This is a close-up of the lip of patient with a herpes simplex lesion on the lower lip due to the (HSV1) pathogen. Herpes simplex virus type 1 usually is the cause for oral lesions sometimes referred to as 'cold sores', 'fever blisters' or more technically known as 'recurrent herpes labialis'. Image courtesy CDC/Dr. Herrmann, 1964. (Photo by Smith Collection/Gado/Getty Images).
