Circadian Rhythm and the Skin: A Review of the Literature.

Disruption of the circadian rhythm has been implicated in a wide variety of dermatologic conditions. Research has shown that previous ultraviolet light exposure can continue to damage the deoxyribonucleic acid (DNA) of the skin, even in the dark, and has demonstrated that repair of these skin cells peaks at night. In this article, the authors reviewed the current literature on circadian rhythm effects on the skin and describe and discuss its basic principles. Better understanding of the role circadian rhythm plays in overall skin health will assist physicians in providing optimal treatment to patients, including appropriate recommendations regarding the use of topical medications and skin care at their most effective times during a 24-hour cycle. Dermatologists should also be aware that adequate sleep is necessary for optimal DNA repair activity in the skin.