Kawasaki disease causes swelling (inflammation) in children in the walls of small to medium-sized blood vessels that carry blood throughout the body. Kawasaki disease commonly leads to inflammation of the coronary arteries, which supply oxygen-rich blood to the heart.
Kawasaki disease was previously called mucocutaneous lymph node syndrome because it also causes swelling in glands (lymph nodes) and mucous membranes inside the mouth, nose, eyes and throat.
Children with Kawasaki disease might have high fever, swollen hands and feet with skin peeling, and red eyes and tongue. But Kawasaki disease is usually treatable, and most children recover without serious problems if they receive treatment within 10 days of onset.
To receive a diagnosis of Kawasaki disease, a child usually will have a fever greater than 102.2 F (39 C) for five or more days and at least four of the following signs and symptoms.
- A rash on the main part of the body or in the genital area
- An enlarged lymph node in the neck
- Extremely red eyes without a thick discharge
- Red, dry, cracked lips and an extremely red, swollen tongue
- Swollen, red skin on the palms of the hands and the soles of the feet, with later peeling of skin on fingers and toes
The symptoms might not occur at the same time, so it's important to let your child's health care provider know about a sign or symptom that has gone away.
Other signs and symptoms that might develop include:
- Abdominal pain
- Joint pain
Children with a high fever for five or more days who have fewer than four of the above signs and symptoms might have what's known as incomplete Kawasaki disease. Children with incomplete Kawasaki disease are still at risk of coronary artery injury and still require treatment within 10 days of the onset of symptoms.
Kawasaki disease can have symptoms similar to that of multisystem inflammatory syndrome in children, which has occurred worldwide in children with COVID-19. Children with these symptoms will likely be checked for COVID-19, as well.
When to see a doctor
If your child has a fever that lasts more than three days, contact your child's health care provider. Treating Kawasaki disease within 10 days of when it began may greatly reduce the chances of lasting damage to the coronary arteries supplying the heart muscle.
No one knows what causes Kawasaki disease, but scientists don't believe the disease is contagious from person to person. Some think that Kawasaki disease happens after a bacterial or viral infection, or that it's linked to other environmental factors. Certain genes might make children more likely to get Kawasaki disease.
Three things are known to increase a child's risk of developing Kawasaki disease.
- Age. Children under 5 years old are at highest risk of Kawasaki disease.
- Sex. Boys are slightly more likely than girls to develop Kawasaki disease.
- Ethnicity. Children of Asian or Pacific Island descent, such as Japanese or Korean, have higher rates of Kawasaki disease.
Kawasaki disease tends to occur seasonally. In North America, it usually occurs in the winter and early spring.
Kawasaki disease is a leading cause of acquired heart disease in children in developed countries. However, with treatment, few children have lasting damage.
Heart complications include:
- Inflammation of blood vessels, usually the coronary arteries, that supply blood to the heart
- Inflammation of the heart muscle
- Heart valve problems
Any of these complications can damage the heart. Inflammation of the coronary arteries can lead to weakening and bulging of the artery wall (aneurysm). Aneurysms increase the risk of blood clots, which could lead to a heart attack or cause life-threatening internal bleeding.
For a small percentage of children who develop coronary artery problems, Kawasaki disease can cause death.
There's no specific test available to diagnose Kawasaki disease. Diagnosis involves ruling out other diseases that cause similar signs and symptoms, including:
- Scarlet fever, which is caused by streptococcal bacteria and results in fever, rash, chills and sore throat
- Juvenile rheumatoid arthritis
- Stevens-Johnson syndrome, a disorder of the mucous membranes
- Toxic shock syndrome
- Certain tick-borne illnesses, such as Rocky Mountain spotted fever
The health care provider will do a physical examination and order blood and urine tests to help in the diagnosis. Tests might include:
- Blood tests. Blood tests help rule out other diseases and check blood cell count. A high white blood cell count and the presence of anemia and inflammation are signs of Kawasaki disease.
- Electrocardiogram. Electrodes are attached to the skin to measure the electrical impulses of the heartbeat. Kawasaki disease can cause heart rhythm problems.
