Werewolf Book from 90s

Read a book in the 90s about a teenage girl who begins to turn into a werewolf. She's running through the forest and kills a racoon then wakes up in her bedroom thinking it was a dream but there was dried blood on her face and a foul taste in her mouth, then she finds what she thinks is a cat on the floor. She also meets another wolf and as a human a mysterious guy on a motorcycle. They never really talk and one morning after a night of running around as a wolf with this guy she wakes up naked on the side of the road and someone stops and drives her back to her parents' house. One day she's sitting in class and looks out the window and sees the guy on the motorcycle. She gets up and walks out of class and climbs on the back of his bike and they drive away, and that's the end of the story. (The two never really speak in the book) I think she might have been scratched by a wolf as a baby in France and when she turns sixteen this scar starts to burn/fester when the moon is full. Please help, I've been thinking of this story for years!