A 6-year-old girl presents to the clinic with scaly patches on the scalp. Primary smears and culture of the skin and hair were negative. A few weeks later, she returned and was found to have inflammatory lesions. The hair fluoresced under Wood's light and primary smears of skin and hair contained septate hyphae. On speaking with the parents, it was discovered that there were several pets in the household. Which of the following is the most likely agent?
High-Yield Explanation
Hairs infected with Microsporum canis and M. audouini both fluoresce with a yellow-green color under Wood's light, while Trichophyton rubrum, T. tonsurans, and Epidermophyton floccosum do not. But M. audouini is an anthropophilic agent of tinea capitis, whereas M. canis is zoophilic. M. canis is primarily seen in children and is associated with infected cats or dogs Reference: Ananthanarayan and Paniker&;s Textbook of Microbiology Tenth edition