but infections can trigger Kawasaki disease.
It is rare for two children in the same family to get Kawasaki disease. When it occurs, it may be related to inherited genes that help to control the immune system.
Diagnosis of Kawasaki disease
The diagnosis of Kawasaki disease is made when a child has at least five consecutive days of fever and at least four out of the other five symptoms mentioned above. In some cases, a child will have fewer than four symptoms. Kawasaki disease often mimics other diseases such as common childhood infections. These factors make the diagnosis of Kawasaki disease more difficult.
Kawasaki disease is a rare illness. It usually affects children under the age of five, but older children can also be affected.
There is no specific test to diagnose Kawasaki disease. However, your child will have a blood test and a urine test, as well as an echocardiogram. This is an ultrasound that takes pictures of your child's heart. It lets doctors see if there are any changes in the coronary arteries. If these arteries are affected, they may look widened or swollen.
Complications of Kawasaki disease
Early and appropriate treatment of Kawasaki disease reduces the chances of injury or damage to the coronary arteries. Injury or damage to the arteries occurs in one in five untreated children. In most children, this damage is minor and does not last long. However, in some children the damage can last longer. In these children, the walls of the coronary arteries can become weak and form aneurysms.
An aneurysm is a localized, balloon-like bulge of the vessel wall. Aneurysms may be dangerous as they can cause problems with blood flow to the heart muscle. Medicine can help prevent further progression of the aneurysm or formation of clots.
Treatment of Kawasaki disease
A child with Kawasaki disease will need to stay in the hospital for several days. The health-care team will give your child medicine to try to prevent damage to the coronary arteries. These medicines are called intravenous immune globulin (IVIG) and ASA (acetylsalicylic acid or Aspirin).
After a child is treated, the fever usually goes away for good. Sometimes a child will need a second treatment with IVIG or other medicines.
IVIG is given through an intravenous (IV) needle in your child's vein. It helps reduce the inflammation in the body. In turn, this can:
- reduce the fever and redness caused by the disease
- help protect against heart problems.
IVIG contains antibodies from donated blood. It is screened for viruses and bacteria before it is used as a treatment. Talk to your doctor if you have concerns about this treatment.
Low dose ASA is given by mouth once a day. During the first four to six weeks, children with Kawasaki disease may have high platelet counts in their blood. Platelets are involved in clot formation. Low dose ASA prevents your child’s platelets from sticking together. This helps prevent blood clots from forming in the blood vessels.
Several different doctors look after children with Kawasaki disease
Kawasaki disease may be diagnosed and managed by a paediatrician, an emergency doctor, or a family doctor.
Two types of paediatric specialists also help care for children with Kawasaki disease. These are rheumatologists and cardiologists.
- A rheumatologist is an inflammation specialist. They can help diagnose Kawasaki disease and decide on treatments with the medical team.
- The cardiologist is a heart specialist. They will look at the echocardiogram. If the coronary arteries are swollen, the cardiologist will determine if the swelling is mild or severe. They will then decide on any further treatments and when they will need to repeat the echocardiogram.
Caring for your child with Kawasaki disease at home
Most children go home from hospital after a few days. Usually, the only medicine your child will keep taking at home is ASA, once a day. ASA prevents your child’s blood platelets from sticking together. This helps prevent blood clots and will protect the heart until your child has another echocardiogram. This will happen about six weeks after the diagnosis.
After the echocardiogram and a blood test, your child will likely be able to stop taking ASA. Your child may have another echocardiogram one year later. This is to make sure the disease has gone away completely.
Most children with Kawasaki disease recover completely. In some cases, the cardiologist will want to do more heart tests or prescribe other medicines.
Your child should continue to exercise regularly and make healthy food choices
At this time, it is not known if children who have had Kawasaki disease and who have normal echocardiograms are more likely to develop heart problems when they are adults. All children should follow a healthy active lifestyle, but it may be even more important in children who have had Kawasaki disease. A healthy lifestyle includes:
- making healthy food choices
- taking part in activities and exercise
- avoiding known risk factors for heart disease, such as smoking.
Please speak with your family doctor or paediatrician for information about healthy active living.
Your child should wait at least six months until their next vaccines
After treatment with IVIG, your child should wait at least six months to have their next scheduled immunizations (vaccines). Before six months, the vaccines will not hurt your child, but they may not work as well.
Your child should have the flu vaccine. It is dangerous to get the flu while taking ASA. The two have been linked with an illness called Reye’s syndrome, which can cause liver and brain damage.
Your child should avoid getting chickenpox
If your child has not had chickenpox (varicella) and has not been vaccinated, they should avoid getting chickenpox while taking ASA. The combination of ASA and chickenpox is dangerous, and has also been linked to Reye's syndrome. Tell your child's teachers about this. Ask them to let you know if any other students in the classroom have chickenpox.
While your child is taking ASA, if they are in contact with chickenpox or get chickenpox, call your child's doctor right away.
If your child has had chickenpox or has been vaccinated, they are protected. Ask your child’s paediatrician if you are not sure.
- Kawasaki disease causes swelling of the blood vessels. It can affect the heart.
- Your child will be admitted to hospital for treatment. Treatment usually involves two medicines: intravenous immune globulin (IVIG) and ASA (Aspirin).
- Most children with Kawasaki disease recover completely.