What are Fever Blisters?
Fever Blisters, also called Cold Sores, are blisters filled with fluid and usually erupt on the lips or between lips and nose, outside the mouth, as opposed to canker sores that occur inside the mouth. Fever blisters occur within hours and are very painful, lasting up to 10 days. Fever blisters are often referred to as Herpes. Herpes is a viral infection. Open herpes blisters can spread from person to person.