It is a condition that causes the skin to appear lighter or darker than normal.
Why does this happen?
This happens when the melanin (pigment that gives skin it’s colour) production goes awry, either by overproducing or under-producing. This can be caused by:
Ageing
Overexposure to the sun
Healing of a wound
Dryness of the skin which causes certain parts to look like a different colour from the others.