每日一题_2025.01.26

A previously healthy 10-month-old girl was referred to the pediatric dermatology clinic with a 6-month history of an intermittently itchy and swollen skin lesion on her neck that had gradually increased in size. On physical examination, a thin, well-demarcated, tan plaque was seen on the neck. The lesion was rubbed firmly with a tongue depressor for 5 seconds, and within a few minutes it became edematous with a flare of surrounding erythema — a finding known as Darier’s sign. What is the most likely diagnosis?

一名既往健康的10个月大女婴因颈部皮肤病变6个月被转诊至儿科皮肤科诊所。该病变间歇性瘙痒和肿胀，并逐渐增大。体格检查发现颈部有一块薄而边界清楚的棕褐色斑块。用压舌板用力摩擦病变部位5秒钟，几分钟内病变部位出现水肿并伴有周围红斑，这一发现称为Darier征。最可能的诊断是什么？

A. Dermatofibroma皮肤纤维瘤

B. Juvenile Xanthogranuloma (JXG) 幼年性黄色肉芽肿（JXG）

C. Langerhans Cell Histiocytosis (LCH)朗格汉斯细胞组织细胞增生症（LCH）

D. Solitary Mastocytoma孤立性肥大细胞瘤

E. Spitz NevusSpitz痣

答案解析：

诊断为孤立性肥大细胞瘤。孤立性肥大细胞瘤是皮肤肥大细胞增多症的一种局部形式，这种疾病的特点是皮肤中肥大细胞数量过多，但没有系统性肥大细胞疾病。孤立性肥大细胞瘤通常在婴儿期发展，并在儿童期逐渐消退。Darier征是由于摩擦皮肤病变时肥大细胞脱颗粒和组胺释放引起的，在大多数孤立性肥大细胞瘤中可见，并支持诊断（尽管通常观察到的表现比本例患者更为轻微）。

正确答案：D