Staphylococcus aureus can cause a number of different disease, including this common skin lesion.

What is this lesion called?

What type of necrosis do you see?

This is a furuncle or boil and is a subcutaneous abscess filled with neutrophils. The localized tissue is completely distorted resulting in liquefactive necrosis. The propensity of Staph Aureus to elicit pyogenic inflammation that rapidly destroys tissue makes it a particularly dangerous.

Methicillin-Resistant Staph Aureus (MRSA) is a dangerous nosocomial (hospital-associated) infection which is resistant to commonly used antibiotics (including methicillin, amoxicillin, penicillin, and oxacillin. About 1% of individuals are colonized with MRSA. Because classical MRSA isn't particularly invasive it tends to prey on immunocompromised individuals through skin defects (e.g. IV lines).

Community-Associated MRSA (CA-MRSA) is an emerging disease that occurs outside the hospital in immunocompetent (often young) individuals. Unlike classical MRSA, CA-MRSA is far more invasive. The average age of people with MRSA in a hospital or healthcare facility is 68. But the average age of a person with CA-MRSA is only 23.