Keloid scars are excessively large scars that form at the site of wounds or trauma, including ear piercings, vaccinations, or surgical sites.
Keloids may form on any part of the body but are most common on the upper chest and shoulders. The tendency to develop keloids is inherited and is more common in dark-skinned people. It is not known what causes some people to develop larger scars than others.
The excessive scar tissue may be itchy or uncomfortable and can become irritated from rubbing against clothing or other adjacent skin.
Keloids are benign and do not cause other medical problems, but they can be uncomfortable and may be a cosmetic concern.
Most keloids flatten and become less noticeable over several years.
Sun exposure can cause keloids to darken more than the surround skin. As this makes them more visible, people with keloids should protect their skin from sun exposure.