Need help to hide cuts?

i need help hiding cuts right below my elbow (about an inch below) i have a concert in a little over a week and the uniform is a short sleeve uniform, no jackets, no jewelry. i have tried make up but one it doesn't cover it and two they are newer cuts. yes these are self inflicted injuries and i am getting some outside help with it (a guy on skype). my close friends and family do not know about it and i do not want them to find out. is there any way to hide them in a week?