Penicillin cannot treat herpes. This is because herpes is most often caused by a varicella-zoster virus infection, and penicillin primarily treats bacterial infections. However, in many cases, herpes occurs on the surface of the skin and can be triggered by localized breaks in the surface of the skin by bacteria such as Staphylococcus epidermidis or Streptococcus haemolyticus, which can result in pus-filled exudates or clustered pustules. In this case, penicillin can be applied for antibacterial and anti-infective treatment. However, before applying this drug, it is necessary to do a normal sensitization test to exclude allergic reactions. If allergy occurs, it is necessary to change other antibiotics for treatment.