Hallo
Thanks for your query.You had acorn on left foot and you were using corn cap for a week and now it has become red and painful This indicates that whatever callosity you had is inflamed now and need to take antibiotic like Cap Doicycline 100 mg twice daily along with inflammatory drug like
Diclofenac 50 mg twice daily..Once the inflammation subsides you may have to excise it under local anesthesia