A New Proposed Diagnostic Algorithm for Lichenoid Cicatricial Alopecias

The term fibrosing alopecia refers to cicatricial entities that share lichenoid folliculitis and fibrosis of the follicle, including lichen planopilaris (LPP), LPP diffuse pattern (LPPDP), Graham–Little–Piccardi–Lassueur syndrome, frontal fibrosing alopecia (FFA), fibrosing alopecia in pattern distribution (FAPD), and cicatricial pattern hair loss (CPHL). A search was carried out on the PubMed database, and a review was made. Finally, it was proposed an algorithm to distinguish the variants of these diseases. These lichenoid alopecias could represent a variable pattern of two main diseases: FFA and LPP. LPP and FFA may be generalized process affecting the scalp. It is advisable to consider lichenoid alopecias in patients with a long-standing history of erythema, scales, alopecic areas, and dysesthesia of the scalp. The most relevant difference between LPPDP, FAPD, and CPHL is that in LPPDP, the inflammatory infiltrate involved terminal and intermediate follicles, while in FAPD and CPHL, it involved miniaturized hair. CPHL does not exhibit erythema and could be considered a postinflammatory variant of FAPD.