Kawasaki disease

Overview

Kawasaki disease causes swelling (inflammation) in the walls of medium-sized arteries throughout the body. It primarily affects children. The inflammation tends to affect the coronary arteries, which supply blood to the heart muscle.

Kawasaki disease is sometimes called mucocutaneous lymph node syndrome because it also affects glands that swell during an infection (lymph nodes), skin, and the mucous membranes inside the mouth, nose and throat.

Signs of Kawasaki disease, such as a high fever and peeling skin, can be frightening. The good news is that Kawasaki disease is usually treatable, and most children recover from Kawasaki disease without serious problems.

Symptoms

Kawasaki disease signs and symptoms usually appear in three phases.

1st phase

Signs and symptoms of the first phase may include:

• A fever that is often is higher than 102.2 F (39 C) and lasts more than three days
• Extremely red eyes without a thick discharge
• A rash on the main part of the body and in the genital area
• 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
• Swollen lymph nodes in the neck and perhaps elsewhere
• Irritability

2nd phase

In the second phase of the disease, your child may develop:

• Peeling of the skin on the hands and feet, especially the tips of the fingers and toes, often in large sheets
• Joint pain
• Diarrhea
• Vomiting
• Abdominal pain

3rd phase

In the third phase of the disease, signs and symptoms slowly go away unless complications develop. It may be as long as eight weeks before energy levels seem normal again.

When to see a doctor

If your child has a fever that lasts more than three days, contact your child's doctor. Also, see your child's doctor if your child has a fever along with four or more of the following signs and symptoms:

• Redness in both eyes
• A very red, swollen tongue
• Redness of the palms or soles
• Skin peeling
• A rash
• Swollen lymph nodes

Treating Kawasaki disease within 10 days of when it began may greatly reduce the chances of lasting damage.

Causes

No one knows what causes Kawasaki disease, but scientists don't believe the disease is contagious from person to person. A number of theories link the disease to bacteria, viruses or other environmental factors, but none has been proved. Certain genes may make your child more likely to get Kawasaki disease.

Risk factors

Three things are known to increase your child's risk of developing Kawasaki disease.

• Age. Children under 5 years old are most at risk of Kawasaki disease.
• Sex. Boys are slightly more likely than girls are to develop Kawasaki disease.
• Ethnicity. Children of Asian or Pacific Island descent, such as Japanese or Korean, have higher rates of Kawasaki disease.

Complications

Kawasaki disease is a leading cause of acquired heart disease in children. However, with effective treatment, only a 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 your child's 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 very small percentage of children who develop coronary artery problems, Kawasaki disease can cause death, even with treatment.

Diagnosis

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
• Measles

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.

Treatment

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?

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