Hi. Greetings. The following precautions would help you :
1. Daily use of sunscreen in day time of SPF 30 applied half hour before sun exposure
2. Daily bed time use of moisturiser like cetaphil or emoderm. Reapply during lunch break during office hours.
3. Peeling agents prescribed by dermatologist for reducing tan
4. Evaluation by dermatologist as to cause of skin pigmentation or dullness
5. Kindly read my blog on daily skin care on Practo health feed.
Hope this helps.
Warm regards. Dr Govind S Mittal, excel care hospital, Bangalore.