WASHINGTON (AFP) ― An airborne toxin that is blown into Japan from northeast China could be the cause of the mysterious Kawasaki disease, a childhood illness that mostly affects the very young, researchers said Monday.

Kawasaki disease occurs worldwide but is most common in Japan and causes fever, rash, peeling fingernails and in about 25 percent of cases it can also lead to coronary aneurysm, a life-threatening ballooning of arteries that supply the heart.

While its cause has eluded researchers ever since the disease was first identified in 1967, scientists noticed it tended to affect children in Japan only at certain times of the year.

“There are certainly other source regions around the globe, but focusing on the link between northeastern China, Japan, Hawaii and the West Coast of North America is our best bet for figuring this out,” said lead author Jane Burns, professor and director of the Kawasaki Disease Research Center at the University of California, San Diego School of Medicine.