Erythromycin can be rubbed on herpes simplex co-infections, but erythromycin does not treat herpes simplex, so it is not recommended for routine treatment. Erythromycin belongs to antibacterial drugs, herpes simplex is caused by herpes simplex virus infection, the use of erythromycin is ineffective, herpes simplex should use antiviral drugs such as topical acyclovir, pentoxifylline ointment. Erythromycin belongs to macrolide antibiotics, topical erythromycin is mainly used for impetigo and other suppurative skin diseases, small area burns, common acne and ulcer surface infections, etc. The use of this product is occasionally seen irritation and allergic reactions and other side effects, allergy to the product is prohibited, allergic to the body with caution. Therefore, herpes simplex cannot be treated with erythromycin, but if the herpes rupture is infected, erythromycin ointment can be used externally under the guidance of the doctor for anti-infection treatment. It is recommended that herpes simplex patients go to the hospital and follow the doctor’s instructions for standardized treatment, and should not blindly use medication to avoid delaying the condition.