Fibrosing Alopecia in a Pattern Distribution

Fibrosing alopecia in a pattern distribution (FAPD) is a newly identified disorder that falls under the category of lymphocytic cicatricial alopecias, showing similarities to both androgenetic alopecia (AGA) and lichen planopilaris (LPP). It is more frequently observed in American hair disease clinics compared to European, Australian, and African clinics. The exact cause of FAPD is still unclear, but it is generally considered a variant of the lymphocytic primary cicatricial alopecia group, with a T-cell–mediated autoimmune reaction observed in some cases. FAPD is a type of scarring alopecia, characterized by patterned hair loss similar to AGA, and shares clinical, dermoscopic, and histopathologic characteristics with both AGA and LPP. Diagnosis of FAPD is based on clinical presentation, dermoscopy/trichoscopy imaging, and histopathologic findings.