Kawasaki disease: A rare, but serious childhood illness

Kids get fevers all the time, but when they spike a high fever or the fever lasts for more than a day, it can make any parent worry.

Take Karie Rego, 47, of Lebanon, New Hampshire, whose 3-year-old daughter Marina came down with a mysterious high fever eight years ago.

“She didn’t have symptoms of the flu or the typical things you would have when you are sick,” Rego said.

But when Marina developed a rash on her trunk which spread to the rest of her body, Rego brought her to the doctor.

“The first time he said something was going around her school,” she recalled.

Yet after three days the fever persisted and Rego asked that Marina be admitted into the hospital.

Once there, the whites of her eyes turned red, her hands swelled up and her tongue became red and inflamed. After doctors ran a few blood tests, they told Rego that Marina had Kawasaki disease, a rare, but potentially serious, even fatal illness.

Marina was treated and discharged within 24 hours but the next day the fever came back and Rego started to worry. The toddler was admitted into a different hospital to be evaluated.

“She remained fever-free for 24 hours so we were able to avoid a second treatment,” Rego said.

What is the Kawasaki Disease?
Kawasaki disease is a rare condition that affects children of all ages, but it’s more common in children between 6 months and 5 years of age. Between 9 and 19 in 100,000 children under the age of 5 will be diagnosed with Kawasaki disease and it’s the leading cause of acquired heart disease in children in the United States, according to the Centers for Disease Control and Prevention (CDC).

“Something triggers the body and it tricks it into having an immune attack on itself,” said Dr. Michael Portman, the director of pediatric cardiovascular research at Seattle Children’s Hospital, who added that it’s usually a bacterial or viral infection that triggers an immune response.

Kawasaki disease is not contagious and most children will recover. Yet what makes it potentially serious and even life-threatening is that it can lead to vasculitis, or an inflammation that affects the medium-size blood vessels in the body, including the coronary arteries in the heart, said Dr. Nadine Choueiter, a pediatric cardiologist at the Children’s Hospital at Montefiore in New York City.

Left untreated, 20 percent of children will develop aneurysms in the coronary arteries which can lead to blood clots. Plus, boys less than a year old have an increased risk for heart disease, Choueiter said.

The healing begins four to six weeks after the onset, but the process can cause narrowing of the arteries. If the child hits the soccer field, for example, he can have a heart attack.

Symptoms of Kawasaki disease

Since there isn’t a blood or a urine test to diagnosis the illness, doctors rely on symptoms:

?        4 to 5 days of a persistent, high fever that can improve and then worsen

?        A splotchy red rash on the body

?        Swollen lymph nodes

?        Red palms, hands and soles of the feet

?        Swollen hands and feet

?        Conjunctivitis, or “pink eye”

?        Red, chapped lips

?        A puffy, “strawberry” tongue

If children have these symptoms, doctors will run blood tests to look for blood count and the level of C-reactive protein (CRP), which indicates that there’s inflammation in the body.

“The blood tests that we do are to support our concern and our diagnosis for Kawasaki disease,” according to Choueiter. “But it doesn’t specifically point to Kawasaki disease because these labs can be abnormal in other infectious diseases.”

Since symptoms like fever, pink eye and swollen lymph nodes are common when children get infections, it can challenging to make an initial diagnosis. Also, children who have a fever but no other symptoms can be misdiagnosed, leaving them at risk for heart problems down the road, Choueiter said.

An echocardiogram can confirm if the coronary arteries have been affected and help guide treatment. Yet not all children with Kawasaki disease will have dilated or abnormal coronary arteries at the time of diagnosis or even up to two months afterwards, Choueiter said.

Risk factors
There is no known cause of Kawasaki disease but it is 10 times more prevalent in the Asian population than in the general United States population.

One theory is that it’s genetic and a recent study in in PLOS ONE found that a variation in the gene ORAI1 may explain why people of Asian descent are more at risk.

Yet researchers haven’t found a single genetic factor responsible.

“There is genetic susceptibility but we don’t find it substantially different between Asians and non-Asians,” Portman said.

Children who consume a diet high in soy may be at an increased risk for the illness, according to a recent study co-authored by Portman.

Treatment
Children diagnosed with Kawasaki disease are given high-dose aspirin for 2 to 3 days and then a course of low-dose aspirin, along with a treatment of intravenous immunoglobulin (IVIG) for 12 hours to reduce inflammation.

Since IVIG is effective in 80 percent of patients, has side effects and has only been shown to work within 10 days after onset, researchers are studying new treatments that can be used alone or along with IVIG.

If a child’s fever persists after 36 hours, they will need a second dose but it’s less effective.

“It’s difficult to understand who is going to respond and who isn’t going to respond to the IVIG,” Choueiter said.

Children who have heart changes will need to be monitored throughout their lives, and although rare, some may need surgery, a stent or even a heart transplant. Those with aneurysms will need to take blood thinners and avoid contact sports, for example.

Research is currently being done to find ways to diagnose Kawasaki disease earlier and avoid misdiagnoses.

Today, Marina is a healthy 11-year-old. Since she was diagnosed and treated early, she didn’t have any problems with her heart but she continues to get an echocardiogram every 3 to 5 years.

“The key thing here is catching it early,” Rego said.