Objective:

To integrate current knowledge of the molecular architecture underlying the cutaneous circadian clock and assess the connection between circadian regulation or disruption with skin physiology and dermatological diseases.

Approach:

• Review Methodology: A narrative review using a targeted PubMed/MEDLINE search with terms related to circadian rhythms and dermatology, focusing on human clinical evidence and translational proposals.

Key Findings:

• Circadian rhythms significantly influence skin physiology, including epidermal turnover, immune responses, and DNA repair.
• Disruption of circadian rhythms can exacerbate major dermatological disorders such as melanoma, atopic dermatitis, and psoriasis.
• Chronodermatology is emerging as a precision-medicine framework; however, clinical benefits from timing treatments have not yet been established.
• Advancements in chronopharmacology and chrono-optimized drug delivery systems could lead to personalized dermatological interventions.

Interpretation:

The skin exhibits temporal rhythms controlled by the circadian clock, which operates autonomously in various skin cell types and is influenced by external factors like light and temperature.

Limitations:

• The review is narrative and not systematic, lacking formal meta-analysis and risk-of-bias assessment.
• Evidence gaps exist that need resolution before time-based therapeutic strategies can be clinically implemented.

Conclusion:

Integrating circadian biology into dermatological practice requires personalized evaluation of skin clock function and validation of chrono-therapeutic strategies through clinical trials.