Pathogenesis and Classification of Male Pattern Hair Loss (Androgenic Alopecia)

The document discussed androgenetic alopecia (AGA), the most common cause of hair loss in men, highlighting the role of androgens, particularly dihydrotestosterone (DHT), and cytokines in its development. AGA was noted to have a strong genetic component, with the most significant genomic region located on the X-chromosome encoding the androgen receptor, along with 11 other associated gene loci on various chromosomes. The condition was also associated with other diseases such as coronary heart disease, insulin resistance, and certain cancers. The Hamilton–Norwood classification system was commonly used to describe patterns of hair loss in AGA.