The herpes group of viruses can affect the oral soft tissues in a variety of ways. Which virus is responsible for the lesion known as a 'cold sore'?

The lesion known as a 'cold sore' is primarily caused by Herpes labialis, which is specifically associated with the herpes simplex virus type 1 (HSV-1). This virus tends to reside in the nerve ganglia and can become reactivated under stressful conditions, leading to the appearance of painful blisters typically around the lips or the oral cavity.

Although Herpes simplex refers more broadly to the group of viruses, Herpes labialis is the specific term for the strain and condition that causes cold sores. It's important to understand the context in which these terms are used, as they highlight different aspects of the same viral infection.

Herpes varicella is the virus responsible for chickenpox, and Herpes zoster refers to the reactivation of the varicella virus leading to shingles. Neither of these is associated with cold sores, reinforcing the specificity of Herpes labialis in relation to oral lesions.