Background

Folliculitis decalvans (FD) is a form of inflamed primary cicatricial alopecia (PCA). FD is classified as a neutrophilic PCA; however, only a few previous studies have described its histopathology, including the assessment of systematically evaluated and quantified follicular changes in horizontally sectioned biopsy specimens with clinical and dermoscopic findings of the early and advanced stages.

Objective

We aimed to clarify the histopathologic and dermoscopic features of early and advanced active stage FD.

Methods

We conducted a case series study of 42 patients with FD by dermoscopy and both horizontally and vertically sectioned biopsy specimens.

Results

The histopathologic findings of the early-stage lesions included loss of sebaceous glands; interfollicular acanthosis; and fibrosis with depressed, fused follicular infundibula showing thickened interfollicular keloid-like areas with tufted hairs on dermoscopy. Active lesions showed a greater number of hair clusters, clefting, and fused infundibula with dense inflammation predominantly in the upper follicles. Neutrophil-predominant infiltrates were observed in fewer than half of the patients, including those with early-stage lesions.

Limitations

This was a retrospective study.

Conclusion

FD has the features of mixed-cell PCA. The features of early-stage FD are thickened interfollicular keloid-like areas with tufted hairs and loss of sebaceous glands.

中文翻译：

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42例脱发性毛囊炎的组织病理学和皮肤镜特征：病例系列

背景

脱发性毛囊炎 (FD) 是一种发炎的原发性瘢痕性脱发 (PCA)。FD被归类为中性粒细胞PCA；然而，只有少数先前的研究描述了其组织病理学，包括对水平切片活检标本中的系统评估和量化的卵泡变化的评估，以及早期和晚期的临床和皮肤镜检查结果。

客观的

我们旨在阐明早期和晚期活动期 FD 的组织病理学和皮肤镜特征。

方法

我们通过皮肤镜检查和水平和垂直切片活检标本对 42 名 FD 患者进行了病例系列研究。

结果

早期病变的组织病理学发现包括皮脂腺丧失；滤泡间棘皮症; 纤维化伴有凹陷、融合的滤泡漏斗部，在皮肤镜检查显示滤泡间瘢痕疙瘩样区域增厚并带有簇状毛发。活动性病变显示更多的毛发簇、裂开和融合的漏斗部，主要在上部毛囊中伴有致密炎症。在不到一半的患者中观察到以中性粒细胞为主的浸润，包括那些有早期病变的患者。

限制

这是一项回顾性研究。

结论

FD具有混合单元PCA的特征。早期 FD 的特征是滤泡间瘢痕疙瘩样区域增厚，毛发丛生，皮脂腺缺失。