I Don't know what this patch on my upper thigh is... I think it may have appeared at least in the last month... No change in diet, I'm not sexually active, I've not been exposed to anything exotic or foreign that I know of but I do it sushi on the regular. It's dry and the darker area is raised slightly, with a sort of rough feeling all around. Not a good picture, but http://imgur.com/yUchO there's an image of it. In more detail there are red lines that look like veins branching off the darker area.