Leighanne Littrell said she is concerned that children who are misdiagnosed or diagnosed too late because their parents or their doctors aren't aware of the syndrome will suffer from KS-related health problems later in life. KS is a leading cause of acquired heart disease in the United States.
"Listen to your instincts and hopefully you're wrong, but maybe you're right," Leighanne Littrell said.
Heart problems are not unknown to the family. Brian Littrell had two heart surgeries: one at age 5 to correct a heart murmur and again at age 23 in 1998 to repair a hole in his heart.
But KS is not hereditary. The latest data and theories suggest KS is viral or bacterial in nature because of how it presents; because it is seasonal, occurring most often during the winter and spring; and because each person responds to the syndrome in a highly individual way.
"Certain kids have certain issues with it and certain kids won't," Bockoven said. "It's each specific body's reaction."
And there is still no definitive way to diagnose KS.
"There is no special test to be able to do to say this is Kawasaki," Frenck said. Aside from the hallmark high fever, "it can look like almost anything."
KS primarily affects children under the age of 5, though it can occur in older children. According to the Centers for Disease Control and Prevention, about nine out of 100,000 children have KS. Incidence is higher among Japanese and Korean children, though KS can occur among any ethnicity.
Baylee's follow-up treatments involve some echocardiograms to monitor swelling in the coronary arteries, doses of aspirin and possibly another course of immunoglobulin.
Brian and Leighanne Littrell are careful now to keep him from activities that might stress his heart.
"We're a little scared now," Leighanne Littrell said. "We don't know how to act. But he's acting perfect."
For being a model hospital patient, she said that Baylee received Batman and Superman outfits.
"He walked out [of the hospital] as Batman," Leighanne Littrell said. "He's our hero."
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