Kawasaki Disease: Causes, Symptoms, Diagnosis, and Treatment

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Parents work hard to keep their kids safe, but preventing illnesses like Kawasaki disease (KD) is not always possible. KD is a rare condition that causes swelling in the walls of the blood vessels, resulting in a fever and other symptoms. It can become dangerous because it causes inflammation of the coronary arteries that supply the heart. 

Coronary arteries deliver blood and oxygen to the heart, so complications from KD can cause serious heart problems in children. KD is the most common cause of acquired (not present at birth) heart problems in the United States. Fortunately, there are effective treatments available. 

Most people who get KD are children under the age of 5, and according to the CDC, between 9 and 20 children out of 100,000 in this age group will develop KD. When your child is sick, it can be hard not to worry. However, it’s important to stay calm and speak with your child’s pediatrician to get the appropriate treatment and monitoring for KD. 

Signs & Symptoms

KD symptoms include a high fever (at least 102.2 F) for five or more days. This high fever will come along with these other symptoms like: 

  • Rash on the body or genitals 
  • Swollen/enlarged neck lymph node
  • Red bloodshot eyes 
  • Swollen hands and feet 
  • Redness on the palms of the hands and soles of the feet 
  • Red, swollen, bumpy-looking tongue (strawberry tongue)
  • Cracked, dry, red lips 

You might notice other symptoms in your child as the illness progresses. They might have stomach pain, diarrhea, joint pain, vomiting, and irritability. 

Whether or not your child has all of these symptoms, if your child is sick, you should take them to the pediatrician so they can get the right diagnosis and treatment.

Kawasaki Disease Complications

Without treatment, children with KD can develop permanent heart problems. Swelling in the walls of the coronary arteries or heart muscle can cause damage such as an aneurysm, which is the bulging of an artery that can result in blood clots, blood vessel rupture, or internal bleeding. After they recover from KD, scarring can build up in the damaged artery walls, causing the blood vessels to narrow. 

Without treatment, about 1 in 4 children will have permanent coronary artery problems. Heart muscle and valve problems may also occur, and a heart attack may occur. The lining outside the heart may become swollen, or fluid may collect in the space between the heart and the outer lining. The good news is that treatment effectively prevents lasting damage to the heart.

Many children with KD develop swelling in the coronary arteries as the disease runs its course. However, they usually make a full recovery with proper treatment. Early treatment of KD within 10 days is important to help prevent permanent heart problems. 

Kawasaki Disease Causes

We still don’t understand what causes Kawasaki disease comes from. Experts don’t think KD is contagious, so children with the illness don’t have to be quarantined. KD may occur after a child is affected by a bacterial or viral infection. There may also be a genetic reason that some kids get it and others don’t.

The biggest risk factors for Kawasaki disease are age and genetic heritage. Although the condition can affect older children and teens, it is overwhelmingly seen in children under the age of 5. It is also slightly more common in males than females and is seen most often in children of Asian descent.

Can Kawasaki Disease Be Prevented? 

KD prevention isn’t really possible. We don’t know what causes KD, so there’s no way to make sure your kids won’t get it. If you have young children, you should keep an eye out for symptoms of KD and consult your doctor anytime your child gets sick. 

A high fever that lasts more than a few days, combined with the other symptoms, is a red flag for Kawasaki disease. If you notice possible signs of KD, call your pediatrician immediately. 

Diagnosis

There is no test for KD. Instead, your pediatrician will review your child’s symptoms and perform a history and physical exam to try to rule out other possible causes. 

Several other conditions and illnesses can cause similar symptoms to KD. Your child’s doctor might check for:  

  • Scarlet fever (a bacterial illness caused by strep throat)
  • Toxic shock syndrome (a rare complication of a bacterial infection)
  • Measles (a viral infection that causes a fever and rash)
  • Rocky Mountain spotted fever (an illness carried by ticks)
  • Stevens-Johnson syndrome (a skin disorder triggered by medication)
  • Juvenile rheumatoid arthritis (a health condition causing joint pain and stiffness) 

Blood tests may be needed to rule out other possible causes of the symptoms. While there is no specific blood test for Kawasaki disease, your child’s bloodwork will typically show signs of infection, such as a high white blood cell count.

Heart function tests may also be used to diagnose Kawasaki disease. An echocardiogram, a specialized ultrasound type, can be used to check the heart and coronary arteries. Since KD can also cause issues with the heart rhythm, an electrocardiogram might also be performed to measure the heart’s electrical signals.  

Kawasaki Disease Treatment

Because early KD treatment is critical for preventing heart problems, children diagnosed with this illness are treated right away. This consists of two main treatments: IVIG and aspirin.

Patients with KD are given an intravenous (through the vein) immunoglobulin, or IVIG, infusion. This treatment reduces blood vessel wall inflammation and can help prevent permanent damage to the coronary arteries. 

Children with KD are also treated with a high dose of aspirin to reduce inflammation and fever. Since aspirin for adults can be dangerous for children and is rarely recommended for other illnesses. It is very important for the treatment to be monitored by a doctor. Children who contract chickenpox, the flu or another viral infection must be taken off aspirin immediately. 

Usually, the high-dose aspirin is given until 48 hours after the fever is gone. Then, KD patients will continue taking aspirin for 6 more weeks until their doctor can be sure that there are no heart problems. Some kids need to be hospitalized during the early stages of KD treatment as a precaution. Your child may also receive other treatments that are aimed at improving their symptoms and making them feel better while they recover.

Most kids recover from the initial symptoms of Kawasaki disease within two weeks, with or without treatment. However, they might be extremely tired for up to eight weeks. Symptoms will last longer without treatment, and kids are more at risk of heart problems if they don’t get treatment. Follow-up heart monitoring might be recommended for some children. 

Next Steps

If you think your child might have KD, it’s important to get your pediatrician’s help immediately. Since many of the symptoms overlap with other illnesses and health conditions, it’s important to rule other causes out before starting treatment. 

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