Kawasaki disease is a rare condition where the body’s immune system attacks the body’s own tissues. This results in inflammation of blood vessels (including the coronary arteries, which supply blood to the heart) and heart muscles.
Kawasaki disease is the most common cause of acquired heart disease in children in developed countries, affects boys more than girls, and most commonly affects children under 5 years of age.1 It’s a poorly understood disease, and its cause is unknown.
When Kawasaki disease attacks tissues in various parts of the body, it may lead to the following symptoms:
- High fever for more than five days
- Skin rash that’s not itchy, followed by peeling of the skin around the fingers and toes
- Swelling and redness of the hands and feet
- Inflammation and redness of the white portion of the eyes, i.e., “bloodshot” eyes (conjunctivitis)
- Redness of the tongue with prominent bumps on the back surface (also known as a “strawberry tongue”)
- Cracked lips
- Enlarged lymph nodes (lymphadenopathy)
The fever is usually above 102°F and can last several days to a few weeks. It’s typically not responsive to fever reducers such as acetaminophen (Tylenol) or ibuprofen (Motrin). Children can be very irritable due to the increased inflammatory process in the body. This is sometimes accompanied by headaches, vomiting, or abdominal pain. Some children can have a fever for less than five days and not all the classic symptoms of Kawasaki disease. These cases are diagnosed as “atypical Kawasaki disease.”
Progression and possible complications
If Kawasaki disease isn’t treated promptly, the heart may be impacted in several ways:
- The heart muscles and valves may function abnormally.
- Fluid may build up in the sac surrounding the heart.
- The coronary arteries (which supply blood to the heart muscle) may become enlarged and dilated (aneurysm) and eventually develop blood clots (occurring in only a small portion of patients.)
There are no tests that can specifically diagnose Kawasaki disease. Blood tests can help suggest this diagnosis. Once Kawasaki disease is diagnosed, treatment should begin immediately to prevent the heart from being affected. Heart-related complications usually occur several days after other symptoms. Rapid recovery from early symptoms is expected following treatment; however, patients usually recover eventually without treatment but continue to have an increased risk for heart problems.
Two medications are used to treat Kawasaki disease:
- Immunoglobulin (IVIG) – This medication must be given through an IV line in the first week of illness, significantly reducing heart artery risks. The condition typically improves within 24 hours after IVIG. This medication can be repeated once if the child does not improve significantly.
- Aspirin – Aspirin is given initially in high doses to reduce inflammation. The dosage is then reduced and continued for at least six weeks and possibly months to years if heart disease is suspected.
Other drugs, such as acetaminophen (Tylenol), aren’t effective. The goal of treatment is to prevent the heart arteries from being affected. If they’re affected, serious conditions such as heart attack may occur.
Examining the coronary arteries using ultrasound (echocardiography) is critical. It should be done once the diagnosis is made, usually at least six weeks later. If a child has problems with the heart arteries, the patient will need long-term follow-up with a cardiologist.