Brown recluse spider bites have an effect that is very similar to this. Also, I don't know how many people in here watch the Ultimate Fighter series on Spike, a few seasons ago they had an outbreak of MRSA in the Vegas gym and (I think it was) Diego Sanchez got an infection in the knee which actually ate a hole in in his leg. I don't know many people who are healthier than Sanchez so I think the compromised immune system could exacerbate the problem but I believe that this kind of stuff is extremely opportunistic and can attack anyone.
I spray my blades with wintergreen flavored rubbing alcohol after a shave to rid them of bacteria. Someone told me once that bacteria actually decreases blade life, so that was my initial reasoning. But now I'll do it because the bacteria will eat my head as well as my blades.