A 35-year-old female schoolteacher from Delhi presents with a 3-month history of pruritic lesions on her groin and inner thighs. On examination, she has well-demarcated, erythematous, scaly plaques with a raised border and central clearing. The lesions spare the scrotum and are bilateral and symmetrical. KOH mount confirms the presence of septate hyphae. She denies any nail involvement. Which of the following is the most likely diagnosis?