What should i do about my dogs itch condition?

well, my dog is 77 years old, yes i know he is old. anyway, he keeps biting his outer thigh. We bought him a cone, but he also keeps barking and yapping! he gets really annoying. We have taken him to the vet, he has no ticks the vet didn't say he had fleas either, and i brush him daily.I also tried neosporin. He only barks when he is alone, outside. before, his fur was gone, but now it is starting to grow back.i really want to help get this itch or pain go away so please help if you can, thanks.