Topical tretinoin therapy: its use in photoaged skin.

Tretinoin cream has been used extensively to reverse the changes of photoaging. It is the first topical therapy to undergo controlled clinical testing and proved to be efficacious. These results have been substantiated with photography, histopathologic examination, and skin surface replicas. The mechanism of action of retinoic acid is unknown, but it may bind to a specific receptor that alters the gene expression of the cell. Therapy is most successful when a liberal amount of tretinoin 0.1% cream is applied to the skin daily. Tretinoin cream has an excellent safety record; a local cutaneous hypervitaminosis A reaction is the only common problem.