Alopecias in humans: biology, pathomechanisms and emerging therapies

Abstract

Background: The hair follicle is a complete mini-organ with a complex biology. Recent discoveries have shed light on the pathogenesis and genetic basis of a number of hair loss conditions, offering novel treatment alternatives. Objective: To explore the biology and physiology of hair growth, the pathomechanism behind alopecias and emerging therapies. Conclusion and clinical importance: Hair growth is influenced by numerous physiological moderators. Greater understanding of the biology and physiology of the hair follicle and the pathomechanisms of hair disease facilitates development of targeted treatments. Sublingual minoxidil is a promising therapy in humans where optimised drug delivery enhances efficacy and reduces systemic adverse effects. Janice kinase inhibitors, which disrupt the inflammatory cascade, help maintain the hair follicle, preserve immune privilege, and regrow hair in alopecia areata. As the pathomechanisms of other forms of alopecia become better understood, new targeted therapies with greater efficacy will emerge.