Abstract
The multifactorial inflammatory skin disorder Acnes vulgaris has a significant association with increased digital screen time, resulting in increasing prevalence in adults. Two new disruptors have emerged: digital light-induced circadian misalignment, and cutaneous microbiome dysbiosis. This review integrates mechanistic connections between exposure to blue light, clock gene dysregulation and changes in Cutibacterium acnes phylotypes in the pathogenesis of acne. Smartphone, tablet, and computer light, especially blue and near-ultraviolet light, inhibits nocturnal melatonin discharge through intrinsically photosensitive retinal ganglion cells and directly elevates the expression of the CLOCK and BMAL1 genes in sebocytes, augmenting lipogenesis and toll-like receptor 2-mediated inflammation. At the same time, circadian disruption leads to a decrease in antimicrobial peptides like LL-37 and human 2-defensin, allowing pro-inflammatory C. acnes phylotypes IA1 and IA2 to develop biofilms, and commensal phylotypes II and III to decrease. There is a gap in knowledge: there is no treatment that is currently able to treat the three components of digital hygiene, circadian restoration, and microbiome modulation together. This review thus examines clinically-approved and pipeline therapies to these pathways, such as chrono-pharmacology (timed low-dose isotretinoin, evening doxycycline), melatonin agonists (ramelteon), digital interventions (blue-blocking glasses, dynamic screen filters), and microbiome-directed treatments (C. acnes-specific bacteriophages, postbiotics A combination of chronobiology and microbiome restoration is a new potentially curative paradigm but phase III studies of dim light melatonin activation, skin metagenomics, real time light exposure are urgently required.