How does a scar form?

Unfortunately, adult skin will scar 100% of the time we cut through it. The scar is a side effect of healing. Luckily, we have techniques to minimize how conspicuous it will be and use a variety of tricks to minimize the scar appearance. Read the excellent excerpt below from by Dr. Lee and colleagues about wound healing:

"Our current understanding of wound healing goes beyond simply categorizing the process into its three stages: inflammation, proliferation, and remodeling.¹ A multitude of growth factors and inflammatory mediators secreted by numerous cell lines play crucial and specialized roles in the healing process, such as angiogenesis, fibroblast proliferation, and wound contraction. To understand and treat a scar, fundamental knowledge of the timeline of wound healing is of critical importance.

The first phase of wound healing, commonly referred to as the inflammatory stage, spans the first 3 to 5 days of healing. In the first few seconds to minutes after a wound occurs, the body instantaneously responds with vasoconstriction and activation of the coagulation cascade.² This causes platelet aggregation and formation of the fibrin-platelet plug, which not only provides hemostasis, but also provides a platform for the progression of wound healing. After this initial period, vasodilation and increased vascular permeability leads to localized edema and an influx of important inflammatory mediators, which through chemotaxis, cause neutrophil transmigration to the wound site. These neutrophils have an important role in phagocytosis of necrotic tissue and killing of bacterial pathogens. Neutrophils are the dominant cell type around 24 hours, and then undergo apoptosis after resolution of inflammatory stimuli. Macrophages become the predominant cell type around 2 to 3 days and have a decisive role in managing the next step of the inflammatory process by either releasing anti-inflammatory cytokines and growth factors signaling resolution of inflammation and progression of wound healing to the proliferative phase, or by releasing inflammatory cytokines that recruit additional neutrophils and prolong the inflammatory process, causing damage to viable tissue and eventually causing a chronic wound.^3 4

During the first phase your skin will be healing with some type of material keeping the skin together. This could be sutures only on the inside, inside & outside, glue or even staples (though if you're having neck surgery and getting staples, they DO NOT heal favorably and should be avoided)

The second phase, known as the proliferative phase, lasts approximately 5 to 15 days and is characterized by re-epithelialization, angiogenesis, fibroblast migration, and collagen deposition. Re-epithelialization occurs through proliferation and migration of epithelial cells from the wound edges to the center of the wound at a rate of 0.5 to 1 mm/d until the wound is completely covered and a protective epithelial layer is established. This process can also occur from dermal structures such as sebaceous glands and hair follicles.⁵ During this proliferative phase, some fibroblasts in the wound secrete disorganized type III collagen, whereas others differentiate into myofibroblasts that cause contraction of the wound.⁶ Simultaneously, new blood vessels begin forming in poorly perfused wounds with low oxygen tensions. These combined processes form the red granular-appearing tissue made of blood vessels and newly formed connective tissue commonly referred to as “granulation tissue.” To improve the rate of re-epithelialization, maintaining a moist environment has been shown to be significantly beneficial.⁷

At this point you may have your incision exposed depending on your surgeon. Usually scars look their best at this point until a few months have passed.

The third and final phase, known as the remodeling phase, lasts up to 1 year and involves collagen cross-linking and replacement of the disorganized type III collagen by organized type I collagen. This remodeling restores the normal dermal composition and provides greater tensile strength to the wound over time. At 6 weeks after wounding, 50% tensile strength of the original skin is regained; at 3 months, 80% is regained, which is the maximum amount able to be salvaged.⁸

During the third phase most of the major cosmetic changes take place. Scar contraction happens in the 3-6 week timeframe where scars tend to become firm, tight and almost lumpy. Tenderness is not uncommon in this stage either. After 1-2 months the scars begin to settle down and are very susceptible to manipulation with scar creams and silicone sheeting. They are are also very sensitive to UV light for 1-2 years and should be protected, especially during prolonged, direct exposures such as sunbathing or tanning beds.

^{Commander SJ, Chamata E, Cox J, Dickey RM, Lee EI. Update on Postsurgical Scar Management. Semin Plast Surg. 2016 Aug;30(3):122-8. doi: 10.1055/s-0036-1584824. PMID: 27478420; PMCID: PMC4961501.}