To be a bit more specific, a scar forms, in general, when the dermal tissue is affected. Remember the general structure of skin (figure 1). A scar may form when the epidermal/dermal junction (EDJ) is damaged and the dermal tissue is penetrated. This penetration can be a result of a puncture, incision, chemical, heat or any mechanical penetration.
The skin reacts by starting the healing process (the body protecting itself). High levels of collagen and elastin are produced to rebuild the tissue in that area. A biochemical cascade starts flooding the area with healing agents in specific sequences. Depending on the depth and type of injury, the resultant scar can be quite minor or significant.
Types of Scars
There are many types of scars, including flat scars, keloid scars, hypertrophic scars, atrophic scars and contracture scars, which are generally caused by burns.