Are they birth marks? If so, and if they TRULY bother you, a plastic surgeon can remove them. I must warn you, though; the procedure isn't fun. The dark skin must be stretched enough to be removed, and this is done by having the doctor insert larger and larger devices under the skin and leaving them until the skin is stretched out and pliable enough for the surgeon to work with. He or she would simply remove the device and trim off the birth mark. You would then be left with a small scar. There are marvelous products on the market today to make scars "invisible". They can be found in any drug store. If, however, the dark spots are just dark spots...first think about if they've been there awhile: Are they moles that are changing? Possible melanoma. Finally, if the are really just dark spots, you can buy bleaching creams in a drug store, or if you want a stronger approach, go to a dermatologist for burning them off with a gas, or a prescription for a stronger cream.
