A herpetic whitlow is a lesion on a finger or thumb cause by the herpes simplex virus. In children the primary source of infection is the orofacial area, and it is commonly inferred that the virus (in this case commonly HSV-1) is transferred by the chewing or sucking of fingers or thumbs. In adults it is more common for the primary source to be the genital region, with a corresponding preponderance of HSV-2. It is also seen in adult health care workers such as dentists because of increased exposure to the herpes virus.