Decreased melanocyte counts in the upper hair follicle in frontal fibrosing alopecia compared to lichen planopilaris: a retrospective histopathologic study

Frontal fibrosing alopecia (FFA) is a primary lymphocytic cicatricial alopecia, characterized by progressive frontotemporal hairline recession and eyebrow loss that mainly affects postmenopausal women.1 Although its exact pathogenesis remains unknown, a Th1-biased cytotoxic T-cell autoimmune reaction that targets the infundibulum and the bulge area of the follicle,2 as well as androgen-dependent mechanisms have been incriminated.3 Due to histological similarities with lichen planopilaris (LPP), some authorities consider FFA a variant of LPP.1,4 On the other hand, parallels have been proposed between alopecia areata (AA) and FFA, in terms of an analogous autoimmune process targeting the bulb or bulge area, respectively.