What Causes An Itchy Red Rash On Pelvic Area?

Hi, may I answer your health queries right now ? Please type your query here... RED ITCHY RASH JUST ON PELVIC AREA NOT OOZING JUST ITCHY AND RED STARTED AS ONE LIKE RED BUMP AND NOW ITS A PRETTY LARGE PATCH. COULD THIS BE FROM LEAVING SWEATY ATTIRE ON AFTER SPORTS