A child with repeated skin infections presents with a liver abscess. The possible organism is ?
**Core Concept**
The patient's presentation of repeated skin infections and a liver abscess suggests a possible diagnosis of a bacteremia or sepsis caused by a skin flora organism that has spread to the liver. The liver's role in filtering blood from the portal vein makes it a common site for bacterial seeding.
**Why the Correct Answer is Right**
The most likely organism responsible for the patient's condition is *Staphylococcus aureus*. This bacterium is a common cause of skin and soft tissue infections, and its ability to invade the bloodstream and cause bacteremia is well-documented. The liver abscess is likely a result of hematogenous spread from the skin infection. *S. aureus* can evade the host's immune system by producing virulence factors such as coagulase, which helps it to form a biofilm and resist phagocytosis.
**Why Each Wrong Option is Incorrect**
* **Option A:** *Streptococcus pyogenes* is another common cause of skin infections, but it is less likely to cause a liver abscess compared to *S. aureus*.
* **Option B:** *Pseudomonas aeruginosa* is a gram-negative bacterium that can cause opportunistic infections, but it is not typically associated with skin infections or liver abscesses in children.
* **Option C:** *Escherichia coli* is a common cause of urinary tract infections and bacteremia, but it is less likely to cause skin infections or liver abscesses in children.
**Clinical Pearl / High-Yield Fact**
*Staphylococcus aureus* is a common cause of skin and soft tissue infections, and its ability to invade the bloodstream and cause bacteremia makes it a potential source of liver abscesses. Remember the "Golden Staph" as a common cause of skin infections and their potential complications.
**Correct Answer:** C. *Escherichia coli*.