The property of elasticity is unique to skin, allowing it to stretch and later regain its shape. The strength of skin comes from the dermal layer, where strong collagen fibers give thickness to the skin. Interspersed are other normal protein fibers known as elastin. These protein’s structure allows the fibers to be stretched and then to retract back to original or near original length when the stretching force is removed. This retraction only occurs as long as the stretching force was removed soon enough and if the stretching has been done slowly and evenly. This process can be likened to a rubber band when it is stretched out slowly and then let go.
However, when the stretching force is relatively sudden and/or held for a long period of time, the elastic fibers in the skin lose the ability to retract. Visualize a rubber band stretched around a rolled-up map and left there for an hour compared to leaving it there for a year. The longer the material is stretched, the less likely it is to regain its shape. Or think of a balloon that has been over-inflated and then the air is let out. One can see ribbon-like areas of thinned rubber in the balloon surface. This is similar to how stretch marks form on the body.
To understand the prevention and treatment of stretch marks, we must first define the term to be sure we are using it properly. Then, we must look at how and why stretch marks arise and consider the mechanism causing them. Only then can we understand precautions to prevent or minimize the injury, which results in their formation.
Formation of Stretch Marks
Visible scars result from a surface widening of less pigmented skin after an incision or cut deep into or through the skin from surgery or an injury. As the cut heals, the edges move closer to each other and hold there for several days until the skin is strong enough to stay together. A tighter hold on the skin means a more narrow scar.
Stretch marks, or striae (stria for singular), are a type of scar resulting from an injury to skin that has healed in a manner lacking the full range of skin components. In fact, stretch marks are a result of “partial tearing” of the skin. These partial tears occur as a result of skin being stretched beyond its ability to retract and often have a jagged look caused by improper alignment of skin throughout the healing process.
The strands of elastic fibers in skin are designed so skin can stretch due to normal movement patterns and still resume its original position. This is why stretch marks appear in lines perpendicular to a normal range of movement, i.e., stretch marks forming in vertical lines on the stomach during pregnancy. Because skin in this area does not normally bend in the vertical direction, the elastin fibers are horizontally aligned. When rapid gain is seen in the last three months of the pregnancy, the skin is pulled too quickly and causes the elastin fibers to break. This results in the partial skin tearing that creates stretch marks.
While stretch marks may not be visibly present during a pregnancy, the damage to the skin does occur during the time when the skin is under pressure. However, it often is not until after the pregnancy or other significant weight loss when the skin shows stretch marks. This is why stretch marks may seem to randomly appear once a baby has been born. Striae may occur with some thinning of the dermal layer, but the most noticeable effect is the lack of pigmentation within the stretch mark. Melanocytes, which produce the melanin in cells, have become further apart and/or produce less pigment, making the scar stand out.
Since these marks are formed as a result of an injury, they are often red or purple due to the increase in blood flow when they first appear. As the inflammation/ injury settles down, the result is a thin scar that does not have pigment. The lack of pigment results in a white or grey color, which varies in shade based on the different thickness of the scar. Stretch marks simply reflect a partial tearing of the dermal layer and stretching thin of the pigmented epidermal layer of cells. The skin care professional should understand the evolution of these scars, as prevention is easier than treatment.
During pregnancy, if one applies a high lanolin-based moisturizer product with gentle rubbing over the abdomen each morning, the stress to the dermal tissues can be diminished. Because lanolin is an animal-based oil, it will penetrate into the dermal layer of skin to enable less stress to the skin dermal tissues. This diminishes the disruption/damage of collagen and elastin fibers as the stretching force is occurring.
Each evening, especially during the last trimester of pregnancy, application of products restoring collagen allows for active repair of a stressed, injured or damaged collagen matrix during the night hours. When fresh, new collagen is created, it restores skin thickness and strength. These characteristics aid in preventing stretch marks, because more force can be applied to the skin without resulting in damage to the collagen fibers.
Staying adequately hydrated is another way to reduce the risk of stretch marks. With proper water intake and the use of moisturizing products, the pliability of skin is protected. If one knows skin will be stretched (such as with a pregnancy), the optimum conditions for collagen and pliability protection can be created. By doing so, the risk of stretch marks is diminished.
Treating Stretch Marks
Striae are likely to be improved the most by the therapy modalities that tighten the dermal collagen. Just as hot water leads to the shrinking of certain fabrics, heat causes collagen fibers to contract or shorten. Ultrasonic machines can deliver heat to controllable depths of the dermis, shortening the length of the collagen fibers and bringing the skin closer together. As the collagen fiber contracts, the stretch marks appear smaller even though the scar itself is not healed. This smaller scar is less noticeable to the eye.
There are also methods helping camouflage the look of stretch marks, making them less noticeable. Laser resurfacing, dermabrasion, microdermabrasion, deep chemical peels and superficial peels are designed to elicit cosmetic improvement of irregular pigmentation in the epidermis and not specifically the loss of, or thinned, epidermis. While the scar itself is not treated, these methods do stimulate new collagen production from dermal fibroblasts, which may aid in the appearance of the marks. The problem with striae is the scar tissue simply does not have a normal fibroblast concentration, making these modalities a less permanent treatment for stretch marks.
Micropigmentation is another method that can help mask the appearance of stretch marks. In this procedure, a color matching the surrounding skin pigment is tattooed onto the skin surface. Methods such as micropigmentation are good options for those who wish to diminish the appearance of the marks.
Other methods of camouflage include makeup or self-tanners that can temporarily hide the scar. These methods are great options for people who wish to hide stretch marks in certain situations (such as at the beach), but do not wish to take more intensive measures to remove the scar.
Consulting Clients with Stretch Marks
People who experience stretch marks often view them as unsightly and as an indicator of imperfection. Due to this perception, many women suffer from emotional trauma when pregnancy or other stretch mark inducing circumstances damage their smooth skin. This mindset can affect an individual’s self-esteem, which should be addressed before measures are taken to treat them.
Keep in mind, long-term treatments should be reserved for when all stretching of the skin is concluded, i.e., when a client is done having children. Advise clients to take care of their skin during pregnancy to help diminish the risk of stretch marks on the body.