海洋生物螫伤伴喙状明脐菌(Exserohilum rostratum)皮肤感染1例分析

Cutaneous Exserohilum rostratum infection secondary to marine biological stings

报道1例海洋生物螫伤伴喙状明脐菌(Exserohilum rostratum)感染。患者女性,47岁,右胫后红色丘疹、斑块5周,伴溃疡4周余,发病前泰国海边游玩时不明海洋生物螫伤。取皮肤组织行病理、真菌培养,并对菌株进行形态学和分子生物学鉴定。HE切片示真皮坏死及透明样真菌结构,脂肪小叶见灶性坏死。PAS、六铵银染色坏死区见菌丝、链状分生孢子及较大孢子结构。真菌培养见菌落扩展生长、羊毛状,棕褐色。胶带粘贴镜下可见棕色4~9个离壁分隔的分生孢子,两端有暗色带。ITS区序列分析鉴定为E.rostratum。依据临床及实验室检查诊断为E.rostratum皮肤感染。治疗:口服伊曲康唑200 mg/次,2次/日,1个月后减量至200 mg/次,1次/日,顿服,共3个月,皮损基本痊愈。E.rostratum引起皮肤感染少见,海洋生物螫伤引起皮肤屏障损伤及接触环境真菌可能是该患者感染E.rostratum的主要因素。

To report one case of cutaneous Exserohilum rostratum infection secondary to marine biological stings.A 47-year-old female presented with dark red plaques covered with ulcers on the flexor side of her right leg over 4 weeks,after being stabbed by unidentified marine organisms while traveling in Thailand.Skin tissues from the patient were obtained by skin biopsy for histopathological examination,then fungal culture and molecular biological identification of the strains were performed.Histopathological examination revealed fungal structure within focal necrotic dermis and lobular adipose necrosis.Fungal culture showed that horizontal expanding dark brown,woolly colonies.Catenulate conidia and macroconidia with branched hyphae were found by PAS and methenamine sliver staining.Under microscope,brown conidia with 3-4 septates and dark bands were observed.Exserohilum rostratum was identified as the pathogen by sequence analysis of ITS region.According to clinical features and laboratory results,the patient was diagnosed as cutaneous Exserohilum rostratum infection.Treatment Lesions lapsed after treatment with itraconazole 400 mg twice daily for one month,and tempering to 200 mg once daily for 3 months.Skin infections caused by Exserohilum rostratum were unusual,and impairment of skin barrier function caused by marine organisms stings and exposured to fungi in the environment were the main risk factors.