Frontal Fibrosing Alopecia: An Example of Disrupted Aryl Hydrocarbon Receptor-Mediated Immunological Homeostasis in the Skin?

The document discussed the hypothesis that frontal fibrosing alopecia (FFA), a type of scarring hair loss, might have been linked to excessive facial photoprotection. This excessive protection could have disrupted immunological homeostasis through the aryl hydrocarbon receptor-kynurenine pathway axis (AHR/KP), potentially leading to the collapse of immune privilege at the hair bulge. The review highlighted the balance needed between sun protection to prevent skin tumors and the necessity of some sun exposure for vitamin D synthesis.