皮肤镜在头皮银屑病和脂溢性皮炎诊断及鉴别诊断中的应用

Roles of dermoscopy in the diagnosis and differential diagnosis of scalp psoriasis and seborrheic dermatitis

目的描述头皮银屑病和脂溢性皮炎的皮肤镜特征，并评估皮肤镜在二者鉴别诊断中的意义。方法选取2013年12月至2014年5月在北京协和医院皮肤科门诊就诊的头皮银屑病和脂溢性皮炎患者共40例，行皮肤镜及皮肤组织病理检查，回顾性评估皮肤镜特征。结果共选取头皮银屑病和脂溢性皮炎各20例患者的皮肤镜照片，点状血管（10／20，50％）、小球状血管（13／20，65％）、环状血管（16／20，80％）、发夹样血管（17／20，85％）、白色鳞屑（10／20，50％）和点状出血（12／20，60％）提示头皮银屑病，分叉血管（16／20，80％）、非典型血管（13／20，65％）、无结构区域（20／20，100％）和蜂窝状色素网（9／20，45％）提示头皮脂溢性皮炎，这些特征发生比例两组间比较差异均有统计学意义（均P＜0．05）。结论头皮银屑病和脂溢性皮炎具有不同的皮肤镜表现，皮肤镜在二者的鉴别诊断中具有很大的应用价值。

Objective To describe the dermoscopic patterns of scalp psoriasis and seborrheic dermatitis and explore the roles of dermoscopy in their diagnosis and differential diagnosis .Methods A total of 40 patients with scalp psoriasis （ n=20 ） and seborrheic dermatitis （ n=20 ） were recruited from Department of Dermatology , Peking Union Medical College Hospital from December 2013 to May 2014.They were examined both dermoscopically and histopathologically .And characteristic dermoscopic features were evaluated.Sensitivity , specificity , positive predictive value and negative predictive value were calculated for predefined dermoscopic criteria in relation to the diagnosis of two diseases .Results The most significant dermoscopic features of scalp psoriasis included dotted vessels （10/20, 50%）, glomerular vessels （13/20, 65%）, red loops （16/20, 80%）, hairpin vessels （17/20, 85%）, white scales （10/20, 50%） and punctate hemorrhages （12/20, 60%）.In contrast, seborrheic dermatitis was characterized by arborizing vessels （16/20, 80%）, atypical red vessels （13/20, 65%）, featureless areas （20/20, 100%） and honeycomb pigment （9/20, 45%）（all P〈0.05）.Conclusions Scalp psoriasis and seborrheic dermatitis have different dermoscopic patterns .Dermoscopy may be valuable for clinical diagnosis and differential diagnosis of scalp psoriasis and seborrheic dermatitis .