Why do keloids form near scars?

Keloids: Keloids can be considered to be "scars that don't know when to stop." a keloid, sometimes referred to as a keloid scar, is a tough heaped-up scar that rises quite abruptly above the rest of the skin. It usually has a smooth top and a pink or purple color.

Keloids are scars: Keloids form within the scar. The keloid is the scar growing out of control. Cause is unknown.