extra virgin coconut oil...it's an all natural way to lighten skin and even skin tone.....or you can try hydroquionine although it's pretty strong or you can try african black soap my fav brand is odusun
Without examination,confirmation of a diagnosis is tough,but it can be due to hyperpigmentation of the skin. This darkening occurs when an excess of melanin, the brown pigment that produces normal skin color, forms deposits in the skin.
Treatment involves hydroquinone, azelaic acid, corticosteroids, tretinoin cream and laser treatment. Pleae discuss these options with your dermatologist before using them.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.