Department of Dermatology, Research Institute for Tropical Medicine, Muntinlupa City, Philippines.
Skines Aesthetic and Laser Center, Bulacan, Philippines.
JMIR Dermatol. 2024 Apr 19;7:e50429. doi: 10.2196/50429.
Lichen planus pigmentosus (LPP) is a condition characterized by persistent and asymptomatic brownish-black-to-blue or purple-gray pigmentation, predominantly in the face and sun-exposed areas, commonly in dark-skinned individuals. Several clinical variants of LPP have been reported. However, the ichthyosiform type of LPP has not been reported. We present a 19-year-old male patient who presented with a 7-year history of asymptomatic grayish macules; patches with fine scales on the face, trunk, and upper extremities; and grayish plaques with thick "ichthyosiform" scales on the lower extremities. The diagnosis of LPP was proven by histopathological findings on both the macular and ichthyosiform plaques. Cluster differentiation (CD) 68 stain highlights the same density of pigment-laden macrophages in both the gray macule and the ichthyosiform plaque. The cause of LPP is unknown. Transcription factor anomalies may play a role in increased keratinization of lichen planus lesions. It can be assumed that the mechanism of the altered distribution of keratinization may occur on the ichthyosiform lesions in this patient. The terminology "ichthyosiform lichen planus pigmentosus" is hereby proposed to be added to the clinical variants of LPP.
色素性扁平苔藓（LPP）是一种以持续性和无症状的棕褐色-黑色至蓝色或灰紫色色素沉着为特征的疾病，主要发生在面部和暴露于阳光的部位，常见于深色皮肤个体。已经报道了几种 LPP 的临床变异型。然而，尚未报道过鱼鳞病样型 LPP。我们报告了一名 19 岁男性患者，他因无症状的灰色斑疹、面部、躯干和上肢有细鳞屑的斑块以及下肢有灰色斑块伴厚的“鱼鳞病样”鳞屑而就诊。灰斑和鱼鳞病样斑块的组织病理学发现证实了 LPP 的诊断。簇分化（CD）68 染色突出显示灰色斑疹和鱼鳞病样斑块中载色巨噬细胞的相同密度。LPP 的病因不明。转录因子异常可能在扁平苔藓病变的过度角化中起作用。可以假设，在该患者的鱼鳞病样病变中，角化的改变分布机制可能发生。因此，建议将“鱼鳞病样色素性扁平苔藓”术语添加到 LPP 的临床变异型中。
