Self-injurious behaviour, self-scratching - any advice?

[lottytheladybird]

My DS1 has autism and scratches his finger such that the skin is always damaged and will do it until it bleeds, too. Do you have any advice on how to prevent him from hurting himself?

No advice I'm afraid, but watching with interest as DS has recently started punching himself in the head. He always announces his intention "and now I must punch the head". So currently we are looking away when he says this, so no audience and no reaction...no entirely convinced this is the right approach

After some insect bites ds1 has started doing this so they never heal. He is really not aware he is doing it but as soon as he gets anxious then the scratching starts. ds2 alarmingly said pain can make him feel better as it is distracting and he will scratch on occasion but not to bleeding state fortunately. We have used plasters or long-sleeved shirts for ds1 which reduces it a bit. The other thing I wondered about (but haven't tried it yet) is a wrist band so he can fiddle discreetly with something to get the sensory input without harming himself.