The cause of stretch marks currently is unknown, but they are known to develop in a variety of physiological and pathological states (eg, pregnancy, adolescent growth spurts, obesity, large weight gain, Cushing syndrome, Marfan syndrome, diabetes mellitus, long-term systemic or topical steroid use).  Clinically, newly formed stretch marks present as pink or purple linear lesions without substantial depression of the skin (striae rubra). Over time, the lesions lose their pigmentation, becoming depressed, atrophic, and white (striae alba). The most commonly affected sites are the breasts, upper arms, abdomen, buttocks, and thighs.