It is a superficial dermatophyte disease that occurs in the skin of the groin, adjacent to the vulva and perianal area, and is often pruritic. The lesions usually start on the inner side of the upper femur as small red papules or erythema flush with the skin, and then gradually expand peripherally into well-defined patches with papules and blisters, with an annular or semi-annular pattern of lesions. Tinea capitis is a fungus that lives in the stratum corneum of the human body and is warm and humid, so it has a high incidence in the south and southeast coastal areas of China. The disease is mainly transmitted by person-to-person contact, but it can also be transmitted from other parts of the body, mostly by tinea pedis (foot fungus) and tinea nail (gray nail), and the sharing of bath tubs, bath towels, and clothes is also a way of transmission. Diabetes and long-term use of glucocorticosteroids can also increase the risk of infection. Sexual contact may be contagious, but it is not highly contagious. There are factors such as genetic susceptibility (certain people are susceptible under the same conditions) and resistance. Treatment: The main treatment is local topical application. There are many antifungal lotions and ointments available on the market, but it is important to keep applying them. The clothing should be boiled and disinfected.