I just recently had this rash on my arms out of nowhere and now it's on my underarm and inner thighs and I'm scared. I had unprotected sex about a month ago :( (it's not on my face nor my palms or private area) it is a bit in my buttcrack area..I'm really terrified. It's very itchy in my armpit area and arms (what could it be?) I'm scared it's hiv.