Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain darkening of skin can be due to exposure to sun and other irritants and chemicals prsent in air, as well as can be a side effect of certain medications, allergies, inflammation on face etc..
You should start washing your face with
salicylic acid or
glycolic acid containing facewash..
Apply creams containing
Kojic acid, glycolic acid and arbutin..
Apply
vitamin E oil at night..
Always apply sunscreen lotion when going out..
Exfoliate your face twice a week using a mild scrub..
Wash your face frequently throughout the day..
Take Vitamin C supplements..
You can also go for photofacial, glycolic acid peels and
microdermabrasion..
Hope this information helps..
Thanks and regards.
Dr. Honey Nandwani Arora.