Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your health concerns. ..
First of all I would like to tell you that in your case it can be a Herpatic
cold sore if in case your boyfriend had a previous history of
Herpes infection and he had cold sores in the past although he does not have an outbreak currently..
If it is so it can be probably a cold sore and need an antiviral Oral and topical therapy to prevent further outbreaks as
antiviral Medication cannot cure persisting infection and can only prevent further outbreaks..
For confirmation that whether it is viral infection or not you can get viral culture or Polymerase chain reaction or antigen antibody reaction etc which are different investigation done under supervision of
Dermatologist..
In case your boyfriend doesn't have any previous history of cold sores then it could be probably an
acne lesion and needs anti- acne treatment like
Clindamycin gel,
Benzoyl Peroxide gel and mouthwash while at times Muricoprin antibiotic orally is also advisable..
You need to ask the history to the guy and visit a Dermatologist and get evaluated accordingly for proper diagnosis and treatment..
Hope this information helps..
Thanks and regards..
Dr.Honey Nandwani Arora..