Atopic dermatitis: diagnosis, molecular pathogenesis, and therapeutics

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by acute and chronic phases with no definitive cure currently available. The diagnosis of AD involves the evaluation of both disease onset and severity, relying on established clinical criteria and, increasingly, on various biomarkers to improve diagnostic accuracy. The molecular pathogenesis of AD is driven by a combination of genetic predispositions, environmental factors, and immune dysregulation. Acute AD is predominantly mediated by T-helper cell 2 (Th2) immune responses, whereas chronic AD involves a shift toward Th1-driven inflammation. Within this immunological context, we emphasize the role of redox imbalance in disease progression and propose a wound-healing model to explain the molecular dynamics of AD. According to this model, the acute phase is marked by excessive oxidative stress, requiring antioxidant intervention, whereas the chronic phase is characterized by insufficient redox signaling, which hinders the clearance of hyperproliferative cells. We further review current and emerging therapeutic strategies, including anti- and pro-oxidative strategies, based on the different AD staging. Notably, we introduced cold atmospheric plasma (CAP), a redox regulatory tool, as a novel treatment modality for AD management that stimulates antioxidant responses at low to moderate doses and induces oxidative stress at higher concentrations, potentially reversing chronic AD pathology. This review offers a comprehensive overview of AD, from clinical manifestations and molecular pathogenesis to therapeutic approaches, and introduces the 'wound healing model' as a conceptual framework to integrate CAP as an innovative treatment modality for AD management and to inform future research.