My 20 year old son woke up w/ some very small blisters on his lips today. He is not sexually active no girlfriend. They are about 1mm if that and look like clear fluid filled. Nothing in his throat or mouth. No fever or any other symptoms at this time. He has not eaten anything different and his lips are not swollen. It does not look like an allergic reaction.
Thanks for your query, I have gone through your query. The blisters on the lip could be because of the viral infection like herpes labials. Consult an oral physician and get it diagnosed. You can take topical antiviral Chat Doctor.  It is a self limiting condition. Nothing to worry it will heal within 5 days. I hope my answer will help you. Take care.