Kawasaki disease is the leading cause of acquired heart disease in infants and young children in the United States. More than 4,200 U.S. children are diagnosed with Kawasaki disease each year.
The condition causes inflammation in the blood vessels, and the symptoms can be severe. In addition to several days of fever, children with Kawasaki disease may develop symptoms such as rash, swollen neck glands, swollen hands and feet, and red eyes, lips and tongue.
Early on, Kawasaki disease can affect the function of the heart muscle or the heart valves. If it is recognized and treated early, children can begin to feel better in a few days with a low likelihood of long-term heart issues.
Fast Facts:
- 80% to 90% of Kawasaki disease cases occur in children under age 5 and older than 6 months. It is less common for older children and adolescents to get the disease, but some do.
- Kawasaki disease is not contagious. It does not spread among family members or children in child care centers.
- Kawasaki disease occurs more frequently in children of Asian or Pacific Island ancestry. However, it can affect people in all racial and ethnic groups.
- The cause of Kawasaki disease is not known, but it is thought to be a reaction by the body's immune system.
Signs & Symptoms:
Kawasaki Disease begins with a fever above 102 degrees F that lasts for at least five days. Other signs and symptoms may include:
- Rash anywhere on the body but more severe in the diaper area.
- Red, bloodshot eyes without pus, drainage, or crusting.
- Swelling and tenderness of a gland (lymph node) on one side of the neck.
- Swollen hands and feet with redness on the palms of the hands and the soles of the feet.
- Very red, swollen, and cracked lips; strawberry-like tongue with rough, red spots.
- Significant irritability and fussiness.
- Peeling fingers and toes (typically 2 to 3 weeks after the beginning of fever).
Note: The following key signs and symptoms may not be present at the same time. In some very young infants, only a few of these actually develop. Other non-specific symptoms may also be present, such as vomiting, diarrhea, stomachache, cough, runny nose, headache, or pain or swelling of the joints.
When to call the doctor:
If your child has a fever for 4 to 5 days with any of the key signs and symptoms above, ask your doctor whether he or she could have Kawasaki disease. It can be challenging to diagnose, so your child may have to be examined several times. See When to Call the Pediatrician: Fever for more information specific to fevers.
Diagnosis:
There is no specific, single test to diagnose Kawasaki disease. If Kawasaki disease is suspected, however, your doctor may order tests to monitor heart function (an echocardiogram) and may take blood and urine samples. In addition, your doctor may refer you to a pediatric specialist in infectious disease, rheumatology or cardiology for more guidance in diagnosis and treatment.
Complications if left untreated:
If Kawasaki disease is left untreated, it can lead to serious complications such as inflammation of the blood vessels. This can be particularly dangerous because it can affect the coronary arteries--the blood vessels that supply blood to the heart muscle--causing coronary artery aneurysms to develop. An aneurysm is a ballooning out of a damaged and weakened blood vessel wall.
Fortunately, treatment within the first 10 days of illness significantly decreases the risk of aneurysms. That's why it is very important to diagnose Kawasaki disease by the 10th day of the illness. Treatment should begin as soon as possible.
Treatment for Kawasaki Disease:
Children diagnosed with Kawasaki disease are admitted to the hospital. The medication used to treat Kawasaki disease in the hospital is called intravenous gamma globulin (IVIG). IVIG is given through a vein over 8 to 12 hours. Children stay in the hospital for at least 24 hours after completing the IVIG dose to make sure the fever does not return and other symptoms are improving.
Children may also be given aspirin to lower the risk of heart problems. (Aspirin should only be given to young children under doctors' supervision, as it can cause a serious liver condition called Reye Syndrome.)
Additional treatments may be needed if a child does not respond well to the single dose of IVIG, the fever returns, or there are abnormal findings on the first echocardiogram. Another dose of IVIG or other medications that fight inflammation such as steroids, infliximab, or etanercept may be recommended. Pediatric specialists in rheumatology, infectious disease, or cardiology may be consulted in this situation.
What to expect after hospital discharge:
Children treated for Kawasaki Disease are sent home from the hospital on a low dose of aspirin to take by mouth every day for 6 to 8 weeks. As they recover, it is not uncommon for these children to be extra tired or seem "off" for several weeks. Rest is very important. Peeling of skin the hands and feet is expected and is not cause for alarm.
Call your doctor right away if your child develops a fever or any of the other symptoms of Kawasaki Disease return. Further evaluation will be needed to determine if your child needs to be go back to the hospital.
Follow-up Care:
It is very important to closely monitor children who have had Kawasaki Disease to make sure they are improving and to check for the development of coronary aneurysms. Aneurysms most often form after the first couple of weeks of illness, so children should be scheduled for an echocardiogram and a check-up at 2 weeks and again at 6 to 8 weeks after their fever first started. More frequent follow up and echocardiograms will be necessary if there are abnormal findings on any of the echocardiograms.
Note: Live viral vaccines should be postponed at least 11 months after IVIG, because IVIG can cause the vaccines to be ineffective. These include the MMR (measles, mumps, rubella) and Varicella (chicken pox) vaccines. Children over 6 months of age should receive the inactivated influenza (flu) vaccine injection.
Long-term follow-up:
Children treated for Kawasaki disease who do not develop aneurysms have an excellent long-term outcome. However, it is important for them to follow a heart healthy diet and lifestyle. Cholesterol levels should be checked every 5 years.
Children who do have coronary aneurysms should be under the care of a pediatric cardiologist as they grow and will require special long-term care and follow-up.
Additional Information & Resources: