Redness, swelling and pain in the genitals of young boys may be caused by diseases such as glansitis and scrotal eczema. 1. glansitis: glansitis is related to a variety of factors, including bacterial, fungal and other pathogenic infections, external material stimulation and so on. The main symptoms are local itching, painful sensation, edema, pressure and pain sensation, and there will be itching, irritation, erythema and other symptoms. 2. Scrotal eczema: the cause of scrotal eczema is not yet clear, and it is considered to be caused by internal factors as well as external factors. Affected children will experience symptoms such as itching, swelling and erosion of the scrotal skin, as well as dry and painful scrotal skin. Redness, swelling and pain in the genitals of young boys may also have other causes, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.