The redness and itchiness of the moist scrotum may be caused by infection, eczema, allergy and other reasons. 1. Infection: local inflammation occurs when the scrotum area is infected by bacteria and fungi, and the inflammation stimulation can cause the scrotum to appear red, swollen, hot and painful symptoms. 2. Eczema: the cause of eczema in the scrotum is not clear, it may be related to abnormal immune function, local stimulation and other factors. The local itching is intense, often due to excessive scratching, hot water washing and redness, swelling, oozing, erosion of the performance. 3. Allergy: the scrotum is moist, itchy and red after the local use of drugs or underwear material allergy. Stopping the use of drugs or changing clothes in time can reduce the symptoms. Because the scrotum dampness, redness and itchy cause more, the patient should go to the hospital in time to improve the examination, clear the cause of the disease to give targeted treatment.