A 30 yr old female presents with history of itching under right breast. On examination annular ring lesion was present under the breast. The diagnosis is :

Ans. is 'a' ie Trichophyton rubrum The findings of itchy annular ring lesions on the trunk point towards the diagnosis by Tinea corporis.Though Tinea corporis can be caused by all the three - Trichophyton Epidermophyton and Microsporum; Trichophyton rubrum is the most common cause.