Staphylococcus infection, or "staph," is caused by bacteria on the skin or in the nose. It is highly contagious, must be both diagnosed and treated by a doctor, and was once primarily associated with hospitals. According to the Mayo Clinic , staph severity can range from minor skin problems (in this case, the inflamed acne is the symptom) to "a life-threatening infection of the inner lining of your heart." And, the clinic notes , "[I]f staph bacteria invade your bloodstream, you may develop a type of infection that affects your entire body."Staph infections are becoming more common. "I am not sure that the staph bug is ever going to go back to just being in hospitals, which is what we used to see," Dr. Grossman told us. "It was just people who were hospital workers that had to worry about it, [but] now we see it coming from the gym and hot-yoga studios. It’s pretty impressive how much it’s around." (Staph may also sound familiar because Khloé Kardashian suffered from it in the fall.)Well, the acne itself is often the host of the infection. Dr. Grossman said she is tipped off when acne doesn't respond to medication and is highly inflamed or giving off heat. She will then diagnose it with a skin culture. "I have been seeing it more...and it’s usually [in] the people whose acne may not be cooperating with other medications, or it’s really what I call hot; it’s really inflammatory... There will be a teeny little white spot with a tremendous amount of red around it," she explained. "So I started culturing [these patients] and all kinds of staph has been growing, and it’s amazing how treating it has been so effective."