Monday, September 24, 2007


You are doing an away fourth year rotation in Cincinnati. Why? You're not sure either. You meet a chicken farmer who is HIV positive with the finding seen above. Here's a silver stain:

Challenge: Certainly, many things could be on the differential. But what's your top suspicion?

Related Questions:
1. What's seen in the first image?
2. What's seen in the second image?

Both images are in the public domain.


Alex said...

boo.. bad case. shouldn't be a picture ID game unless your audience consists of pathologists. what about symptoms?

Craig said...

haha, this is a popular question on the boards. Ohio River Valley / Mississippi + AIDS => histoplasmosis

Craig said...


The image shows a skin lesion on the upper lip. This ulcer is a manifestation of disseminated histoplasmosis, which is more common in immunosuppresed patients. The fungal pathogen Histoplasma capsulatum can spread throughout the skin, bone marrow, brain, and other organs. In nondisseminated histoplasmosis, the lungs are primarily affected. The histology image is a methenamine silver stain with budding yeast cells. This is histoplasmosis, also known as Darling's disease. It is endemic in states bordering the Ohio River valley and lower Mississippi. It's associated with bats and chickens. It is treated with antifungals like amphoteriin B and itraconazole.

Source: Wikipedia.