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.
Kawasaki disease signs and symptoms usually appear in three phases.
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
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
- Abdominal pain
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.
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.
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.
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
- 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 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.