Blue line growing in thumb nail bed?

I have a thin but very obviously blue line growing in my thumb nail bed. I havent hurt it and it is growing with my nail; visible from both sides.

I dont know when it started but i have been aware of it for over 6months.

Any ideas. I would post a picture of it but i cant figure out how to post a pic in the box here.. Any ideas?

Thanks

You can use something like a Photobucket account, or just upload it to Imageshack, and link it from there.

http://photobucket.com/fingernail?albumview=slideshow[img]

can you see this picture?

woah!

Sorry I had not seen this response sooner.

If it's not a trauma injury to the site, unless it was a casual thing, you didn't notice, you know like when someone gets pain and can't remember how, then my other thoughts are, it could be caused by some kind of viral infection, vitamin or mineral toxicity / deficiency, or possible exposure to some kind of substance.

mineral toxicity, generally, grows across the nail bed, such that periods of exposure v non exposure come out in stripes, like the rings on a tree. i'd aim for trauma. at least it looks neat?