From the groin to the leg with erythema and crepitus, what's the bug! - USMLE Forums
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  #1  
Old 07-20-2011
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Bacteria From the groin to the leg with erythema and crepitus, what's the bug!

A 32-year-old woman presents with complaints of severe right leg pain. The pain started in her groin 12 hours prior and has since extended down to her knee. Physical examination shows a well demarcated region of blanching erythema from the right groin to the right knee with a few areas of subcutaneous crepitus. What is the likely causative organism?
A. Clostridia perfringens
B. Escherichia coli
C. Enterococcus
D. Streptococcus pyogenes
E. Streptococcus pneumonia
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Old 07-21-2011
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the answer is D
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  #3  
Old 07-21-2011
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GAS GANGRENE, ans is A
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Old 07-21-2011
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D. Streptococcus pyogenes
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Old 07-21-2011
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A) Clostridium perfringens...gas gangrene
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Old 07-21-2011
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answer is A...gas ganrene
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Old 07-21-2011
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Yes, the crepitus gave this one away.. its Clostridia
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Old 07-24-2011
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So what's the answer?
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Old 07-24-2011
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Post A

A. Clostridia perfringens

Its because of lecithinase
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Old 07-24-2011
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Quote:
Originally Posted by ricko335 View Post
A 32-year-old woman presents with complaints of severe right leg pain. The pain started in her groin 12 hours prior and has since extended down to her knee. Physical examination shows a well demarcated region of blanching erythema from the right groin to the right knee with a few areas of subcutaneous crepitus. What is the likely causative organism?
A. Clostridia perfringens
B. Escherichia coli
C. Enterococcus
D. Streptococcus pyogenes
E. Streptococcus pneumonia
The "crepitus" here is due to "gas production" which is due to A ( Clostridium Perfringens )...

Answer Is A.
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Old 07-24-2011
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Why C. Perfingens instead of S. Pyogenes?

The question is clearly describing a gas gangrene / necrotising fasciitis, both organisms can cause the infection, but I thought perfingens was more likely to occur following a penetrating injury and group A strep (pyogenes) was just more common, especially as the infection started near the groin and there was no indication of injury?
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Old 07-25-2011
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A .. Clostridia
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