Trichoscopic Features of Lichen Planopilaris versus Frontal Fibrosing Alopecia: A Systematic Review

Abstract

Introduction: Lichen planopilaris (LPP) and frontal fibrosing alopecia (FFA) are primary scarring alopecias that few authors consider the same entity, and some consider them different. Objective: We describe and summarize the trichoscopy features of both conditions. Methods: We performed extensive literature search using the PubMed and Google Scholar databases. The Chi-square test was applied to for calculating the proportions of dermoscopic features in LPP and FFA. P- values less than 0.05 were considered statistically significant. Results: Out of 60 articles, 33 (16 LPP, 17 FFA) were considered for quantitative analysis due to availability in English literature with full text. We found that peripilar cylindrical casts and perifollicular redness with arborizing vessels were predominant features suggesting early LPP. In contrast, yellow dots, perifollicular erythema, and scattered pigmentation suggested active FFA. Shiny white area was seen in both groups in the inactive stages. The target arrangement of blue-grey dots, milky-red areas, and irregularly arranged white fibrotic dots were seen in late LPP, and black dots, lonely hairs, and loss of vellus hairs were detected in the later stages of FFA. Features such as blue-grey structureless areas, blue-white veil, and variability in morphologies of hair shafts were nonspecific. Conclusion: This article provides a comprehensive literature review, correlating dermoscopic features with histopathological findings and the similarities, differences, and peculiarities of LPP and FFA.

Keywords

• dermoscopy
• Lichen planopilaris
• trichology