Herpetic Whitlow – Don’t Cut It!

Incision of a paronychia may be the very first procedure that I ever did in my medical career, and because of that, it has always held a special place in hierarchy of medical conditions we manage.  Generally it is a simple diagnosis and simple procedure (that must be why my simple brain likes it).  The purulence is contained superficially, along the edge of the fingernail, and easily extracted.

A Felon (also known as a Whitlow) is slightly more complicated, however, as it involved the deep pulp space of the finger and, hence, requires a more substantial incision and drainage.  This is still a “rewarding” and useful procedure… at least once you deal with the patient’s pain and anxiety.

But before you numb that digit and perform a incision extending across the entire width of the digit, first consider one thing: is this a Herpetic Whitlow?

Herpetic Whitlow basics

1. Due to HSV infection of the distal phalanx.
2. Is actually a misnomer: “Whitlow” refers to a painful, pus-producing infection of the deep space of the finger. Herpetic Whitlows do not have purulence, so not really a “whitlow”… but let’s not quibble over semantics.
3. Often associated with:
   1. In children – primary gingivostoatitis and autoinoculation, or trauma
   2. In Adolescents/Adults – may be associated with genital HSV infections
   3. In Adults – often are medical professionals who get inoculated by patients (so wear gloves!
4. Presentation
   1. May have antecedent pain and tingling of the fingertip.
   2. Swelling and redness then occurs.
   3. Fevers, constitutional symptoms, lymphadenopathy can be present.
   4. Then appear one or more vesicles that enlarge and can become coalescent.
   5. The central, large collection of vesicles can be easily confused for superficial purulence… so look for smaller vesicles on the periphery.
   6. The vesicles remain for 7-10 days and eventually crust over.
   7. Peeling occurs within week, revealing normal skin. (it is a self-limited condition)
1. Easily mistaken for a bacterial felon, which can lead, unfortunately, to unnecessary and potentially harmful I+D
   1. Look for vesicles!
   2. Check mouth and other mucous membranes for vesicles.
   3. Herpetic Whitlow usually will not have tense pulp space like Felon.
   4. Serous drainage rather than purulence
   5. Consider Tzack smear (should be rapid, culture takes too long).
   6. If your lab does not perform Tzank smears, you can also order a viral DFA (which is super quick) in the pink viral transport media to look for HSV 1,2, varicella.
2. Unfortunately, super-infection can also occur… again, your job is tough!

Treatment for Herpetic Whitlow

1. Avoid I+D (may increase risk for super-infection and won’t help it heal)
2. Pain management
3. Dry Dressings (to help limit further spread)
4. Consider needle-aspiration of larger, tense vesicles.
5. Acyclovir/valacyclovir can be used… but not studies about this specific use… but reasonable if it has only been 1-2 days of symptoms.

Feder HM, Long SS. Herpetic Whitlow: Epidemiology, Clinical Characteristics, Diagnosis, and Treatment. Am J Dis Child. Sept 1983; 137: 861-863