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 doctor will do a physical examination and order blood and urine tests to help in the diagnosis. Tests may include:
Blood tests. Blood tests help rule out other diseases and check your child's blood cell count. A high white blood cell count and the presence of anemia and inflammation are signs of Kawasaki disease.
Testing for a substance called B-type natriuretic peptide (BNP) that's released when the heart is under stress may be helpful in diagnosing Kawasaki disease. However, more research is needed to confirm this finding.
- Electrocardiogram. Electrodes are attached to the skin to measure the electrical impulses of your child's 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 complications, your child's doctor 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 may include:
- Gamma globulin. Infusion of an immune protein (gamma globulin) through a vein (intravenously) can lower the risk of coronary artery problems.
Aspirin. High doses of aspirin may help treat inflammation. Aspirin can also decrease pain and joint inflammation, as well as reduce the fever.
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 should be given aspirin only under the supervision of a doctor.
Because of the risk of serious complications, initial treatment for Kawasaki disease usually is given in a hospital.
After the initial treatment
Once the fever goes down, your child may need to take low-dose aspirin for at least six weeks and longer if he or she develops a coronary artery aneurysm. Aspirin helps prevent clotting.
However, if your child develops flu or chickenpox during treatment, he or she may 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, your child may start to improve soon after the first gamma globulin treatment. Without treatment, Kawasaki disease lasts an average of 12 days. However, heart complications may be longer lasting.
Monitoring heart problems
If your child has any signs of heart problems, the doctor may recommend follow-up tests to check your child's heart health at regular intervals, often at six to eight weeks after the illness began, and then again after six months.
If heart problems continue, you may 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 what type of heart condition is present. If a coronary artery aneurysm ruptures, treatment may include anticoagulant drugs, stent placement, or bypass surgery.
Wait to vaccinate
If your child was given gamma globulin, it's a good idea to wait at least 11 months to get the chickenpox or measles vaccine, because gamma globulin can affect how well these vaccinations work.
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, though it may be a little while before your child is back to normal and not feeling so tired and irritable. The Kawasaki Disease Foundation offers trained support volunteers to families currently dealing with the disease.
Preparing for your appointment
You'll probably first see your family doctor or pediatrician. However, in some cases your child may also be referred to a doctor who specializes in treating children with heart conditions (pediatric cardiologist).
Because appointments can be brief and there's often a lot to discuss, it's a good idea to be well prepared. Here's some information to help you get ready for your appointment, as well as what you can expect from your child's doctor.
What you can do
- Write down any signs and symptoms your child is experiencing, including any that may seem unrelated. Try to keep track of how high your child's fever has been and how long it has lasted.
- Make a list of any medications, vitamins or supplements that your child is taking.
- Ask a family member or friend to join you, if possible. Sometimes it can be difficult to remember all of the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.
- Write down questions to ask your doctor.
Your time with your doctor may be limited, so preparing a list of questions will help you make the most of your appointment. For Kawasaki disease, some basic questions to ask your child's doctor 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 any tests?
- How long will the signs and symptoms last?
- What treatments are available, and which do you recommend?
- What are the possible side effects of the treatments?
- Are there any steps I can take to make my child more comfortable?
- What signs or symptoms should I watch for that might indicate that he or she is getting worse?
- What's my child's long-term prognosis?
- Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask any additional questions that may come up during your appointment.
What to expect from your doctor
Your child's doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your child's doctor may ask:
- When did your child begin experiencing symptoms?
- 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?