Hello, i am from pakistan , age 36, female, have brown patches inside of my inner thighs, looks like dirt, can't remove it. ?

Thigh Lesions: Without knowing much more info, my response is limited. These can be acquired, such as a fungal infection (tinea versicolor) or from systemic disease such as diabetes mellitus (acanthosis nigricans), or have been present since birth (congenital), such as large pigmented nevi or vascular port-wine stains. I recommend seeing a physician to first render a diagnosis then consider cosmesis options.