Marci I think it was in 'Maggie' that he says he just couldn't get clean. Like Adam's review said it was dirt from his son's grave but it also reminded me of mentally ill people who harm themselves by cutting themselves.
Adam It was first introduced after he buried his son. He recognized that he still had Maggie's blood on his arm, picked up a handful of dirt from his son's grave and rubbed his arm with that dirt until his blood replaced her blood. It was implied that he would also tend to pick at it as it itched and scabbed over. Amanda noticed this constant picking, which kept the raw skin from healing, and attempted to bandage it sufficiently as to keep Dylan from messing with the scarring tissue further.
Ursula Did you ever figure it out? I'm halfway through the book and I haven't figured it out yet. I, too, thought I had missed something. It's obvious he picked at it until it was in that condition, but from what specifically? Was it from getting hurt and he picked at it unconsciously, and just "dealt" with it as a way to take his focus away from what he was going through... or what?