Monday, March 22, 2010

Blue Devils



A 60 year old man with diabetes complicated by dialysis-dependent renal failure, mitral valve prolapse, benign prostatic hyperplasia, and dyslipidemia presents with fever, chills, night sweats, and a rash. Unfortunately, he can't give a really good history.

His temperature is 38.5 C, his blood pressure is 125/80, his pulse is 85, and his respiratory rate is 16. Physical exam findings are shown above. The second image shows painful nodules. The third image shows painless macules. Two separate blood cultures are positive, but the lab has not been able to determine the organism yet.

Challenge: What are the likely organisms?

Related Questions:
1. What does each image show?
2. What's the diagnosis?

All three images shown under Fair Use.

2 comments:

tree said...

1. Roth spots
2. Osler nodes
3. Janeway lesions

(My medicine clerkship drilled the Duke's criteria into my brain!)

Diagnosis: bacterial endocarditis

Craig Chen said...

yes :)
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Blue Devils

Infective endocarditis is caused by S. aureus (31%), viridans group Streptococci (17%), enterococci (11%), coagulase-negative staphylococci (11%), other Strep, gram negative bacteria, HACEK organisms, and fungi. Risk factors include IV drug use, prosthetic heart valves, structural heart disease, hemodialysis, and HIV infection. The case title Blue Devils refers to Duke; the clinical criteria for the diagnosis of infective endocarditis is the Duke criteria. Major criteria include positive blood cultures, positive echocardiogram, or new valvular regurgitgation and minor criteria include risk factors, fever, vascular phenomena (arterial emboli, septic emboli, mycotic aneurysm, Janeway lesion), and immunologic phenomena (glomerulonephritis, Osler nodes, Roth spots).

The first image shows Roth spots, white-centered exudative edematous hemorrhages of the retina. The second image shows Osler's nodes, painful violaceous nodules found on the pulp of the fingers and toes. The third image shows Janeway lesions, blanching, nonpainful, erythematous macules on the palms and soles.

Sources: UpToDate; www.kellogg.umich.edu; meded.ucsd.edu.