Thanks for your query. This is a kind of pigmentation disorder, which is autoimmune in nature known as lichen planus pigmentosus
. There is no definite treatment for this kind of pigmentatory disoder. Depigmentation
creams like Hydroquinone
or Chemical peels
will reduce slightly the pigmentation. Sunscreens of broad spectrum nature should be used strictly, atleast 20 minutes before sun exposure on sunexposed areas and repeated every 3 hours.