At first, Deborah Kogan of New York says, she thought it would pass. Her 4-year-old son's fever had been on the rise for hours, and he was looking puffy. Kogan took Leo to the pediatrician, who thought it might be strep throat. It wasn't.
A few days later, Leo "woke up, and he looked as if he was one of the characters in The Nutty Professor. His face ballooned about twice its normal size." She posted a photo of Leo on Facebook. That's when the crowdsourced diagnosis took shape.
On Facebook, a cousin wrote, "Look, I really think you should check and make sure it's not Kawasaki disease." A pediatrician from the Bay Area posted, "I hope the doctors have ruled out Kawasaki disease." And so it continued.
Kogan had never heard of the disease but didn't need more warnings. She took him to the nearest hospital, where, indeed, he was diagnosed with Kawasaki disease.
Kawasaki disease was discovered by Japanese pediatrician Tomisaku Kawasaki in 1967, but it wasn't until the 1970s that the Japanese Ministry of Health made a further inquiry. That's when they realized that children were dying — not from the disease, but from the heart attacks that followed, says Dr. Jane Burns of the University of California, San Diego.
Burns is the foremost expert on Kawasaki disease, but even so, not a lot is understood about it. It's a condition that causes arterial inflammation and also affects lymph nodes and mucous membranes. Symptoms include swelling, like Leo's face, fever and even peeling skin.
It's a rare disease that mainly affects children younger than 4. It's estimated that more than 4,000 children get the disease each year in the U.S., but it's far more common in Asia, particularly in Japan, where 1 out of 150 children are infected. Scientists say it's unclear how the disease spreads.
But a few years ago, Burns started to notice a pattern: The disease appeared to be seasonal. "That meant that in January, February, March we were going to be very busy, and then in September, October, that was a good time to take our vacations," she says.
Japanese researchers noticed a similar pattern. Together, they worked with a group of climate scientists who started to analyze atmospheric data.
What the climate researchers found was an association with the direction of wind circulating in the troposphere at heights of 3,000 meters, Burns says. When those wind currents blew in one direction, across Japan, then across the Pacific, to the West Coast and Hawaii, the number of U.S. cases increased. When the wind blew in the opposite direction, the number of cases fell.
The data were so overwhelming that Burns and her team thought it couldn't be coincidental. If this theory about Kawasaki disease is true, it could open up a whole new understanding of how other human pathogens are spread. No human disease has ever been shown to cross an ocean by wind and still remain infectious.
Meanwhile, Leo Kogan recovered fairly quickly after being pumped with a blood product made up of antibodies, a process that his mother says was terrifying.
"I don't think I have been traumatized by anything as much as I was traumatized by having a child with Kawasaki disease," she says. "What is extremely difficult about having a kid with Kawasaki disease, before the diagnosis, is just the not knowing."
Leo is now a healthy 5-year-old. While Kawasaki disease is still rare, the number of cases both in the U.S. and Japan have been rising steadily each year.
Copyright 2012 National Public Radio. To see more, visit http://www.npr.org/.