I Was Misdiagnosed Sunday. The PA Said I Had Poison

I was misdiagnosed Sunday. The PA said I had poison ivy on my forehead and started me on Medrol Dose pack (6 days). I'm on day 3 but got a 2nd opinion today and I really have shingles. Now I'm on Valtrax. I don't know if I can just stop the Medrol or if I have to taper off? I read where Medrol suppresses the immune system and part of why shingles happens could be because of stress and weaker immune system. So I wonder if I can just stop it after day 3.