Does anyone personally know someone who was diagnosed with histrionic personality disorder?

Yes: I have several friends with hpd. They can be quite delightful companions, but one learns over time that their lives nearly always are full of drama and turmoil seemingly outside their control. Emotions can rapidly shift, and their reactions even to relatively minor snags in life can be suggest that the world as they knew it is about to end. That said, they also can be the life an any party.