Friday, January 18, 2008

The Name is a Misnomer

It is early summer. A 40 year old Caucasian male in North Carolina presents with the rash seen above. He said for the past two days, he's had fever, severe headache, malaise, myalgias, arthralgias, and nausea. The rash started on his ankles and wrists and has proceeded to affect his other limbs and move centrally. He went fishing at a wooded lake a couple days ago. This is a life-threatening condition.

Challenge: What is the most likely diagnosis? What is the causative agent?

Image shown under fair use.


tree said...

In this case, should the disease name be changed to Appalachian Mountain spotted fever? :P

Alex said...

rocky mountain spotted fever?

Rickettsia rickettsii from ticks

Craig said...

The Name is a Misnomer

Rocky Mountain Spotted Fever is caused by Rickettsia rickettsii, a gram negative obligate intracellular bacterium. In the US, it is most prevalent in the southeastern and south central states (not necessarily the Rocky Mountains). The principal vectors are the American dog tick and Rocky Mountain wood tick, and the disease is typically transmitted in a tick bite. The rash is one of the few that affects the palms and soles.

Source: Wikipedia; UpToDate.