When you've been without a date for a long, long time, haven't seen your Mom for ages, and no one has hugged you forever and you need someone to touch and hug you, that's skin hunger.
When you are lying in bed or sitting on a park bench and begin fantasizing about lying in bed holding another person and NOT thinking about sex. That's skin hunger!
"Wow. I just met this guy and he grabbed and hugged me the first time he saw me and he said, "Hello!!". My skin felt like it had been electrically buzzed! I have such terrible skin hunger."
I went to a masseuse. As he was massaging my legs and back and my skin was sizzling, I realized no one had touched me in a long, long time. Pure skin hunger!
When all you want is to makeout/have sex with the opposite sex.
Joe: Man, I haven't gotten any action in weeks. I just wanna do something!
Dave: Dude, thats just skin hunger.