Androgenetic Alopecia

Androgenetic alopecia (AGA) commonly causes hair loss in older men and women and has been increasing in prevalence as the global population ages. The diagnosis is typically made in the dermatologist's office through history, physical examination, and perhaps trichoscopic examination, although many patients will not present for a formal evaluation. In this chapter, we discuss the current understanding of AGA from epidemiology, pathogenesis and presentation through management, and active areas of research. Despite the pervasiveness of the disease, and the vested public and commercial interest in developing an effective intervention, no real cure exists to date. Minoxidil and finasteride are two popular agents that, when used long-term, can stave off balding progression, but since their discovery nearly 3 decades ago few therapeutic approaches as effective have become available. A better understanding of the molecular basis of AGA will be key for uncovering novel pharmacologic targets, and recent studies have amassed enormous amounts of population-based genetic data toward this end. Apart from novel drug discovery, the ultimate utility of such large-scale population studies will lie in translating this data to predict AGA progression and individual response to specific therapeutic approaches, for optimizing personalized patient care.