I really like this photo. It's got the right balance of creepy/horror and a subtle innocence. She doesn't look like she's posing as angry or vile; just kind of vaguely interested.
First off let me just say that the fake blood=amazing. Why? It doesn't have that weird pink-ish undertone to it, it looks like actual blood-- and that's the creepy part! You can just see how realistic it looks on her chin when it's that dark, opaque red... it looks truly gory and legitimate. Brownie points for you.
I also like the softening details like the animal print or cursive writing tattoos, and the way she holds the clump of hair. It kind of triggers your mind to think there was some kind of story that the hair has to it (or maybe she just went crazy and tore it out xD). Either way, it's a great detail.
The only constructive critisism I have is that the eyes seem a little too black. I feel like there should be a bit more of a catchlight in them to show the complete black eyes realistically, but I didn't even really notice that until I stared at it for a while. So obviously this had me impressed at first glance!
Overall I really like this picture and the mood it presents. This is a very intriguing phto-- keep up the good work!