My son is on day 46 and his derm says yes, it works from the top down. His forehead is the clearest part of his face now, when it used to be the worst. It definitely seems to be clearing from top down. His neck is worse than it ever was, with many more cysts, sort of like yours. Chest/back are another story altogether 
Hope you have a positive experience and it clears you
Yeah I think that's how it is for most, guess it could work differently for everyone. And my forehead is also the clearest, although it never got much acne to begin with. My neck is definitely the worst part right now as well, but tell him to keep trudging through because I heard month 3/4 are the real turnaround months.
Thanks, and best of luck with his course as well!
Ahhh, I hope you're right about month 3/4! If that's the case, I can't wait for those months! Halfway through the 2nd month, and it's so hard to be patient. I took Accutane myself as a teen (many years ago) and I wish I could remember when it really started to clear, but it was so long ago that I cannot remember those types of details. I should have kept a log or a diary. But that was way back in the old days- the 80s 
The main thing I do remember is being so happy and relieved to be so much improved. So, it was a good experience for me. And I haven't had any ill health effects from it to this day.
I'm hoping my son will 'inherit" the same positive experience with the drug. I am not in favor of prescription drugs, but rather prefer natural treatments. But after trying so so sooo many other things, this was the last resort. Severe cystic acne can be so brutally devastating to one's psyche.
Keep us posted!