Paul Karason is feeling blue - literally.

The US man used a silver extract to treat a skin condition. But it ended up changing the colour of his face, leaving him with a deep blue tinge.

The 57-year-old was fair-skinned and freckled 14 years ago, until he developed a bad case of dermatitis caused by stress. When it got so bad that the skin on his face began to peel and crack he began to use a substance called colloidal silver, he told US television.

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The product is said to be made by extracting silver from metal into water with an electrical current before it is drunk.

But Mr Karason said drinking the potion did not cause his skin to discolour - the change happened when he rubbed he potion directly onto his face. He said: "The change was so gradual that I didn't perceive it and other people around me likewise.

"It wasn't until a friend I hadn't seen in several months came by my parents' place to see me and he asked me 'What did you do?'"

He has since moved from Oregon to Madera, California, in a bid to start a new life. He said: "I hope that they just accept me and learn to like me. And I think that will happen here. Where I was, I rather doubt it would have. This is a different kind of community here."

Girlfriend Jackie Northup told a local television station: "The only time now I really think about it or notice it is if we're out in public and people start staring."