As of 2015, there is no cure for fever blisters, which are caused by the herpes simplex virus, states MedlinePlus. Although antiviral drugs can help heal the blisters, they usually clear up without treatment within two weeks, according to the Mayo Clinic. The blisters merge, burst and crust over before healing completely.
Some prescription antiviral drugs that can be used to treat fever blisters are acyclovir, valacyclovir and famiciclovir, reports the Mayo Clinic. However, the Mayo Clinic also recommends home remedies to clear up cold sores, such as the over-the-counter docosanol cream and other preparations with drying agents.
Other possible cold sore treatments include putting ice on the blister, taking lysine supplements and using lip balm with lemon extract, states Healthline. It also recommends finding ways to reduce stress, as stress is often responsible for herpes outbreaks.
Those with the herpes simplex virus may be asymptomatic, claims the Mayo Clinic. However, these people can still spread the virus. Those who do have symptoms may feel an on-site itching or tingling sensation before the fever blister outbreak. They may also experience fever, sore throat, headaches and swollen lymph nodes.
Fever blisters can occur on lips, chin, cheeks, or inside the mouth or nostrils, states MedlinePlus. When inside the mouth, herpes simplex usually manifests on the gums or the roof of the mouth.