- Echocardiogram. This test uses ultrasound images to show how well the heart is working and can help identify problems with the coronary arteries.
To reduce the risk of long-term complications, your child's health care provider will want to begin treatment for Kawasaki disease as soon as possible, preferably while your child still has a fever. The goals of initial treatment are to lower fever and inflammation and prevent heart damage.
Treatment for Kawasaki disease can include:
- Gamma globulin. Infusion of an immune protein (gamma globulin) through a vein (intravenously) can lower the risk of coronary artery problems. This helps to reduce inflammation in the vessels.
Aspirin. High doses of aspirin might help treat inflammation. Aspirin can also decrease pain, joint inflammation and fever. The aspirin dose will likely be lowered once the fever has been gone for 48 hours.
Kawasaki treatment is a rare exception to the rule that says aspirin shouldn't be given to children. Aspirin has been linked to Reye's syndrome, a rare but potentially life-threatening condition, in children recovering from chickenpox or flu. Children with Kawasaki disease should be given aspirin only under the supervision of a health care provider.
Because of the risk of serious complications, initial treatment for Kawasaki disease is usually given in a hospital where doctors can continue to monitor the child.
After the initial treatment
Once the fever goes down, a child might need to take low-dose aspirin for at least six weeks — longer if he or she develops a coronary artery aneurysm. Aspirin helps prevent blood clotting.
However, children who develop flu or chickenpox during treatment might need to stop taking aspirin. Taking aspirin has been linked to Reye's syndrome, a rare but potentially life-threatening condition that can affect the blood, liver and brain of children and teenagers after a viral infection.
With treatment, a child might start to improve soon after the first gamma globulin treatment. Without treatment, Kawasaki disease lasts about 12 days. However, heart complications might last longer.
Monitoring heart problems
If your child has any signs of heart problems, the health care provider might recommend follow-up tests to check your child's heart health at regular intervals, often at 6 to 8 weeks after the illness began, and then again after six months.
If heart problems continue, your child might be referred to a doctor who specializes in treating heart disease in children (pediatric cardiologist). Treatment for heart complications related to Kawasaki disease depends on the type of heart condition.
Wait to vaccinate
If your child was given gamma globulin, it's a good idea to wait at least 11 months to get a live vaccine, such as the chickenpox or measles vaccine, because gamma globulin can affect how well these vaccinations work. Tell your child's health care provider that your child has had Kawasaki disease.
Coping and support
Find out all you can about Kawasaki disease so that you can make informed choices with your child's health care team about treatment options.
Most children with Kawasaki disease recover completely. Generally, children who have been treated for Kawasaki get well fast and return to normal activities. If your child's heart has been affected, talk to the pediatric cardiologist about whether activity restriction is needed.
Preparing for an appointment
You'll probably first see your family health care provider or pediatrician. Sometimes a child may also be referred to a doctor who specializes in treating children with heart conditions (pediatric cardiologist), a doctor who specializes in treating children with bone and joint disorders (rheumatologist), or one who specializes in treating children with infectious diseases.
Here's some information to help you get ready for your appointment.
What you can do
Bring a family member or friend to the appointment, if possible, to help you remember all the information you're given.
Make a list of:
- Your child's signs and symptoms, including any that seem unrelated, and when they began. Try to keep track of how high your child's fever has been and how long it has lasted.
- All medications, vitamins or supplements your child takes, including doses.
- Write down questions to ask your doctor.
For Kawasaki disease, some questions to ask your child's health care professional include:
- What's the most likely cause of my child's signs and symptoms?
- Are there any other possible causes for his or her signs and symptoms?
- Does my child need tests?
- How long will the signs and symptoms last?
- What treatments are available, and which do you recommend?
- How can I make my child more comfortable?
- Can you give me brochures or other printed information? What websites do you recommend?
Don't hesitate to ask additional questions.
What to expect from your doctor
Your child's health care provider is likely to ask you questions, such as:
- How severe are the signs and symptoms? How high has your child's fever been? How long did it last?
- What, if anything, seems to improve the symptoms?
- What, if anything, appears to worsen the symptoms?
- Has your child been exposed to any infectious diseases?
- Has your child been taking any medications?
- Does your child have any allergies?