We aren't sure that's what this is yet...waiting for culture today (rapid test was neg.), but other than that possibility this rash on my upper leg is mystifying 2 doctors and the PAs my primary pulled into the room. I have a derm appt set for Monday if the strep culture is neg. It is NOT itchy, has well-defined borders. Via emailed photo my rheumatologist thought it looked strep-related (I have psoriatic arthritis). It appeared VERy suddenly. It's big...about 6 inches by 7 inches.