A 19-year-old girl complains of moderate itching and hair loss on her head. Objectively, on the skin of her occipital region there is a single round erythematous focus 3 cm in diameter with clear margins. Asbestos-like scales can be observed on the surface of the lesion. The hair in the focus of the lesion is broken off at the length of 6-8 mm. What is the most likely diagnosis?