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Kawasaki disease

What is Kawasaki disease?

  • Kawasaki disease is a febrile illness with inflammation of blood vessels throughout the body, including the coronary arteries (blood vessels around the heart).
  • Kawasaki disease is the leading cause of heart disease in children after birth.
  • It was first described in Japan in 1967 by the pediatrician Dr. Tomisaku Kawasaki.
  • 15 – 25% of cases will develop heart problems if left untreated and in rare cases sudden death may occur.

What causes Kawasaki disease?

  • Investigators have suspected an infectious cause, but until recently no definitive cause has been identified.
  • Results of a 2006 study suggest a single viral cause that enters the body through the respiratory system.
  • It is possible that after exposure to an infectious agent, that the disease develops because of an abnormal response of the immune system in genetically susceptible children.

Who gets Kawasaki disease?

  • In 2000, over 4,000 families in the U.S. had children diagnosed with the disease.
  • Over 75% of cases occur in children younger than 5 years of age and 95% less than 10; the peak age is between 1 to 2 years.
  • The disease is very uncommon in children over 14 years old or adults.
  • It is more common in boys than girls.
  • Although cases of Kawasaki disease have been reported in children of all ethnic origins, the highest incidence remains in children of Asian descent especially Japanese.
  • Within 1 year after onset of the first case in a family, the chance of a sibling having the disease is approximately 2% (based on Japanese literature).
  • In Japan, the risk of a twin getting the disease is about 13% (would be considered much less in the US).
  • In the US, most cases occur in late winter and early spring.

What are the signs and symptoms of Kawasaki disease?

There are several clinically apparent stages of Kawasaki disease.
Not every sign and symptom will necessarily be seen in all kids with the disease.

Stage 1 (illness days 1-11)

  1. Sudden onset of high fever (> 102°F) that lasts for 1 week or longer and does not respond to antibiotic treatment
  2. An extremely irritable child (meningitis may be present)
  3. Red eyes without pus  (see photo called Kawasaki disease)
  4. Dry, red and cracked lips  (see photo called Kawasaki disease 2)
  5. Red and spotty tongue (strawberry tongue) (see photo called Strawberry tongue)
  6. Hands and feet that are red and swollen, in some cases causing difficulty with walking (see photo calledKawasaki disease 3)
  7. Rashes that involve the trunk, arms and legs, which usually appears within 5 days after onset of fever. The rashes may appear in several forms and can be itchy.
    In some cases the child may have a bright red and scaling rash in the groin area (see photo called Kawasaki disease 4)
  8. Enlarged lymph node (usually on one side of the neck)
  9. Abnormal liver test
  10. Abdominal pain with or without diarrhea may be present
  11. Gall bladder problems
  12. Heart problems may develop in this stage

Stage 2 (illness days 11-21)

  1. Fever, rash and enlarged lymph nodes have usually resolved by this stage.
  2. Persistent irritability, poor appetite, and red eyes
  3. Peeling of skin of the fingertips and toes begins (see photo called Kawasaki 5)
  4. High number of platelets in the blood (this increases the chance of blood clots)
  5. Arthritis and arthralgia (muscle and joint aches) may occur
  6. Heart problems (aneurysms or ballooning of blood vessels) may develop during this stage

Stage 3 (illness days 21-60)

  • Clinical signs begin to disappear and laboratory test results return to normal
  • Most significant clinical finding that persists through this stage is that, if present, coronary artery aneurysms (ballooning of blood vessels to and from the heart) continue to enlarge. This may lead to rupture of the blood vessels, heart attack and death

Who is at risk for aneurysms?

Risk factors for developing aneurysms include the following:

  1. male
  2. younger than 1 year or older than 5 years
  3. persistent fever despite appropriate therapy
  4. certain lab abnormalities (e.g., anemia)

Are there any long-term complications of Kawasaki disease?

  • During the first year or two after the illness, coronary aneurysms heal and the amount of coronary artery dilation can become less (amount of healing depends on the amount of damage).
  • Aneurysms formed during an episode of Kawasaki disease is of lifetime significance as these may be the cause of heart disease in adulthood.

How is Kawasaki disease diagnosed?

There is no specific lab test that definitively diagnoses Kawasaki disease.

The diagnosis is established by meeting the following diagnostic criteria:

  1. High fever persisting at least 5 days lasting 1 to 2 weeks or longer and not responding to antibiotics

In addition to fever, 4 of the following 5 conditions should also be met.

  1. Changes of the hands & feet: swelling and redness followed by peeling of fingertips and toes after fever improves
  2. Red rash covering most of the body, usually appearing within 5 days after the start of fever
  3. Red eyes without a discharge
  4. Mouth changes such as a strawberry tongue and dry cracked lips
  5. Enlarged lymph glands in the neck, usually on one side
  • An echocardiogram (ultrasound of the heart) is the study of choice to look for any heart complications.

“Atypical” or “incomplete” cases of Kawasaki disease, in which patients have, fever plus less than 4 of the principal criteria are becoming more common.

  •  ”Incomplete” Kawasaki disease is more common in young infants than older children.
  • The 2 most commonly missing findings in these cases are a swollen lymph node and a rash.
  • In 2004, the American Heart Association published revised guidelines to help physicians diagnose and treat Kawasaki disease (these were endorsed by the American Academy of Pediatrics.  This includes guidelines for cases in which only 2 or 3 criteria of classic Kawasaki disease are met. 

What is the treatment of Kawasaki disease?

  • The main goal of treatment is to prevent coronary artery disease and relieve symptoms.
  • Full doses of salicylates (aspirin) and intravenous immunoglobulin are the mainstays of treatment.


  • When given during the 1st stage of the disease, immunoglobulin lowers the risk of coronary artery abnormalities.
  • A single dose is given within the first 10 days of the illness.
  • The dose may be given in a child after 10 days if the diagnosis was missed earlier and the child still has fever or other signs of inflammation.
  • A second dose is may be given if fever persist for 36 hours or more after the initial dose (10% of cases).
  • Approximately 5% of children with Kawasaki disease develop coronary artery problems despite treatment with immunoglobulin.
  • Measles and varicella (chickenpox) vaccines cannot be given for 11 months after a child receives immunoglobulin.


  • High dose aspirin helps to reduce inflammation in the body and has anti-blood clotting effects.
  • Unlike immunoglobulin, aspirin does not prevent long-term development of coronary artery abnormalities.
  • High doses of aspirin will be continued until the child has a normal temperature for at least a few days, at which time the dose can be reduced.
  • All kids are re-evaluated 6-8 weeks after the onset of symptoms and if all looks well the aspirin can be stopped.
  • In rare instances long term aspirin therapy in children can be complicated by Reye Syndrome.
  • This rare disorder affecting the liver and the brain is thought to be associated with influenza and chickenpox infection along with aspirin therapy.
  • If the child develops influenza or chickenpox, aspirin must be stopped temporarily.
  • Children who need to take aspirin indefinitely should be vaccinated against chickenpox and influenza.
  • Aspirin therapy also should not be given during the six weeks after a chickenpox vaccine.

What are the complications from Kawasaki disease?

  • The main complication of Kawasaki disease is development and rupture of coronary artery aneurysms.
    These aneurysms may also cause heart problems in later life.

When should I call my pediatrician concerning signs of Kawasaki disease in my child?

  • It is best to call for specific instructions when your child first develops a high fever, looks ill or is extremely irritable.
  • It would also be important to contact your pediatrician if your child has fever with some of the other signs and symptoms of Kawasaki disease as described above.
  • You should also call your doctor if your child has had fever for more than two to three days and poor fluid intake with signs of dehydration.