Hello,
The brown spots that you have are due to post inflammatory hyperpigmentation after
acne. The
treatment for post inflammatory hyperpigmentation includes various
skin creams like hydroquinone, azelaic acid, corticosteroids, tretinoin cream and laser treatment but they should be used only under a dermatologist’s guidance. If it still persists then you can go in for laser treatment, Chemical peeling or microdermabrasion.
I hope it helps. Take care and regards.