It's really hard for me to say. Pre-T the only way I could control the acne was to use the BC pill. I went off the pill about 2-3 months before starting T, so it started getting bad again right around the time the testosterone was hitting my system. Not sure if it was the presence of T, or the absence of E, or both that was at issue then. It continued to be a problem until about 4 or 5 months ago when I finally worked out something with my doctor that worked reasonably well for me. I still have some problems with acne, but now it's mostly small eruptions on my forehead and cheeks, rather than the cystic acne I used to get on my chin and back. Shortly after starting T I also got a little bit on my chest, which I had never had (other than occasionally under the dread fat bags.) Fortunately, that seems to have finally cleared up. My skin is definitely more oily than before.
P.S. I have found that I get less "bacne" if I use dandruff shampoo when I wash my hair. A lot of dandruff shampoos use the same ingredients as acne medications. I thought I'd throw that out there as something to try, for those of you who are having trouble with acne on your backs. 🙂