Brief answer:Fever Blisters / Cold sores. Hi.. Can understand your concern.. As per your complain you may have fever blisters which are caused by herpes simplex virus infection. Although this is not curable with antiviral medication but medicines are given to reduce fever and discomfort caused by the blisters and to prevent further outbreaks. The boils or blisters mostly resolve themselves in 10 to 12 days time but if it is associated with itching pain or discharge you can apply antiviral cream like Acyclovir to reduce viral population at the site thereby relieving your symptoms.. To reduce Fever and pain Tylenol or calpol containing acetaminophen can be helpful as it is a fever reducing medicine. Taking any anti viral medicines lie acyclovir, pencyclovir, famicyclovir orally has less significance as they do not cure herpes but they help in preventing outbreaks. Avoid any direct contact with other individuals as it is contagious and can effect other individuals too.. Avoid touching or picking the lesions.. Keep yourself well hydrated by drinking plenty of water.. Use natural lip lubricants to avoid drying or chapping of lips.. Always wear sunscreen containing lip balms while going to sun.. Hoping you get well soon.. Thanks and regards.. Dr.Honey Nandwani Arora.