Hi, Most probably you might have herpes simplex labialis. It is a viral infection caused by HSV virus type . It may recure off and on. It may be precipitated by poor immunity,stress,sleeplessness,fever,drugs..etc it is a relapsing disease. It may be complicated with secondary bacterial infection.. Antiviral like acyclovir 400 mg thrice a day for few weeks along with antibiotics may be taken. Immunomodulator like levamesole 50 mg daily for few months might improve immunity and thereby prevent relapse. Apply antibiotic cream like gentamycine. After clearance of infection,apply antiviral cream like acyclovir cream. Take all precautions to improve health and immunity. If there is relapse, repeate the treatment. I hope you got my answer. Thanks. Dr. Ilyas Patel MD