40 years of topical tretinoin use in review.

Topical tretinoin has been approved for use in dermatology for 40 years and is currently approved for the treatment of acne vulgaris and photodamage. During this time, topical tretinoin has accumulated significant efficacy and safety data in the treatment of acne and photodamaged skin and demonstrated clinical potential for treating a range of other dermatologic conditions. The diverse effects may be due to complex underlying mechanisms of action associated with tretinoin, including keratolytic activity, collagenesis, and other mechanisms associated with the activation of nuclear retinoic acid receptors (RARα, RARβ, and RARγ). In this article, we review the history of topical tretinoin use to date and outline emerging research suggesting that topical tretinoin may have potential clinical use for treating a multitude of other dermatological conditions when used either as monotherapy or in combination with other agents. We also describe newer formulations of topical tretinoin that have been designed to reduce irritation potential. In light of the substantial history of safety and efficacy of topical tretinoin in acne and photodamage, we speculate that it holds promise in treating many additional dermatological conditions, which may be explored in future research.