my body acne just wouldnt go away

hi.. i;m a 22 year old female and i;ve been having body acne (chest, arms, back) since i was 13.  
i;ve consulted many dermatologists but my condition has not gotten any better.
3 years ago, i was on acnotin for around 8 months. during the course of treatment, my condition improved tremendously especially my arms.  after 8 months, my dermatologist said that my treatment has completed.  however, in less than a year, body acne came back, concentrated more on the back and chest.  then, i went to another GP, and i was given clindamycin for 3 months.. as expected, my condition got better during the course of treatment.  once i stopped taking clindamycin, acne reappeared.  then, i consulted another GP and this time i was given tetralysal for 4 months and clindamycin gel as topical treatment.  while i was on this medication, my conditioned improved but again, once i stopped taking it, my body acne reappeared.
my body acne just wouldnt go away..
i;m just wondering, is there anymore treatment that i can try that have long term improvemtn result?