每日一题_2025.04.17

A previously healthy 3-year-old boy was brought to the emergency department with a 6-week history of painless bumps and ulcers on his left leg. He initially had itchy insect bites on his foot and then bumps and ulcers had developed slowly on his leg. The boy had recently immigrated from Venezuela after a months-long journey by land with his family. On physical examination, ulcerated plaques with rolled borders and satellite papules were observed on the left lower leg, buttocks, and back. Three biopsy samples were obtained from one of the lesions. Histopathological analysis was notable for severe lymphohistiocytic infiltration with no organisms identified by routine microbiologic stains. What is the most likely diagnosis?

一名既往健康的3岁男孩因左腿出现无痛性肿块和溃疡6周而被送往急诊科。他最初脚上有瘙痒的虫咬伤，随后腿上慢慢出现了肿块和溃疡。这名男孩最近与家人一起经过数月的陆路旅行后从委内瑞拉移民而来。体格检查发现，左小腿、臀部和背部可见有卷边溃疡性斑块和卫星状丘疹。从一个病变处取了3份活检标本。组织病理学分析显示有严重的淋巴组织细胞浸润，常规微生物染色未发现病原体。最可能的诊断是什么？

A. Brown recluse spider bites疥螨病

B. Cutaneous Leishmaniasis皮肤利什曼病

C. Leprosy麻风病

D. Phaeohyphomycosis暗色丝孢霉病

E. Pyoderma gangrenosum坏疽性脓皮病

答案解析：

对一个组织样本进行聚合酶链反应检测，鉴定出为圭亚那利什曼原虫。利什曼病是由一种通过白蛉叮咬传播的原生动物寄生虫引起的。皮肤利什曼病是该疾病最常见的表现形式，可能会导致毁容性瘢痕。气候变化正在通过改变白蛉种群的地理分布和规模来影响利什曼病的传播。贫困人群和移民感染这种疾病的几率最高。

正确答案：B