Internal Medicine

(Wang) #1

0521779407-19 CUNY1086/Karliner 0 521 77940 7 June 6, 2007 17:50


1372 Staphylococcal Infections

■Osteomyelitis:
➣S. aureuscause of 60% cases of osteomyelitis
➣Can be direct (e.g.: open fracture) or by hematogenous spread
➣Present acutely or insidiously with localized pain
➣Epidural abscesses may arise from vertebral osteomyelitis; sus-
pect if fever, back pain and radiculopathy
■Bacteremia:
➣Usually a result of direct infection or inoculation (e.g.: intra-
venous devices, intravenous drug use) but no source identified
in 30%
➣May present with fevers, chills or rigors, arthralgias, myalgias;
patient looks acutely ill
➣Careful examination of the patient may reveal the source (e.g.,
infected intravenous catheter, petechiae or other stigmata of
endocarditis)
■Device associated infections:
➣Primarily due to S. epidermidis
➣May present as bacteremia in a patient who does not look ill and
whose intravenous catheter does not appear infected
➣In CSF shunt infections, the patient may present with a low-grade
fever or local wound but without meningismus
➣Common cause of peritonitis in chronic ambulatory peritoneal
dialysis patients
➣Prosthetic joint infection may be suggested by joint pain, swelling
and fevers
■Endocarditis:
➣Presentation may be fever and malaise only; peripheral stigmata
of endocarditis often absent
➣Compared to other etiologies, S aureus endocarditis is noted for
its rapid onset, high fevers, involvement of previously normal
valves and lack of physical findings supporting endocarditis on
admission
➣S. aureusendocarditis usually related to intravenous drug use;
often right sided disease
➣Prosthetic valve endocarditis is usually due toS. epidermidis
➣Suspect in any patient with a prosthetic heart valve with a fever
and bacteremia
➣High rate of complications with sewing ring dehiscence and
arrhythmias
■Metastatic infections:
➣PrimarilyS. aureus
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