Small blisters on the penis may be genital herpes, a sexually transmitted disease caused by the herpes simplex virus (HSV). Treatment may include acyclovir antiviral therapy and saline wash. The clinical manifestation of genital herpes is clustered blisters on an erythematous base. After secondary bacterial infection, the blisters may become pustules, which will form vesicles or shallow ulcers after rupture, and are painful. 1. Antiviral therapy: e.g. acyclovir, can be used for skin and mucosal infections caused by genital herpes due to herpes simplex virus. Adverse reactions commonly include vomiting, nausea, diarrhea, loss of appetite, and thirst. It is contraindicated for those who are allergic to the product. 2. Local care: such as saline, its main role is to keep the local clean and dry. Use isotonic saline to wash the affected area daily. If small blisters grow on the penis and the symptoms are not relieved or aggravated, it is recommended to go to the hospital, clarify the cause of the disease and then standardize the treatment under the guidance of the doctor.