Department of Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India.
Department of Pathology, All India Institute of Medical Sciences, New Delhi, India.
Indian J Dermatol Venereol Leprol. 2017 Nov-Dec;83(6):656-662. doi: 10.4103/ijdvl.IJDVL_469_16.
Lichen planus pigmentosus (LPP) is a common cause of facial melanosis in the dark-skinned population. At present, information on dermoscopy and patch testing in LPP is limited.
To describe dermoscopic findings and study the role of patch testing in patients with LPP on the face.
Facial lesions of 50 patients with LPP were studied dermoscopically, followed by histological evaluation. Patch and photopatch tests with the Indian Standard Series and Scandinavian series, respectively, and patient's own cosmetics were performed on all patients.
The most common dermoscopic finding was dots and/or globules (43/50, 86%) in different patterns: hem-like (20.9%), arcuate (18.6%), incomplete reticular (39.5%), complete reticular (7%), and not otherwise specified (14%). Other patterns were exaggerated pseudoreticular pattern, accentuation of pigmentation around follicular openings, targetoid appearance, and obliteration of the pigmentary network. There were 26 relevant patch tests in 17 (34%) patients: para-phenylenediamine (n = 5), nickel (n = 3), colophony, perfume mix and fragrance mix (n = 2 each), thiuram mix and 3,3,4,5-tetrachlorosalicylanilide (n = 1 each), and patients' own products (n = 9). The only positive photopatch test was to fentichlor. No clinical or histological finding differed significantly based on patch test results. The only dermoscopic finding to be statistically associated with a positive patch test was the non-characteristic arrangement of dots/globules (P = 0.042).
Dermoscopic features were not correlated with clinical features or disease duration. Implications of patch testing on the management of LPP cannot be commented upon as ours was a cross-sectional study.
The present study describes the dermoscopic findings of facial lesions in LPP. Our patch test results suggest a probable role of allergens in causing LPP on the face.
色素性扁平苔藓（LPP）是深色皮肤人群面部色素沉着的常见原因。目前，关于 LPP 的皮肤镜检查和斑贴试验的信息有限。
描述 LPP 面部病变的皮肤镜表现，并研究斑贴试验在 LPP 患者中的作用。
对 50 例 LPP 患者的面部皮损进行皮肤镜检查，随后进行组织学评估。所有患者均进行了印度标准系列和斯堪的纳维亚系列的斑贴和光贴试验，以及患者自身的化妆品。
最常见的皮肤镜表现是不同模式的点和/或小球（43/50，86%）：半形（20.9%）、弧形（18.6%）、不完全网状（39.5%）、完全网状（7%）和未特指（14%）。其他模式包括夸大的假性网状模式、毛囊开口周围色素沉着的加重、靶形外观和色素网的消失。17 例（34%）患者中有 26 例相关斑贴试验：对苯二胺（n=5）、镍（n=3）、松香、香水混合物和香薰混合物（n=2）、噻二唑混合物和 3,3,4,5-四氯邻苯二甲酰亚胺（n=1），以及患者自身的产品（n=9）。唯一阳性的光贴试验是芬替氯。基于斑贴试验结果，临床或组织学发现无显著差异。唯一与阳性斑贴试验具有统计学关联的皮肤镜表现是非特征性的点/小球排列（P=0.042）。
皮肤镜特征与临床特征或疾病持续时间无相关性。由于我们的研究是一项横断面研究，因此无法对斑贴试验对 LPP 管理的影响发表评论。
本研究描述了 LPP 面部病变的皮肤镜表现。我们的斑贴试验结果提示面部 LPP 可能与过敏原有关。
