Stretch marks, also known as striae, are a form of scarring that occurs on the skin. They typically have an off hue colour. Stretch marks are formed during the rapid growth of the body such as during puberty or pregnancy, or after a massive weight gain. The abrupt change causes the collagen and elastin which support our skin to stretch and rupture. As the skin heals, scarring appears. This is why these scars are referred to as stretch marks.
When stretch marks first appear, they tend to be red, purple, pink/reddish-brown or dark brown depending on your own skin colour. Stretch marks that have just formed can be slightly raised and itchy.
With time, the colour fades and the bands sink beneath the skin which can lead to a slight depression. Like any scar, stretch marks are permanent. While topical creams may help with their appearance, there are medical devices that can do the job more effectively and make them less noticeable. They can also alleviate the itching. The key is early treatment.