Ultrastructural study of exclamation‐mark hair shafts in alopecia areata
Ultrastructural study of exclamation‐mark hair shafts in alopecia areata
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斑秃感叹号毛干的超微结构研究
DOI：
10.1111/j.1600-0560.1990.tb00111.x
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发表时间：
1990
影响因子：
1.7
通讯作者：
M. Kendall
中科院分区：
文献类型：
--
作者：
D. Tobin;D. Fenton;M. Kendall
急性斑秃的主要诊断特征是感叹号毛发的存在。这些特征性的毛发在其远端断裂，并向头皮近端逐渐变细，使它们看起来像一个感叹号。对8例未经治疗的急性斑秃患者和3例正常人的头发形态进行了研究。光学显微镜，透射和扫描电子显微镜显示，在头发的远端与其长度的其余部分，并与正常的毛干相比，有明显的结构差异。磨损的刷状尖端下方的毛发横切面通常显示不对称的皮质崩解。一侧致密且均匀，而另一侧深深裂开和/或破碎成皮质、角质层和表皮成分的离散异质染色碎片以及明显退化的皮质。许多感叹号发梢缺乏角质层，轮廓不规则。黑色素被发现在皮质和髓质碎片的尖端，虽然它是缺席的更退化形式的皮质。这些病理性休止期毛发的近端切片显示几乎正常的毛干超微结构。
The prime diagnostic feature of acute alopecia areata is the presence of exclamation mark hairs. These characteristic hairs fracture at their distal end and taper proximally towards the scalp, giving them the appearance of an exclamation mark. Hair morphology was studied in 8 patients with untreated acute alopecia areata and 3 normal adults without hair loss. Light microscopy, transmission and scanning electron microscopy revealed distinct structural differences in the distal end of hairs compared with the remainder of their length and with normal hair shafts. Transverse sections of hairs just below the frayed brush‐like tip often displayed asymmetrical cortex disintegration. One side was compact and homogeneous while the other was deeply fissured and/or broken up into discrete heterogeneous‐staining fragments of cortical, stratum corneum and cuticular components in addition to apparently degenerate cortex. Many exclamation mark hair tips lacked cuticle and had irregular profiles. Melanin was found in cortical and medullary fragments at the tip, although it was absent in the more degenerate forms of cortex. More proximal sections of these pathognomic telogen hairs revealed nearly normal hair shaft ultrastructure.