Will any of these medicines give me a rash?

I have strep throat and mono. My doctor prescribed me Prednisone, pennicillin, sudogest (sudafed), ibuprofen and pepto bismal chewable tablets. I just recently noticed a red rash coming on my arms, it does not itch but it just started showing today. i have been on the meds since friday. and i also get random shakiness. almost like i havent ate in awhile even if i have. I just wanted to know if this is an allergic reation, if i should quit taking the meds or not?