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.