Acne: epidemiology, risk factors, pathogenesis, management and cutting-edge research.

Acne vulgaris is a widespread chronic inflammatory skin condition particularly affecting the pilosebaceous unit, with its pathogenesis intricately linked to excessive sebum production, abnormal follicular keratinization, overcolonization by Cutibacterium acnes (C. acnes), and dysregulated host immune responses. Beyond its dermatological manifestations, the disorder is frequently associated with psychological comorbidities such as anxiety and depression, significantly impacting patients' quality of life. A genetic predisposition is evident, with associated polymorphisms involving pathways related to sebaceous gland activity, inflammatory regulation, and hormonal metabolism. Interactions among immune cells, including macrophages and dendritic cells, along with underlying molecular mechanisms, further contribute to its pathogenesis. Conventional acne treatments face challenges such as increasing antibiotic resistance and limited patient adherence. As a result, clinical research and practice are increasingly focusing on targeted, mechanism-based precision strategies. Recent advances in targeted biologics and vaccines directed against C. acnes have demonstrated promise in clinical studies, offering new avenues for acne management. This review provides a systematic overview of the epidemiology, risk factors, diagnostic classifications, and comorbidities associated with acne, with a particular focus on contemporary insights into its immunopathogenesis and molecular mechanisms. Additionally, it synthesizes current treatment modalities and explores emerging directions, such as acne vaccines and biologics, to serve as a reference for further mechanistic investigation and therapeutic advancement.