Osteomyelitis in Diabetes?

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Most common cause is staph aureus or pseudomonas?
UW tests this as S. aureus still being most common overall despite the increased proclivity for pseudomonas aetiology in diabetics.

However, I recall specifically on one of the online NBMEs for Step 2 (yeah, Step 2, not Step 1), Pseudomonas was the answer over S. aureus. And another guy and I who had both scored 260s on that NBME acknowledged UW had S. aureus, even though the NBME answer was Pseudomonas.

If UW has been updated, that's good. Because the NBME is the real deal, and I'd go with that answer. (Hence why it's important to do the NBMEs!).
 
UW tests this as S. aureus still being most common overall despite the increased proclivity for pseudomonas aetiology in diabetics.

However, I recall specifically on one of the online NBMEs for Step 2 (yeah, Step 2, not Step 1), Pseudomonas was the answer over S. aureus. And another guy and I who had both scored 260s on that NBME acknowledged UW had S. aureus, even though the NBME answer was Pseudomonas.

If UW has been updated, that's good. Because the NBME is the real deal, and I'd go with that answer. (Hence why it's important to do the NBMEs!).
Thank you 🙂
 
It's classically taught that Staph aureus is the most common cause for ALL osteomyelitis. BUT there are certain organisms that cause osteomyelitis more often in certain patient populations than the others (ex. Pseudomonas for diabetes, salmonella for sickle cell), BUT staph aureus is still the most common cause in those populations. In other words, if a diabetic were to get osteomyelitis, it's likely staph aureus; but the likelihood of getting osteomyelitis from pseudomonas is a lot higher in diabetics than if you were nondiabetic.

Also, NBME questions are questions that are retired; in other words, they are old. Though, the concepts are still likely to be tested.

Per uptodate:
Hematogenous osteomyelitis is usually monomicrobial, while contiguous osteomyelitis may be either polymicrobial or monomicrobial. Staphylococcus aureus, coagulase-negative staphylococci, and aerobic gram-negative bacilli are the most common organisms; other pathogens including streptococci, enterococci, anaerobes, fungi, and mycobacteria have also been implicated.
 
The most common way you get osteomyelitis in DM is contiguous (foot ulcers), and its most commonly polymicrobial. If they say its monomicrobial, then the most common organism would be S aureus. This information is in a UW table, and I just confirmed it from uptodate.

Salmonella is the most common cause of osteomyelitis in SCD patients. Confirmed form uptodate as well:

"The incidence of osteomyelitis is also increased in individuals with SCD. Long bones are usually affected, often at multiple sites, resulting from infection of infarcted bone. The most common organisms are Salmonella species. Staphylococcus aureus, the most common organism in patients without SCD, accounts for less than a quarter of cases."
 
Pseudomonas likelihood increases with deep wounds and chronic infections. The classic example is a nail puncturing through your shoes.
 
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