The term you might be thinking of is "Furnunculus Curse", which is a jinx that causes boils to erupt on the victim's skin.
It's used in the Triwizard Tournament, specifically in the second task, where the merpeople give Harry this curse as a distraction. It is not a particularly powerful curse, but it is quite unpleasant.
The curse is mentioned in both the book and the movie, and it's one of the many curses Harry has to contend with during the Triwizard Tournament.