Thanks for writing in.
The problem can be fixed drug eruption
Without actual visualisation of the skin it is not possible to comment on nature of pigmentation.
Sun protection is most important for any cosmetic treatment.
Use good quality sunscreen.
Avoid sun exposure.
Use brevoxyl face wash.
Apply Kojivit cream at night over dark spots.
Take lot of vitamin C
Visit a dermatologist
for proper examination and diagnosis who can also provide you some clinic based procedure like surgery and laser.
Hope this helps.