What Causes Acne On Upper Part Of Hand, Shoulders And Back?

I have acne on upper parts of my hand and shoulders and entire back which started 6 years ago. I saw a dermatologist today and she gave me flucos 150 tablets for 15 days and candid tv suspension to be put on the affected areas and then bath after 1 hour and then apply benzonak 5%lotion.
Do you think it will help?
And also if acne goes away from these regions,will it start to come on my face or any other part of my body?