LB1029 The common fragrance, linalool, promotes core hair follicle pathology events associated with frontal fibrosing alopecia through activating a cognate olfactory receptor in the bulge

This study investigates the role of the common fragrance linalool in promoting frontal fibrosing alopecia (FFA) pathogenesis. Researchers found that linalool, a frequent allergen in personal care products, can induce core FFA pathology events, such as the collapse of immune privilege and damage to epithelial hair follicle stem cells (eHFSCs), by activating the olfactory receptor OR1A1 in the hair follicle bulge. In experiments with scalp skin from FFA patients and healthy individuals, linalool reduced keratin 15+ eHFSCs and increased expression of MHC class Ia and MICA, markers associated with immune response and cell stress. Silencing OR1A1 counteracted these effects, suggesting that fragrances like linalool can affect hair follicle health through olfactory receptors, raising concerns about their use in consumer products.