How are stretch marks formed?

Stretch marks, also known as striae, occur when the dermis (middle layer of skin) over stretches to accommodate excess fat or body enlargement (as in pregnancy( resulting in the break down of elastin fiber, which is responsible for the skin’s firmness. The stretching causes tissue inflammation and bleeding of the micro-vessels resulting in the formation of the typical stretch mark on the surface of the skin. These bright streaks are characterized by pink, red or purple raised scars. Over time these marks may fade into a silvery white to dark brown color, although it is usuall a few shades lighter than the skin’s natural tone because of the disruption in the collagen and melanin (pigment cells) production.

Causes of Stretch Marks

• Pregnancy. In the late stage of pregnancy, as the growth of the fetus accelerates, stretching of the skin occurs around the abdomen,although the hips, thighs and breasts may also be affected. Pregnant women with large or multiple babies (for example twins) are more susceptible to the increased development of stretch marks.

• Puberty. During this stage of life adolescents undergo a growth spurt. To accommodate the increase in height and body development the skin stretches resulting in stretch marks.

• Obesity is a common condition responsible for the formation of stretch marks due to the increase in fat deposition thereby stretching the skin.

• Zinc. A deficiency in zinc often contributes to the development of stretch marks

• Weight lifters develop stretch marks as the skin stretches to accommodate the increased amount of muscle bulk. Some body builders use steroids to develop muscle bulk quickly which affects the blood cortisone levels.

• Medication. The use of both oral and topical medication such as contraceptive pills, chronic use of steroid creams and medication contribute to the formation of stretch marks.M

• Medical disorders and conditions such as Cushing’s syndrome, other adrenal gland disorder and hereditary disorders play a role in the development of stretch marks.

Treatment of Stretch Marks

The treatments for stretch marks are partly effective as these marks cannot be completely removed.

• Topical applications of preparations such as tretinoin creams improves the appearance of newly formed stretch marks of less than 6 weeks old and are still pink in colour. Tretinoin rebuilds collagen and elastin fibres making stretch marks less visible but it is not effective on old stretch marks.

• Pulsed laser and excimer laser are the 2 types of effective laser therapies commonly used in the treatment of stretch marks. Pulsed laser therapy remodels the dermis (middle layer of skin) by stimulating the growth of elastin and collagen fibres. This type of therapy is effective on newly formed stretch marks. Excimer laser stimulates the production of melanin cells (pigment cells). This allows the hypopigmented stretch marks to blend into the surrounding skin marking it less visible. Excimer laser therapy is effective for both new and old stretch marks.

• Micro-dermabrasion resurfaces the skin by using minute sand-like crystals. These crystals erode the surface of the skin while a thin tube suctions the crystals and dead skin cells. Microdermabrasion is effective on old stretch marks as it removes the upper layer of skin (epidermis) resulting in the growth of new cells.