Small red blood packets on the surface of the scrotum may be caused by scrotal inflammation, scrotal eczema, herpes zoster viral infection and other causes. 1. Scrotal inflammation: Inflammatory diseases can be induced when the scrotum area is stimulated by physical and chemical factors or bacterial infection. After the skin in the scrotum area is stimulated by inflammation, the symptom of small red blood bags on the surface of the scrotum can appear. 2. Scrotal eczema: prolonged sitting or not changing underwear in time may lead to scrotal irritation, inducing scrotal eczema, which may also cause the symptoms of small red blood bags on the surface of the scrotum. 3. Herpes zoster virus infection: close contact with a person infected with herpes zoster may cause herpes zoster virus infection, resulting in skin irritation on the surface of the scrotum, the appearance of small red blood packets, can also be accompanied by a certain degree of itching and pain and other symptoms. Small red blood bags on the surface of the scrotum may also be caused by other reasons, such as allergies or capillary hemangiomas, etc., should go to the hospital in time to clarify the cause of the disease, and choose the appropriate method of treatment.