Abstract: 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.

Key words: marine organism, Exserohilum rostratum, infection