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

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. Only a few reviews focus on trichoscopic findings in delineating these two alopecias.

OBJECTIVE

We describe and summarize the trichoscopic features of both conditions.

METHODS

We performed an extensive literature search using the PubMed and Google Scholar databases. The Chi-square test was applied to compare the trichoscopic 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 erythema 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 not significantly different between the two groups.

CONCLUSION

This article provides a comprehensive literature review on the trichoscopic features of LPP and FFA, including comparing the similarities, differences, and peculiarities of both conditions.