The itchy lower body of male students is commonly caused by several diseases: 1. scrotal scabies, a skin venereal disease caused by scabies mites infecting the scrotal skin, often spread by unclean sex can also be infected by contact with unclean bath towels, unclean underwear, bedding, etc. Patients often have intense itching in the scrotal area, and local skin can appear scabies nodules. 2. fungal infections of the perineum, such as ringworm, mycosis fungoides, etc., mainly The patient is often not bathed in time after sweating, and can also be cross-transmitted due to contact with foci of infection in other parts of the body, such as ringworm of the head and foot if the patient scratches the head and foot and then touches the perineum can cause itching of the lower body. 3, can also be seen in pubic lice disease, pubic lice parasites in the pubic hair area of the perineum, often due to unclean sex after. 4, long-term failure to change and clean underwear, bedding, perineum Poor cleanliness and hygiene can also lead to itching in the lower part, usually characterized by strange itching at night.