MRSA, Methicillin-resistant Staphylococcus aureus, is a staph infection that is resistant to most antibiotics. It's a skin disease that will not go away on its own, but can be successfully treated with very specific strong antibiotics. It could start out as a rash, or as folliculitis, an inflamed hair follicle (not the same as acne). People can die from it if they ignore it and it gets into the blood stream. So don't ignore skin infections. Use Neosporin or other triple-antibiotic cream at the first sign of a skin infection. And if an inflamed hair follicle starts radiating, that is you start seeing streaks running out from the central bump, that means it's gotten into your lymphatic system and you need to get on antibiotics immediately.
(I'm not a doctor, but I was married* to one.)
* legal in Massachusetts, Canada, UK and other parts of Europe
(during the four years of his residency, then he dumped me)