Kawasaki disease

Kawasaki disease is a condition that causes inflammation in the walls of medium-sized arteries throughout the body, including the coronary arteries, which supply blood to the heart muscle. Kawasaki disease is also called mucocutaneous lymph node syndrome because it also affects 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 symptoms appear in phases.

First phase

Signs and symptoms of the first phase may include:

Fever which often is higher than 102.2 F (39 C) and lasts more than five daysExtremely red eyes (conjunctivitis) without a thick dischargeA rash on the main part of the body (trunk) and in the genital areaRed, dry, cracked lips and an extremely red, swollen tongue (strawberry tongue)Swollen, red skin on the palms of the hands and the soles of the feetSwollen lymph nodes in the neck and perhaps elsewhereIrritability

Second 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 sheetsJoint painDiarrheaVomitingAbdominal pain

Third 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 four days, contact your child's doctor. Or 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 eyesA very red, swollen tongueRedness of the palms or solesSkin peelingA rashSwollen lymph nodes

Treating Kawasaki disease within 10 days of its onset 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 increase your child's susceptibility to Kawasaki disease.

COMPLICATIONS
Kawasaki disease is a leading cause of acquired heart disease in children, but with effective treatment, only a small percentage of children have lasting damage.

Heart complications include:

Inflammation of blood vessels (vasculitis), usually the coronary arteries, that supply blood to the heartInflammation of the heart muscle (myocarditis)Heart valve problems (mitral regurgitation)Abnormal heart rhythm (dysrhythmia)

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 forming and blocking the artery, 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 is fatal, even with treatment.

DIAGNOSIS
There's no specific test available to diagnose Kawasaki disease. Diagnosis largely is a process of ruling out diseases that cause similar signs and symptoms, including:

Scarlet fever, which is caused by streptococcal bacteria and results in fever, rash, chills and sore throatJuvenile rheumatoid arthritisStevens-Johnson syndrome, a disorder of the mucous membranesToxic shock syndromeMeaslesCertain tick-borne illnesses, such as Rocky Mountain spotted fever

The doctor may do a physical examination and have your child take other tests to help in the diagnosis. These tests may include:

Urine tests. These tests help rule out other diseases.Blood tests. Besides helping to rule out other diseases, blood tests look at white blood cell count, which is likely to be elevated, and the presence of anemia and inflammation, indications of Kawasaki disease.Electrocardiogram. This test uses electrodes attached to the skin to measure the electrical impulses of your child's heartbeat. Kawasaki disease can cause heart rhythm complications.Echocardiogram. This test uses ultrasound images to show how well the heart is functioning and provides indirect evidence on how the coronary arteries are functioning.

TREATMENT
To reduce the risk of complications, your child's doctor will want to begin treatment for Kawasaki disease as soon as possible after the appearance of signs and symptoms, preferably while your child still has a fever. The goals of initial treatment are to lower fever and inflammation and prevent heart damage.

To accomplish those goals, your child's doctor may recommend:

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 against aspirin use in children.

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 serious illness that can affect the blood, liver, and brain of children and teenagers after a viral infection.

Without treatment, Kawasaki disease lasts an average of 12 days, though heart complications may be evident later and be longer lasting. With treatment, your child may start to improve soon after the first gamma globulin treatment.

Monitoring heart problems

If your child has any indication of heart problems, the doctor may recommend follow-up tests to monitor heart health at regular intervals, often at six to eight weeks after the illness began. If your child develops continuing heart problems, the doctor may refer you to a doctor who specializes in treating heart disease in children (pediatric cardiologist). In some cases, a child with a coronary artery aneurysm may require:

Anticoagulant drugs. These medications — such as aspirin, clopidogrel (Plavix), warfarin (Coumadin) and heparin — help prevent clots from forming.Coronary artery angioplasty. This procedure opens arteries that have narrowed to the point that they impede blood flow to the heart.Stent placement. This procedure involves implanting a device in the clogged artery to help prop it open and decrease the chance of reblockage. Stent placement may accompany angioplasty.Coronary artery bypass graft. This operation involves rerouting the blood around a diseased coronary artery by grafting a section of blood vessel from the leg, chest or arm to use as the alternate route.