Mark each spot induvidually, then blur them? Or make a new layer, and draw the skintone over the spot, then blur that. :-) I think that would work.
Before:
http://i43.tinypic.com/okac7n.jpg
Yah, its meant to be dithered. (It actually looked better then. xD) This is the most recent picture of me on my laptop, since it, frankly, is the only one I bothered to move over. You've got to admit it though, I was a awesome baby.