Hi, I can understand your concern for having a puss filled bubbly sore on the leg. There can be multiple possibilities of the red rashes and it requires a close physical examination to diagnose the exact entity of the problem. In my view correlating with the facts you have provided it appears to be simple folliculitis with secondary infection of the area. I suggest you to meet a dermatologist to for proper antibiotic therapy. In between you should avoid contact of dust to the area properly. If I were your dermatologist then presumptively would have preferred to apply fluticasone with mupirocin cream. You can take an antihistamine and pain killer such as loratadine and paracetamol for twice a day if itching is present. Do not try to pinch, pop or squeeze the area as it may cause secondary infection of the area. All the best