Blaschkoid lichen planus in dark phototype: Dermoscopic diagnosis and follow-up

Abstract

Blaschkoid lichen planus (BLP) is a rare variant of lichen planus, accounting for less than 1% of cases, characterized by lesions distributed along the lines of Blaschko. This variant poses diagnostic challenges, particularly in patients with darker phototypes (IV–VI), in whom hyperpigmentation may obscure classic inflammatory findings. Early recognition is clinically relevant, as it helps prevent misdiagnosis and allows appropriate therapeutic management.

Dermoscopy is a valuable diagnostic tool that enables visualization of Wickham striae, a characteristic feature of this condition. We present the case of an adolescent patient with a dark phototype who showed a favorable response to treatment with topical corticosteroids. Dermoscopy was used for both diagnosis and follow-up. Dermoscopic examination played a fundamental role in early diagnosis and monitoring, demonstrating progressive resolution of inflammation and development of residual hyperpigmentation after treatment with high-potency topical corticosteroids.

This case highlights the diagnostic and follow-up utility of dermoscopy in BLP among patients with darker phototypes, emphasizing its clinical value in cases with less characteristic presentations.