Acne cysts

I am 25 years old a male and develop Acne cysts usually on the jaw line and neck area every two weeks or so i develop one of these cysts. i go to the local doctor and have cortisone injected into them which makes the cysts go down.after 24-48 hours. this works well, however I am curous if anyone else has any ideas. I use differn and ery Acne gel morning and night which helps but still have recurring cysts.
It is not worth going on roaccutane as i have very little Acne its just these darn cysts. any advice treatments recommendations would be great.
thanks
John Tweet