Too many rivulets of blood as well- blood is thick and has cohesion so it tends to stick together. Maybe only one or two branches as it runs down the arm. Also, it'll be rounded at the ends where the drops pool up, not spiky, and won't thin out so much- nearly as wide at the bottom of the stream as at the middle. If you can actually bump-map or distortion-map the drops at the end, that'll add even more realism.