Topical tretinoin has been used by dermatologists for over 30 years to treat a number of chronie skin diseases, including psoriasis, ichthyosis, acne and others. Over a period of about 22 years, more than 20 million patients have applied topical tretinoin for the treatment of acne vulgaris. Experience over this time has shown a very low incidence of serions side-effects. The most commonly reported adverse experiences have been local cutaneous reactions, such as crythema and dryness of the skin.

Patients applying tretinoin for the treatment of acne noted that their skin became softer and less wrinkled following long-term treatment. Excess exposure to ultraviolet (UV) irradiation damages the skin and results in the skin becoming rongh, scaly and wrinkled with mottled hyperpigmentation. Klignan et al. first proposed that topical tretinoin could have a potential role in the treatment of certain clinical signs associated with cumulative damage caused by years of exposure to sun, a process referred to as photodamage.

When considering the potential use of topical retinoid therapy in the treatment of photodamage, the clinician has to weigh up carefully the long-term risks against the benefits of the treatment. This paper reviews the safety profile of topical tretinoin therapy using three lines of evidence: per cutaneous absorption studies; data from controlled long-term clinical studies; and animal studies. In addition, the results of studies are reviewed in which the benefits of long-term application of tretinoin were assessed in patients with mild to moderate and more severe photodamage with solar keratoses.

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