Abstract: Objective To report a case of facial verrucous proliferating nodules caused by Malassezia pachydermatis.Methods Direct microscopic examination,fungal culture,temperature test,catalase test,pathological examination,PAS staining,and scanning electron microscopy were used to identify the fungus isolated from a woman with facial verrucous proliferating nodules.Results Pathological examination with HE and PAS staining of the lesion showed diffuse infiltration of chronic inflammatory cells and sparse distribution of spores in the dermis.Microscopically,Gram staining of lesional secretions and pet dog scales showed many yeast-like spores and germs.After culture of the lesion specimen at 27℃ for 2 weeks, yeast-like milky colonies apppeared on Sabouraud's agar (SDA) medium with/without olive oil.The fungus grew well on SDA medium with olive oil at 27℃,and was catalase-negative.The ultrastructural examination of the fungus under a scanning electon microscope showed small cells,broad budding collarette,thick budding base,and spherical,oval or ellipse spores,etc.The above-mentioned characteristics suggested that the fungus was Malassezia pachydermatis.Conclusion It is the first case report of facial verrucous proliferating nodules due to Malassezia pachydermatis transmitted by pet dogs in China,and fluconazole plus lesional freezing has good therapeutic effects.

Key words: Mycoses, Malassezia, Fluconazole