A sore next to the mouth is considered a boil caused by bacterial infection. Clinical treatment requires anti-inflammatory and antibacterial therapy, either oral penicillin v potassium tablets or amoxicillin capsules, or in severe cases, intravenous penicillin sodium injection or amoxicillin injection. If the patient has an allergic reaction to this drug, it needs to be changed to a static dose of levofloxacin hydrochloride injection or clindamycin phosphate injection. Topical medications can be chosen from Esaacridine lactate solution for wet compresses and rinses, or Gentamicin saline solution for wet compresses, in addition to applying fusidic acid cream for treatment.