Suggest Treatament To Cure Old Scars

Hello, I have old scars from a bad horseriding accident 30 years ago. The scars have been quiet and settled but now they are all raised, red and itchy/sore. Only the scars from that particular accident are involved (the horse was shot, and she and I went off a cliff together). The skin over some of the smaller scars seems to be disintegrating. I don't want this to happen on the bigger scars. What can I do?