Scanning electron microscopy of normal human scar tissue and keloids.

The fibrous architecture of 5 normal human scars between 1 week and 1 year old and 4 keloid scars has been studied by scanning electron microscopy. In normal wounds, significant changes in fibril and fibre orientations and mode of aggregation take place as the scars mature, indicating that remodelling carries on for many months. There are also major differences between the edge and centre of the wound. These changes can be related to the stresses placed on the fibroblasts which have responded by laying down collagen aligned in such a way as to resist these forces. It is suggested that keloid fibroblasts may lack this ability to respond appropriately to orientational stress.