Hi, I am Dr. Shreyash Mehta, MD Community Medicine As you told that a girl scratched your forehead badly with her nail and removed the top layer of skin quite deeply. It bled quite a lot and has left a claw-scratch shape (about 2cm). You did not mention whether 2 cm was the length of scar or depth of it. The skin would grow by itself. You should get regular dressing(twice daily) of the wound. This may help it heal without scarring. The scar will take about a week to heal.