Abstract:

A 68-year old female farmer presented with hair loss for 3 months.Physical examination showed irregularly dark red patch with a little amount of scales.The hairs in the red lesion broke off from the scalp presented with black dotted like, while the hair follicles showed swollen with mild fluctuation.Direct fungal microscopic examination presented a large amount of chain-like spores distribution along the inside of hair shaft.Fungal culture isolated yellow-white woolly colony presented with short rod-like or pear-shaped microconidiain by slide culture and positive urease test.Molecular identification by BLAST based on rDNA ITS sequencing confirmed as Trichophyton tonsurans.The diagnosis was confirmed as black-dot ringworm caused by Trichophyton tonsurans.Therapeutic drugs included oral itraconazole, 0.2-0.4 per day, external ketoconazole lotion, triamcinolone acetonide and econazole nitrate cream, and ketoconazole cream.After 2 months treatment, skin lesions completely faded and broken hair grew back without scarring alopecia.No recurrence after treatment was observed in 6-month follow-up.

Key words: black dot ringworm, tinea capitis, Trichophyton tonsurans, itraconazole, adult