UV-A Nail Lamps and Skin Health: Molecular Damage, Physiological Responses, Genetic Susceptibility, and Cosmetic Safety

The rising popularity of gel-based manicures has intensified public health concerns regarding ultraviolet A (UV-A) nail lamps, which emit radiation within a spectrum capable of inducing DNA damage, oxidative stress, and accelerated skin aging. Although the exposure duration is shorter than recreational sun exposure, repeated and cumulative use raises important questions about long-term dermatological safety. This review synthesizes current evidence on the physiological mechanisms underlying skin responses to UV-A nail lamps, with a particular focus on DNA repair pathways, oxidative stress responses, melanin-mediated photoprotection, and immune modulation. Genetic variation in pigmentation, DNA repair, oxidative stress, and DNA damage response pathways is discussed as a potential modifier of individual susceptibility; however, direct evidence linking specific polymorphisms to clinical responses to nail lamp exposure remains limited. We further evaluate safety guidelines, protective measures such as sunscreens and UV-blocking gloves, and differences in lamp technologies (UV vs. light-emitting diode). Despite growing clinical reports of photoaging and skin cancer cases linked to chronic exposure, critical research gaps persist, particularly regarding the interplay of genetic variability with clinical outcomes. Future directions include longitudinal cohort studies, integration of dermatogenomic risk profiling, and development of safer curing technologies. Collectively, this review emphasizes the need for balanced awareness—maximizing cosmetic benefits while minimizing potential health risks—through evidence-based safety practices, personalized recommendations, and targeted research initiatives.