Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA.
Department of Dermatology, Washington University School of Medicine, St. Louis, Missouri, USA.
J Cutan Pathol. 2020 Nov;47(11):1063-1066. doi: 10.1111/cup.13816. Epub 2020 Aug 26.
Demodex folliculorum is a mite that commonly inhabits the pilosebaceous units of facial skin, particularly in a perioral and periorbital distribution. While typically an incidental and asymptomatic parasite, Demodex spp. are proposed to contribute to the pathogenesis of facial folliculitis, chronic blepharitis and papulopustular rosacea. Reports of demodicosis in anatomic locations other than the face are exceedingly rare. Here we report a 36-year-old woman with symptomatic Demodex spp. infestation of Fordyce spots of the labia minora. She was referred to dermatology after a 9-month history of tender red bumps on the vulva that would arise and drain over a 24 to 72 hours period, several times per week. Physical examination revealed erythema of the labia minora and introitus with a 4 mm, pink, dome-shaped soft papule on the left labium minus. Wet mount, microbiologic cultures and sexually transmitted infection (STI) screenings were unremarkable. Histopathologic examination revealed a well-circumscribed nodule of suppurative granulomatous inflammation arising in a background of mucosa with Fordyce spots, the majority of which were infiltrated by Demodex spp. Treatment with oral ivermectin and topical metronidazole cream resulted in a symptom-free period of 22 months. This case represents an unusual presentation of symptomatic Demodex infestation.
毛囊蠕形螨是一种常见于面部皮肤的毛囊皮脂腺单位的螨虫，尤其常见于口周和眶周分布。虽然毛囊蠕形螨通常是一种偶然的无症状寄生虫，但它被认为与面部毛囊炎、慢性睑缘炎和丘疹脓疱性酒渣鼻的发病机制有关。除面部以外的解剖部位发生蠕形螨病的报道极为罕见。在此，我们报告了一例 36 岁女性，患有外阴唇下部的福代斯斑（Fordyce spots）部位的毛囊蠕形螨感染。她因外阴出现触痛的红色丘疹而被转诊至皮肤科，这些丘疹会在每周数次的 24 至 72 小时内出现并排出。体格检查显示外阴唇和阴道入口处呈红斑状，左侧小阴唇有一个 4 毫米、粉红色、圆顶状的软丘疹。湿片检查、微生物培养和性传播感染（STI）筛查均无异常。组织病理学检查显示，在福代斯斑的背景下，出现了一个界限清楚的化脓性肉芽肿性炎症结节，大多数结节被毛囊蠕形螨浸润。口服伊维菌素和局部甲硝唑乳膏治疗后，患者症状缓解期长达 22 个月。本病例代表了一种不常见的症状性毛囊蠕形螨感染表现。
