Dandruff Lesional Scalp Skin Exhibits Epidermal T Cell Infiltration and a Weakened Hair Follicle Immune Privilege

The study examines the immune environment of dandruff-affected scalp skin, focusing on T cell infiltration and hair follicle immune privilege (IP). It reveals increased CD4+ and CD8+ T cell presence in the epidermis of dandruff lesions, indicating an immune response, while hair follicle compartments show no significant T cell changes. A weakened IP is observed in dandruff-associated hair follicles, particularly in the suprabulbar outer root sheath, with increased MHC class I and β2M expression and decreased MIF expression. These findings suggest that enhancing hair follicle IP could be a novel strategy for managing dandruff, potentially reducing hair shedding by prolonging the anagen phase. The study involved 16 female subjects, providing insights into the immune dynamics of dandruff-affected skin.