cicatrization

Cicatrization, or scar formation, is the biological process by which tissue repairs itself after injury, leading to the development of fibrous tissue that replaces normal parenchyma. In skin, cicatrization proceeds through distinct phases: hemostasis and inflammation to control bleeding and clear debris; proliferation, in which fibroblasts deposit collagen, extracellular matrix, and new blood vessels while keratinocytes re-epithelialize the surface; and remodeling, where collagen is reorganized and scar strength gradually increases over time.

During remodeling, collagen Type III is replaced by Type I and fibers are cross-linked, producing a scar that typically becomes flatter and paler but may remain weaker than the original tissue for months to years. The tensile strength of a healing wound often reaches a fraction of its pre-injury level, commonly around two-thirds to four-fifths, and can continue to improve for a long period.

Scar types include normal scars, hypertrophic scars (raised but contained within the original wound borders), and keloids (raised scars that extend beyond the wound margins). Atrophic scars are depressed lesions resulting from loss of underlying tissue. Abnormal cicatrization can result from excessive or deficient collagen deposition and remodeling, with factors such as infection, mechanical tension, poor perfusion, aging, malnutrition, diabetes, smoking, and certain medications influencing the process.

Clinical considerations aim to optimize functional and aesthetic outcomes and may involve wound care optimization, tension reduction, and interventions for abnormal scarring, such as silicone therapy, corticosteroid injections, laser treatment, or other modalities depending on the case.