Fibrosing alopecia in a pattern distribution.

Background/objectives: Fibrosing alopecia in a pattern distribution (FAPD) is a newly recognized form of scarring alopecia sharing characteristics of both androgenetic alopecia (AGA) and lichen planopilaris. The existing literature on FAPD and current understanding of the epidemiology, pathogenesis, clinical features, diagnosis, and treatment of this disease are reviewed.

Methods: PubMed searches were performed to identify all articles discussing FAPD. The references of articles were used to identify additional articles.

Results: A total of 15 articles were found describing FAPD in a total of 188 patients (164 women and 24 men; average age, 53.8).

Conclusions: FAPD affects the androgen-dependent scalp and is typically associated with hair follicle miniaturization. The scalp affected by FAPD shows features of both lichen planopilaris and AGA, and FAPD may possibly represent an exaggerated inflammatory response to damaged hair follicles, triggered by AGA. Physical examination and trichoscopic evidence of follicular inflammation and, occasionally, fibrosis are important to identify the condition, and a dermoscopy-guided biopsy can confirm the diagnosis. Unless recognized, clinicians may misdiagnose FAPD as AGA associated with seborrheic dermatitis. Data on treatment modalities are limited; however, based on pathogenesis, combined therapy with anti-inflammatory and hair growth-promoting agents is warranted.