Hi, In your case one can think either of addisonian pigmentation or acanthosis Nigerians. The first one is associated with blood pressure changes,variable heart rate, weight loss nausea vomiting and skin pigmentation. The diagnosis can be made with serum cortisol, serum sodium and serum potassium levels. Acanthosis can either be solitary occurrence or might be associated with Pcod where in excessive hair growth and irregular periods are associated and it can be ruled out with pelvic ultrasound and hormonal tests. As you haven t mentioned any other complaints,I presume you are having acanthosis. It can be treated to some extent with creams containing tretinoinor glycolic acid or hydro quinine with tretinoin and steroids.Glycolic acid, TCA peels can be used at some areas. A good emollient is also required to keep the skin supple. Lasers and microdermabrasion can also be tried. However as the disease seems to be extensive, kindly consult your dermatologist to decide upon the treatment.