MRSA skin infections are hard to spot, often misdiagnosed as heat rash, razor burn, spider bites, ingrown hair or pimples. Here are answers to frequently asked questions about MRSA.
Q. What does MRSA look like under a microscope? 
A. Staphylococcus aureus is Greek for "golden grapes," which is what the bacteria look like under a microscope, as shown here. Staph and its resistant form, methicillin-resistant staphylococcus aureus (MRSA) look the same.
Q. I understand that so-called "turf burns" athletes suffer after sliding on artificial turf are more prone to MRSA infections. What does a MRSA-infected turf burn look like?
A. Because MRSA infections are "opportunistic," slide or turf burns give the bacteria a place to enter the body. In this wound, the top abrasions near the knee are becoming infected with MRSA, as seen by the pustules.
Q. Why is the sharing of razors by athletes discouraged as a way of preventing the spread of MRSA?
A. Any skin cut or abrasion, including nicks from shaving, can become infected with MRSA. Here's a photo of a shaven chin beginning to become infected with MRSA. At this early stage, MRSA can be mistaken for razor burn or fever blisters. This is one reason athletes are encouraged not to share razors.
Q. I have been told that MRSA is often mistaken for heat rash. Is this true, and, if so, how do you know it's MRSA?
A. It is true that, in its very early stages, a MRSA infection can appear as red bumps (as shown here), which are often confused for heat rash. The difference is the significant pain associated with the "rash" and how quickly it gets worse.
Q. I understand that MRSA infections are often mistaken in their initial stages for an ingrown hair or pimple. How can you tell it is a MRSA infection?
A. This image shows perhaps the most common initial stage of MRSA. The difference between an ingrown hair and MRSA at this point is that MRSA causes disproportionately more pain than would be expected from the size of the affected area. Again, this is shown in an area that has been shaven, potentially providing a knick in the skin for the infection to enter.
Q. My son has what looks like an infected spider bite. Could it be MRSA? 
A. This image shows an early stage MRSA infection as it begins to necrotize the tissue around it. It is at this stage that a MRSA infection is most commonly misdiagnosed as a spider bite. Because spider bites are very rare, the recent trend is for health care professionals to treat "spider bites" as MRSA, unless a dead brown recluse spider can be produced.
Q. Is a MRSA skin infection serious? 
A. A MRSA skin infection can be a life-threatening illness. Want proof? Here's the story of Chris Bettinski, a wrestler who nearly lost his leg to MRSA, in his own words:
"At first, I thought it was just a bug bite, or maybe an ingrown hair on my calf. A couple of days later the "bite" turned into a baseball-sized swelling and started to throb. Then, I was admitted into the hospital with a leg swollen to twice its normal size. A day later my wife was told by the doctor that the infection (MRSA) may necessitate the amputation of my leg, and, if it reached my internal organs, it could kill me. It was touch and go for a while. Luckily, I'm back to normal, I wish I could say the same for my leg."
Grant Doornbos, MD, is a resident in the department of anesthesiology at the University of Louisville Medical Center and a former NCAA Division I wrestler.
