Korean J Med Mycol.  2017 Sep;22(3):129-134. 10.17966/KJMM.2017.22.3.129.

Tinea Capitis Caused by Microsporum canis Misdiagnosed as Seborrheic Dermatitis in a 79-Year-Old Woman

• Park MW
• Hong JS
• Suh MK
• Ha GY
• Jang TJ
• Choi JS

• KMID: 2392699
• DOI: http://doi.org/10.17966/KJMM.2017.22.3.129

Abstract

Microspoum canis is a zoophilic dermatophyte that is often transmitted to humans from cats and dogs. It has become one of the most important causative agents in tinea capitis ane kerion celsi. Tinea capitis is uncommon in an adult. Moreover, tinea capitis caused by Microspoum canis is rare in an elderly. The location of the lesion and the clinical course of tinea capitis might have led physicians into misdiagnosis as the seborrheic dermatitis. Therefore, we report this case to emphasize the importance of KOH mount and fungal culture of the skin lesions mimicking seborrheic dermatitis. We report a case of tinea capitis caused by Microspoum canis in a 79-year-old woman. The lesions were manifested by fine scaly erythematous patches on the fronto-vertex scalp for 2 weeks. She was diagnosed as seborrheic dermatitis in local clinic and was treated with topical steroid. However, the lesion was not improved. She kept a cat as a pet. Culture from biopsy specimen on Sabouraud's dextrose agar showed typical cottony colonies of Microspoum canis. The nucleotide sequence of internal transcribed spacer for clinical isolate was identical to that of Arthroderma otae strain ATCC 23828 (GenBank accession number AY213657). She was treated with 200 mg of oral itraconazole daily for 12 weeks. The skin lesions improved after treatment, and recurrence has not been observed.

Keyword

Microsporum canis; Seborrheic dermatitis; Tinea capitis