Anyone with experience with someone with histrionic personality disorder?

Yes: Psychiatrists, psychologists, and other mental health professionals have experience with people who have histrionic personality disorder. Many other physicians encounter and work with them also, but are not the primary ones to treat this problem. Mental health professionals would be best suited to help such a person directly.

Histrionic: The hallmark of a histrionic is that the person has to be at the center of attention at all times. It's like watching an actor who is always playing a role "on stage" and very uncomfortable with NOT being the center of attention.