Monday, September 17, 2007

A Thousand Words

Darkfield microscopy, 400x

Challenge: How is this disease transmitted?

Related Questions:
1. What is seen in the first image?
2. What is seen in the second image?
3. What is the diagnosis?

First image is in the public domain.
Second image is shown under fair use.


emily hw said...

bulls-eye rash

lyme disease

Alex said...

1. annular rash or "Erythema chronicum migrans"
2. spirochetes.. this one of the borrelia bacteria
3. Lyme Disease

Craig said...

A Thousand Words

The first image shows a rash called "erythema migrans." The characteristic "bulls-eye" pattern is diagnostic of Lyme disease. It is often found near the axilla, inguinal region, behind the knees, or at the belt line. It is usually asymptomatic, expanding over the course of a few days either uniformly red or “bulls-eye” due to central clearing. The second image shows spirochete ("corkscrew-shaped") bacteria - Borrelia burgdorferi. This gram negative bacterium causes Lyme disease. It is helical, 10-25 um and transmitted most commonly by the bite of an infected deer tick (Ixodes).

Sources: Wikipedia, UpToDate.