Senile Purpura - Old people's purple splotches is the loose translation.
My arms are currently healing. I hit my hand on a locker at the pool and then massaged it, which has, once in awhile, spread it around so that it was nearly invisible. Today, it took one small dark purple dot to a large geographic looking splotch. ARUGH.
On the upside, my latest google search method is really panning out for me. I've gotten so that I use search terms based on looks and when I get results, click on images, find one that looks like what I want and follow it to the page. It's solved a bunch of mysteries for me recently.