Face, Dekollté and the back of hands form an aesthetic whole. Here it is able to guess your age. It must match as well.
If the back of your hand looks older, may be due to volume depletion, but also to pigmentation.
The volume depletion can be remedied by body fat, hyaluronic acid or Radiesse. As a result, the contours are gentle and soft. Pigmentation can be treated with laser surgery or cryotherapy.