After five and a half years as Elle’s publicist, including a starring role on MTV’s The City, Erin is leaving the magazine for Teen Vogue, she announced in an e-mail to her contacts today. She starts Tuesday and has not said what her title over there will be. Kaplan’s television experience — you know, the real behind-the-scenes work in addition to making Olivia Palermo look dopey on camera — must make her an attractive candidate to the many fashion magazines desperate for a hit TV show. And that is something Teen Vogue is working on. Update: Erin tells us her new title at Teen Vogue is senior director of PR.