Dr Bollmann, Skin Care Specialist, Anti-Aging Expert
This is an answer to a question I was asked to answer on Quora (Quora.com).
Cystic acne, as you realize, is difficult to treat - but not impossible. It would be best to go to a good cosmetic dermatologist to get advice.
First to your concerns. Even though you feel this is not hormonal, you might try a different contraception method. Many IUD's contain progesterone, and this can contribute to acne. You might be better off with a combined oral contraceptive, one with estrogen and low in progesterone.
As you mention, it might be due to the pollution. A simple method would be a good skin care program. What I used in my med-spa was my own products, see Bare Skin Care Basic Program (sorry for the commercial, but you asked me how I would treat this). We do ship to China.
Below is a before and after of one of my patients with severe cystic acne. She is a beautiful Mexican patient, and I think her diet and environment contributed to her acne.



Initially she was treated with Doxycycline (an antibiotic) and my Bare Skin Care Program for six weeks. Then Levulan (alpha-levulanic acid), followed by IPL and light therapy.
After this healed, then an Obagi Blue Peel. The Levulan treatments can be repeated every 3 months if necessary. The Doxycyline continued for 90 days.
Residual scars can be treated by a Pixel or Fraxel laser, if not deep. Deep scarring requires a CO2 laser.
As you can see, there is hope, but cystic acne is difficult to treat and should be left to a competent cosmetic dermatologist.