Some info on stretch marks (striae distensae)

A question came up in lecture on Tuesday regarding stretch marks. What causes these dermal scars is not fully understood, though mast cell release of histamine, cytokines, and other chemicals when the skin is stretched seems to be involved; these substances will damage collagen and elastic fibers in the matrix of the dense irregular connective tissue of the dermis. See Striae Distensae: eMedicine Dermatology for more info.