每日一题_2024.01.11

A 55-year-old woman presented to the dermatology clinic with a 1-year history of skin darkening on her face. Two years before presentation, she had started applying a skin-lightening cream containing hydroquinone to her face daily to treat melasma. On physical examination, bluish-brown patches with background erythema and telangiectasias were observed on the cheeks, nasal bridge, and perioral region, with lesser involvement on the forehead (left). Dermoscopy of the affected areas revealed hyperchromic, pinpoint macules (middle). A skin-biopsy sample from the left cheek showed extracellular deposition of yellow-brown, banana-shaped bodies in the dermis (right, hematoxylin and eosin stain). What is the most likely diagnosis?

一名55岁女性因面部皮肤变黑1年到皮肤科门诊就诊。就诊前2年，患者开始每日在面部涂抹含有对苯二酚的皮肤美白霜，以治疗黄褐斑。体格检查时，在面颊、鼻梁和口周区域观察到蓝棕色斑块，背景有红斑和毛细血管扩张，前额受累较少(左)。皮肤镜检查显示受累区域出现高色素、针尖状斑(中间)。左面颊的皮肤活检样本显示，真皮层有黄褐色香蕉形小体沉积(右，苏木精-伊红染色)。最有可能的诊断是什么?

A. Contact dermatitis 接触性皮炎

B. Eczematous drug eruption 湿疹性药疹

C. Exogenous ochronosis 外源性黄褐病

D. Lichen planus pigmentosus 色素性扁平苔藓

E. Solar lentigenes 太阳能小透镜

答案解析：

诊断为皮肤美白膏引起的外源性黄褐病。黄褐病是一种由组织中赭色沉积物的积累引起的色素沉着障碍。当与尿黑酸有关时被认为是内源性的，当与使用皮肤美白剂有关时被认为是外源性的。外源性褐黄病治疗困难，可能不可逆。医师开出了外用润肤剂和类视黄醇凝胶。2个月随访时，患者色素沉着轻微减轻。

正确答案：C