An 11-year-old Texas boy died suddenly this past weekend from a mysterious condition that causes inflammation of blood vessels throughout the body.

Paul Roscoe, of North Richland Hills, Texas, died after collapsing at his home Saturday morning.

His death was triggered by Kawasaki disease — a condition that affects children, especially boys, under the age of 5, and causes aneurysms and blockages in the blood vessels.

Dr. Scott Alenick, a pediatric cardiologist in Northern and Central New Jersey, said Kawasaki disease is fairly common; however it is extremely rare for someone to die from it.

We usually see it in the winter, but it can occur year-round,” Alenick, who has treated hundreds of cases of Kawasaki disease, told FOXNews.com. “It is very unusual to die from Kawasaki disease. This is really just a tragic case.”

Paul was a vibrant boy who loved to play baseball and go fishing, the boy’s father Paul Roscoe Sr. told myFOXdfw.com. "It's very rare that you could have a little boy, 11-years-old and honestly say you never had a bummer day,” said Connie Roscoe. “I never had a bummer day. He was always, always the most awesome kid.”

His death on Saturday came as a complete shock.

"He got up and as he walked to the door he collapsed,” Paul Roscoe Sr. said.

The family laid the boy down. “We turned the fan around on him, and he said that feels good. Those were his last words,” Paul Roscoe Sr. added.

About the Disease

According to the American heart Association, more than 4,000 cases of Kawasaki disease are diagnosed annually in the United States. It occurs more often in boys of Japanese and Korean descent, but has been identified in children of all ethnicities and races, said Alenick.

While the condition is not preventable, it is treatable with most children recovering from the disease. In fact, less than 1 percent of Kawasaki cases are fatal.

Sadly for the Roscoe family, their young son was among that 1 percent.

The danger of Kawasaki disease is that it can cause large aneurysms in the blood vessels that feed blood to the heart, said Alenick.

“Kawasaki doesn’t come in degrees of severity, but it varies in that it may cause no aneurysms, small aneurysms, moderate aneurysms or giant aneurysms,” he said. “Giant aneurysms are more common in babies. But it’s the aneurysms that form in the vessels and the arteries that feed the heart that have the potential to cause a fatal heart attack.”

The disease was first identified in Japan in 1967 by Dr. Tomisaku Kawasaki, AND the cause of the illness is still unknown, said Alenick. There also is no blood test to identify the illness. Instead, patients are given a clinical diagnosis based on whether they display at least five of these six symptoms: a high fever that lasts for more than five days, red lips and tongue, swelling of the hands and feet, bloodshot eyes, rash and swollen glands.

Once a diagnosis is made, patients are given high doses of aspirin to control the inflammation and put on an IV drip consisting of gamma globulin. Once the initial inflammation is brought under control, most children are kept on a low dose of aspirin to prevent clots and aneurysms from forming in the veins, Alenick said.

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