关键词：太田节皮菌；条形码样发；皮肤镜检查；摩斯电码发；头癣；紫外光
Keywords:Arthrodermaotae;barcode-likehair;dermoscopy;Morsecodehair;tineacapitis;ultraviolet.
临床表现
CLINICALPRESENTATION
患者为2岁男孩，2月内逐渐出现头皮散在无症状脱发斑，伴轻微鳞屑（图1）。
A2-year-oldboyhadgraduallydevelopedsporadicasymptomaticpatchesofalopeciawithslightscalesonthescalpinthepast2months(Fig1).
图1.头癣：头皮散在脱发斑伴鳞屑
fig1.Tineacapitis.Sporadicalopeciapatcheswithscalesonthescalp
皮肤镜表现
DERMOSCOPICAPPEARANCE
偏正光皮肤镜检查见发根周围鳞屑堆积、黑点征和伴白色横纹的条形码样发（barcode-likehair）。紫外光皮肤镜检查可见毛干处亮绿色荧光以及堆积鳞屑处的亮白色荧光。值得注意的是，在条形码样发白色横纹处未见亮白色荧光（图2）。
Accumulatedscalesaroundhairroots,blackdots,andbarcode-likehairswithhorizontalwhitebandswereobservedbypolarizeddermoscopy.Bright-greenfluorescenceinhairshaftsandbright-whitefluorescenceofaccumulatedscaleswereobservedbyultravioletdermoscopy.Notably,thebright-whitefluorescencedisappearedatthewhitebandsofthebarcode-likehairs(Fig2).
图2.头癣皮肤镜检查（原始放大X40）：A.偏正光皮肤镜检查见发根周围鳞屑堆积、黑点征（红箭头）和条形码样发（白箭头）；B.在相同区域，紫外光皮肤镜检查见堆积鳞屑处的亮白色荧光和毛干处亮绿色荧光（白圈），条形码样发白色横纹处未见亮白色荧光（白色箭头）
Fig2.Tineacapitis.Dermoscopyobservation(originalmagnification:).A,Accumulatedscalesandblackdots(redarrows)andbarcode-likehairs(whitearrows)underpolarizeddermoscopy.B,Inthesamearea,bright-whitefluorescenceofaccumulatedscalesandbright-greenfluorescenceofhairshaftsunderultravioletdermoscopy(whitecircles).Thebright-whitefluorescencedisappearedatthewhitebandsofthebarcode-likehairs(whitearrows).
直接显微镜检查和病原真菌鉴定
DIRECTMICROSCOPYAIDENTIFICATIONOFPATHOGENICFUNGUS
条形码样发的直接显微镜检查可见真菌、“毛发穿通”现象和毛发宽度不等。通过真菌培养和测序分析（GenBank登录号KU）鉴定为太田节皮菌（Arthrodermaotae）。
Directmicroscopyofbarcode-likehairsshowedfungalinvasion,‘‘hairperforation’’appearance,andwidthinequality(Fig3).Arthrodermaotae(teleomorphofMicrosporumcanis)wasidentifiedbycultureandsequenceanalysis(GenBankaccessionnumberKU).
图3.条形码样发的直接显微镜检查：毛发较细部分和“穿通”处大量真菌孢子（原始放大x）。白三角表示真菌孢子，白箭头示毛发较细部分，白圈示“毛发穿通”现象。
Fig3.Tineacapitis.Directmicroscopyofthebarcode-likehair:numeroussporesformedaroundthinnerfragmentand"perforating"siteofthehair.(Originalmagnification:x).
关键信息
KEYMESSAGE
近期有报道称条形码样发或摩斯电码发（Morsecodehair）是头皮、眉毛和手臂毳毛真菌感染的皮肤镜特异性表现1-4。此病例中，条形码样发特征性表现为偏振光皮肤镜下白色横纹、紫外光皮肤镜下荧光消失以及显微镜下毛发较细部分周围大量孢子。文献4称皮肤镜下的白色横纹可能与局部真菌感染相关，直接镜检可见毛发穿通，我们的病例也是如此。
Ithasbeenrecentlyreportedthatbarcode-likehairorMorsecodehairisanewandspecificdermoscopicfeatureoffungalinfectionofthescalp,eyebrow,andvellushairsonthearm.1-4Thedistinctivefeaturesofthebarcode-likehairarehorizontalwhitebandsbypolarizeddermoscopy,fluorescencedisappearingatthebandsbyultravioletdermoscopy,andnumeroussporesaroundthinnerfragmentbymicroscopyinthiscase.Horizontalwhitebandsobservedwithdermoscopyareprobablyrelatedtolocalizedareasoffungalinfection,showingahairperforationvisiblewithdirectmicroscopy,4whichisseeninourpatientaswell.
此外，使用紫外线光源（自然光用不透光材料遮挡）的皮肤镜相当于便携式Wood灯设备，可精准观察单根受感染发干的荧光情况，而不是以往的整片荧光。发干亮绿色荧光可用于鉴别偏正光皮肤镜下白色鳞屑的假阳性表现（即亮白色荧光）。
Furthermore,adermoscopeusingultravioletlight,withnaturallightdodgedbyalight-proofsheet,actsasaminiatureandportableWood’slampdevice,whichcanpreciselyobservethefluorescencefromeachsinglefungalinfectedhairshaft,insteadofapatchoffluorescenceasusual.Thebright-greenfluorescenceinhairshaftscoulddifferentiatethefalsepositiveofwhitescale(presentingbright-whitefluorescence)observedbypolarizeddermoscopy.
JAmAcadDermatol;76:S28-30.?PublishedbyElsevieronbehalfoftheAmericanAcademy