A scar represents the body’s natural solution to an injury, forming a patch of repaired tissue after the skin has been damaged. For growing individuals, the question is whether this repaired tissue expands at the same rate as the rest of the body. A scar does not “grow” by adding new, organized tissue in proportion to overall body size. Instead, the mechanical forces of growth significantly alter its appearance over time, often causing it to widen or stretch.
The Biology of Scar Formation
Normal, undamaged skin is a highly organized structure, particularly the dermis. Collagen fibers are arranged in a three-dimensional, basket-weave pattern, providing tensile strength and elasticity. Elastic fibers are interspersed, allowing the skin to stretch and recoil easily.
In contrast, a scar forms when the body rapidly deposits replacement tissue, primarily Type I collagen fibers. These fibers are laid down quickly in dense, parallel alignment, unlike the organized basket-weave of normal skin. This parallel structure is less pliable and less elastic than the surrounding healthy tissue. Mature scar tissue also lacks elastic fibers, hair follicles, and sweat glands, making it weaker and less resilient to physical stress.
Scar Dynamics During Body Growth
The scar itself does not biologically expand with the body as undamaged skin cells multiply and stretch. Instead, the rapid growth phases of childhood and adolescence subject the less-elastic scar tissue to constant mechanical tension. As underlying bone structure and muscles increase in size, they pull on the overlying skin.
Because scar tissue is stiffer and less compliant than the surrounding skin, it cannot easily accommodate this stretching. The constant pull causes the scar to physically widen, flattening and spreading out the dense collagen fibers. This widening is a deformation caused by tension, not proportional growth, leading to a more noticeable scar line.
The final appearance of a scar is influenced by its orientation relative to the skin’s natural tension lines (Langer’s lines). Scars running parallel to these lines experience less tension and heal as fine lines. Scars that cross perpendicular to these lines are subjected to maximum pulling force, making them more likely to stretch and widen during growth. This mechanical stress is why scars on joints, the chest, or the back often become broader.
Scar Maturation and Long-Term Changes
Scar formation is a multi-phase biological process that continues for months, independent of the body’s overall growth rate. The process begins with the inflammatory phase, transitions into the proliferative phase where granulation tissue and collagen are deposited, and concludes with the remodeling or maturation phase, which lasts between 12 to 24 months.
During the remodeling phase, dense, disorganized collagen is slowly broken down and replaced in a more organized manner, though it never achieves the structure of unwounded skin. Initially, scars appear raised and red or purple due to increased blood vessel density. Over this period, these blood vessels regress, and the scar typically flattens, softens, and fades to a paler, often hypopigmented color.
Even after full maturation, changes can occur over decades. Over time, the scar tissue may become thinner and more fragile because it lacks the regenerative capacity and structural support of normal skin. This long-term thinning makes older scars more susceptible to minor injury or breakdown, confirming that scar tissue never fully regains the strength of the original skin.
Minimizing Scar Appearance and Tension
Managing scar appearance focuses on controlling mechanical tension and abnormal collagen production. Consistent, gentle scar massage is often recommended once the wound has fully closed (typically a few weeks after injury). This technique helps mechanically break down the dense, parallel collagen fibers and encourages a more flexible, pliable scar texture.
Silicone products (sheets or gels) are a widely accepted non-invasive treatment to minimize scar visibility. Their mechanism involves occlusion, which increases the hydration of the outermost skin layer (the stratum corneum). This increased moisture signals fibroblasts to reduce excessive collagen synthesis, promoting a more normal maturation process that results in a flatter, softer scar.
Sun protection is important for all new and maturing scars, as UV radiation can cause permanent hyperpigmentation. Applying a broad-spectrum sunscreen with a high SPF is necessary for at least the first 12 to 18 months of healing. For scars that become excessively raised, red, or itchy (such as hypertrophic or keloid scars), medical interventions like corticosteroid injections or laser therapy may be utilized to manage the abnormal collagen growth and vascularity.