Herpetic Whitlow:
Information for adults

Herpetic whitlow—also called digital herpes simplex, finger herpes, or hand herpes—is a painful viral infection occurring on the fingers or around the fingernails. Herpetic whitlow is caused by infection with the herpes simplex virus (HSV).

Infections with the herpes simplex virus are very contagious and are easily spread by direct contact with infected skin lesions. HSV infection usually appears as small blisters or sores around the mouth, nose, genitals, and buttocks, though infections can develop almost anywhere on the skin. Furthermore, these tender sores may recur periodically in the same sites.

There are 2 types of HSV: Type 1 and Type 2. HSV Type 1 (HSV-1) infections usually occur around the mouth, lips, nose, or face, while HSV Type 2 (HSV-2) infections usually involve the genitals or buttocks. However, HSV-1 can sometimes cause infections in the genitals or buttocks, while HSV-2 can occasionally cause infections around the mouth, lips, nose, or face.

Both types of herpes simplex virus produce 2 kinds of infections: primary and recurrent. Because it is so contagious, the herpes simplex virus causes a primary infection in most people who are exposed to the virus. However, only about 20% of people who have a primary infection with the herpes simplex virus actually develop visible blisters or sores. Appearing 2–20 days after a person's first exposure to HSV, the sores of a primary infection last about 1–3 weeks. These sores heal completely, rarely leaving a scar.  Nevertheless, the virus remains in the body, hibernating in nerve cells.

Certain triggers can cause the hibernating (latent) virus to wake up, become active, and travel back to the skin. These recurrent herpes simplex virus infections may develop frequently (every few weeks), or they may never develop. Recurrent infections tend to be milder than primary infections and generally occur in the same location as the primary infection.

People develop herpetic whitlow when they come into contact with areas already infected with HSV, either on their own bodies or on someone else's body. Usually, there is a break in the skin, especially a torn cuticle at the base of the fingernail, which allows the virus to enter the finger tissue and establish an infection. HSV-1 causes approximately 60% of herpetic whitlow infections, while HSV-2 causes the remaining 40%.