A state of extreme worrying in which the man/woman/boy/girl is so nervous about something that they experience a severe acne breakout. Often, but not exclusively, occurs the night or morning before a big date. In high school, this phenomenon has been known to occur before school picture day, or before a big test.
Jack was so worried that he might do something stupid on his date with Diane on friday, that he had a nervous breakout. Needless to say he cancelled the date. It is better to cancel at the last minute than to show up with a pizza face.