What Causes Breakouts On Chin While On Medication For Acne?

I am 5ft 3inches, weigh 54 kgs and am 27 yr old. I have been suffering from acne trouble since puberty and have taken a number of treatments for the same ranging from oral medication to creams to ointments. However, I still continue to get breakouts with my chin area being the most problematic area. What would you advise?