Hypertrophic scars are scars that are elevated and thickened at the site of the initial injury. Keloids on the other hand, are a type of scar in which the excess tissue extends beyond where the initial injury is sustained. They most often occur on the trunk and arms following trauma such as acne and surgical procedures and on the earlobes from ear piercing. Treatment involves injections into the keloid with steroids and chemotherapeutic agents, laser treatments, and surgical excision.