The appearance of a scar is due to several factors including irregularities in the amount of collagen, abnormal pigmentation and abnormal blood vessel regrowth. A scar is a scar, much like a rose is a rose. If you have a scar you will always have a scar but you can improve the appearance with retinoic acid creams, bleach creams, topical steroids and different laser combinations including the CO2 laser, Gentlelase and V-beam laser. Stretch marks are really just a specific type of scar where the collagen has become thinned out. Stretch marks are virtually impossible to treat and topical retinoic acid is probably your best bet.