Keloid

Overview
  • Keloids represent an inappropriately exuberant wound healing response that extends beyond the original site of the initiating scar. Keloids can occur anywhere on the skin and are more common in Blacks.
Pathogenesis
  • Fibroblast activation and collagen deposition are natural parts of the wound healing response to injury. Keloids form when the wound healing response becomes chronically activated far beyond what is necessary to heal the original site of injury. The molecular mechanisms for this inappropriate response are still under investigation.
Morphology
  • Keloids appear as firm papules and plaques that follow the distribution of the original injury and by definition extend beyond it. If the lesion does not extend beyond the original wound's boundaries then this is termed a "Hypertrophic Scar". Keloids can be red to purple in fair-skinned individuals or hyperpigmented in Blacks. In essence, keloids look like over-grown scars.
  • Histologically, keloids appear as highly compacted focal areas of collagen deposition. In some cases fibroblastic hyperplasia can be observed although in most patients fibroblast numbers are not increased.
Clinical Consequences
  • Keloids are harmless in and of themselves but can be cosmetically undesirable. In any patient who does form a keloid the probability that new injuries will form keloids is high.
Treatment
  • Sadly, surgical excision of keloids is largely unhelpful given the creation of a new wound that will often develop a new keloid. Lesions can be slowly softened over time by intralesional injections of corticosteroids