What Is Kawasaki Disease? Experts Say This Childhood Illness May Be 'Wind-Borne'
The autoimmune condition causes a bright red rash and, in rare cases, a serious form of heart disease.
Doctors in California made headlines this week when they issued a statement about a recent rise in Kawasaki disease in San Diego County. Kawasaki disease is a rare childhood illness that can cause fever and a red, bumpy rash, and in a small percentage of cases, a life-threatening form of heart disease.
That sounds scary enough, but one detail of recent news reports really stood out to us: The disease is sometimes described as wind-borne, with experts warning that the number of cases is likely to increase in the coming months because of seasonal weather patterns.
So what does this mean, exactly, and should we be worried about a disease that’s supposedly traveling on the wind? To find out more, Health spoke with Michael Portman, MD, a pediatric cardiologist at Seattle Children's Hospital with a specialty in Kawasaki disease. Here's his take on the latest news, and what parents need to know.
What is Kawasaki disease?
Kawasaki disease occurs mainly in children between 6 months and 5 years old, although older children and teenagers can get it as well. The symptoms resemble many other childhood illnesses, says Dr. Portman, which means that it’s sometimes missed or misdiagnosed by doctors who aren’t familiar with it.
“Kids get a fever, a rash, red eyes, swollen lymph nodes, and swelling of their hands and feet,” says Dr. Portman. “They can also get cherry-red lips and cracking of their lips, and eventually because of the swelling, they develop peeling around their fingertips.”
Most children who develop Kawasaki disease will make a full recovery. But about 7% of patients develop a dangerous complication known as coronary artery aneurysms. “These are little sacs that swell in arteries that supply blood to the heart, and they can cause clotting and block blood flow and actually cause heart attacks,” says Dr. Portman.
Kawasaki disease first appeared in Japan in the 1960s and Hawaii in the 1970s. Today, in the continental United States, the incidence rate of Kawasaki disease is estimated to be between nine and 19 per every 100,000 children under age 5. In other words, it affects about 5,000 U.S. children a year. Sixteen San Diego kids have been diagnosed so far in 2019.
What causes Kawasaki disease?
There’s a lot that doctors don’t know about Kawasaki disease. But they do know that it’s an autoimmune condition, which means its symptoms are caused by the body’s own immune system overreacting and attacking itself.
Researchers suspect that some people are genetically predisposed to Kawasaki disease. Asian Americans and Pacific Islanders, for example, have a significantly higher risk than Caucasian Americans.
“There’s also a theory that there’s some sort of infection that children get prior to Kawasaki disease, which sort of resets the immune system and triggers this type of reaction,” says Dr. Portman. “We don’t know what that infection is—it could be multiple types of infections, and it could be viral or bacterial.”
Other Kawasaki experts suspect that weather patterns may be involved—which is where reports of a “wind-borne” disease come from, says Dr. Portman. Some studies have noted that Kawasaki disease peaks on the West Coast of the United States in the winter and spring, soon after it peaks in Hawaii and Japan.
“One theory is that there’s a wind that comes from Central Asia that carries something—some infectious agent—that causes Kawasaki disease,” says Dr. Portman. “But this hasn’t been proven, and if it is something in the wind, we don’t know what it is.”
Dr. Portman also worries that the “wind-borne” description could imply that Kawasaki disease may be contagious from person to person. “That’s definitely not the case,” he says.
There’s no evidence that Kawasaki disease can be transmitted through coughing, sneezing, or sharing utensils, Dr. Portman adds. “We don’t see Kawasaki disease going through entire families the way the flu or the common cold does,” he says. “If one child gets sick, it’s not like other children are going to catch it from him or her.”
How is Kawasaki disease treated?
Without treatment, most cases of Kawasaki disease will go away on their own—and most kids will go on to lead perfectly normal lives. But children will feel better faster if they receive a treatment called intravenous immunoglobulin (IVIG)—a blood infusion that’s delivered over a 12-hour period. This treatment can also reduce a child’s risk of developing dangerous cardiovascular complications.
Clinical trials suggest that this treatment is most effective if it’s given within the first 10 days, “but that’s not a hard and fast rule,” says Dr. Portman. “If someone comes in and has had a fever for 11 or 12 days, we’d still give IVIG.” Children who do develop coronary artery aneurysms might require further treatment, like blood thinners or even surgery.
High doses of aspirin can also help reduce pain and inflammation associated with Kawasaki disease. Since aspirin isn’t usually recommended for children, however, it should only be given under a doctor’s supervision.
How can your protect yourself—and your kids?
Parents shouldn’t freak out about a slight increase in Kawasaki disease and shouldn’t worry about their children catching it from the wind or from other kids nearby, says Dr. Portman.
“Here in Seattle, we are in our high-frequency period and are seeing an uptick in cases—about one to two a week right now,” he says. “But that’s still nowhere near the incidence of other childhood diseases, so it’s not something to panic about.”
It is helpful for parents to be aware of Kawasaki disease, however, and to know how to recognize the signs. “If your child does have these symptoms, you should ask your pediatrician about it,” he says. (And see a pediatrician specifically, he says, since doctors who don’t specialize in children may not be familiar enough with Kawasaki disease to diagnose it.)
A fever that lasts more than five days can be a warning sign, as well, especially if it’s accompanied by any type of rash. “Sometimes doctors will prescribe antibiotics for the fever,” says Dr. Portman. “But if the antibiotics don’t work after a few days and the fever doesn’t go away, you need to be thinking about Kawasaki.”
Dr. Portman also points out that Kawasaki disease can mimic measles, another childhood disease that has experienced an uptick in cases in recent months. “There can be some confusion as to what’s actually causing these types of symptoms, especially if a child isn’t immunized against measles,” he says.
While keeping children up-to-date on their vaccines won’t necessarily protect them from Kawasaki disease, Dr. Portman points out, it will protect against other illnesses that are more common—and a bigger threat to their health.
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