Hi kdlynn,
it sounds like a typical TAT:
Tiny Accidental Tattoo!
(I just invented a disease!)
Some tiny particles, may be blue-black
dusty bits entered the skin and have
been fixed and engulfed by macrophages.
Just like in a tattoo.
Take care
ikod
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fhealth.yahoo.com%2Fmedia%2Fmayoclinic%2Fimages%2Fslideshow%2Fc22_rtmark.jpg&hash=a436abc38a92f50ed571969857f39802)
http://health.yahoo.com/media/mayoclinic/images/slideshow/c22_rtmark.jpg
more about tiny tiny tattoos: http://health.yahoo.com/topic/cancer/treatment/article/mayoclinic/491544AC-2A5D-9994-EBE274EA4E6F431B