A dermal scar is the natural outcome when an injury extends into the dermis, the skin’s deep, thick layer. When damaged, the body initiates a healing sequence, forming scar tissue composed primarily of a protein called collagen. This new tissue is a functional, albeit imperfect, replacement for the original skin. A scar represents the successful conclusion of the healing process, creating a durable patch that protects the body from external elements.
The Biological Process of Scar Formation
The formation of a scar begins when the dermis is injured. The initial phase is inflammation, which typically lasts for one to three days. During this period, the body works to control bleeding and clean the wound area, as inflammatory cells prevent infection and remove debris.
Following inflammation is the proliferative phase, which can continue for several weeks. In this stage, specialized cells called fibroblasts enter the wound site. These fibroblasts produce new collagen to create a framework for new tissue, which begins to fill the wound and pull the edges closer together.
The final stage is remodeling, where the newly formed tissue undergoes significant changes. The initial collagen laid down is somewhat disorganized. Over months, this tissue is remodeled as the collagen fibers become stronger and more organized. Unlike the basket-weave pattern of collagen in normal skin, scar tissue collagen aligns in a dense, parallel fashion, which gives it a different texture and appearance.
Common Types of Dermal Scars
Atrophic scars present as depressions or pits in the skin. This sunken appearance is the result of insufficient collagen production during healing or the loss of underlying tissue structures. Common examples of atrophic scars include those left behind by severe acne or chickenpox.
A hypertrophic scar is raised and often red but remains within the boundaries of the original injury. These scars develop due to an overproduction of collagen during the healing process. The excess collagen creates a thickened, elevated area of scar tissue that can be firm to the touch. Prolonged inflammation can contribute to their formation.
Keloid scars are a more aggressive form of raised scar that extends beyond the borders of the initial wound. This occurs when the body’s healing process produces an excessive amount of collagen that continues to form even after the wound has closed. The tendency to develop keloids can be influenced by genetics and is more common in individuals with darker skin tones. Unlike hypertrophic scars, keloids do not regress on their own and can grow over time.
Scar Maturation Over Time
After a wound has closed, the initial scar enters a long-term maturation phase that can last up to two years. During this time, the scar’s appearance continues to evolve. The initial redness or purplish color, caused by increased blood vessels in the healing tissue, will gradually fade.
As maturation progresses, the scar typically becomes paler, softer, and flatter. For raised scars like hypertrophic ones, this process involves the gradual breakdown and reorganization of the dense collagen bundles, leading to a less elevated profile. The texture may change from firm to more pliable as the collagen fibers realign and the tissue becomes more stable.
Even after fully maturing, scar tissue remains different from uninjured skin. It is a permanent replacement tissue that lacks structures found in normal skin, such as hair follicles or sweat glands. Its final appearance is the result of the complex interplay between the injury and the body’s individual healing response.