For as long as I can remember, I have always had to have something to mess with with my hands. I have always bitten my nails, apart from brief periods where they have grown, before I chewed them all off again. I bite and pull at the bits of skin around my nails. This isn't too bad at the moment, but when I was younger I used to do it even though I bled.
If I get a cut or anything that forms a scab I pick and pick at it until it is a mess and have lots of small marks on my body from when I have done this.
As I teenager I could never leave spots well alone.
Currently I have 3 insect bites that would have gone had I not scratched and scratched them til they became sores.
DH has a real go at me over it, which doesn't really help. I don't know what would. I don't want to be covered in marks, but I can't help myself.