Herpes labialis

Definition: Herpes simplex, caused by type 1 virus, primarily spread by oral secretions and usually occurring as a concomitant of fever. It may also develop in the absence of fever or prior illness. It commonly involves the facial region, especially the lips and the nares. (Dorland, 27th ed.)

Synonyms (terms occurring on more labels are shown first): cold sores, herpes labialis, cold sore, fever sore, fever blisters

More information: PubMed search and possibly Wikipedia