A Retrospective Study of the Effect of Long-Term Topical Application of Retinaldehyde (0.05%) on the Development of Actinic Keratosis

Abstract

Background: The role of topical retinoids on photocarcinogenesis is still unclear. Retinaldehyde is a natural metabolite of vitamin A used as a cosmetic product. Its effect on actinic keratoses has not been studied to date. Objective: To study the incidence of actinic keratoses during long-term application of retinaldehyde in order to evaluate a possible chemoprophylactic effect. Methods: We conducted a retrospective study on 61 patients who had applied retinaldehyde on photoexposed body areas for a period ranging from 6 to 142 months. We counted the total number of actinic keratoses and cutaneous tumors that appeared over the time of exposure to retinaldehyde. Results: The epidemiological characteristics of actinic keratoses were not modified by the application of retinaldehyde. Irregular application as compared to regular application of retinaldehyde was not associated with a change in the risk of actinic keratoses, suggesting that continuous use is not associated per se with a higher risk of actinic keratoses. Conclusion: With the statistical power limitation of this study, retinaldehyde applied alone does not appear to have prophylactic effects on the development of actinic keratoses. The design adopted is feasible to study the safety of cosmetic products applied for a long period of time.