Immunopathogenesis of alopecia areata.

Alopecia areata (AA) is an autoimmune disorder resulting in hair loss. It has numerous variants or patterns, including diffuse type, patchy type, AA totalis, AA universalis, and more. In this graphical review, we provide an overview of AA immunopathogenesis, highlighting loss of immune privilege in the hair follicle as well as key immune cell types, cytokines and chemokines that drive autoimmune attack of the hair follicle. We also summarize recent literature identifying agents that block these pathways that could serve as new immunomodulatory treatments for AA.