What is MRSA?
The bacteria called Staphylococcus Aureus or “staph” for short, is responsible for most skin infections. MRSA (pronounced “mersa”) stands for Methicillin Resistant Staphylococcus Aureus. This is a bacteria that is resistant to many of the common antibiotics that are used to treat infections, such as Keflex or Amoxicillin.
What kind of skin infections does MRSA cause?
Most commonly we see MRSA causing folliculitis or boils:
- Folliculitis looks like pimples filled with pus and often occurs on the buttocks or thighs.
- A “boil” (the correct medical term is “carbuncle”) is an infected hair follicle that is swollen, tender, red hot, and is filled with pus (see photo). MRSA can also infect cuts and scrapes and cause other skin infections such as impetigo or cellulitis.
It is NOT a spider bite:
Most “boils” that we see these days are caused by MRSA. Many people come to us thinking that their boil is a spider bite (some were even told this by a doctor). If you look at the map for the distribution of the brown recluse spider, which is the spider that most people are referring to when they have a spider bite, they do not really live in Florida. Almos every “spider bite” that I have been shown since starting to practice in Florida in 2002, was actually a carbuncle.
How common is it?
We see it every day. In fact, most skin infections that we culture, come back as MRSA. Most of the infections we see with MRSA are not severe and are easily treated because it is not resistant to every antibiotic, just to some.
How do you treat MRSA?
Treatment depends on the type of infection. A “boil” is treated by incision and drainage. The area is numbed, and a small hole is poked to allow the pus to drain out. The patient then applies warm compresses at home. No antibiotics are necessary for this type of infection.
Folliculitis or multiple “boils” often do require an antibiotic, and while MRSA is resistant to methicillin and other common antibiotics, it is not resistant to every antibiotic. The MRSA in our community is often sensitive to Bactrim or doxycycline. We will culture the pus to determine the sensitivity, but we do not wait for the results to start treatment.