Topical use of tretinoin (RA) 0.1% cream has been demonstrated to improve clinical as well as histologic changes associated with photodamaged skin. Improvement in skin wrinkles by RA appears to be related to dermal changes. RA causes accumulation of epidermal and dermal TGF-alpha 1, a cytokine known to stimulate the synthesis of collagen I and VII, both of which, by ultrastructural criteria, are increased by RA in photodamaged skin. In fact, induction of dermal collagen formation by topically applied RA has been demonstrated in animal studies, and this has been confirmed in human studies. Therefore, it is postulated that topical treatment of BP prone skin with RA would buttress up cutaneous blood vessels by increasing the supporting collagenous structures around them. Such vessels ought to withstand shearing forces better, which would lead to some protection against the development of BP.