Abstract: Objective To report a case of kerion caused by Geotrichum in China. Methods A 9 year-old-boy had kerion-form lesion on his scalp with swollen posterior auricular lymph nodes, and did not show other definite underlying disease. The pathogenic fungus was identified according to culture, scanning electron microscopy, biochemical tests and DNA sequencing. The hair infection test was performed and the infected hairs were examined by scanning electron microscope. Animal test confirmed the pathogenicity of the fungus. Results The fungal colonies were the same when the tissue cultures were repeated. The colonies showed milky white to yellowish in color. The hyphae could be identified at the periphery on Sabouraud's agar culture at 27℃, which were moist and smooth on the surface at 37℃. Under microscope, there were many rectangular arthrospores, round or oval spores with or without buddings, as well as branched hyphae. The isolated fungus was identified as a Geotrichum silvicola by culture, scanning electron microscope, biochemical test and DNA sequencing. The patient's condition was improved markedly after treatment of terbinafine for 4 weeks. Conclusions This is the first case report of kerion caused by Geotrichum in China, and terbinafine is effective.

Key words: Mycoses, Saccharomycopsis, Geotrichum, Kerion