It is a difficult condition to treat as it's known for relapses. a seasoned Dermatologist will explain you more about the condition.
A good skin care regimen comprises 4 steps - cleansing, toning, moisturizing and sunblock.
Based on your skin type, a dermatologist will recommend you appropriate products. Peels like glycolic acid and lactic acid will help in lightening. Dermapen in combination with mesotherapy also helps.You may need oral medications. Consult a skin specialist .Skin is the mirror of internal health and to get a perfect skin you need to treat both ways - internally and externally. a broad range Sunscreens to filter the harmful UV rays.
People usually don't use sunscreens as they may be greasy or make your face appear white.There are different type of sunscreens available and there is one for everyone, so find the one that will help you.
Kindly meet a dermatologist to get your skin condition diagnosed and he will also recommend a sunblock along with other necessary measures.
Hope it helps you