A REAL-life "blue man" who became an online sensation after his skin turned deep blue from drinking silver has died in hospital.

American Paul Karason died on Monday at a hospital in Washington after suffering a heart attack last week, the US Today show reports. Karason, who also had pneumonia and suffered a stroke, was 62, said his estranged wife Jo Anna Karason.

The reclusive Karason shot to fame after appearing on the US Today show in 2008 to discuss his unusual condition, called argyria. His skin began to turn blue 15 years ago, after he started using a silver colloidal drink to treat dermatitis on his face, after spotting an ad touting its health benefits in a new age magazine, US ABC News reports.

Collodial silver –silver dispersed in liquid- was used to fight infections and colds for thousands of years, but fell out of use with the invention of penicillin in the 1930s. It was banned in the US for causing argyria when the silver reacts with light to turn skin blue.

Mrs Karason said her late husband was sometimes called "Papa Smurf" because of his blue skin and bushy white beard. He didn’t like going out in public often, she said.

"That was a nickname he didn’t appreciate, depending on who said it," she said. "If it was a kid who ran up to him saying ‘Papa Smurf’, it would put a smile on his face. But if it was an adult, well…"

Karason didn’t realise his skin had turned blue until a friend pointed it out, he told US ABC News.

“He looks at me and says ‘What have you got on your face?’ ‘I don’t have anything on my face,” Karason said. “He says ‘well it looks like you’ve got camouflage makeup on or something. And by golly, he came in and he was very fair-skinned, as I used to be. And that’s when it hit me.”

Despite the extreme side effect, Karason was convinced the colloidal silver cured his other health problems, including his acid reflux and arthritis.

