Monday, September 21, 2009


A 40 year old dentist presents with the skin lesion shown above, pain, and low grade fever. To make the diagnosis, you remove the blister roof with a no. 15 blade, blot excess fluid, then scrape the base with a scalpel blade. You spread the material on a slide, add 95% methanol for 5 seconds, air dry for 1-2 minutes, then add a nuclear stain for 30-60 seconds. Finally, you wash with distilled water and restain with methanol. Here is what you see:

Challenge: What's the diagnosis?

Related Questions:
1. What stain was that?

Both images shown under fair use.


Kelly said...

Herpes simplex
This is a tzanck smear.

Craig Chen said...

well done!

This is herpetic whitlow, a herpes simplex infection of the finger, often seen in medical personnel that work with oral secretions. The stain is the Tzanck prep.

Sources: UpToDate; first image from Nikkels, Peirard, Am J Clin Dermatol 2002; second image from