Keloids are benign (non cancerous) fibrous skin tumors. Keloids can develop in any place where an abrasion has occurred. They can be the result of pimples, insect bites, scratching, burns, or other skin trauma. Keloid scars can develop after surgery. They are more common in some sites such as the central chest, the back and shoulders and the ear lobes. They can also occur on body piercings. The most common spots are earlobes, arms, and over the collar bone.
The cause is currently unknown but there is speculation that fibroblasts, MMP-2 (Matrix Metalloproteinase-2), and/or TIMP (Tissue Inhibitors of Metalloproteinases) could have some relation to the cause.
The best treatment is prevention in patients with a known predisposition. This includes preventing unnecessary trauma or surgery (including ear piercing, elective mole removal), whenever possible. Any skin problems in predisposed individuals (e.g., acne, infections) should be treated as early as possible to minimize areas of inflammation.