I noticed that when I render sss without AO and added a light the sss did not cause the light around the skin. When I added ao and fastao, any sss skin of the same character that intersected with itself tended to have a glow around it. If however, I intersected with another character I did not have the glow and the skin surface.
Two examples. One with intersecting sss skin without ao and one with. There is no glow on either hand.