A keloid is a scar that grows bigger and wider than the original injury. Keloids most commonly grow on the breastbone, shoulder, upper chest and back, earlobes, and face.
Keloids do not become cancer. But they can be bothersome or painful enough that you seek treatment. Keloids often grow back after treatment.
It's possible to prevent a keloid from forming if you take steps to protect the skin after it is damaged.
Keloids can form where the skin is damaged, such as by a surgery cut, a piercing, a burn, chickenpox, or acne. Thick tissue grows up and out from the healing area, making the scar bigger than the original injury. For some people, even a scratch can lead to keloids.
Keloids do run in families, and they rarely grow in light-colored skin. Experts think that keloids may be linked to a gene that is linked to dark skin pigment.