Stretch marks are a form of scarring on the skin with an off-color hue. They are caused by tearing of the dermis, and over time can diminish but not disappear completely. It is a common misconception that stretch marks are solely the result of the rapid stretching of the skin associated with rapid growth (common in puberty) or weight gain (e.g. pregnancy or muscle building) that overcomes the dermis's elasticity. Stretch marks are influenced by hormonal changes associated with puberty, pregnancy, muscle building etc.

Between 75% and 90% of women develop stretch marks to some degree during pregnancy.

The sustained hormonal levels as a result of pregnancy usually means stretch marks may appear during the sixth or seventh month, primarily during the 3rd trimester, as that is when skin tends to be subjected to higher levels of stretching forces.

Often, of all the factors involved in stretch mark development, the only one over which an individual can retain control is that of diet.

Symptoms and signs

• First appear as reddish or purple lines, but tend to gradually fade to a lighter color
• The affected areas appear empty and are soft to the touch
• Stretch marks occur in the dermis, no stretch marks will form as long as there is support within the dermis
• Most likely to appear in places where larger amounts of fat are stored
• Most common places are the abdomen (especially near the belly-button), breasts, upper arms, underarms, thighs (both inner and outer), hips, and buttocks

Causes

The glucocorticoid hormones responsible for the development of stretch marks affect the epidermis by preventing the fibroblasts from forming collagen and elastin fibers, necessary to keep rapidly growing skin taut.

This creates a lack of supportive material, as the skin is stretched and leads to dermal and epidermal tearing.

If the epidermis and the dermis have been penetrated, laser will not remove the stretch marks.

What can I do about stretch marks?

There are several treatment options for stretch marks. The degree of success with any treatment will be impacted by your age, your skin tone and even your diet.

Diet and exercise

• Drink plenty of water. Adequate hydration keeps your skin soft and less likely to develop stretch marks
• Caffeine can increase your risk of stretch marks. If you're stuck on your caffeinated coffee or tea, make sure you balance the fluids
• Drink just as much—or more—water as you drink coffee, tea, or soda
• Stretch marks can also result from nutritional deficiency. Be sure to consume foods that promote skin health: foods rich in zinc, such as nuts or fish
• Foods high in vitamins A and C, such as carrots and citrus fruits and milk; protein-rich foods, such as eggs

Lotions and creams

Daily application of a cream (Trofolastin) containing Centella asiatica extract, vitamin E, and collagen-elastin hydrolysates was associated with fewer stretch marks during pregnancy.

Cocoa butter is an effective moisturizer to reduce their appearance once a stretch mark has already formed.

Surgical methods

• Dermabrasion
• Chemical peels
• Laser surgery