Influence of Persistent Blue Light Exposure on Melanocyte Activity and Hyperpigmentation in Skin of Color

Persistent blue light exposure has been increasingly recognized as a significant factor influencing melanocyte activity and contributing to hyperpigmentation, particularly in individuals with skin of color. Blue light, a high-energy visible (HEV) light spectrum emitted by digital devices, artificial lighting, and sunlight, penetrates deeper into the skin than ultraviolet radiation, directly affecting dermal and epidermal cells. In skin of color, melanocytes exhibit heightened sensitivity to blue light, leading to increased melanin production through the activation of signaling pathways, including the upregulation of reactive oxygen species (ROS) and the induction of pro-inflammatory cytokines such as IL-6 and TNF-α. These pathways stimulate melanogenesis via microphthalmia-associated transcription factor (MITF) and its downstream targets, tyrosinase and tyrosinase-related proteins, resulting in persistent hyperpigmentation. Studies have shown that blue light exposure exacerbates conditions such as melasma, post-inflammatory hyperpigmentation (PIH), and uneven skin tone, posing a significant aesthetic and psychosocial concern for individuals with darker skin types. Recent evidence also suggests that blue light-induced oxidative stress compromises skin barrier integrity, further intensifying pigmentary disorders. Preventative and therapeutic strategies targeting blue light-induced hyperpigmentation are advancing, with antioxidants such as niacinamide, vitamin C, and plant-derived polyphenols demonstrating efficacy in mitigating oxidative stress and reducing melanin production. Broad-spectrum sunscreens containing iron oxides and tinted formulations have been shown to offer superior protection against blue light-induced pigmentation compared to traditional UV-only blockers. An evaluation of the molecular and cellular effects of blue light on melanocyte activity highlights the importance of tailored photoprotection and antioxidant-based therapies in managing hyperpigmentation in skin of color, addressing a critical gap in dermatological care for diverse populations.