Therapeutic update on alopecia areata: a critical review of standard and emerging targeted therapies
摘要
Background and objectives: This narrative review provides a comprehensive update on the pathogenesis and therapeutic management of alopecia areata (AA), critically evaluating the transition from non-specific immunosuppression to targeted molecular therapies. Methods: A literature search was conducted across PubMed, Scopus, and the Cochrane Library (inception to 2024). A strict hierarchy of evidence was applied, prioritizing Phase III randomized controlled trials (RCTs) for emerging treatments while contextualizing conventional therapies within long-standing clinical practice and observational data. Results: AA pathogenesis centers on the collapse of hair follicle immune privilege, driven by the IFN-γ/IL-15 axis. Conventional treatments (topical/intralesional corticosteroids, contact immunotherapy) remain first-line for localized disease but lack high-level evidence for extensive cases. Systemic Janus kinase (JAK) inhibitors represent a paradigm shift. Baricitinib is the first FDA-approved treatment for severe AA, supported by Level 1 evidence from the BRAVE-AA trials. Other JAK inhibitors (ritlecitinib, deuruxolitinib) show potent dose-dependent efficacy in advanced clinical phases. A critical safety appraisal highlights class-wide concerns, including upper respiratory infections and a recently identified risk of weight gain linked to leptin signaling interference. Furthermore, lifestyle factors such as smoking, sleep disorders, and metabolic health are identified as significant adjunctive modulators of disease progression. Conclusions: Targeted therapies, specifically JAK inhibitors, have transformed the prognosis for severe AA. However, high costs, relapse post-discontinuation, and long-term safety profiles necessitate careful patient selection. Future management must integrate advanced pharmacotherapy with holistic lifestyle interventions and personalized medicine based on prognostic biomarkers