Is the skin bleeding or the feathers? Sometimes when a blood feather is damaged they will bleed like crazy. What you have to do in this case is actually pluck out the blood feather to stop the bleeding. You need to pluck it out, or else the bird could actually hemorrhage and die as a result. If the skin is bleeding then the bird needs to be separated until the bleeding stops and then have the bleeding area camouflaged with something like Blukote.
Good luck.