Microsporum canis Infection in Three Familial Cases with Tinea Capitis and Tinea Corporis

Abstract

We report a familial infection caused by Microsporum canis. The first two patients were a 30-year-old female and her son, a 5-year-old boy, who came in contact with a pet dog at a farm house. The boy then suffered from hair loss for 3 months. There were circular and patchy alopecia with diffuse scaling on his scalp. Meanwhile, his mother also developed patchy erythema and scaling on her face. Several weeks later, the boy’s sister, a 4-year-old girl, was noted to have inconspicuous scaly plaques in the center of her scalp. The development of tinea capitis in the two children and tinea corporis in their mother were diagnosed based on the positive KOH examination. Morphologic characteristics and sequencing of the internal transcribed spacers 1 and 2, amplified from primary culture isolates, confirmed that their infections were caused by the zoophilic M. canis. Repetitive sequence-based molecular typing using the DiversiLab system secreted enzymatic activity analysis, and antifungal susceptibility indicated that these isolates might share the same source. The boy and girl were cured by the treatment with oral itraconazole and topical naftifine–ketoconazole cream after washing the hair with 2 % ketoconazole shampoo, and their mother was successfully treated by terbinafine orally in combination with topical application of naftifine–ketoconazole cream.