It seems partly OCD
I thought this in the back of my mind, and I've pondered an e-collar for him. Sometimes he genuinely itches, but other times it seems like he's doing it out of habit. But my goodness, his nickname is "Destruct-o" without an e-collar, I can't imagine him banging around the house in one of those!
Guess we'll find out!
Will definitely swing by Petco and pick up the Sulfadene on my way home today, thanks for the recommendation!