What exactly is this Kawasaki Syndrome—the rare disorder that John Travolta had said his son had suffered from before dying today at the age of sixteen?

According to the Mayo Clinic's website, it's an uncommon disorder that affects children, "that causes inflammation in the walls of small- and medium-sized arteries throughout the body, including the coronary arteries." It comes with a variety of unpleasant symptoms, including diarrhea and lots of skin peeling. But in most cases children suffering from Kawasaki Syndrome make complete recoveries after receiving proper treatment. However, Jett Travolta—whose parents described him as a Kawasaki sufferer amid reports that the boy was actually autistic—has had medical problems for years.

While promoting Ladder 49 in 2005, Travolta described what he said was the first time Jett suffered from Kawasaki Syndrome when he was 15 months old:

"He was hospitalised for five days. His whole body swelled up, it was chemical poisoning, from picking up toys or food particles from the carpet."

The supposed culprit was a carpet cleaner, so the family decided to go natural. Travolta's wife Kelly Preston told the Mirror in 2004:

Jett's whole immune system shut down and he got really sick with high fevers - 104and 105. He developed a rash on his body and swollen lymph glands - it was horrible. ... We're 90 per cent organic, though there's some canned foods - a little bit of junk food here and there.

But lots of folks just didn't believe this story, claiming that the boy's parents' rigid devotion to the Church of Scientology—a cult that doesn't eagerly recognize mental illness as anything that vitamins and exercise can't fix—was causing them to willfully deny what some saw as painfully obvious: that Jett was suffering from autism. Folks picketed the Travolta/Preston family, saying that their refusal to seek treatment for the boy bordered on—or, you know, flat out was—child abuse. Travolta's brother Joey even produced a movie about the condition, but the family continued to shut down any reports that autism was involved. They hewed to the Kawasaki Syndrome story while a glib world believed there to be some bigger secret truth.