I know you don't want to see a doctor, BUT *ducks*, just listen...

I'd probably leapfrog the dermatologist and go to a rheumatologist (not to offend the derma, but the rheumy is going to know more, heh). Furthermore, you should no doubt get your blood checked. I checked online and it said, "MRSA can be detected in asymptomatic patients by a blood test". So, go get that blood test, which I am sure the rheumy would be familiar with.

Unless there's a rare form of acne I never knew about, that does NOT look like acne to me. If you don't have an open access insurance plan, call your normal doctor and tell him/her to refer you to a rheumatologist.

That looks quite painful, and an infection isn't something to mess around with. I can tell you're kind of PO'd with doctors right now but finding the right one might be what finds you a diagnosis and hopefully a cure so you can find some comfort.

You should at least try to get the lab work done, so you can find out if it is MRSA or rule it out. Regardless, keep in touch about what you find.